// File: contracts/facade/FacadeWrite.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "contracts/interfaces/IFacadeWrite.sol";
import "contracts/facade/lib/FacadeWriteLib.sol";

/**
 * @title FacadeWrite
 * @notice A UX-friendly layer to interact with the protocol
 * @dev Under the hood, uses two external libs to deal with blocksize limits.
 */
contract FacadeWrite is IFacadeWrite {
    using FacadeWriteLib for address;

    IDeployer public immutable deployer;

    constructor(IDeployer deployer_) {
        require(address(deployer_) != address(0), "invalid address");
        deployer = deployer_;
    }

    /// Step 1
    function deployRToken(ConfigurationParams calldata config, SetupParams calldata setup)
        external
        returns (address)
    {
        // Perform validations
        require(setup.primaryBasket.length > 0, "no collateral");
        require(setup.primaryBasket.length == setup.weights.length, "invalid length");

        // Validate backups
        for (uint256 i = 0; i < setup.backups.length; ++i) {
            require(setup.backups[i].backupCollateral.length > 0, "no backup collateral");
        }

        // Deploy contracts
        IRToken rToken = IRToken(
            deployer.deploy(
                config.name,
                config.symbol,
                config.mandate,
                address(this), // set as owner
                config.params
            )
        );

        // Get Main
        IMain main = rToken.main();

        // Register assets
        for (uint256 i = 0; i < setup.assets.length; ++i) {
            IAssetRegistry(address(main.assetRegistry())).register(setup.assets[i]);
            main.backingManager().grantRTokenAllowance(setup.assets[i].erc20());
        }

        // Setup basket
        {
            IERC20[] memory basketERC20s = new IERC20[](setup.primaryBasket.length);

            // Register collateral
            for (uint256 i = 0; i < setup.primaryBasket.length; ++i) {
                IAssetRegistry(address(main.assetRegistry())).register(setup.primaryBasket[i]);
                IERC20 erc20 = setup.primaryBasket[i].erc20();
                basketERC20s[i] = erc20;
                main.backingManager().grantRTokenAllowance(erc20);
            }

            // Set basket
            main.basketHandler().setPrimeBasket(basketERC20s, setup.weights);
            main.basketHandler().refreshBasket();
        }

        // Set backup config
        {
            for (uint256 i = 0; i < setup.backups.length; ++i) {
                IERC20[] memory backupERC20s = new IERC20[](
                    setup.backups[i].backupCollateral.length
                );

                for (uint256 j = 0; j < setup.backups[i].backupCollateral.length; ++j) {
                    ICollateral backupColl = setup.backups[i].backupCollateral[j];
                    IAssetRegistry(address(main.assetRegistry())).register(backupColl);
                    IERC20 erc20 = backupColl.erc20();
                    backupERC20s[j] = erc20;
                    main.backingManager().grantRTokenAllowance(erc20);
                }

                main.basketHandler().setBackupConfig(
                    setup.backups[i].backupUnit,
                    setup.backups[i].diversityFactor,
                    backupERC20s
                );
            }
        }

        // Pause until setupGovernance
        main.pause();

        // Setup deployer as owner to complete next step - do not renounce roles yet
        main.grantRole(OWNER, msg.sender);

        // Return rToken address
        return address(rToken);
    }

    /// Step 2
    /// @return newOwner The address of the new owner
    function setupGovernance(
        IRToken rToken,
        bool deployGovernance,
        bool unpause,
        GovernanceParams calldata govParams,
        address owner,
        address guardian,
        address pauser
    ) external returns (address newOwner) {
        // Get Main
        IMain main = rToken.main();

        require(main.hasRole(OWNER, address(this)), "ownership already transferred");
        require(main.hasRole(OWNER, msg.sender), "not initial deployer");

        // Remove ownership to sender
        main.revokeRole(OWNER, msg.sender);

        if (deployGovernance) {
            require(owner == address(0), "owner should be empty");

            TimelockController timelock = new TimelockController(
                govParams.timelockDelay,
                new address[](0),
                new address[](0)
            );

            // Deploy Governance contract
            address governance = FacadeWriteLib.deployGovernance(
                IStRSRVotes(address(main.stRSR())),
                timelock,
                govParams.votingDelay,
                govParams.votingPeriod,
                govParams.proposalThresholdAsMicroPercent,
                govParams.quorumPercent
            );
            emit GovernanceCreated(rToken, governance, address(timelock));

            // Setup Roles
            timelock.grantRole(timelock.PROPOSER_ROLE(), governance); // Gov only proposer
            timelock.grantRole(timelock.CANCELLER_ROLE(), guardian); // Guardian as canceller
            timelock.grantRole(timelock.EXECUTOR_ROLE(), address(0)); // Anyone as executor
            timelock.revokeRole(timelock.TIMELOCK_ADMIN_ROLE(), address(this)); // Revoke admin role

            // Set new owner to timelock
            newOwner = address(timelock);
        } else {
            require(owner != address(0), "owner not defined");
            newOwner = owner;
        }

        // Setup guardian as freeze starter / extender + pauser
        if (guardian != address(0)) {
            // As a further decentralization step it is suggested to further differentiate between
            // these two roles. But this is what will make sense for simple system setup.
            main.grantRole(SHORT_FREEZER, guardian);
            main.grantRole(LONG_FREEZER, guardian);
            main.grantRole(PAUSER, guardian);
        }

        // Setup Pauser
        if (pauser != address(0)) {
            main.grantRole(PAUSER, pauser);
        }

        // Unpause if required
        if (unpause) {
            main.unpause();
        }

        // Transfer Ownership and renounce roles
        main.grantRole(OWNER, newOwner);
        main.grantRole(SHORT_FREEZER, newOwner);
        main.grantRole(LONG_FREEZER, newOwner);
        main.grantRole(PAUSER, newOwner);
        main.renounceRole(OWNER, address(this));
        main.renounceRole(SHORT_FREEZER, address(this));
        main.renounceRole(LONG_FREEZER, address(this));
        main.renounceRole(PAUSER, address(this));
    }
}

// File: contracts/interfaces/IFacadeWrite.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "./IDeployer.sol";

/**
 * @title ConfigurationParams
 * @notice The set of protocol params needed to deploy an RToken
 */
struct ConfigurationParams {
    // === RToken info ===
    string name;
    string symbol;
    string mandate;
    // === Deployer params ===
    DeploymentParams params;
}

/**
 * @title SetupParams
 * @notice The set of protocol params needed to setup a full instance of an RToken
 */
struct SetupParams {
    // ===  Assets  ===
    IAsset[] assets;
    // === Basket  ===
    ICollateral[] primaryBasket;
    uint192[] weights;
    // === Basket Backup ===
    BackupInfo[] backups;
}

/**
 * @title BackupInfo
 * @notice The set of params to define a basket backup
 */
struct BackupInfo {
    bytes32 backupUnit;
    uint256 diversityFactor;
    ICollateral[] backupCollateral;
}

/**
 * @title GovernanceParams
 * @notice The set of params required to setup decentralized governance
 */
struct GovernanceParams {
    uint256 votingDelay; // in blocks
    uint256 votingPeriod; // in blocks
    uint256 proposalThresholdAsMicroPercent; // e.g. 1e4 for 0.01%
    uint256 quorumPercent; // e.g 4 for 4%
    uint256 timelockDelay; // in seconds (used for timelock)
}

/**
 * @title IFacadeWrite
 * @notice A UX-friendly layer for interactin with the protocol
 */
interface IFacadeWrite {
    /// Emitted when a new Governance is deployed
    /// @param rToken The address of the RToken
    /// @param governance The address of the new governance
    /// @param timelock The address of the timelock
    event GovernanceCreated(
        IRToken indexed rToken,
        address indexed governance,
        address indexed timelock
    );

    /// Deploys an instance of an RToken
    function deployRToken(ConfigurationParams calldata config, SetupParams calldata setup)
        external
        returns (address);

    /// Sets up governance for an RToken
    function setupGovernance(
        IRToken rToken,
        bool deployGovernance,
        bool unfreeze,
        GovernanceParams calldata govParams,
        address owner,
        address guardian,
        address pauser
    ) external returns (address);
}

// File: contracts/facade/lib/FacadeWriteLib.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "contracts/plugins/governance/Governance.sol";

library FacadeWriteLib {
    /// @return The new Governance contract address
    function deployGovernance(
        IStRSRVotes stRSR,
        TimelockController timelock,
        uint256 votingDelay,
        uint256 votingPeriod,
        uint256 proposalThresholdAsMicroPercent,
        uint256 quorumPercent
    ) external returns (address) {
        return
            address(
                new Governance(
                    stRSR,
                    timelock,
                    votingDelay,
                    votingPeriod,
                    proposalThresholdAsMicroPercent,
                    quorumPercent
                )
            );
    }
}

// File: contracts/interfaces/IDeployer.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "./IAsset.sol";
import "./IDistributor.sol";
import "./IFacade.sol";
import "./IGnosis.sol";
import "./IMain.sol";
import "./IRToken.sol";
import "./IStRSR.sol";
import "./ITrade.sol";

/**
 * @title DeploymentParams
 * @notice The set of protocol params needed to configure a new system deployment.
 * meaning that after deployment there is freedom to allow parametrizations to deviate.
 */
struct DeploymentParams {
    // === Revenue sharing ===
    RevenueShare dist; // revenue sharing splits between RToken and RSR
    //
    // === Trade sizing ===
    uint192 minTradeVolume; // {UoA}
    uint192 rTokenMaxTradeVolume; // {UoA}
    //
    // === Freezing ===
    uint48 shortFreeze; // {s} how long an initial freeze lasts
    uint48 longFreeze; // {s} how long each freeze extension lasts
    //
    // === Rewards (Furnace + StRSR) ===
    uint192 rewardRatio; // the fraction of available revenues that stRSR holders get each PayPeriod
    uint48 rewardPeriod; // {s} the atomic unit of rewards, determines # of exponential rounds
    //
    // === StRSR ===
    uint48 unstakingDelay; // {s} the "thawing time" of staked RSR before withdrawal
    //
    // === BackingManager ===
    uint48 tradingDelay; // {s} how long to wait until starting auctions after switching basket
    uint48 auctionLength; // {s} the length of an auction
    uint192 backingBuffer; // {1} how much extra backing collateral to keep
    uint192 maxTradeSlippage; // {1} max slippage acceptable in a trade
    //
    // === RToken ===
    uint192 issuanceRate; // {1/block} number of RToken to issue per block / (RToken value)
    uint192 scalingRedemptionRate; // {1/hour} max fraction of supply that can be redeemed hourly
    uint256 redemptionRateFloor; // {qRTok/hour} the lowest possible hourly redemption limit
}

/**
 * @title Implementations
 * @notice The set of implementation contracts to be used for proxies in the Deployer
 */
struct Implementations {
    IMain main;
    Components components;
    ITrade trade;
}

/**
 * @title IDeployer
 * @notice Factory contract for an RToken system instance
 */
interface IDeployer {
    /// Emitted when a new RToken and accompanying system is deployed
    /// @param main The address of `Main`
    /// @param rToken The address of the RToken ERC20
    /// @param stRSR The address of the StRSR ERC20 staking pool/token
    /// @param owner The owner of the newly deployed system
    event RTokenCreated(
        IMain indexed main,
        IRToken indexed rToken,
        IStRSR stRSR,
        address indexed owner
    );

    //

    /// Deploys an instance of the entire system
    /// @param name The name of the RToken to deploy
    /// @param symbol The symbol of the RToken to deploy
    /// @param mandate An IPFS link or direct string; describes what the RToken _should be_
    /// @param owner The address that should own the entire system, hopefully a governance contract
    /// @param params Deployment params
    /// @return The address of the newly deployed Main instance.
    function deploy(
        string calldata name,
        string calldata symbol,
        string calldata mandate,
        address owner,
        DeploymentParams calldata params
    ) external returns (address);
}

interface TestIDeployer is IDeployer {
    /// A top-level ENS domain that should always point to the latest Deployer instance
    // solhint-disable-next-line func-name-mixedcase
    function ENS() external view returns (string memory);

    function rsr() external view returns (IERC20Metadata);

    function gnosis() external view returns (IGnosis);

    function rsrAsset() external view returns (IAsset);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: contracts/interfaces/IAsset.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "contracts/libraries/Fixed.sol";
import "./IMain.sol";

/**
 * @title IAsset
 * @notice Supertype. Any token that interacts with our system must be wrapped in an asset,
 * whether it is used as RToken backing or not. Any token that can report a price in the UoA
 * is eligible to be an asset.
 */
interface IAsset {
    /// Can return 0, can revert
    /// Shortcut for price(false)
    /// @return {UoA/tok} The current price(), without considering fallback prices
    function strictPrice() external view returns (uint192);

    /// Can return 0
    /// Should not revert if `allowFallback` is true. Can revert if false.
    /// @param allowFallback Whether to try the fallback price in case precise price reverts
    /// @return isFallback If the price is a failover price
    /// @return {UoA/tok} The current price(), or if it's reverting, a fallback price
    function price(bool allowFallback) external view returns (bool isFallback, uint192);

    /// @return {tok} The balance of the ERC20 in whole tokens
    function bal(address account) external view returns (uint192);

    /// @return The ERC20 contract of the token with decimals() available
    function erc20() external view returns (IERC20Metadata);

    /// @return The number of decimals in the ERC20; just for gas optimization
    function erc20Decimals() external view returns (uint8);

    /// @return If the asset is an instance of ICollateral or not
    function isCollateral() external view returns (bool);

    /// @param {UoA} The max trade volume, in UoA
    function maxTradeVolume() external view returns (uint192);

    // ==== Rewards ====

    /// Get the message needed to call in order to claim rewards for holding this asset.
    /// Returns zero values if there is no reward function to call.
    /// @return _to The address to send the call to
    /// @return _calldata The calldata to send
    function getClaimCalldata() external view returns (address _to, bytes memory _calldata);

    /// The ERC20 token address that this Asset's rewards are paid in.
    /// If there are no rewards, will return a zero value.
    function rewardERC20() external view returns (IERC20 reward);
}

interface TestIAsset is IAsset {
    function chainlinkFeed() external view returns (AggregatorV3Interface);
}

/// CollateralStatus must obey a linear ordering. That is:
/// - being DISABLED is worse than being IFFY, or SOUND
/// - being IFFY is worse than being SOUND.
enum CollateralStatus {
    SOUND,
    IFFY, // When a peg is not holding or a chainlink feed is stale
    DISABLED // When the collateral has completely defaulted
}

/// Upgrade-safe maximum operator for CollateralStatus
library CollateralStatusComparator {
    /// @return Whether a is worse than b
    function worseThan(CollateralStatus a, CollateralStatus b) internal pure returns (bool) {
        return uint256(a) > uint256(b);
    }
}

/**
 * @title ICollateral
 * @notice A subtype of Asset that consists of the tokens eligible to back the RToken.
 */
interface ICollateral is IAsset {
    /// Emitted whenever the collateral status is changed
    /// @param newStatus The old CollateralStatus
    /// @param newStatus The updated CollateralStatus
    event DefaultStatusChanged(
        CollateralStatus indexed oldStatus,
        CollateralStatus indexed newStatus
    );

    /// Refresh exchange rates and update default status.
    /// The Reserve protocol calls this at least once per transaction, before relying on
    /// this collateral's prices or default status.
    /// @dev This default check assumes that the collateral's price() value is expected
    /// to stay close to pricePerTarget() * targetPerRef(). If that's not true for the
    /// collateral you're defining, you MUST redefine refresh()!!
    function refresh() external;

    /// @return The canonical name of this collateral's target unit.
    function targetName() external view returns (bytes32);

    /// @return The status of this collateral asset. (Is it defaulting? Might it soon?)
    function status() external view returns (CollateralStatus);

    // ==== Exchange Rates ====

    /// @return {ref/tok} Quantity of whole reference units per whole collateral tokens
    function refPerTok() external view returns (uint192);

    /// @return {target/ref} Quantity of whole target units per whole reference unit in the peg
    function targetPerRef() external view returns (uint192);

    /// @return {UoA/target} The price of the target unit in UoA (usually this is {UoA/UoA} = 1)
    function pricePerTarget() external view returns (uint192);
}

// File: contracts/interfaces/IDistributor.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IComponent.sol";

struct RevenueShare {
    uint16 rTokenDist; // {revShare} A value between [0, 10,000]
    uint16 rsrDist; // {revShare} A value between [0, 10,000]
}

/// Assumes no more than 1024 independent distributions.
struct RevenueTotals {
    uint24 rTokenTotal; // {revShare}
    uint24 rsrTotal; // {revShare}
}

/**
 * @title IDistributor
 * @notice The Distributor Component maintains a revenue distribution table that dictates
 *   how to divide revenue across the Furnace, StRSR, and any other destinations.
 */
interface IDistributor is IComponent {
    /// Emitted when a distribution is set
    /// @param dest The address set to receive the distribution
    /// @param rTokenDist The distribution of RToken that should go to `dest`
    /// @param rsrDist The distribution of RSR that should go to `dest`
    event DistributionSet(address dest, uint16 rTokenDist, uint16 rsrDist);

    /// Emitted when revenue is distributed
    /// @param erc20 The token being distributed, either RSR or the RToken itself
    /// @param source The address providing the revenue
    /// @param amount The amount of the revenue
    event RevenueDistributed(IERC20 indexed erc20, address indexed source, uint256 indexed amount);

    // Initialization
    function init(IMain main_, RevenueShare memory dist) external;

    /// @custom:governance
    function setDistribution(address dest, RevenueShare memory share) external;

    /// Distribute the `erc20` token across all revenue destinations
    /// @custom:interaction
    function distribute(
        IERC20 erc20,
        address from,
        uint256 amount
    ) external;

    /// @return revTotals The total of all  destinations
    function totals() external view returns (RevenueTotals memory revTotals);
}

interface TestIDistributor is IDistributor {
    // solhint-disable-next-line func-name-mixedcase
    function FURNACE() external view returns (address);

    // solhint-disable-next-line func-name-mixedcase
    function ST_RSR() external view returns (address);
}

// File: contracts/interfaces/IFacade.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "contracts/p1/RToken.sol";
import "./IRToken.sol";
import "./IStRSR.sol";

/**
 * @title IFacade
 * @notice A UX-friendly layer for non-governance protocol interactions
 *
 * - @custom:static-call - Use ethers callStatic() in order to get result after update
 * - @custom:view - Regular view
v */
interface IFacade {
    /// Returns the next call a keeper of MEV searcher should make in order to progress the system
    /// Returns zero bytes to indicate no action should be made
    /// @custom:static-call
    function getActCalldata(RTokenP1 rToken) external returns (address to, bytes memory calldata_);

    // ============

    struct Pending {
        uint256 index;
        uint256 availableAt;
        uint256 amount;
    }

    /// @param account The account for the query
    /// @return All the pending RToken issuances for an account
    /// @custom:view
    function pendingIssuances(RTokenP1 rToken, address account)
        external
        view
        returns (Pending[] memory);

    /// @param account The account for the query
    /// @return All the pending StRSR unstakings for an account
    /// @custom:view
    function pendingUnstakings(RTokenP1 rToken, address account)
        external
        view
        returns (Pending[] memory);

    /// Return the highest index that could be completed by a vestIssuances call.
    /// @dev Use with `vest`
    function endIdForVest(RTokenP1 rToken, address account) external view returns (uint256);

    /// @return How many RToken `account` can issue given current holdings
    /// @custom:static-call
    function maxIssuable(IRToken rToken, address account) external returns (uint256);

    /// @return tokens The erc20 needed for the issuance
    /// @return deposits The deposits necessary to issue `amount` RToken
    /// @custom:static-call
    function issue(IRToken rToken, uint256 amount)
        external
        returns (address[] memory tokens, uint256[] memory deposits);

    /// @return erc20s The ERC20 addresses in the current basket
    /// @return uoaShares The proportion of the basket associated with each ERC20
    /// @return targets The bytes32 representations of the target unit associated with each ERC20
    /// @custom:static-call
    function basketBreakdown(RTokenP1 rToken)
        external
        returns (
            address[] memory erc20s,
            uint192[] memory uoaShares,
            bytes32[] memory targets
        );

    /// @return tokens The addresses of the ERC20s backing the RToken
    /// @custom:view
    function basketTokens(IRToken rToken) external view returns (address[] memory tokens);

    /// @return stTokenAddress The address of the corresponding stToken address
    /// @custom:view
    function stToken(IRToken rToken) external view returns (IStRSR stTokenAddress);

    /// @return backing The worst-case collaterazation % the protocol will have after done trading
    /// @return insurance The insurance value relative to the fully-backed value
    function backingOverview(IRToken rToken)
        external
        view
        returns (uint192 backing, uint192 insurance);

    /// @return {UoA/tok} The price of the RToken as given by the relevant RTokenAsset
    function price(IRToken rToken) external view returns (uint192);
}

// File: contracts/interfaces/IGnosis.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

struct GnosisAuctionData {
    IERC20 auctioningToken;
    IERC20 biddingToken;
    uint256 orderCancellationEndDate;
    uint256 auctionEndDate;
    bytes32 initialAuctionOrder;
    uint256 minimumBiddingAmountPerOrder;
    uint256 interimSumBidAmount;
    bytes32 interimOrder;
    bytes32 clearingPriceOrder;
    uint96 volumeClearingPriceOrder;
    bool minFundingThresholdNotReached;
    bool isAtomicClosureAllowed;
    uint256 feeNumerator;
    uint256 minFundingThreshold;
}

/// The relevant portion of the interface of the live Gnosis EasyAuction contract
/// https://github.com/gnosis/ido-contracts/blob/main/contracts/EasyAuction.sol
interface IGnosis {
    function initiateAuction(
        IERC20 auctioningToken,
        IERC20 biddingToken,
        uint256 orderCancellationEndDate,
        uint256 auctionEndDate,
        uint96 auctionedSellAmount,
        uint96 minBuyAmount,
        uint256 minimumBiddingAmountPerOrder,
        uint256 minFundingThreshold,
        bool isAtomicClosureAllowed,
        address accessManagerContract,
        bytes memory accessManagerContractData
    ) external returns (uint256 auctionId);

    function auctionData(uint256 auctionId) external view returns (GnosisAuctionData memory);

    /// @param auctionId The external auction id
    /// @dev See here for decoding: https://git.io/JMang
    /// @return encodedOrder The order, encoded in a bytes 32
    function settleAuction(uint256 auctionId) external returns (bytes32 encodedOrder);

    /// @return The numerator over a 1000-valued denominator
    function feeNumerator() external returns (uint256);
}

// File: contracts/interfaces/IMain.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/access/IAccessControlUpgradeable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IAssetRegistry.sol";
import "./IBasketHandler.sol";
import "./IBackingManager.sol";
import "./IBroker.sol";
import "./IGnosis.sol";
import "./IFurnace.sol";
import "./IDistributor.sol";
import "./IRToken.sol";
import "./IRevenueTrader.sol";
import "./IStRSR.sol";
import "./ITrading.sol";

// === Auth roles ===

bytes32 constant OWNER = bytes32(bytes("OWNER"));
bytes32 constant SHORT_FREEZER = bytes32(bytes("SHORT_FREEZER"));
bytes32 constant LONG_FREEZER = bytes32(bytes("LONG_FREEZER"));
bytes32 constant PAUSER = bytes32(bytes("PAUSER"));

/**
 * Main is a central hub that maintains a list of Component contracts.
 *
 * Components:
 *   - perform a specific function
 *   - defer auth to Main
 *   - usually (but not always) contain sizeable state that require a proxy
 */
struct Components {
    // Definitely need proxy
    IRToken rToken;
    IStRSR stRSR;
    IAssetRegistry assetRegistry;
    IBasketHandler basketHandler;
    IBackingManager backingManager;
    IDistributor distributor;
    IFurnace furnace;
    IBroker broker;
    IRevenueTrader rsrTrader;
    IRevenueTrader rTokenTrader;
}

interface IAuth is IAccessControlUpgradeable {
    /// Emitted when `unfreezeAt` is changed
    /// @param oldVal The old value of `unfreezeAt`
    /// @param newVal The new value of `unfreezeAt`
    event UnfreezeAtSet(uint48 indexed oldVal, uint48 indexed newVal);

    /// Emitted when the short freeze duration governance param is changed
    /// @param oldDuration The old short freeze duration
    /// @param newDuration The new short freeze duration
    event ShortFreezeDurationSet(uint48 indexed oldDuration, uint48 indexed newDuration);

    /// Emitted when the long freeze duration governance param is changed
    /// @param oldDuration The old long freeze duration
    /// @param newDuration The new long freeze duration
    event LongFreezeDurationSet(uint48 indexed oldDuration, uint48 indexed newDuration);

    /// Emitted when the system is paused or unpaused
    /// @param oldVal The old value of `paused`
    /// @param newVal The new value of `paused`
    event PausedSet(bool indexed oldVal, bool indexed newVal);

    /**
     * Paused: Disable everything except for OWNER actions and RToken.redeem/cancel
     * Frozen: Disable everything except for OWNER actions
     */

    function pausedOrFrozen() external view returns (bool);

    function frozen() external view returns (bool);

    function shortFreeze() external view returns (uint48);

    function longFreeze() external view returns (uint48);

    // ====

    // onlyRole(OWNER)
    function freezeForever() external;

    // onlyRole(SHORT_FREEZER)
    function freezeShort() external;

    // onlyRole(LONG_FREEZER)
    function freezeLong() external;

    // onlyRole(OWNER)
    function unfreeze() external;

    function pause() external;

    function unpause() external;
}

interface IComponentRegistry {
    // === Component setters/getters ===

    event RTokenSet(IRToken indexed oldVal, IRToken indexed newVal);

    function rToken() external view returns (IRToken);

    event StRSRSet(IStRSR indexed oldVal, IStRSR indexed newVal);

    function stRSR() external view returns (IStRSR);

    event AssetRegistrySet(IAssetRegistry indexed oldVal, IAssetRegistry indexed newVal);

    function assetRegistry() external view returns (IAssetRegistry);

    event BasketHandlerSet(IBasketHandler indexed oldVal, IBasketHandler indexed newVal);

    function basketHandler() external view returns (IBasketHandler);

    event BackingManagerSet(IBackingManager indexed oldVal, IBackingManager indexed newVal);

    function backingManager() external view returns (IBackingManager);

    event DistributorSet(IDistributor indexed oldVal, IDistributor indexed newVal);

    function distributor() external view returns (IDistributor);

    event RSRTraderSet(IRevenueTrader indexed oldVal, IRevenueTrader indexed newVal);

    function rsrTrader() external view returns (IRevenueTrader);

    event RTokenTraderSet(IRevenueTrader indexed oldVal, IRevenueTrader indexed newVal);

    function rTokenTrader() external view returns (IRevenueTrader);

    event FurnaceSet(IFurnace indexed oldVal, IFurnace indexed newVal);

    function furnace() external view returns (IFurnace);

    event BrokerSet(IBroker indexed oldVal, IBroker indexed newVal);

    function broker() external view returns (IBroker);
}

/**
 * @title IMain
 * @notice The central hub for the entire system. Maintains components and an owner singleton role
 */
interface IMain is IAuth, IComponentRegistry {
    function poke() external; // not used in p1

    // === Initialization ===

    event MainInitialized();

    function init(
        Components memory components,
        IERC20 rsr_,
        uint48 shortFreeze_,
        uint48 longFreeze_
    ) external;

    function rsr() external view returns (IERC20);
}

interface TestIMain is IMain {
    /// @custom:governance
    function setShortFreeze(uint48) external;

    /// @custom:governance
    function setLongFreeze(uint48) external;

    function shortFreeze() external view returns (uint48);

    function longFreeze() external view returns (uint48);

    function longFreezes(address account) external view returns (uint256);

    function paused() external view returns (bool);
}

// File: contracts/interfaces/IRToken.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol";
// solhint-disable-next-line max-line-length
import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-IERC20PermitUpgradeable.sol";
import "contracts/libraries/Fixed.sol";
import "./IAsset.sol";
import "./IComponent.sol";
import "./IMain.sol";
import "./IRewardable.sol";

/**
 * @title IRToken
 * @notice An RToken is an ERC20 that is permissionlessly issuable/redeemable and tracks an
 *   exchange rate against a single unit: baskets, or {BU} in our type notation.
 */
interface IRToken is IRewardable, IERC20MetadataUpgradeable, IERC20PermitUpgradeable {
    /// Emitted when issuance is started, at the point collateral is taken in
    /// @param issuer The account performing the issuance
    /// @param index The index off the issuance in the issuer's queue
    /// @param amount The quantity of RToken being issued
    /// @param baskets The basket unit-equivalent of the collateral deposits
    /// @param erc20s The ERC20 collateral tokens corresponding to the quantities
    /// @param quantities The quantities of tokens paid with
    /// @param blockAvailableAt The (continuous) block at which the issuance vests
    event IssuanceStarted(
        address indexed issuer,
        uint256 indexed index,
        uint256 indexed amount,
        uint192 baskets,
        address[] erc20s,
        uint256[] quantities,
        uint192 blockAvailableAt
    );

    /// Emitted when an RToken issuance is canceled, such as during a default
    /// @param issuer The account of the issuer
    /// @param firstId The first of the cancelled issuances in the issuer's queue
    /// @param endId The index _after_ the last of the cancelled issuances in the issuer's queue
    /// @param amount {qRTok} The amount of RTokens canceled
    /// That is, id was cancelled iff firstId <= id < endId
    event IssuancesCanceled(
        address indexed issuer,
        uint256 indexed firstId,
        uint256 indexed endId,
        uint256 amount
    );

    /// Emitted when an RToken issuance is completed successfully
    /// @param issuer The account of the issuer
    /// @param firstId The first of the completed issuances in the issuer's queue
    /// @param endId The id directly after the last of the completed issuances
    /// @param amount {qRTok} The amount of RTokens canceled
    event IssuancesCompleted(
        address indexed issuer,
        uint256 indexed firstId,
        uint256 indexed endId,
        uint256 amount
    );

    /// Emitted when an issuance of RToken occurs, whether it occurs via slow minting or not
    /// @param issuer The address of the account issuing RTokens
    /// @param amount The quantity of RToken being issued
    /// @param baskets The corresponding number of baskets
    event Issuance(address indexed issuer, uint256 indexed amount, uint192 indexed baskets);

    /// Emitted when a redemption of RToken occurs
    /// @param redeemer The address of the account redeeeming RTokens
    /// @param amount The quantity of RToken being redeemed
    /// @param baskets The corresponding number of baskets
    /// @param amount {qRTok} The amount of RTokens canceled
    event Redemption(address indexed redeemer, uint256 indexed amount, uint192 baskets);

    /// Emitted when the number of baskets needed changes
    /// @param oldBasketsNeeded Previous number of baskets units needed
    /// @param newBasketsNeeded New number of basket units needed
    event BasketsNeededChanged(uint192 oldBasketsNeeded, uint192 newBasketsNeeded);

    /// Emitted when RToken is melted, i.e the RToken supply is decreased but basketsNeeded is not
    /// @param amount {qRTok}
    event Melted(uint256 amount);

    /// Emitted when the IssuanceRate is set
    event IssuanceRateSet(uint192 indexed oldVal, uint192 indexed newVal);

    /// Emitted when the redemption battery max charge is set
    event ScalingRedemptionRateSet(uint192 indexed oldVal, uint192 indexed newVal);

    /// Emitted when the dust supply is set
    event RedemptionRateFloorSet(uint256 indexed oldVal, uint256 indexed newVal);

    // Initialization
    function init(
        IMain main_,
        string memory name_,
        string memory symbol_,
        string memory mandate_,
        uint192 issuanceRate_,
        uint192 redemptionBattery_,
        uint256 redemptionVirtualSupply_
    ) external;

    /// Begin a time-delayed issuance of RToken for basket collateral
    /// @param amount {qRTok} The quantity of RToken to issue
    /// @custom:interaction
    function issue(uint256 amount) external;

    /// Cancels a vesting slow issuance of _msgSender
    /// If earliest == true, cancel id if id < endId
    /// If earliest == false, cancel id if endId <= id
    /// @param endId One edge of the issuance range to cancel
    /// @param earliest If true, cancel earliest issuances; else, cancel latest issuances
    /// @custom:interaction
    function cancel(uint256 endId, bool earliest) external;

    /// Completes vested slow issuances for the account, up to endId.
    /// @param account The address of the account to vest issuances for
    /// @custom:interaction
    function vest(address account, uint256 endId) external;

    /// Redeem RToken for basket collateral
    /// @param amount {qRTok} The quantity {qRToken} of RToken to redeem
    /// @custom:interaction
    function redeem(uint256 amount) external;

    /// Mints a quantity of RToken to the `recipient`, callable only by the BackingManager
    /// @param recipient The recipient of the newly minted RToken
    /// @param amount {qRTok} The amount to be minted
    /// @custom:protected
    function mint(address recipient, uint256 amount) external;

    /// Melt a quantity of RToken from the caller's account
    /// @param amount {qRTok} The amount to be melted
    function melt(uint256 amount) external;

    /// Set the number of baskets needed directly, callable only by the BackingManager
    /// @param basketsNeeded {BU} The number of baskets to target
    ///                      needed range: pretty interesting
    /// @custom:protected
    function setBasketsNeeded(uint192 basketsNeeded) external;

    /// @return {BU} How many baskets are being targeted
    function basketsNeeded() external view returns (uint192);

    /// @return {qRTok} The maximum redemption that can be performed in the current block
    function redemptionLimit() external view returns (uint256);
}

interface TestIRToken is IRToken {
    /// Set the issuance rate as a % of RToken supply
    function setIssuanceRate(uint192) external;

    /// @return {1} The issuance rate as a percentage of the RToken supply
    function issuanceRate() external view returns (uint192);

    /// Set the fraction of the RToken supply that can be reedemed at once
    function setScalingRedemptionRate(uint192 val) external;

    /// @return {1/hour} The maximum fraction of the RToken supply that can be redeemed at once
    function scalingRedemptionRate() external view returns (uint192);

    /// Set the RToken supply at which full redemptions become enabled
    function setRedemptionRateFloor(uint256 val) external;

    /// @return {qRTok/hour} The lowest possible hourly redemption limit
    function redemptionRateFloor() external view returns (uint256);
}

// File: contracts/interfaces/IStRSR.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol";
// solhint-disable-next-line max-line-length
import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-IERC20PermitUpgradeable.sol";
import "contracts/libraries/Fixed.sol";
import "./IComponent.sol";
import "./IMain.sol";

/**
 * @title IStRSR
 * @notice An ERC20 token representing shares of the RSR insurance pool.
 *
 * StRSR permits the BackingManager to take RSR in times of need. In return, the BackingManager
 * benefits the StRSR pool with RSR rewards purchased with a portion of its revenue.
 *
 * In the absence of collateral default or losses due to slippage, StRSR should have a
 * monotonically increasing exchange rate with respect to RSR, meaning that over time
 * StRSR is redeemable for more RSR. It is non-rebasing.
 */
interface IStRSR is IERC20MetadataUpgradeable, IERC20PermitUpgradeable, IComponent {
    /// Emitted when RSR is staked
    /// @param era The era at time of staking
    /// @param staker The address of the staker
    /// @param rsrAmount {qRSR} How much RSR was staked
    /// @param stRSRAmount {qStRSR} How much stRSR was minted by this staking
    event Staked(
        uint256 indexed era,
        address indexed staker,
        uint256 rsrAmount,
        uint256 indexed stRSRAmount
    );

    /// Emitted when an unstaking is started
    /// @param draftId The id of the draft.
    /// @param draftEra The era of the draft.
    /// @param staker The address of the unstaker
    ///   The triple (staker, draftEra, draftId) is a unique ID
    /// @param rsrAmount {qRSR} How much RSR this unstaking will be worth, absent seizures
    /// @param stRSRAmount {qStRSR} How much stRSR was burned by this unstaking
    event UnstakingStarted(
        uint256 indexed draftId,
        uint256 indexed draftEra,
        address indexed staker,
        uint256 rsrAmount,
        uint256 stRSRAmount,
        uint256 availableAt
    );

    /// Emitted when RSR is unstaked
    /// @param firstId The beginning of the range of draft IDs withdrawn in this transaction
    /// @param endId The end of range of draft IDs withdrawn in this transaction
    ///   (ID i was withdrawn if firstId <= i < endId)
    /// @param draftEra The era of the draft.
    ///   The triple (staker, draftEra, id) is a unique ID among drafts
    /// @param staker The address of the unstaker

    /// @param rsrAmount {qRSR} How much RSR this unstaking was worth
    event UnstakingCompleted(
        uint256 indexed firstId,
        uint256 indexed endId,
        uint256 draftEra,
        address indexed staker,
        uint256 rsrAmount
    );

    /// Emitted whenever the exchange rate changes
    event ExchangeRateSet(uint192 indexed oldVal, uint192 indexed newVal);

    /// Emitted whenever RSR are paids out
    event RewardsPaid(uint256 indexed rsrAmt);

    /// Emitted if all the RSR in the staking pool is seized and all balances are reset to zero.
    event AllBalancesReset(uint256 indexed newEra);
    /// Emitted if all the RSR in the unstakin pool is seized, and all ongoing unstaking is voided.
    event AllUnstakingReset(uint256 indexed newEra);

    event UnstakingDelaySet(uint48 indexed oldVal, uint48 indexed newVal);
    event RewardPeriodSet(uint48 indexed oldVal, uint48 indexed newVal);
    event RewardRatioSet(uint192 indexed oldVal, uint192 indexed newVal);

    // Initialization
    function init(
        IMain main_,
        string memory name_,
        string memory symbol_,
        uint48 unstakingDelay_,
        uint48 rewardPeriod_,
        uint192 rewardRatio_
    ) external;

    /// Gather and payout rewards from rsrTrader
    /// @custom:interaction
    function payoutRewards() external;

    /// Stakes an RSR `amount` on the corresponding RToken to earn yield and insure the system
    /// @param amount {qRSR}
    /// @custom:interaction
    function stake(uint256 amount) external;

    /// Begins a delayed unstaking for `amount` stRSR
    /// @param amount {qStRSR}
    /// @custom:interaction
    function unstake(uint256 amount) external;

    /// Complete delayed unstaking for the account, up to (but not including!) `endId`
    /// @custom:interaction
    function withdraw(address account, uint256 endId) external;

    /// Seize RSR, only callable by main.backingManager()
    /// @custom:protected
    function seizeRSR(uint256 amount) external;

    /// Return the maximum valid value of endId such that withdraw(endId) should immediately work
    function endIdForWithdraw(address account) external view returns (uint256 endId);

    /// @return {qRSR/qStRSR} The exchange rate between RSR and StRSR
    function exchangeRate() external view returns (uint192);
}

interface TestIStRSR is IStRSR {
    function rewardPeriod() external view returns (uint48);

    function setRewardPeriod(uint48) external;

    function rewardRatio() external view returns (uint192);

    function setRewardRatio(uint192) external;

    function unstakingDelay() external view returns (uint48);

    function setUnstakingDelay(uint48) external;

    function setName(string calldata) external;

    function setSymbol(string calldata) external;

    function increaseAllowance(address, uint256) external returns (bool);

    function decreaseAllowance(address, uint256) external returns (bool);

    /// @return {qStRSR/qRSR} The exchange rate between StRSR and RSR
    function exchangeRate() external view returns (uint192);
}

// File: contracts/interfaces/ITrade.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

/**
 * Simple generalized trading interface for all Trade contracts to obey
 *
 * Usage: if (canSettle()) settle()
 */
interface ITrade {
    function sell() external view returns (IERC20Metadata);

    function buy() external view returns (IERC20Metadata);

    /// @return The timestamp at which the trade is projected to become settle-able
    function endTime() external view returns (uint48);

    /// @return True if the trade can be settled
    /// @dev Should be guaranteed to be true eventually as an invariant
    function canSettle() external view returns (bool);

    /// Complete the trade and transfer tokens back to the origin trader
    /// @return soldAmt {qSellTok} The quantity of tokens sold
    /// @return boughtAmt {qBuyTok} The quantity of tokens bought
    function settle() external returns (uint256 soldAmt, uint256 boughtAmt);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

  // getRoundData and latestRoundData should both raise "No data present"
  // if they do not have data to report, instead of returning unset values
  // which could be misinterpreted as actual reported values.
  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
}

// File: contracts/libraries/Fixed.sol



// SPDX-License-Identifier: BlueOak-1.0.0
// solhint-disable func-name-mixedcase func-visibility
pragma solidity ^0.8.9;

/// @title FixedPoint, a fixed-point arithmetic library defining the custom type uint192
/// @author Matt Elder <matt.elder@reserve.org> and the Reserve Team <https://reserve.org>

/** The logical type `uint192 ` is a 192 bit value, representing an 18-decimal Fixed-point
    fractional value.  This is what's described in the Solidity documentation as
    "fixed192x18" -- a value represented by 192 bits, that makes 18 digits available to
    the right of the decimal point.

    The range of values that uint192 can represent is about [-1.7e20, 1.7e20].
    Unless a function explicitly says otherwise, it will fail on overflow.
    To be clear, the following should hold:
    toFix(0) == 0
    toFix(1) == 1e18
*/

// Analysis notes:
//   Every function should revert iff its result is out of bounds.
//   Unless otherwise noted, when a rounding mode is given, that mode is applied to
//     a single division that may happen as the last step in the computation.
//   Unless otherwise noted, when a rounding mode is *not* given but is needed, it's FLOOR.
//   For each, we comment:
//   - @return is the value expressed  in "value space", where uint192(1e18) "is" 1.0
//   - as-ints: is the value expressed in "implementation space", where uint192(1e18) "is" 1e18
//   The "@return" expression is suitable for actually using the library
//   The "as-ints" expression is suitable for testing

// A uint value passed to this library was out of bounds for uint192 operations
error UIntOutOfBounds();

// Used by P1 implementation for easier casting
uint256 constant FIX_ONE_256 = 1e18;
uint8 constant FIX_DECIMALS = 18;

// If a particular uint192 is represented by the uint192 n, then the uint192 represents the
// value n/FIX_SCALE.
uint64 constant FIX_SCALE = 1e18;

// FIX_SCALE Squared:
uint128 constant FIX_SCALE_SQ = 1e36;

// The largest integer that can be converted to uint192 .
// This is a bit bigger than 3.1e39
uint192 constant FIX_MAX_INT = type(uint192).max / FIX_SCALE;

uint192 constant FIX_ZERO = 0; // The uint192 representation of zero.
uint192 constant FIX_ONE = FIX_SCALE; // The uint192 representation of one.
uint192 constant FIX_MAX = type(uint192).max; // The largest uint192. (Not an integer!)
uint192 constant FIX_MIN = 0; // The smallest uint192.

/// An enum that describes a rounding approach for converting to ints
enum RoundingMode {
    FLOOR, // Round towards zero
    ROUND, // Round to the nearest int
    CEIL // Round away from zero
}

RoundingMode constant FLOOR = RoundingMode.FLOOR;
RoundingMode constant ROUND = RoundingMode.ROUND;
RoundingMode constant CEIL = RoundingMode.CEIL;

/* @dev Solidity 0.8.x only allows you to change one of type or size per type conversion.
   Thus, all the tedious-looking double conversions like uint256(uint256 (foo))
   See: https://docs.soliditylang.org/en/v0.8.9/080-breaking-changes.html#new-restrictions
 */

/// Explicitly convert a uint256 to a uint192. Revert if the input is out of bounds.
function _safeWrap(uint256 x) pure returns (uint192) {
    if (FIX_MAX < x) revert UIntOutOfBounds();
    return uint192(x);
}

/// Convert a uint to its Fix representation.
/// @return x
// as-ints: x * 1e18
function toFix(uint256 x) pure returns (uint192) {
    return _safeWrap(x * FIX_SCALE);
}

/// Convert a uint to its fixed-point representation, and left-shift its value `shiftLeft`
/// decimal digits.
/// @return x * 10**shiftLeft
// as-ints: x * 10**(shiftLeft + 18)
function shiftl_toFix(uint256 x, int8 shiftLeft) pure returns (uint192) {
    return shiftl_toFix(x, shiftLeft, FLOOR);
}

/// @return x * 10**shiftLeft
// as-ints: x * 10**(shiftLeft + 18)
function shiftl_toFix(
    uint256 x,
    int8 shiftLeft,
    RoundingMode rounding
) pure returns (uint192) {
    shiftLeft += 18;

    if (x == 0) return 0;
    if (shiftLeft <= -77) return (rounding == CEIL ? 1 : 0); // 0 < uint.max / 10**77 < 0.5
    if (57 <= shiftLeft) revert UIntOutOfBounds(); // 10**56 < FIX_MAX < 10**57

    uint256 coeff = 10**abs(shiftLeft);
    uint256 shifted = (shiftLeft >= 0) ? x * coeff : _divrnd(x, coeff, rounding);

    return _safeWrap(shifted);
}

/// Divide a uint by a uint192, yielding a uint192
/// This may also fail if the result is MIN_uint192! not fixing this for optimization's sake.
/// @return x / y
// as-ints: x * 1e36 / y
function divFix(uint256 x, uint192 y) pure returns (uint192) {
    // If we didn't have to worry about overflow, we'd just do `return x * 1e36 / _y`
    // If it's safe to do this operation the easy way, do it:
    if (x < uint256(type(uint256).max / FIX_SCALE_SQ)) {
        return _safeWrap(uint256(x * FIX_SCALE_SQ) / y);
    } else {
        return _safeWrap(mulDiv256(x, FIX_SCALE_SQ, y));
    }
}

/// Divide a uint by a uint, yielding a  uint192
/// @return x / y
// as-ints: x * 1e18 / y
function divuu(uint256 x, uint256 y) pure returns (uint192) {
    return _safeWrap(mulDiv256(FIX_SCALE, x, y));
}

/// @return min(x,y)
// as-ints: min(x,y)
function fixMin(uint192 x, uint192 y) pure returns (uint192) {
    return x < y ? x : y;
}

/// @return max(x,y)
// as-ints: max(x,y)
function fixMax(uint192 x, uint192 y) pure returns (uint192) {
    return x > y ? x : y;
}

/// @return absoluteValue(x,y)
// as-ints: absoluteValue(x,y)
function abs(int256 x) pure returns (uint256) {
    return x < 0 ? uint256(-x) : uint256(x);
}

/// Divide two uints, returning a uint, using rounding mode `rounding`.
/// @return numerator / divisor
// as-ints: numerator / divisor
function _divrnd(
    uint256 numerator,
    uint256 divisor,
    RoundingMode rounding
) pure returns (uint256) {
    uint256 result = numerator / divisor;

    if (rounding == FLOOR) return result;

    if (rounding == ROUND) {
        if (numerator % divisor > (divisor - 1) / 2) {
            result++;
        }
    } else {
        if (numerator % divisor > 0) {
            result++;
        }
    }

    return result;
}

library FixLib {
    /// Again, all arithmetic functions fail if and only if the result is out of bounds.

    /// Convert this fixed-point value to a uint. Round towards zero if needed.
    /// @return x
    // as-ints: x / 1e18
    function toUint(uint192 x) internal pure returns (uint136) {
        return toUint(x, FLOOR);
    }

    /// Convert this uint192 to a uint
    /// @return x
    // as-ints: x / 1e18 with rounding
    function toUint(uint192 x, RoundingMode rounding) internal pure returns (uint136) {
        return uint136(_divrnd(uint256(x), FIX_SCALE, rounding));
    }

    /// Return the uint192 shifted to the left by `decimal` digits
    /// (Similar to a bitshift but in base 10)
    /// @return x * 10**decimals
    // as-ints: x * 10**decimals
    function shiftl(uint192 x, int8 decimals) internal pure returns (uint192) {
        return shiftl(x, decimals, FLOOR);
    }

    /// Return the uint192 shifted to the left by `decimal` digits
    /// (Similar to a bitshift but in base 10)
    /// @return x * 10**decimals
    // as-ints: x * 10**decimals
    function shiftl(
        uint192 x,
        int8 decimals,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        uint256 coeff = uint256(10**abs(decimals));
        return _safeWrap(decimals >= 0 ? x * coeff : _divrnd(x, coeff, rounding));
    }

    /// Add a uint192 to this uint192
    /// @return x + y
    // as-ints: x + y
    function plus(uint192 x, uint192 y) internal pure returns (uint192) {
        return x + y;
    }

    /// Add a uint to this uint192
    /// @return x + y
    // as-ints: x + y*1e18
    function plusu(uint192 x, uint256 y) internal pure returns (uint192) {
        return _safeWrap(x + y * FIX_SCALE);
    }

    /// Subtract a uint192 from this uint192
    /// @return x - y
    // as-ints: x - y
    function minus(uint192 x, uint192 y) internal pure returns (uint192) {
        return x - y;
    }

    /// Subtract a uint from this uint192
    /// @return x - y
    // as-ints: x - y*1e18
    function minusu(uint192 x, uint256 y) internal pure returns (uint192) {
        return _safeWrap(uint256(x) - uint256(y * FIX_SCALE));
    }

    /// Multiply this uint192 by a uint192
    /// Round truncated values to the nearest available value. 5e-19 rounds away from zero.
    /// @return x * y
    // as-ints: x * y/1e18  [division using ROUND, not FLOOR]
    function mul(uint192 x, uint192 y) internal pure returns (uint192) {
        return mul(x, y, ROUND);
    }

    /// Multiply this uint192 by a uint192
    /// @return x * y
    // as-ints: x * y/1e18
    function mul(
        uint192 x,
        uint192 y,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        return _safeWrap(_divrnd(uint256(x) * uint256(y), FIX_SCALE, rounding));
    }

    /// Multiply this uint192 by a uint
    /// @return x * y
    // as-ints: x * y
    function mulu(uint192 x, uint256 y) internal pure returns (uint192) {
        return _safeWrap(x * y);
    }

    /// Divide this uint192 by a uint192
    /// @return x / y
    // as-ints: x * 1e18 / y
    function div(uint192 x, uint192 y) internal pure returns (uint192) {
        return div(x, y, FLOOR);
    }

    /// Divide this uint192 by a uint192
    /// @return x / y
    // as-ints: x * 1e18 / y
    function div(
        uint192 x,
        uint192 y,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        // Multiply-in FIX_SCALE before dividing by y to preserve precision.
        return _safeWrap(_divrnd(uint256(x) * FIX_SCALE, y, rounding));
    }

    /// Divide this uint192 by a uint
    /// @return x / y
    // as-ints: x / y
    function divu(uint192 x, uint256 y) internal pure returns (uint192) {
        return divu(x, y, FLOOR);
    }

    /// Divide this uint192 by a uint
    /// @return x / y
    // as-ints: x / y
    function divu(
        uint192 x,
        uint256 y,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        return _safeWrap(_divrnd(x, y, rounding));
    }

    uint64 constant FIX_HALF = uint64(FIX_SCALE) / 2;

    /// Raise this uint192 to a nonnegative integer power.
    /// Intermediate muls do nearest-value rounding.
    /// Presumes that powu(0.0, 0) = 1
    /// @dev The gas cost is O(lg(y))
    /// @return x_ ** y
    // as-ints: x_ ** y / 1e18**(y-1)    <- technically correct for y = 0. :D
    function powu(uint192 x_, uint48 y) internal pure returns (uint192) {
        // The algorithm is exponentiation by squaring. See: https://w.wiki/4LjE
        if (y == 1) return x_;
        if (x_ == FIX_ONE || y == 0) return FIX_ONE;
        uint256 x = uint256(x_);
        uint256 result = FIX_SCALE;
        while (true) {
            if (y & 1 == 1) result = (result * x + FIX_HALF) / FIX_SCALE;
            if (y <= 1) break;
            y = y >> 1;
            x = (x * x + FIX_HALF) / FIX_SCALE;
        }
        return _safeWrap(result);
    }

    /// Comparison operators...
    function lt(uint192 x, uint192 y) internal pure returns (bool) {
        return x < y;
    }

    function lte(uint192 x, uint192 y) internal pure returns (bool) {
        return x <= y;
    }

    function gt(uint192 x, uint192 y) internal pure returns (bool) {
        return x > y;
    }

    function gte(uint192 x, uint192 y) internal pure returns (bool) {
        return x >= y;
    }

    function eq(uint192 x, uint192 y) internal pure returns (bool) {
        return x == y;
    }

    function neq(uint192 x, uint192 y) internal pure returns (bool) {
        return x != y;
    }

    /// Return whether or not this uint192 is less than epsilon away from y.
    /// @return |x - y| < epsilon
    // as-ints: |x - y| < epsilon
    function near(
        uint192 x,
        uint192 y,
        uint192 epsilon
    ) internal pure returns (bool) {
        uint192 diff = x <= y ? y - x : x - y;
        return diff < epsilon;
    }

    // ================ Chained Operations ================
    // The operation foo_bar() always means:
    //   Do foo() followed by bar(), and overflow only if the _end_ result doesn't fit in an uint192

    /// Shift this uint192 left by `decimals` digits, and convert to a uint
    /// @return x * 10**decimals
    // as-ints: x * 10**(decimals - 18)
    function shiftl_toUint(uint192 x, int8 decimals) internal pure returns (uint256) {
        return shiftl_toUint(x, decimals, FLOOR);
    }

    /// Shift this uint192 left by `decimals` digits, and convert to a uint.
    /// @return x * 10**decimals
    // as-ints: x * 10**(decimals - 18)
    function shiftl_toUint(
        uint192 x,
        int8 decimals,
        RoundingMode rounding
    ) internal pure returns (uint256) {
        decimals -= 18; // shift so that toUint happens at the same time.
        uint256 coeff = uint256(10**abs(decimals));
        return decimals >= 0 ? uint256(x * coeff) : uint256(_divrnd(x, coeff, rounding));
    }

    /// Multiply this uint192 by a uint, and output the result as a uint
    /// @return x * y
    // as-ints: x * y / 1e18
    function mulu_toUint(uint192 x, uint256 y) internal pure returns (uint256) {
        return mulDiv256(uint256(x), y, FIX_SCALE);
    }

    /// Multiply this uint192 by a uint, and output the result as a uint
    /// @return x * y
    // as-ints: x * y / 1e18
    function mulu_toUint(
        uint192 x,
        uint256 y,
        RoundingMode rounding
    ) internal pure returns (uint256) {
        return mulDiv256(uint256(x), y, FIX_SCALE, rounding);
    }

    /// Multiply this uint192 by a uint192 and output the result as a uint
    /// @return x * y
    // as-ints: x * y / 1e36
    function mul_toUint(uint192 x, uint192 y) internal pure returns (uint256) {
        return mulDiv256(uint256(x), uint256(y), FIX_SCALE_SQ);
    }

    /// Multiply this uint192 by a uint192 and output the result as a uint
    /// @return x * y
    // as-ints: x * y / 1e36
    function mul_toUint(
        uint192 x,
        uint192 y,
        RoundingMode rounding
    ) internal pure returns (uint256) {
        return mulDiv256(uint256(x), uint256(y), FIX_SCALE_SQ, rounding);
    }

    /// Compute x * y / z avoiding intermediate overflow
    /// @dev Only use if you need to avoid overflow; costlier than x * y / z
    /// @return x * y / z
    // as-ints: x * y / z
    function muluDivu(
        uint192 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint192) {
        return muluDivu(x, y, z, FLOOR);
    }

    /// Compute x * y / z, avoiding intermediate overflow
    /// @dev Only use if you need to avoid overflow; costlier than x * y / z
    /// @return x * y / z
    // as-ints: x * y / z
    function muluDivu(
        uint192 x,
        uint256 y,
        uint256 z,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        return _safeWrap(mulDiv256(x, y, z, rounding));
    }

    /// Compute x * y / z on Fixes, avoiding intermediate overflow
    /// @dev Only use if you need to avoid overflow; costlier than x * y / z
    /// @return x * y / z
    // as-ints: x * y / z
    function mulDiv(
        uint192 x,
        uint192 y,
        uint192 z
    ) internal pure returns (uint192) {
        return mulDiv(x, y, z, FLOOR);
    }

    /// Compute x * y / z on Fixes, avoiding intermediate overflow
    /// @dev Only use if you need to avoid overflow; costlier than x * y / z
    /// @return x * y / z
    // as-ints: x * y / z
    function mulDiv(
        uint192 x,
        uint192 y,
        uint192 z,
        RoundingMode rounding
    ) internal pure returns (uint192) {
        return _safeWrap(mulDiv256(x, y, z, rounding));
    }
}

// ================ a couple pure-uint helpers================
// as-ints comments are omitted here, because they're the same as @return statements, because
// these are all pure uint functions

/// Return (x*y/z), avoiding intermediate overflow.
//  Adapted from sources:
//    https://medium.com/coinmonks/4db014e080b1, https://medium.com/wicketh/afa55870a65
//    and quite a few of the other excellent "Mathemagic" posts from https://medium.com/wicketh
/// @dev Only use if you need to avoid overflow; costlier than x * y / z
/// @return result x * y / z
function mulDiv256(
    uint256 x,
    uint256 y,
    uint256 z
) pure returns (uint256 result) {
    unchecked {
        (uint256 hi, uint256 lo) = fullMul(x, y);
        if (hi >= z) revert UIntOutOfBounds();
        uint256 mm = mulmod(x, y, z);
        if (mm > lo) hi -= 1;
        lo -= mm;
        uint256 pow2 = z & (0 - z);
        z /= pow2;
        lo /= pow2;
        lo += hi * ((0 - pow2) / pow2 + 1);
        uint256 r = 1;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        r *= 2 - z * r;
        result = lo * r;
    }
}

/// Return (x*y/z), avoiding intermediate overflow.
/// @dev Only use if you need to avoid overflow; costlier than x * y / z
/// @return x * y / z
function mulDiv256(
    uint256 x,
    uint256 y,
    uint256 z,
    RoundingMode rounding
) pure returns (uint256) {
    uint256 result = mulDiv256(x, y, z);
    if (rounding == FLOOR) return result;

    uint256 mm = mulmod(x, y, z);
    if (rounding == CEIL) {
        if (mm > 0) result += 1;
    } else {
        if (mm > ((z - 1) / 2)) result += 1; // z should be z-1
    }
    return result;
}

/// Return (x*y) as a "virtual uint512" (lo, hi), representing (hi*2**256 + lo)
///   Adapted from sources:
///   https://medium.com/wicketh/27650fec525d, https://medium.com/coinmonks/4db014e080b1
/// @dev Intended to be internal to this library
/// @return hi (hi, lo) satisfies  hi*(2**256) + lo == x * y
/// @return lo (paired with `hi`)
function fullMul(uint256 x, uint256 y) pure returns (uint256 hi, uint256 lo) {
    unchecked {
        uint256 mm = mulmod(x, y, uint256(0) - uint256(1));
        lo = x * y;
        hi = mm - lo;
        if (mm < lo) hi -= 1;
    }
}

// File: @openzeppelin/contracts-upgradeable/access/IAccessControlUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

// File: contracts/interfaces/IAssetRegistry.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "contracts/interfaces/IAsset.sol";
import "./IComponent.sol";

/**
 * @title IAssetRegistry
 * @notice The AssetRegistry is in charge of maintaining the ERC20 tokens eligible
 *   to be handled by the rest of the system. If an asset is in the registry, this means:
 *      1. Its ERC20 contract has been vetted
 *      2. The asset is the only asset for that ERC20
 *      3. The asset can be priced in the UoA, usually via an oracle
 */
interface IAssetRegistry is IComponent {
    /// Emitted when an asset is added to the registry
    /// @param erc20 The ERC20 contract for the asset
    /// @param asset The asset contract added to the registry
    event AssetRegistered(IERC20 indexed erc20, IAsset indexed asset);

    /// Emitted when an asset is removed from the registry
    /// @param erc20 The ERC20 contract for the asset
    /// @param asset The asset contract removed from the registry
    event AssetUnregistered(IERC20 indexed erc20, IAsset indexed asset);

    // Initialization
    function init(IMain main_, IAsset[] memory assets_) external;

    /// Fully refresh all asset state
    /// @custom:interaction
    function refresh() external;

    /// @return The corresponding asset for ERC20, or reverts if not registered
    function toAsset(IERC20 erc20) external view returns (IAsset);

    /// @return The corresponding collateral, or reverts if unregistered or not collateral
    function toColl(IERC20 erc20) external view returns (ICollateral);

    /// @return If the ERC20 is registered
    function isRegistered(IERC20 erc20) external view returns (bool);

    /// @return A list of all registered ERC20s
    function erc20s() external view returns (IERC20[] memory);

    function register(IAsset asset) external returns (bool);

    function swapRegistered(IAsset asset) external returns (bool swapped);

    function unregister(IAsset asset) external;
}

// File: contracts/interfaces/IBasketHandler.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "contracts/libraries/Fixed.sol";
import "./IAsset.sol";
import "./IComponent.sol";

/**
 * @title IBasketHandler
 * @notice The BasketHandler aims to maintain a reference basket of constant target unit amounts.
 * When a collateral token defaults, a new reference basket of equal target units is set.
 * When _all_ collateral tokens default for a target unit, only then is the basket allowed to fall
 *   in terms of target unit amounts. The basket is considered defaulted in this case.
 */
interface IBasketHandler is IComponent {
    /// Emitted when the prime basket is set
    /// @param erc20s The collateral tokens for the prime basket
    /// @param targetAmts {target/BU} A list of quantities of target unit per basket unit
    /// @param targetNames Each collateral token's targetName
    event PrimeBasketSet(IERC20[] erc20s, uint192[] targetAmts, bytes32[] targetNames);

    /// Emitted when the reference basket is set
    /// @param nonce The basket nonce
    /// @param erc20s The list of collateral tokens in the reference basket
    /// @param refAmts {ref/BU} The reference amounts of the basket collateral tokens
    /// @param disabled True when the list of erc20s + refAmts may not be correct
    event BasketSet(uint256 indexed nonce, IERC20[] erc20s, uint192[] refAmts, bool disabled);

    /// Emitted when a backup config is set for a target unit
    /// @param targetName The name of the target unit as a bytes32
    /// @param max The max number to use from `erc20s`
    /// @param erc20s The set of backup collateral tokens
    event BackupConfigSet(bytes32 indexed targetName, uint256 indexed max, IERC20[] erc20s);

    // Initialization
    function init(IMain main_) external;

    /// Set the prime basket
    /// @param erc20s The collateral tokens for the new prime basket
    /// @param targetAmts The target amounts (in) {target/BU} for the new prime basket
    ///                   required range: 1e9 values; absolute range irrelevant.
    /// @custom:governance
    function setPrimeBasket(IERC20[] memory erc20s, uint192[] memory targetAmts) external;

    /// Set the backup configuration for a given target
    /// @param targetName The name of the target as a bytes32
    /// @param max The maximum number of collateral tokens to use from this target
    ///            Required range: 1-255
    /// @param erc20s A list of ordered backup collateral tokens
    /// @custom:governance
    function setBackupConfig(
        bytes32 targetName,
        uint256 max,
        IERC20[] calldata erc20s
    ) external;

    /// Default the basket in order to schedule a basket refresh
    /// @custom:protected
    function disableBasket() external;

    /// Governance-controlled setter to cause a basket switch explicitly
    /// @custom:governance
    /// @custom:interaction
    function refreshBasket() external;

    /// @return If the BackingManager has sufficient collateral to redeem the entire RToken supply
    function fullyCollateralized() external view returns (bool);

    /// @return status The worst CollateralStatus of all collateral in the basket
    function status() external view returns (CollateralStatus status);

    /// @return {tok/BU} The whole token quantity of token in the reference basket
    /// Returns 0 if erc20 is not registered, disabled, or not in the basket
    /// Returns FIX_MAX (in lieu of +infinity) if Collateral.refPerTok() is 0.
    /// Otherwise, returns (token's basket.refAmts / token's Collateral.refPerTok())
    function quantity(IERC20 erc20) external view returns (uint192);

    /// @param amount {BU}
    /// @return erc20s The addresses of the ERC20 tokens in the reference basket
    /// @return quantities {qTok} The quantity of each ERC20 token to issue `amount` baskets
    function quote(uint192 amount, RoundingMode rounding)
        external
        view
        returns (address[] memory erc20s, uint256[] memory quantities);

    /// @return baskets {BU} The quantity of complete baskets at an address. A balance for BUs
    function basketsHeldBy(address account) external view returns (uint192 baskets);

    /// @param allowFallback Whether to fail over to the fallback price or not
    /// @return isFallback If any fallback prices were used
    /// @return p {UoA/BU} The protocol's best guess at what a BU would be priced at in UoA
    function price(bool allowFallback) external view returns (bool isFallback, uint192 p);

    /// @return The basket nonce, a monotonically increasing unique identifier
    function nonce() external view returns (uint48);

    /// @return timestamp The timestamp at which the basket was last set
    function timestamp() external view returns (uint48);
}

// File: contracts/interfaces/IBackingManager.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IComponent.sol";
import "./ITrading.sol";

/**
 * @title IBackingManager
 * @notice The BackingManager handles changes in the ERC20 balances that back an RToken.
 *   - It computes which trades to perform, if any, and initiates these trades with the Broker.
 *   - If already capitalized, excess assets are transferred to RevenueTraders.
 *
 * `manageTokens(erc20s)` and `manageTokensSortedOrder(erc20s)` are handles for getting at the
 *   same underlying functionality. The former allows an ERC20 list in any order, while the
 *   latter requires a sorted array, and executes in O(n) rather than O(n^2) time. In the
 *   vast majority of cases we expect the the O(n^2) function to be acceptable.
 */
interface IBackingManager is IComponent, ITrading {
    event TradingDelaySet(uint48 indexed oldVal, uint48 indexed newVal);
    event BackingBufferSet(uint192 indexed oldVal, uint192 indexed newVal);

    // Initialization
    function init(
        IMain main_,
        uint48 tradingDelay_,
        uint192 backingBuffer_,
        uint192 maxTradeSlippage_,
        uint192 minTradeVolume_
    ) external;

    // Give RToken max allowance over a registered token
    /// @custom:refresher
    /// @custom:interaction
    function grantRTokenAllowance(IERC20) external;

    /// Mointain the overall backing policy; handout assets otherwise
    /// @dev Performs a uniqueness check on the erc20s list in O(n^2)
    /// @custom:interaction
    function manageTokens(IERC20[] memory erc20s) external;

    /// Mointain the overall backing policy; handout assets otherwise
    /// @dev Tokens must be in sorted order!
    /// @dev Performs a uniqueness check on the erc20s list in O(n)
    /// @custom:interaction
    function manageTokensSortedOrder(IERC20[] memory erc20s) external;
}

interface TestIBackingManager is IBackingManager, TestITrading {
    function tradingDelay() external view returns (uint48);

    function backingBuffer() external view returns (uint192);

    function setTradingDelay(uint48 val) external;

    function setBackingBuffer(uint192 val) external;
}

// File: contracts/interfaces/IBroker.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "./IAsset.sol";
import "./IComponent.sol";
import "./IGnosis.sol";
import "./ITrade.sol";

/// The data format that describes a request for trade with the Broker
struct TradeRequest {
    IAsset sell;
    IAsset buy;
    uint256 sellAmount; // {qSellTok}
    uint256 minBuyAmount; // {qBuyTok}
}

/**
 * @title IBroker
 * @notice The Broker deploys oneshot Trade contracts for Traders and monitors
 *   the continued proper functioning of trading platforms.
 */
interface IBroker is IComponent {
    event AuctionLengthSet(uint48 indexed oldVal, uint48 indexed newVal);
    event DisabledSet(bool indexed prevVal, bool indexed newVal);

    // Initialization
    function init(
        IMain main_,
        IGnosis gnosis_,
        ITrade tradeImplementation_,
        uint48 auctionLength_
    ) external;

    /// Request a trade from the broker
    /// @dev Requires setting an allowance in advance
    /// @custom:interaction
    function openTrade(TradeRequest memory req) external returns (ITrade);

    /// Only callable by one of the trading contracts the broker deploys
    function reportViolation() external;

    function disabled() external view returns (bool);
}

interface TestIBroker is IBroker {
    function gnosis() external view returns (IGnosis);

    function auctionLength() external view returns (uint48);

    function setAuctionLength(uint48 newAuctionLength) external;

    function setDisabled(bool disabled_) external;
}

// File: contracts/interfaces/IFurnace.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "contracts/libraries/Fixed.sol";
import "./IComponent.sol";

/**
 * @title IFurnace
 * @notice A helper contract to burn RTokens slowly and permisionlessly.
 */
interface IFurnace is IComponent {
    // Initialization
    function init(
        IMain main_,
        uint48 period_,
        uint192 ratio_
    ) external;

    /// Emitted when the melting period is changed
    /// @param oldPeriod The old period
    /// @param newPeriod The new period
    event PeriodSet(uint48 indexed oldPeriod, uint48 indexed newPeriod);

    function period() external view returns (uint48);

    /// @custom:governance
    function setPeriod(uint48) external;

    /// Emitted when the melting ratio is changed
    /// @param oldRatio The old ratio
    /// @param newRatio The new ratio
    event RatioSet(uint192 indexed oldRatio, uint192 indexed newRatio);

    function ratio() external view returns (uint192);

    ///    Needed value range: [0, 1], granularity 1e-9
    /// @custom:governance
    function setRatio(uint192) external;

    /// Performs any RToken melting that has vested since the last payout.
    /// @custom:refresher
    function melt() external;
}

interface TestIFurnace is IFurnace {
    function lastPayout() external view returns (uint256);

    function lastPayoutBal() external view returns (uint256);
}

// File: contracts/interfaces/IRevenueTrader.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "./IComponent.sol";
import "./ITrading.sol";

/**
 * @title IRevenueTrader
 * @notice The RevenueTrader is an extension of the trading mixin that trades all
 *   assets at its address for a single target asset. There are two runtime instances
 *   of the RevenueTrader, 1 for RToken and 1 for RSR.
 */
interface IRevenueTrader is IComponent, ITrading {
    // Initialization
    function init(
        IMain main_,
        IERC20 tokenToBuy_,
        uint192 maxTradeSlippage_,
        uint192 minTradeVolume_
    ) external;

    /// Processes a single token; unpermissioned
    /// @dev Intended to be used with multicall
    /// @custom:interaction
    function manageToken(IERC20 sell) external;
}

// solhint-disable-next-line no-empty-blocks
interface TestIRevenueTrader is IRevenueTrader, TestITrading {
    function tokenToBuy() external view returns (IERC20);
}

// File: contracts/interfaces/ITrading.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "contracts/libraries/Fixed.sol";
import "./IAsset.sol";
import "./ITrade.sol";
import "./IRewardable.sol";

/**
 * @title ITrading
 * @notice Common events and refresher function for all Trading contracts
 */
interface ITrading is IRewardable {
    event MaxTradeSlippageSet(uint192 indexed oldVal, uint192 indexed newVal);
    event MinTradeVolumeSet(uint192 indexed oldVal, uint192 indexed newVal);

    /// Emitted when a trade is started
    /// @param trade The one-time-use trade contract that was just deployed
    /// @param sell The token to sell
    /// @param buy The token to buy
    /// @param sellAmount {qSellTok} The quantity of the selling token
    /// @param minBuyAmount {qBuyTok} The minimum quantity of the buying token to accept
    event TradeStarted(
        ITrade indexed trade,
        IERC20 indexed sell,
        IERC20 indexed buy,
        uint256 sellAmount,
        uint256 minBuyAmount
    );

    /// Emitted after a trade ends
    /// @param trade The one-time-use trade contract
    /// @param sell The token to sell
    /// @param buy The token to buy
    /// @param sellAmount {qSellTok} The quantity of the token sold
    /// @param buyAmount {qBuyTok} The quantity of the token bought
    event TradeSettled(
        ITrade indexed trade,
        IERC20 indexed sell,
        IERC20 indexed buy,
        uint256 sellAmount,
        uint256 buyAmount
    );

    /// Settle a single trade, expected to be used with multicall for efficient mass settlement
    /// @custom:refresher
    function settleTrade(IERC20 sell) external;

    /// @return {%} The maximum trade slippage acceptable
    function maxTradeSlippage() external view returns (uint192);

    /// @return {UoA} The minimum trade volume in UoA, applies to all assets
    function minTradeVolume() external view returns (uint192);

    /// @return The ongoing trade for a sell token, or the zero address
    function trades(IERC20 sell) external view returns (ITrade);
}

interface TestITrading is ITrading {
    /// @custom:governance
    function setMaxTradeSlippage(uint192 val) external;

    /// @custom:governance
    function setMinTradeVolume(uint192 val) external;

    /// @return The number of ongoing trades open
    function tradesOpen() external view returns (uint48);
}

// File: contracts/interfaces/IComponent.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "./IMain.sol";

/**
 * @title IComponent
 * @notice A Component is the central building block of all our system contracts. Components
 *   contain important state that must be migrated during upgrades, and they delegate
 *   their ownership to Main's owner.
 */
interface IComponent {
    function main() external view returns (IMain);
}

// File: contracts/interfaces/IRewardable.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "./IComponent.sol";
import "./IMain.sol";

/**
 * @title IRewardable
 * @notice A simple component mixin interface to support claiming + monetization of rewards
 */
interface IRewardable is IComponent {
    /// Emitted whenever rewards are claimed
    event RewardsClaimed(address indexed erc20, uint256 indexed amount);

    /// Claim reward tokens from integrated defi protocols such as Compound/Aave
    /// @custom:interaction
    function claimAndSweepRewards() external;
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20MetadataUpgradeable is IERC20Upgradeable {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-IERC20PermitUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20PermitUpgradeable {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: contracts/p1/RToken.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

// solhint-disable-next-line max-line-length
import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import "contracts/interfaces/IMain.sol";
import "contracts/interfaces/IRewardable.sol";
import "contracts/interfaces/IRToken.sol";
import "contracts/libraries/Fixed.sol";
import "contracts/libraries/RedemptionBattery.sol";
import "contracts/p1/mixins/Component.sol";
import "contracts/p1/mixins/RewardableLib.sol";
import "contracts/vendor/ERC20PermitUpgradeable.sol";

// MIN_BLOCK_ISSUANCE_LIMIT: {rTok/block} 10k whole RTok
uint192 constant MIN_BLOCK_ISSUANCE_LIMIT = 10_000 * FIX_ONE;

// MAX_ISSUANCE_RATE: 100%
uint192 constant MAX_ISSUANCE_RATE = 1e18; // {1}

/**
 * @title RTokenP1
 * An ERC20 with an elastic supply and governable exchange rate to basket units.
 */
contract RTokenP1 is ComponentP1, IRewardable, ERC20PermitUpgradeable, IRToken {
    using RedemptionBatteryLib for RedemptionBatteryLib.Battery;
    using SafeERC20Upgradeable for IERC20Upgradeable;

    /// The mandate describes what goals its governors should try to achieve. By succinctly
    /// explaining the RToken’s purpose and what the RToken is intended to do, it provides common
    /// ground for the governors to decide upon priorities and how to weigh tradeoffs.
    ///
    /// Example Mandates:
    ///
    /// - Capital preservation first. Spending power preservation second. Permissionless
    ///     access third.
    /// - Capital preservation above all else. All revenues fund the insurance pool.
    /// - Risk-neutral pursuit of profit for token holders.
    ///     Maximize (gross revenue - payments for insurance and governance).
    /// - This RToken holds only FooCoin, to provide a trade for hedging against its
    ///     possible collapse.
    ///
    /// The mandate may also be a URI to a longer body of text
    string public mandate;

    // ==== Governance Params ====

    // {qRTok} The min value of total supply to use for redemption throttling
    // The redemption capacity is always at least maxRedemptionCharge * redemptionVirtualSupply
    uint256 public redemptionVirtualSupply;

    // D18{1} fraction of supply that may be issued per block
    // Always, issuanceRate <= MAX_ISSUANCE_RATE = FIX_ONE
    uint192 public issuanceRate;

    // {1} fraction of supply that may be redeemed at once. Set to 0 to disable.
    // Always, maxRedemptionCharge <= FIX_ONE
    uint192 public maxRedemptionCharge;

    // ==== End Governance Params ====

    // The number of baskets that backingManager must hold
    // in order for this RToken to be fully collateralized.
    // The exchange rate for issuance and redemption is totalSupply()/basketsNeeded {BU}/{qRTok}.
    uint192 public basketsNeeded; // D18{BU}

    // ==== Slow Issuance State====

    // When all pending issuances will have vested.
    uint192 private allVestAt; // D18{fractional block number}

    // Enforce a fixed issuanceRate throughout the entire block by caching it.
    // Both of these MUST only be modified by whenFinished()
    uint192 private lastIssRate; // D18{rTok/block}
    uint256 private lastIssRateBlock; // {block number}

    // IssueItem: One edge of an issuance
    struct IssueItem {
        uint192 when; // D18{fractional block number}
        uint256 amtRToken; // {qRTok} Total amount of RTokens that have vested by `when`
        uint192 amtBaskets; // D18{BU} Total amount of baskets that should back those RTokens
        uint256[] deposits; // {qTok}, Total amounts of basket collateral deposited for vesting
    }

    struct IssueQueue {
        uint256 basketNonce; // The nonce of the basket this queue models deposits against
        address[] tokens; // Addresses of the erc20 tokens modelled by deposits in this queue
        uint256 left; // [left, right) is the span of currently-valid items
        uint256 right; //
        IssueItem[] items; // The actual items (The issuance "fenceposts")
    }

    mapping(address => IssueQueue) public issueQueues;

    // Redemption throttle
    RedemptionBatteryLib.Battery private battery;

    // For an initialized IssueQueue queue:
    //     queue.right >= left
    //     queue.right == left  iff  there are no more pending issuances in this queue
    //
    // The short way to describe this is that IssueQueue stores _cumulative_ issuances, not raw
    // issuances, and so any particular issuance is actually the _difference_ between two adjaacent
    // TotalIssue items in an IssueQueue.
    //
    // The way to keep an IssueQueue striaght in your head is to think of each TotalIssue item as a
    // "fencepost" in the queue of actual issuances. The true issuances are the spans between the
    // TotalIssue items. For example, if:
    //    queue.items[queue.left].amtRToken == 1000 , and
    //    queue.items[queue.right - 1].amtRToken == 6000,
    // then the issuance "between" them is 5000 RTokens. If we waited long enough and then called
    // vest() on that account, we'd vest 5000 RTokens *to* that account.
    //
    // You can vestUpTo an IssueItem queue[i] if
    //   left < i <= right, and
    //   block.number >= queue[i].when.toUint()
    //
    // We define a (partial) ordering on IssueItems: item1 < item2 iff the following all hold:
    //   item1.when < item2.when
    //   item2.amtRToken < item2.amtRToken
    //   item1.amtBaskets < item2.amtBaskets
    //   for all valid indices i, item1[i].deposits < item2[i].deposits
    //
    // And, in fact, item2 - item1 is then well-defined (and also piecewise).
    //
    // We'll also define lastItem(addr) as a function of contract state:
    //     if queue.right == 0 then IssueItem.zero else queue.items[queue.right]
    //     where queue = issueQueues[addr]
    //
    // ==== Invariants ====
    // For any queue in value(issueQueues):
    //   if 0 <= i < j <= queue.right, then item[i] < item[j]
    //   queue.items[queue.right] <= allVestAt
    //
    // If queue.left < queue.right, then:
    // - all the issue() calls it models happened while basketHandler.nonce() was queue.basketNonce
    // - queue.tokens = erc20s for each of those issuances, where (erc20s, _) = basket.quote()
    //     so, queue.tokens was the bskt token list when basketHandler.nonce() was queue.basketNonce
    // - for each item in queue.items: queue.tokens.length == item.deposits.length

    function init(
        IMain main_,
        string calldata name_,
        string calldata symbol_,
        string calldata mandate_,
        uint192 issuanceRate_,
        uint192 maxRedemptionCharge_,
        uint256 redemptionVirtualSupply_
    ) external initializer {
        require(bytes(name_).length > 0, "name empty");
        require(bytes(symbol_).length > 0, "symbol empty");
        require(bytes(mandate_).length > 0, "mandate empty");
        __Component_init(main_);
        __ERC20_init(name_, symbol_);
        __ERC20Permit_init(name_);
        mandate = mandate_;
        setIssuanceRate(issuanceRate_);
        setScalingRedemptionRate(maxRedemptionCharge_);
        setRedemptionRateFloor(redemptionVirtualSupply_);
    }

    /// Begin a time-delayed issuance of RToken for basket collateral
    /// @param amtRToken {qTok} The quantity of RToken to issue
    /// @custom:interaction nearly CEI, but see comments around handling of refunds
    function issue(uint256 amtRToken) external notPausedOrFrozen {
        require(amtRToken > 0, "Cannot issue zero");

        // == Refresh ==
        main.assetRegistry().refresh();

        address issuer = _msgSender(); // OK to save: it can't be changed in reentrant runs
        IBasketHandler bh = main.basketHandler(); // OK to save: can only be changed by gov

        uint48 basketNonce = bh.nonce();
        IssueQueue storage queue = issueQueues[issuer];

        // Refund issuances against old baskets
        if (queue.basketNonce > 0 && queue.basketNonce != basketNonce) {
            // == Interaction ==
            // This violates simple CEI, so we have to renew any potential transient state!
            refundSpan(issuer, queue.left, queue.right);

            // Refresh collateral after interaction
            main.assetRegistry().refresh();

            // Refresh local values after potential reentrant changes to contract state.
            basketNonce = bh.nonce();
            queue = issueQueues[issuer];
        }

        // == Checks-effects block ==
        CollateralStatus status = bh.status();
        require(status == CollateralStatus.SOUND, "basket unsound");

        main.furnace().melt();

        // AT THIS POINT:
        //   all contract invariants hold
        //   furnace melting is up-to-date
        //   asset states are up-to-date
        //   queue.basketNonce = basketHandler.nonce()

        // Compute the whole issuance span. We want to accumulate the issuance:
        // iss = {when: vestingEnd' - vestingEnd, amtRToken, amtBaskets, deposits}

        // amtBaskets: the BU change to be recorded by this issuance
        // D18{BU} = D18{BU} * {qRTok} / {qRTok}
        // Downcast is safe because an actual quantity of qBUs fits in uint192
        uint192 amtBaskets = uint192(
            totalSupply() > 0 ? mulDiv256(basketsNeeded, amtRToken, totalSupply()) : amtRToken
        );

        (address[] memory erc20s, uint256[] memory deposits) = bh.quote(amtBaskets, CEIL);

        // Add amtRToken's worth of issuance delay to allVestAt
        uint192 vestingEnd = whenFinished(amtRToken); // D18{block number}

        // ==== If the issuance can fit in this block, and nothing is blocking it, then
        // just do a "quick issuance" of iss instead of putting the issuance in the queue:
        // effects and actions if we go this way are the combined actions to create and vest iss:
        //   basketsNeeded += iss.amtBaskets
        //   mint(issuer, iss.amtRToken)
        //   for each token index i, erc20s[i].transferFrom(issuer, backingManager, iss.deposits[i])
        if (
            // D18{blocks} <= D18{1} * {blocks}
            vestingEnd <= FIX_ONE_256 * block.number &&
            queue.left == queue.right &&
            status == CollateralStatus.SOUND
        ) {
            // Fixlib optimization:
            // D18{BU} = D18{BU} + D18{BU}; uint192(+) is the same as Fix.plus
            uint192 newBasketsNeeded = basketsNeeded + amtBaskets;
            emit BasketsNeededChanged(basketsNeeded, newBasketsNeeded);
            basketsNeeded = newBasketsNeeded;

            // Note: We don't need to update the prev queue entry because queue.left = queue.right
            emit Issuance(issuer, amtRToken, amtBaskets);

            address backingMgr = address(main.backingManager());

            // == Interactions then return: transfer tokens ==
            // Complete issuance
            _mint(issuer, amtRToken);
            for (uint256 i = 0; i < erc20s.length; ++i) {
                IERC20Upgradeable(erc20s[i]).safeTransferFrom(issuer, backingMgr, deposits[i]);
            }
            return;
        }

        // ==== Otherwise, we're going to create and enqueue the issuance "iss":
        // effects and actions down this route are:
        //   lastItem'(issuer) = lastItem(issuer) + iss
        //   for each token index i, erc20s[i].transferFrom(issuer, this, iss.deposits[i])

        // Append issuance to queue (whether that needs a new allocation with push() or not)
        IssueItem storage curr = (queue.right < queue.items.length)
            ? queue.items[queue.right]
            : queue.items.push();
        curr.when = vestingEnd;

        // Accumulate
        if (queue.right > 0) {
            IssueItem storage prev = queue.items[queue.right - 1];
            curr.amtRToken = prev.amtRToken + amtRToken;

            // D18{BU} = D18{BU} + D18{BU}; uint192(+) is the same as Fix.plus
            curr.amtBaskets = prev.amtBaskets + amtBaskets;

            curr.deposits = new uint256[](deposits.length);
            for (uint256 i = 0; i < deposits.length; ++i) {
                curr.deposits[i] = prev.deposits[i] + deposits[i];
            }
        } else {
            // queue.right == 0
            curr.amtRToken = amtRToken;
            curr.amtBaskets = amtBaskets;
            curr.deposits = deposits;
        }

        // overwrite intentionally: we may have stale values in `tokens` and `basketNonce`
        queue.basketNonce = basketNonce;
        queue.tokens = erc20s;
        queue.right++;

        emit IssuanceStarted(
            issuer,
            queue.right - 1,
            amtRToken,
            amtBaskets,
            erc20s,
            deposits,
            vestingEnd
        );

        // == Interactions: accept collateral ==
        for (uint256 i = 0; i < erc20s.length; ++i) {
            IERC20Upgradeable(erc20s[i]).safeTransferFrom(issuer, address(this), deposits[i]);
        }
    }

    /// Add amtRToken's worth of issuance delay to allVestAt, and return the resulting finish time.
    /// @return finished D18{block} The new value of allVestAt
    function whenFinished(uint256 amtRToken) private returns (uint192 finished) {
        // Calculate the issuance rate (if this is the first issuance in the block)
        if (lastIssRateBlock < block.number) {
            lastIssRateBlock = block.number;

            // D18{rTok/block} = D18{1/block} * D18{rTok} / D18{1}
            // uint192 downcast is safe, max value representations are 1e18 * 1e48 / 1e18
            lastIssRate = uint192((issuanceRate * totalSupply()) / FIX_ONE);
            // uint192(<) is equivalent to Fix.lt
            if (lastIssRate < MIN_BLOCK_ISSUANCE_LIMIT) lastIssRate = MIN_BLOCK_ISSUANCE_LIMIT;
        }

        // make `before` be the fractional-block when this issuance should start;
        // before = max(allVestAt, block.number - 1)
        uint192 before = allVestAt; // D18{block number}
        // uint192 downcast is safe: block numbers are smaller than 1e38
        uint192 nowStart = uint192(FIX_ONE * (block.number - 1)); // D18{block} = D18{1} * {block}
        if (nowStart > before) before = nowStart;

        // finished: D18{block} = D18{block} + D18{1} * D18{RTok} / D18{rtok/block}
        // uint192() downcast here is safe because:
        //   lastIssRate is at least 1e24 (from MIN_ISS_RATE), and
        //   amtRToken is at most 1e48, so
        //   what's downcast is at most (1e18 * 1e48 / 1e24) = 1e38 < 2^192-1
        finished = before + uint192((FIX_ONE_256 * amtRToken + (lastIssRate - 1)) / lastIssRate);
        allVestAt = finished;
    }

    /// Vest all available issuance for the account
    /// Callable by anyone!
    /// @param account The address of the account to vest issuances for
    /// @custom:completion
    /// @custom:interaction CEI
    // Thin wrapper over refundSpan() and vestUpTo(); see those for correctness analysis
    function vest(address account, uint256 endId) external notPausedOrFrozen {
        // == Keepers ==
        main.assetRegistry().refresh();

        // == Checks ==
        CollateralStatus status = main.basketHandler().status();
        require(status == CollateralStatus.SOUND, "basket unsound");

        IssueQueue storage queue = issueQueues[account];
        uint48 basketNonce = main.basketHandler().nonce();

        // == Interactions ==
        // ensure that the queue models issuances against the current basket, not previous baskets;
        // refund all old issuances if there are any
        if (queue.basketNonce != basketNonce) {
            refundSpan(account, queue.left, queue.right);
        } else {
            vestUpTo(account, endId);
        }
    }

    /// Cancel some vesting issuance(s)
    /// If earliest == true, cancel id if id < endId
    /// If earliest == false, cancel id if endId <= id
    /// @param endId The issuance index to cancel through
    /// @param earliest If true, cancel earliest issuances; else, cancel latest issuances
    /// @custom:interaction CEI
    function cancel(uint256 endId, bool earliest) external notFrozen {
        address account = _msgSender();
        IssueQueue storage queue = issueQueues[account];

        require(queue.left <= endId && endId <= queue.right, "out of range");

        // == Interactions ==
        if (earliest) {
            refundSpan(account, queue.left, endId);
        } else {
            refundSpan(account, endId, queue.right);
        }
    }

    /// Redeem RToken for basket collateral
    /// @param amount {qTok} The quantity {qRToken} of RToken to redeem
    /// @custom:action
    /// @custom:interaction CEI
    // checks:
    //   balanceOf(caller) >= amount
    //   basket is not DISABLED
    //
    // effects:
    //   (so totalSupply -= amount and balanceOf(caller) -= amount)
    //   basketsNeeded' / totalSupply' >== basketsNeeded / totalSupply
    //
    // actions:
    //   let erc20s = basketHandler.erc20s()
    //   burn(caller, amount)
    //   for each token in erc20s:
    //     let tokenAmt = (amount * basketsNeeded / totalSupply) baskets of support for token
    //     let prorataAmt = (amount / totalSupply) * token.balanceOf(backingManager)
    //     do token.transferFrom(backingManager, caller, min(tokenAmt, prorataAmt))
    function redeem(uint256 amount) external notFrozen {
        require(amount > 0, "Cannot redeem zero");

        // == Refresh ==
        main.assetRegistry().refresh();

        // == Checks and Effects ==
        address redeemer = _msgSender();
        require(balanceOf(redeemer) >= amount, "not enough RToken");
        // Allow redemption during IFFY + UNPRICED
        require(main.basketHandler().status() != CollateralStatus.DISABLED, "collateral default");

        // Failure to melt results in a lower redemption price, so we can allow it when paused
        // solhint-disable-next-line no-empty-blocks
        try main.furnace().melt() {} catch {}

        uint192 basketsNeeded_ = basketsNeeded; // gas optimization

        // ==== Get basket redemption ====
        // i.e, set (erc20s, amounts) = basketHandler.quote(amount * basketsNeeded / totalSupply)

        // D18{BU} = D18{BU} * {qRTok} / {qRTok}
        // downcast is safe: amount < totalSupply and basketsNeeded_ < 1e57 < 2^190 (just barely)
        uint256 supply = totalSupply();
        uint192 baskets = uint192(mulDiv256(basketsNeeded_, amount, supply));
        emit Redemption(redeemer, amount, baskets);

        (address[] memory erc20s, uint256[] memory amounts) = main.basketHandler().quote(
            baskets,
            FLOOR
        );

        // ==== Prorate redemption ====
        // i.e, set amounts = min(amounts, balances * amount / totalSupply)
        //   where balances[i] = erc20s[i].balanceOf(this)

        IBackingManager backingMgr = main.backingManager();
        uint256 erc20length = erc20s.length;

        // D18{1} = D18 * {qRTok} / {qRTok}
        // downcast is safe: amount <= balanceOf(redeemer) <= totalSupply(), so prorate < 1e18
        uint192 prorate = uint192((FIX_ONE_256 * amount) / supply);

        // Bound each withdrawal by the prorata share, in case we're currently under-capitalized
        for (uint256 i = 0; i < erc20length; ++i) {
            // {qTok} = D18{1} * {qTok} / D18
            uint256 prorata = (prorate *
                IERC20Upgradeable(erc20s[i]).balanceOf(address(backingMgr))) / FIX_ONE;
            if (prorata < amounts[i]) amounts[i] = prorata;
        }

        // Revert if redemption exceeds battery capacity
        battery.discharge(supply, amount); // reverts on over-redemption

        basketsNeeded = basketsNeeded_ - baskets;
        emit BasketsNeededChanged(basketsNeeded_, basketsNeeded);

        // == Interactions ==
        // Accept and burn RToken
        _burn(redeemer, amount);

        bool allZero = true;
        for (uint256 i = 0; i < erc20length; ++i) {
            if (amounts[i] == 0) continue;
            if (allZero) allZero = false;

            // Send withdrawal
            IERC20Upgradeable(erc20s[i]).safeTransferFrom(
                address(backingMgr),
                redeemer,
                amounts[i]
            );
        }

        if (allZero) revert("Empty redemption");
    }

    /// Mint a quantity of RToken to the `recipient`, decreasing the basket rate
    /// @param recipient The recipient of the newly minted RToken
    /// @param amtRToken {qRTok} The amtRToken to be minted
    /// @custom:protected
    // checks: unpaused; unfrozen; caller is backingManager
    // effects:
    //   bal'[recipient] = bal[recipient] + amtRToken
    //   totalSupply' = totalSupply + amtRToken
    function mint(address recipient, uint256 amtRToken) external notPausedOrFrozen {
        require(_msgSender() == address(main.backingManager()), "not backing manager");
        _mint(recipient, amtRToken);
        requireValidBUExchangeRate();
    }

    /// Melt a quantity of RToken from the caller's account, increasing the basket rate
    /// @param amtRToken {qRTok} The amtRToken to be melted
    // checks: not paused or frozen
    // effects:
    //   bal'[caller] = bal[caller] - amtRToken
    //   totalSupply' = totalSupply - amtRToken
    function melt(uint256 amtRToken) external notPausedOrFrozen {
        _burn(_msgSender(), amtRToken);
        emit Melted(amtRToken);
        requireValidBUExchangeRate();
    }

    /// An affordance of last resort for Main in order to ensure re-capitalization
    /// @custom:protected
    // checks: unpaused; unfrozen; caller is backingManager
    // effects: basketsNeeded' = basketsNeeded_
    function setBasketsNeeded(uint192 basketsNeeded_) external notPausedOrFrozen {
        require(_msgSender() == address(main.backingManager()), "not backing manager");
        emit BasketsNeededChanged(basketsNeeded, basketsNeeded_);
        basketsNeeded = basketsNeeded_;
        requireValidBUExchangeRate();
    }

    /// Claim all rewards and sweep to BackingManager
    /// @custom:interaction
    function claimAndSweepRewards() external notPausedOrFrozen {
        RewardableLibP1.claimAndSweepRewards();
    }

    /// @param val {1/block}
    /// @custom:governance
    function setIssuanceRate(uint192 val) public governance {
        require(val > 0 && val <= MAX_ISSUANCE_RATE, "invalid issuanceRate");
        emit IssuanceRateSet(issuanceRate, val);
        issuanceRate = val;
    }

    /// @return {1/hour} The max redemption charging rate
    function scalingRedemptionRate() external view returns (uint192) {
        return battery.scalingRedemptionRate;
    }

    /// @param val {1/hour}
    /// @custom:governance
    function setScalingRedemptionRate(uint192 val) public governance {
        require(val <= FIX_ONE, "invalid fraction");
        emit ScalingRedemptionRateSet(battery.scalingRedemptionRate, val);
        battery.scalingRedemptionRate = val;
    }

    /// @return {qRTok/hour} The min redemption charging rate, in {qRTok}
    function redemptionRateFloor() external view returns (uint256) {
        return battery.redemptionRateFloor;
    }

    /// @param val {qRTok/hour}
    /// @custom:governance
    function setRedemptionRateFloor(uint256 val) public governance {
        emit RedemptionRateFloorSet(battery.redemptionRateFloor, val);
        battery.redemptionRateFloor = val;
    }

    /// @dev This function is only here because solidity can't autogenerate our getter
    function issueItem(address account, uint256 index) external view returns (IssueItem memory) {
        IssueQueue storage item = issueQueues[account];
        require(index >= item.left && index < item.right, "out of range");
        return item.items[index];
    }

    /// @return {qRTok} The maximum redemption that can be performed in the current block
    function redemptionLimit() external view returns (uint256) {
        return battery.currentCharge(totalSupply());
    }

    /// @return left The index of the left sides of the issuance queue for the account
    /// @return right The index of the right sides of the issuance queue for the account
    function queueBounds(address account) external view returns (uint256 left, uint256 right) {
        return (issueQueues[account].left, issueQueues[account].right);
    }

    // ==== private ====
    /// Refund all deposits in the span [left, right)
    /// @custom:interaction

    // Precisely: if right > left, then:
    //
    //   let iss = item(right) - item(left)
    //     where item(0) = the zero item
    //         | item(n) = issueQueues[account].items[n-1]
    //
    //   (effect) ELIMINATE ISSUANCE SPAN: Set queue.left and queue.right so that:
    //     [queue'.left, queue'.right) intersect [left, right) == empty set
    //     [queue'.left, queue'.right) union [left, right) == [queue.left, queue.right)
    //     If [queue'.left, queue'.right) == empty set, then queue'.left == queue'.right == 0
    //
    //   (action) REFUND DEPOSITS: For i in [0, iss.deposits.length):
    //     issueQueues[account].erc20s[i].transfer(account, iss.deposits[i])
    function refundSpan(
        address account,
        uint256 left,
        uint256 right
    ) private {
        if (left >= right) return; // refund an empty span

        IssueQueue storage queue = issueQueues[account];

        // compute total deposits to refund
        uint256 tokensLen = queue.tokens.length;
        uint256[] memory amt = new uint256[](tokensLen);
        uint256 amtRToken; // {qRTok}
        IssueItem storage rightItem = queue.items[right - 1];

        // compute item(right-1) - item(left-1)
        // we could dedup this logic for the zero item, but it would take more SLOADS
        if (left == 0) {
            amtRToken = rightItem.amtRToken;
            for (uint256 i = 0; i < tokensLen; ++i) {
                amt[i] = rightItem.deposits[i];
            }
        } else {
            IssueItem storage leftItem = queue.items[left - 1];
            amtRToken = rightItem.amtRToken - leftItem.amtRToken;
            for (uint256 i = 0; i < tokensLen; ++i) {
                amt[i] = rightItem.deposits[i] - leftItem.deposits[i];
            }
        }

        if (queue.left == left && right == queue.right) {
            // empty entire queue
            queue.left = 0;
            queue.right = 0;
        } else if (queue.left == left && right < queue.right) {
            queue.left = right; // remove span from beginning
        } else if (queue.left < left && right == queue.right) {
            queue.right = left; // refund span from end
        } else {
            revert("Bad refundSpan");
        } // error: can't remove [left,right) from the queue, and leave just one interval

        emit IssuancesCanceled(account, left, right, amtRToken);

        // == Interactions ==
        for (uint256 i = 0; i < queue.tokens.length; ++i) {
            IERC20Upgradeable(queue.tokens[i]).safeTransfer(account, amt[i]);
        }
    }

    /// Vest all RToken issuance in queue = queues[account], from queue.left to < endId
    /// Fixes up queue.left and queue.right
    /// @custom:interaction
    // let iss = item(endId) - item(queue.left)
    //     where item(0) = the zero item
    //         | item(n) = issueQueues[account].items[n-1]
    //
    // checks:
    //   queue.left <= endId <= queue.right
    //   item(endId).when <= block.number + 1
    //
    //
    //   (effect) ELIMINATE ISSUANCE SPAN: Set queue.left so that:
    //     [queue'.left, queue'.right) intersect [queue.left, endId) == empty set
    //     [queue'.left, queue'.right) union [queue.left, endId) == [queue.left, queue.right)
    //     If [queue'.left, queue'.right) == empty set, then queue'.left == queue'.right == 0
    //
    //   (effect + action) COMPLETE ISSUANCE of iss:
    //     for i in [0, iss.deposits.length):
    //       issueQueues[account].erc20s[i].transfer(backingManager, iss.deposits[i]
    //     _mint(account, iss.amtRToken)
    function vestUpTo(address account, uint256 endId) private {
        IssueQueue storage queue = issueQueues[account];
        if (queue.left == endId) return;

        require(queue.left <= endId && endId <= queue.right, "out of range");

        // Vest the span up to `endId`.
        uint256 amtRToken;
        uint192 amtBaskets;
        IssueItem storage rightItem = queue.items[endId - 1];
        // D18{block} ~~ D18 * {block}  // TODO: should be block.number + 1.
        // TODO ticket: https://app.asana.com/0/1202557536393044/1203033852623707/f
        require(rightItem.when <= FIX_ONE_256 * block.number, "issuance not ready");

        uint256 tokensLen = queue.tokens.length;
        uint256[] memory amtDeposits = new uint256[](tokensLen);

        // compute item(right - 1) - item(left - 1)
        // we could dedup this logic for the zero item, but it would take more SLOADS
        if (queue.left == 0) {
            amtRToken = rightItem.amtRToken;
            amtBaskets = rightItem.amtBaskets;
            for (uint256 i = 0; i < tokensLen; ++i) {
                amtDeposits[i] = rightItem.deposits[i];
            }
        } else {
            IssueItem storage leftItem = queue.items[queue.left - 1];
            amtRToken = rightItem.amtRToken - leftItem.amtRToken;
            amtBaskets = rightItem.amtBaskets - leftItem.amtBaskets;
            for (uint256 i = 0; i < tokensLen; ++i) {
                amtDeposits[i] = rightItem.deposits[i] - leftItem.deposits[i];
            }
        }

        emit BasketsNeededChanged(basketsNeeded, basketsNeeded + amtBaskets);
        // uint192(+) is safe for Fix.plus()
        basketsNeeded = basketsNeeded + amtBaskets;

        emit Issuance(account, amtRToken, amtBaskets);
        emit IssuancesCompleted(account, queue.left, endId, amtRToken);

        if (endId == queue.right) {
            // empty the queue - left is implicitly queue.left already
            queue.left = 0;
            queue.right = 0;
        } else {
            queue.left = endId;
        }

        // == Interactions ==
        _mint(account, amtRToken);

        for (uint256 i = 0; i < tokensLen; ++i) {
            IERC20Upgradeable(queue.tokens[i]).safeTransfer(
                address(main.backingManager()),
                amtDeposits[i]
            );
        }
    }

    /// Require the BU to RToken exchange rate to be in [1e-9, 1e9]
    function requireValidBUExchangeRate() private view {
        uint256 supply = totalSupply();
        if (supply == 0) return;

        // Note: These are D18s, even though they are uint256s. This is because
        // we cannot assume we stay inside our valid range here, as that is what
        // we are checking in the first place
        uint256 low = (FIX_ONE_256 * basketsNeeded) / supply; // D18{BU/rTok}
        uint256 high = (FIX_ONE_256 * basketsNeeded + (supply - 1)) / supply; // D18{BU/rTok}

        // 1e9 = FIX_ONE / 1e9; 1e27 = FIX_ONE * 1e9
        require(uint192(low) >= 1e9 && uint192(high) <= 1e27, "BU rate out of range");
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     */
    function _beforeTokenTransfer(
        address,
        address to,
        uint256
    ) internal virtual override {
        require(to != address(this), "RToken transfer to self");
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[42] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";
import "../extensions/draft-IERC20PermitUpgradeable.sol";
import "../../../utils/AddressUpgradeable.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20Upgradeable {
    using AddressUpgradeable for address;

    function safeTransfer(
        IERC20Upgradeable token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20Upgradeable token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20Upgradeable token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20Upgradeable token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20Upgradeable token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20PermitUpgradeable token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20Upgradeable token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/libraries/RedemptionBattery.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "contracts/interfaces/IRToken.sol";
import "./Fixed.sol";

// NOTE: This algorithm assumes the contract is running on PoS Ethereum and 100% of the
// network is online. It is possible for the battery to recharge up to 2/3 as fast
// depending on validator participation levels. Below 2/3 the chain halts, in which case
// the battery stops charging completely.
uint48 constant BLOCKS_PER_HOUR = 300; // {blocks/hour}

/// Throttling mechanism:
/// Models a "battery" which "recharges" linearly block by block, over roughly 1 hour.
/// Calls to discharge() will revert if the battery doesn't have enough "charge".
/// @dev This implementation basically assumes that maxCapacity is always the same value.
///      It won't misbehave badly if maxCapacity is changed, but it doesn't have sharply-defined
///      behavior in that case. (But keeping maxCapacity outside storage saves SLOADs)
library RedemptionBatteryLib {
    using FixLib for uint192;

    struct Battery {
        uint256 redemptionRateFloor; // {qRTok/hour} the floor of the battery charging rate
        uint192 scalingRedemptionRate; // {1/hour} charging rate as a fraction of supply
        // for either: set to 0 to disable
        // ===
        uint48 lastBlock; // {blocks}
        uint256 lastCharge; // {qRTok}
    }

    /// @param supply {qRTok} Total RToken supply before redemption
    /// @param amount {qRTok} Amount of RToken being redeemed
    function discharge(
        Battery storage battery,
        uint256 supply,
        uint256 amount
    ) internal {
        if (battery.redemptionRateFloor == 0 && battery.scalingRedemptionRate == 0) return;

        // {qRTok}
        uint256 charge = currentCharge(battery, supply);

        // A nice error message so people aren't confused why redemption failed
        require(amount <= charge, "redemption battery insufficient");

        // Update battery
        battery.lastBlock = uint48(block.number);
        battery.lastCharge = charge - amount;
    }

    /// @param supply {qRTok} Total RToken supply before the burn step
    /// @return charge {qRTok} The current total charge as an amount of RToken
    function currentCharge(Battery storage battery, uint256 supply)
        internal
        view
        returns (uint256 charge)
    {
        // {qRTok/hour} = {qRTok} * D18{1/hour} / D18
        uint256 amtPerHour = (supply * battery.scalingRedemptionRate) / FIX_ONE_256;

        if (battery.redemptionRateFloor > amtPerHour) amtPerHour = battery.redemptionRateFloor;

        // {blocks}
        uint48 blocks = uint48(block.number) - battery.lastBlock;

        // {qRTok} = {qRTok} + {qRTok/hour} * {blocks} / {blocks/hour}
        charge = battery.lastCharge + (amtPerHour * blocks) / BLOCKS_PER_HOUR;

        uint256 maxCharge = amtPerHour > supply ? supply : amtPerHour;
        if (charge > maxCharge) charge = maxCharge;
    }
}

// File: contracts/p1/mixins/Component.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
import "contracts/interfaces/IComponent.sol";
import "contracts/interfaces/IMain.sol";

/**
 * Abstract superclass for system contracts registered in Main
 */
abstract contract ComponentP1 is Initializable, ContextUpgradeable, UUPSUpgradeable, IComponent {
    IMain public main;

    /// @custom:oz-upgrades-unsafe-allow constructor
    // solhint-disable-next-line no-empty-blocks
    constructor() initializer {}

    // Sets main for the component - Can only be called during initialization
    // solhint-disable-next-line func-name-mixedcase
    function __Component_init(IMain main_) internal onlyInitializing {
        require(address(main_) != address(0), "main is zero address");
        __UUPSUpgradeable_init();
        main = main_;
    }

    // === See docs/security.md ===

    modifier notPausedOrFrozen() {
        require(!main.pausedOrFrozen(), "paused or frozen");
        _;
    }

    modifier notFrozen() {
        require(!main.frozen(), "frozen");
        _;
    }

    modifier governance() {
        require(main.hasRole(OWNER, _msgSender()), "governance only");
        _;
    }

    // solhint-disable-next-line no-empty-blocks
    function _authorizeUpgrade(address newImplementation) internal view override governance {}

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// File: contracts/p1/mixins/RewardableLib.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "contracts/interfaces/IAssetRegistry.sol";
import "contracts/interfaces/IBackingManager.sol";
import "contracts/interfaces/IRewardable.sol";

/**
 * @title RewardableLibP1
 * @notice An library that allows a contract to claim rewards
 * @dev The caller must implement the IRewardable interface!
 */
library RewardableLibP1 {
    using AddressUpgradeable for address;
    using SafeERC20Upgradeable for IERC20Upgradeable;

    /// Redefines event for when rewards are claimed, to be able to emit from library
    event RewardsClaimed(address indexed erc20, uint256 indexed amount);

    struct Claim {
        IERC20 reward;
        address callTo;
        bytes _calldata;
    }

    /// Claim all rewards and sweep to BackingManager
    /// Collective Action
    /// @custom:interaction mostly CEI but see comments
    // where:
    //   this: the contract from which this function is being delegateCall'dd
    //   claims = {{rewardToken: erc20.rewardERC20(), to, calldata}
    //     for erc20 in assetRegistry
    //     where (to, calldata) = erc20.getClaimCalldata(){caller: this}
    //     if to != 0 and rewardToken in assetRegistry}
    //   rewards = {claim.rewardToken for claim in claims}
    // actions:
    //   first, do to.functionCall(calldata) for claim in claims
    //   then, if this is not backingManager
    //     then do
    //       reward.transfer(bal, backingManager) for claim in claims if bal > 0
    //       where reward = claim.reward and bal = reward.balanceOf(this)
    function claimAndSweepRewards() external {
        IAssetRegistry reg = assetRegistry();
        IERC20[] memory erc20s = reg.erc20s();

        IERC20[] memory rewardTokens = new IERC20[](erc20s.length);
        uint256 numRewardTokens = 0;

        Claim[] memory claims = new Claim[](erc20s.length);
        uint256 numClaims = 0;

        // Compute the interactions to have...
        for (uint256 i = 0; i < erc20s.length; ++i) {
            // Does erc20s[i] _have_ a reward function and reward token?
            IAsset asset = reg.toAsset(erc20s[i]);

            IERC20 rewardToken = asset.rewardERC20();
            if (address(rewardToken) == address(0) || !reg.isRegistered(rewardToken)) continue;

            (address _to, bytes memory _calldata) = asset.getClaimCalldata();
            if (_to == address(0)) continue;

            // Save Claim
            claims[numClaims] = Claim({ reward: rewardToken, callTo: _to, _calldata: _calldata });
            ++numClaims;

            // Save rewardToken address, if new
            uint256 rtIndex = 0;
            while (rtIndex < numRewardTokens && rewardToken != rewardTokens[rtIndex]) rtIndex++;
            if (rtIndex >= numRewardTokens) {
                rewardTokens[rtIndex] = rewardToken;
                numRewardTokens++;
            }
        }

        // == Interactions ==
        // Claim rewards
        for (uint256 i = 0; i < numClaims; i++) {
            // Safe violation of strict CEI: we're reading balanceOf() here, but oldBal and newBal
            // are only used here to emit the right event. Their definitions don't leave the inner
            // block of this loop.
            uint256 oldBal = claims[i].reward.balanceOf(address(this));
            claims[i].callTo.functionCall(claims[i]._calldata, "rewards claim failed");
            uint256 newBal = claims[i].reward.balanceOf(address(this));

            emit RewardsClaimed(address(claims[i].reward), newBal - oldBal);
        }

        // Sweep reward tokens to the backingManager
        if (address(this) != address(backingManager())) {
            for (uint256 i = 0; i < numRewardTokens; ++i) {
                // Safe violation of strict CEI: we're reading balanceOf() here, too, but it's
                // actually our intention to sweep all of rewardTokens[i] at this point, regardless
                // of whatever else we may have computed in the function above.
                uint256 bal = rewardTokens[i].balanceOf(address(this));
                if (bal > 0) {
                    IERC20Upgradeable(address(rewardTokens[i])).safeTransfer(
                        address(backingManager()),
                        bal
                    );
                }
            }
        }
    }

    /// @return The AssetRegistry
    function assetRegistry() private view returns (IAssetRegistry) {
        return IRewardable(address(this)).main().assetRegistry();
    }

    /// @return The BackingManager
    function backingManager() private view returns (IBackingManager) {
        return IRewardable(address(this)).main().backingManager();
    }
}

// File: contracts/vendor/ERC20PermitUpgradeable.sol



// SPDX-License-Identifier: MIT
// Taken from OZ release 4.7.3 at commit a035b235b4f2c9af4ba88edc4447f02e37f8d124
// The only modification that has been made is in the body of the `permit` function at line 83,
/// where we failover to SignatureChecker in order to handle approvals for smart contracts.

pragma solidity 0.8.9;
import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-IERC20PermitUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/cryptography/draft-EIP712Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/CountersUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "contracts/libraries/Permit.sol";

/**
 * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 *
 * Note: We have modified `permit` to support EIP-1271, technically violating EIP-2612.
 *
 * _Available since v3.4._
 *
 * @custom:storage-size 51
 */
abstract contract ERC20PermitUpgradeable is
    Initializable,
    ERC20Upgradeable,
    IERC20PermitUpgradeable,
    EIP712Upgradeable
{
    using CountersUpgradeable for CountersUpgradeable.Counter;

    mapping(address => CountersUpgradeable.Counter) private _nonces;

    // solhint-disable-next-line var-name-mixedcase
    bytes32 private constant _PERMIT_TYPEHASH =
        keccak256(
            "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
        );
    /**
     * @dev In previous versions `_PERMIT_TYPEHASH` was declared as `immutable`.
     * However, to ensure consistency with the upgradeable transpiler, we will continue
     * to reserve a slot.
     * @custom:oz-renamed-from _PERMIT_TYPEHASH
     */
    // solhint-disable-next-line var-name-mixedcase
    bytes32 private _PERMIT_TYPEHASH_DEPRECATED_SLOT;

    /**
     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
     *
     * It's a good idea to use the same `name` that is defined as the ERC20 token name.
     */
    function __ERC20Permit_init(string memory name) internal onlyInitializing {
        __EIP712_init_unchained(name, "1");
    }

    function __ERC20Permit_init_unchained(string memory) internal onlyInitializing {}

    /**
     * @dev See {IERC20Permit-permit}.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        require(block.timestamp <= deadline, "ERC20Permit: expired deadline");

        bytes32 structHash = keccak256(
            abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline)
        );

        /// ==== MODIFICATIONS START ====

        PermitLib.requireSignature(owner, _hashTypedDataV4(structHash), v, r, s);

        /// ==== MODIFICATIONS END ====

        _approve(owner, spender, value);
    }

    /**
     * @dev See {IERC20Permit-nonces}.
     */
    function nonces(address owner) public view virtual override returns (uint256) {
        return _nonces[owner].current();
    }

    /**
     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
        return _domainSeparatorV4();
    }

    /**
     * @dev "Consume a nonce": return the current value and increment.
     *
     * _Available since v4.1._
     */
    function _useNonce(address owner) internal virtual returns (uint256 current) {
        CountersUpgradeable.Counter storage nonce = _nonces[owner];
        current = nonce.current();
        nonce.increment();
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[48] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/UUPSUpgradeable.sol)

pragma solidity ^0.8.0;

import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
import "./Initializable.sol";

/**
 * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
 * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
 *
 * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
 * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
 * `UUPSUpgradeable` with a custom implementation of upgrades.
 *
 * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is Initializable, IERC1822ProxiableUpgradeable, ERC1967UpgradeUpgradeable {
    function __UUPSUpgradeable_init() internal onlyInitializing {
    }

    function __UUPSUpgradeable_init_unchained() internal onlyInitializing {
    }
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
    address private immutable __self = address(this);

    /**
     * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
     * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
     * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
     * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        require(address(this) != __self, "Function must be called through delegatecall");
        require(_getImplementation() == __self, "Function must be called through active proxy");
        _;
    }

    /**
     * @dev Check that the execution is not being performed through a delegate call. This allows a function to be
     * callable on the implementing contract but not through proxies.
     */
    modifier notDelegated() {
        require(address(this) == __self, "UUPSUpgradeable: must not be called through delegatecall");
        _;
    }

    /**
     * @dev Implementation of the ERC1822 {proxiableUUID} function. This returns the storage slot used by the
     * implementation. It is used to validate that the this implementation remains valid after an upgrade.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
     */
    function proxiableUUID() external view virtual override notDelegated returns (bytes32) {
        return _IMPLEMENTATION_SLOT;
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeTo(address newImplementation) external virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(newImplementation, new bytes(0), false);
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(newImplementation, data, true);
    }

    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeTo} and {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal override onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/interfaces/draft-IERC1822Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)

pragma solidity ^0.8.0;

/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822ProxiableUpgradeable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}

// File: @openzeppelin/contracts-upgradeable/proxy/ERC1967/ERC1967UpgradeUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)

pragma solidity ^0.8.2;

import "../beacon/IBeaconUpgradeable.sol";
import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/StorageSlotUpgradeable.sol";
import "../utils/Initializable.sol";

/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967UpgradeUpgradeable is Initializable {
    function __ERC1967Upgrade_init() internal onlyInitializing {
    }

    function __ERC1967Upgrade_init_unchained() internal onlyInitializing {
    }
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822ProxiableUpgradeable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);

    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }

    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), data);
        }
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function _functionDelegateCall(address target, bytes memory data) private returns (bytes memory) {
        require(AddressUpgradeable.isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return AddressUpgradeable.verifyCallResult(success, returndata, "Address: low-level delegate call failed");
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/proxy/beacon/IBeaconUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)

pragma solidity ^0.8.0;

/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeaconUpgradeable {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}

// File: @openzeppelin/contracts-upgradeable/utils/StorageSlotUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)

pragma solidity ^0.8.0;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlotUpgradeable {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20Upgradeable.sol";
import "./extensions/IERC20MetadataUpgradeable.sol";
import "../../utils/ContextUpgradeable.sol";
import "../../proxy/utils/Initializable.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeable, IERC20MetadataUpgradeable {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    function __ERC20_init(string memory name_, string memory symbol_) internal onlyInitializing {
        __ERC20_init_unchained(name_, symbol_);
    }

    function __ERC20_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[45] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/cryptography/draft-EIP712Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/cryptography/draft-EIP712.sol)

pragma solidity ^0.8.0;

import "./ECDSAUpgradeable.sol";
import "../../proxy/utils/Initializable.sol";

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * _Available since v3.4._
 *
 * @custom:storage-size 52
 */
abstract contract EIP712Upgradeable is Initializable {
    /* solhint-disable var-name-mixedcase */
    bytes32 private _HASHED_NAME;
    bytes32 private _HASHED_VERSION;
    bytes32 private constant _TYPE_HASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");

    /* solhint-enable var-name-mixedcase */

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    function __EIP712_init(string memory name, string memory version) internal onlyInitializing {
        __EIP712_init_unchained(name, version);
    }

    function __EIP712_init_unchained(string memory name, string memory version) internal onlyInitializing {
        bytes32 hashedName = keccak256(bytes(name));
        bytes32 hashedVersion = keccak256(bytes(version));
        _HASHED_NAME = hashedName;
        _HASHED_VERSION = hashedVersion;
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view returns (bytes32) {
        return _buildDomainSeparator(_TYPE_HASH, _EIP712NameHash(), _EIP712VersionHash());
    }

    function _buildDomainSeparator(
        bytes32 typeHash,
        bytes32 nameHash,
        bytes32 versionHash
    ) private view returns (bytes32) {
        return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return ECDSAUpgradeable.toTypedDataHash(_domainSeparatorV4(), structHash);
    }

    /**
     * @dev The hash of the name parameter for the EIP712 domain.
     *
     * NOTE: This function reads from storage by default, but can be redefined to return a constant value if gas costs
     * are a concern.
     */
    function _EIP712NameHash() internal virtual view returns (bytes32) {
        return _HASHED_NAME;
    }

    /**
     * @dev The hash of the version parameter for the EIP712 domain.
     *
     * NOTE: This function reads from storage by default, but can be redefined to return a constant value if gas costs
     * are a concern.
     */
    function _EIP712VersionHash() internal virtual view returns (bytes32) {
        return _HASHED_VERSION;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/CountersUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library CountersUpgradeable {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

// File: contracts/libraries/Permit.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/cryptography/SignatureCheckerUpgradeable.sol";

/// Externally-included library for verifying metatx sigs for EOAs and smart contract wallets
/// See ERC1271
library PermitLib {
    function requireSignature(
        address owner,
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external view {
        if (AddressUpgradeable.isContract(owner)) {
            require(
                IERC1271Upgradeable(owner).isValidSignature(hash, abi.encodePacked(r, s, v)) ==
                    0x1626ba7e,
                "ERC1271: Unauthorized"
            );
        } else {
            require(
                SignatureCheckerUpgradeable.isValidSignatureNow(
                    owner,
                    hash,
                    abi.encodePacked(r, s, v)
                ),
                "ERC20Permit: invalid signature"
            );
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/cryptography/ECDSAUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.3) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.0;

import "../StringsUpgradeable.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSAUpgradeable {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        } else if (error == RecoverError.InvalidSignatureV) {
            revert("ECDSA: invalid signature 'v' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }
        if (v != 27 && v != 28) {
            return (address(0), RecoverError.InvalidSignatureV);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", StringsUpgradeable.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/cryptography/SignatureCheckerUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.1) (utils/cryptography/SignatureChecker.sol)

pragma solidity ^0.8.0;

import "./ECDSAUpgradeable.sol";
import "../AddressUpgradeable.sol";
import "../../interfaces/IERC1271Upgradeable.sol";

/**
 * @dev Signature verification helper that can be used instead of `ECDSA.recover` to seamlessly support both ECDSA
 * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets like
 * Argent and Gnosis Safe.
 *
 * _Available since v4.1._
 */
library SignatureCheckerUpgradeable {
    /**
     * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
     * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECDSA.recover`.
     *
     * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
     * change through time. It could return true at block N and false at block N+1 (or the opposite).
     */
    function isValidSignatureNow(
        address signer,
        bytes32 hash,
        bytes memory signature
    ) internal view returns (bool) {
        (address recovered, ECDSAUpgradeable.RecoverError error) = ECDSAUpgradeable.tryRecover(hash, signature);
        if (error == ECDSAUpgradeable.RecoverError.NoError && recovered == signer) {
            return true;
        }

        (bool success, bytes memory result) = signer.staticcall(
            abi.encodeWithSelector(IERC1271Upgradeable.isValidSignature.selector, hash, signature)
        );
        return (success &&
            result.length == 32 &&
            abi.decode(result, (bytes32)) == bytes32(IERC1271Upgradeable.isValidSignature.selector));
    }
}

// File: @openzeppelin/contracts-upgradeable/interfaces/IERC1271Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC1271.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC1271 standard signature validation method for
 * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
 *
 * _Available since v4.1._
 */
interface IERC1271Upgradeable {
    /**
     * @dev Should return whether the signature provided is valid for the provided data
     * @param hash      Hash of the data to be signed
     * @param signature Signature byte array associated with _data
     */
    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}

// File: contracts/plugins/governance/Governance.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts/governance/Governor.sol";
import "@openzeppelin/contracts/governance/extensions/GovernorCountingSimple.sol";
import "@openzeppelin/contracts/governance/extensions/GovernorSettings.sol";
import "@openzeppelin/contracts/governance/extensions/GovernorTimelockControl.sol";
import "@openzeppelin/contracts/governance/extensions/GovernorVotes.sol";
import "@openzeppelin/contracts/governance/extensions/GovernorVotesQuorumFraction.sol";
import "contracts/interfaces/IStRSRVotes.sol";

/*
 * @title Governance
 * @dev Decentralized Governance for the Reserve Protocol.
 *
 * Note that due to the elastic supply of StRSR, proposalThreshold is handled
 *   very differently than the typical approach. It is in terms of micro %,
 *   as is _getVotes().
 *
 * 1 * {micro %} = 1e8
 */
contract Governance is
    Governor,
    GovernorSettings,
    GovernorCountingSimple,
    GovernorVotes,
    GovernorVotesQuorumFraction,
    GovernorTimelockControl
{
    // solhint-disable no-empty-blocks
    constructor(
        IStRSRVotes token_,
        TimelockController timelock_,
        uint256 votingDelay_, // in blocks
        uint256 votingPeriod_, // in blocks
        uint256 proposalThresholdAsMicroPercent_, // e.g. 1e4 for 0.01%
        uint256 quorumPercent // e.g 4 for 4%
    )
        Governor("Reserve Governor")
        GovernorSettings(votingDelay_, votingPeriod_, proposalThresholdAsMicroPercent_)
        GovernorVotes(IVotes(address(token_)))
        GovernorVotesQuorumFraction(quorumPercent)
        GovernorTimelockControl(timelock_)
    {}

    // solhint-enable no-empty-blocks

    function votingDelay() public view override(IGovernor, GovernorSettings) returns (uint256) {
        return super.votingDelay();
    }

    function votingPeriod() public view override(IGovernor, GovernorSettings) returns (uint256) {
        return super.votingPeriod();
    }

    /// @return The proposal threshold in units of micro %, e.g 1e6 for 1% of the supply
    function proposalThreshold()
        public
        view
        override(Governor, GovernorSettings)
        returns (uint256)
    {
        return super.proposalThreshold();
    }

    /// @return Returns the quorum required, in units of micro %, e.g 4e6 for 4%
    function quorum(uint256)
        public
        view
        override(IGovernor, GovernorVotesQuorumFraction)
        returns (uint256)
    {
        return quorumNumerator() * 1e6;
    }

    function state(uint256 proposalId)
        public
        view
        override(Governor, GovernorTimelockControl)
        returns (ProposalState)
    {
        return GovernorTimelockControl.state(proposalId);
    }

    function propose(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        string memory description
    ) public override(Governor, IGovernor) returns (uint256 proposalId) {
        // The super call checks that getVotes() >= proposalThreshold()
        return super.propose(targets, values, calldatas, description);
    }

    function queue(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public override returns (uint256 proposalId) {
        proposalId = super.queue(targets, values, calldatas, descriptionHash);
        require(startedInSameEra(proposalId), "new era");
    }

    function cancel(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) external {
        uint256 proposalId = _cancel(targets, values, calldatas, descriptionHash);
        require(!startedInSameEra(proposalId), "same era");
    }

    function _execute(
        uint256 proposalId,
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) internal override(Governor, GovernorTimelockControl) {
        super._execute(proposalId, targets, values, calldatas, descriptionHash);
        require(startedInSameEra(proposalId), "new era");
    }

    function _cancel(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) internal override(Governor, GovernorTimelockControl) returns (uint256) {
        return super._cancel(targets, values, calldatas, descriptionHash);
    }

    function _executor()
        internal
        view
        override(Governor, GovernorTimelockControl)
        returns (address)
    {
        return super._executor();
    }

    /// @return {micro %} The portion of the StRSR supply the account had at a previous blocknumber
    function _getVotes(
        address account,
        uint256 blockNumber,
        bytes memory /*params*/
    ) internal view override(Governor, GovernorVotes) returns (uint256) {
        uint256 bal = token.getPastVotes(account, blockNumber); // {qStRSR}
        uint256 totalSupply = token.getPastTotalSupply(blockNumber); // {qStRSR}

        if (totalSupply == 0) return 0;

        // {micro %} = {qStRSR} * {micro %} / {qStRSR}
        return (bal * 1e8) / totalSupply;
    }

    function supportsInterface(bytes4 interfaceId)
        public
        view
        override(Governor, GovernorTimelockControl)
        returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }

    // === Private ===

    function startedInSameEra(uint256 proposalId) private view returns (bool) {
        uint256 startBlock = proposalSnapshot(proposalId);
        uint256 pastEra = IStRSRVotes(address(token)).getPastEra(startBlock);
        uint256 currentEra = IStRSRVotes(address(token)).currentEra();
        return currentEra == pastEra;
    }
}

// File: @openzeppelin/contracts/governance/Governor.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (governance/Governor.sol)

pragma solidity ^0.8.0;

import "../token/ERC721/IERC721Receiver.sol";
import "../token/ERC1155/IERC1155Receiver.sol";
import "../utils/cryptography/ECDSA.sol";
import "../utils/cryptography/draft-EIP712.sol";
import "../utils/introspection/ERC165.sol";
import "../utils/math/SafeCast.sol";
import "../utils/structs/DoubleEndedQueue.sol";
import "../utils/Address.sol";
import "../utils/Context.sol";
import "../utils/Timers.sol";
import "./IGovernor.sol";

/**
 * @dev Core of the governance system, designed to be extended though various modules.
 *
 * This contract is abstract and requires several function to be implemented in various modules:
 *
 * - A counting module must implement {quorum}, {_quorumReached}, {_voteSucceeded} and {_countVote}
 * - A voting module must implement {_getVotes}
 * - Additionanly, the {votingPeriod} must also be implemented
 *
 * _Available since v4.3._
 */
abstract contract Governor is Context, ERC165, EIP712, IGovernor, IERC721Receiver, IERC1155Receiver {
    using DoubleEndedQueue for DoubleEndedQueue.Bytes32Deque;
    using SafeCast for uint256;
    using Timers for Timers.BlockNumber;

    bytes32 public constant BALLOT_TYPEHASH = keccak256("Ballot(uint256 proposalId,uint8 support)");
    bytes32 public constant EXTENDED_BALLOT_TYPEHASH =
        keccak256("ExtendedBallot(uint256 proposalId,uint8 support,string reason,bytes params)");

    struct ProposalCore {
        Timers.BlockNumber voteStart;
        Timers.BlockNumber voteEnd;
        bool executed;
        bool canceled;
    }

    string private _name;

    mapping(uint256 => ProposalCore) private _proposals;

    // This queue keeps track of the governor operating on itself. Calls to functions protected by the
    // {onlyGovernance} modifier needs to be whitelisted in this queue. Whitelisting is set in {_beforeExecute},
    // consumed by the {onlyGovernance} modifier and eventually reset in {_afterExecute}. This ensures that the
    // execution of {onlyGovernance} protected calls can only be achieved through successful proposals.
    DoubleEndedQueue.Bytes32Deque private _governanceCall;

    /**
     * @dev Restricts a function so it can only be executed through governance proposals. For example, governance
     * parameter setters in {GovernorSettings} are protected using this modifier.
     *
     * The governance executing address may be different from the Governor's own address, for example it could be a
     * timelock. This can be customized by modules by overriding {_executor}. The executor is only able to invoke these
     * functions during the execution of the governor's {execute} function, and not under any other circumstances. Thus,
     * for example, additional timelock proposers are not able to change governance parameters without going through the
     * governance protocol (since v4.6).
     */
    modifier onlyGovernance() {
        require(_msgSender() == _executor(), "Governor: onlyGovernance");
        if (_executor() != address(this)) {
            bytes32 msgDataHash = keccak256(_msgData());
            // loop until popping the expected operation - throw if deque is empty (operation not authorized)
            while (_governanceCall.popFront() != msgDataHash) {}
        }
        _;
    }

    /**
     * @dev Sets the value for {name} and {version}
     */
    constructor(string memory name_) EIP712(name_, version()) {
        _name = name_;
    }

    /**
     * @dev Function to receive ETH that will be handled by the governor (disabled if executor is a third party contract)
     */
    receive() external payable virtual {
        require(_executor() == address(this));
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
        // In addition to the current interfaceId, also support previous version of the interfaceId that did not
        // include the castVoteWithReasonAndParams() function as standard
        return
            interfaceId ==
            (type(IGovernor).interfaceId ^
                this.castVoteWithReasonAndParams.selector ^
                this.castVoteWithReasonAndParamsBySig.selector ^
                this.getVotesWithParams.selector) ||
            interfaceId == type(IGovernor).interfaceId ||
            interfaceId == type(IERC1155Receiver).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IGovernor-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IGovernor-version}.
     */
    function version() public view virtual override returns (string memory) {
        return "1";
    }

    /**
     * @dev See {IGovernor-hashProposal}.
     *
     * The proposal id is produced by hashing the ABI encoded `targets` array, the `values` array, the `calldatas` array
     * and the descriptionHash (bytes32 which itself is the keccak256 hash of the description string). This proposal id
     * can be produced from the proposal data which is part of the {ProposalCreated} event. It can even be computed in
     * advance, before the proposal is submitted.
     *
     * Note that the chainId and the governor address are not part of the proposal id computation. Consequently, the
     * same proposal (with same operation and same description) will have the same id if submitted on multiple governors
     * across multiple networks. This also means that in order to execute the same operation twice (on the same
     * governor) the proposer will have to change the description in order to avoid proposal id conflicts.
     */
    function hashProposal(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public pure virtual override returns (uint256) {
        return uint256(keccak256(abi.encode(targets, values, calldatas, descriptionHash)));
    }

    /**
     * @dev See {IGovernor-state}.
     */
    function state(uint256 proposalId) public view virtual override returns (ProposalState) {
        ProposalCore storage proposal = _proposals[proposalId];

        if (proposal.executed) {
            return ProposalState.Executed;
        }

        if (proposal.canceled) {
            return ProposalState.Canceled;
        }

        uint256 snapshot = proposalSnapshot(proposalId);

        if (snapshot == 0) {
            revert("Governor: unknown proposal id");
        }

        if (snapshot >= block.number) {
            return ProposalState.Pending;
        }

        uint256 deadline = proposalDeadline(proposalId);

        if (deadline >= block.number) {
            return ProposalState.Active;
        }

        if (_quorumReached(proposalId) && _voteSucceeded(proposalId)) {
            return ProposalState.Succeeded;
        } else {
            return ProposalState.Defeated;
        }
    }

    /**
     * @dev See {IGovernor-proposalSnapshot}.
     */
    function proposalSnapshot(uint256 proposalId) public view virtual override returns (uint256) {
        return _proposals[proposalId].voteStart.getDeadline();
    }

    /**
     * @dev See {IGovernor-proposalDeadline}.
     */
    function proposalDeadline(uint256 proposalId) public view virtual override returns (uint256) {
        return _proposals[proposalId].voteEnd.getDeadline();
    }

    /**
     * @dev Part of the Governor Bravo's interface: _"The number of votes required in order for a voter to become a proposer"_.
     */
    function proposalThreshold() public view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Amount of votes already cast passes the threshold limit.
     */
    function _quorumReached(uint256 proposalId) internal view virtual returns (bool);

    /**
     * @dev Is the proposal successful or not.
     */
    function _voteSucceeded(uint256 proposalId) internal view virtual returns (bool);

    /**
     * @dev Get the voting weight of `account` at a specific `blockNumber`, for a vote as described by `params`.
     */
    function _getVotes(
        address account,
        uint256 blockNumber,
        bytes memory params
    ) internal view virtual returns (uint256);

    /**
     * @dev Register a vote for `proposalId` by `account` with a given `support`, voting `weight` and voting `params`.
     *
     * Note: Support is generic and can represent various things depending on the voting system used.
     */
    function _countVote(
        uint256 proposalId,
        address account,
        uint8 support,
        uint256 weight,
        bytes memory params
    ) internal virtual;

    /**
     * @dev Default additional encoded parameters used by castVote methods that don't include them
     *
     * Note: Should be overridden by specific implementations to use an appropriate value, the
     * meaning of the additional params, in the context of that implementation
     */
    function _defaultParams() internal view virtual returns (bytes memory) {
        return "";
    }

    /**
     * @dev See {IGovernor-propose}.
     */
    function propose(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        string memory description
    ) public virtual override returns (uint256) {
        require(
            getVotes(_msgSender(), block.number - 1) >= proposalThreshold(),
            "Governor: proposer votes below proposal threshold"
        );

        uint256 proposalId = hashProposal(targets, values, calldatas, keccak256(bytes(description)));

        require(targets.length == values.length, "Governor: invalid proposal length");
        require(targets.length == calldatas.length, "Governor: invalid proposal length");
        require(targets.length > 0, "Governor: empty proposal");

        ProposalCore storage proposal = _proposals[proposalId];
        require(proposal.voteStart.isUnset(), "Governor: proposal already exists");

        uint64 snapshot = block.number.toUint64() + votingDelay().toUint64();
        uint64 deadline = snapshot + votingPeriod().toUint64();

        proposal.voteStart.setDeadline(snapshot);
        proposal.voteEnd.setDeadline(deadline);

        emit ProposalCreated(
            proposalId,
            _msgSender(),
            targets,
            values,
            new string[](targets.length),
            calldatas,
            snapshot,
            deadline,
            description
        );

        return proposalId;
    }

    /**
     * @dev See {IGovernor-execute}.
     */
    function execute(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public payable virtual override returns (uint256) {
        uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);

        ProposalState status = state(proposalId);
        require(
            status == ProposalState.Succeeded || status == ProposalState.Queued,
            "Governor: proposal not successful"
        );
        _proposals[proposalId].executed = true;

        emit ProposalExecuted(proposalId);

        _beforeExecute(proposalId, targets, values, calldatas, descriptionHash);
        _execute(proposalId, targets, values, calldatas, descriptionHash);
        _afterExecute(proposalId, targets, values, calldatas, descriptionHash);

        return proposalId;
    }

    /**
     * @dev Internal execution mechanism. Can be overridden to implement different execution mechanism
     */
    function _execute(
        uint256, /* proposalId */
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 /*descriptionHash*/
    ) internal virtual {
        string memory errorMessage = "Governor: call reverted without message";
        for (uint256 i = 0; i < targets.length; ++i) {
            (bool success, bytes memory returndata) = targets[i].call{value: values[i]}(calldatas[i]);
            Address.verifyCallResult(success, returndata, errorMessage);
        }
    }

    /**
     * @dev Hook before execution is triggered.
     */
    function _beforeExecute(
        uint256, /* proposalId */
        address[] memory targets,
        uint256[] memory, /* values */
        bytes[] memory calldatas,
        bytes32 /*descriptionHash*/
    ) internal virtual {
        if (_executor() != address(this)) {
            for (uint256 i = 0; i < targets.length; ++i) {
                if (targets[i] == address(this)) {
                    _governanceCall.pushBack(keccak256(calldatas[i]));
                }
            }
        }
    }

    /**
     * @dev Hook after execution is triggered.
     */
    function _afterExecute(
        uint256, /* proposalId */
        address[] memory, /* targets */
        uint256[] memory, /* values */
        bytes[] memory, /* calldatas */
        bytes32 /*descriptionHash*/
    ) internal virtual {
        if (_executor() != address(this)) {
            if (!_governanceCall.empty()) {
                _governanceCall.clear();
            }
        }
    }

    /**
     * @dev Internal cancel mechanism: locks up the proposal timer, preventing it from being re-submitted. Marks it as
     * canceled to allow distinguishing it from executed proposals.
     *
     * Emits a {IGovernor-ProposalCanceled} event.
     */
    function _cancel(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) internal virtual returns (uint256) {
        uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);
        ProposalState status = state(proposalId);

        require(
            status != ProposalState.Canceled && status != ProposalState.Expired && status != ProposalState.Executed,
            "Governor: proposal not active"
        );
        _proposals[proposalId].canceled = true;

        emit ProposalCanceled(proposalId);

        return proposalId;
    }

    /**
     * @dev See {IGovernor-getVotes}.
     */
    function getVotes(address account, uint256 blockNumber) public view virtual override returns (uint256) {
        return _getVotes(account, blockNumber, _defaultParams());
    }

    /**
     * @dev See {IGovernor-getVotesWithParams}.
     */
    function getVotesWithParams(
        address account,
        uint256 blockNumber,
        bytes memory params
    ) public view virtual override returns (uint256) {
        return _getVotes(account, blockNumber, params);
    }

    /**
     * @dev See {IGovernor-castVote}.
     */
    function castVote(uint256 proposalId, uint8 support) public virtual override returns (uint256) {
        address voter = _msgSender();
        return _castVote(proposalId, voter, support, "");
    }

    /**
     * @dev See {IGovernor-castVoteWithReason}.
     */
    function castVoteWithReason(
        uint256 proposalId,
        uint8 support,
        string calldata reason
    ) public virtual override returns (uint256) {
        address voter = _msgSender();
        return _castVote(proposalId, voter, support, reason);
    }

    /**
     * @dev See {IGovernor-castVoteWithReasonAndParams}.
     */
    function castVoteWithReasonAndParams(
        uint256 proposalId,
        uint8 support,
        string calldata reason,
        bytes memory params
    ) public virtual override returns (uint256) {
        address voter = _msgSender();
        return _castVote(proposalId, voter, support, reason, params);
    }

    /**
     * @dev See {IGovernor-castVoteBySig}.
     */
    function castVoteBySig(
        uint256 proposalId,
        uint8 support,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override returns (uint256) {
        address voter = ECDSA.recover(
            _hashTypedDataV4(keccak256(abi.encode(BALLOT_TYPEHASH, proposalId, support))),
            v,
            r,
            s
        );
        return _castVote(proposalId, voter, support, "");
    }

    /**
     * @dev See {IGovernor-castVoteWithReasonAndParamsBySig}.
     */
    function castVoteWithReasonAndParamsBySig(
        uint256 proposalId,
        uint8 support,
        string calldata reason,
        bytes memory params,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override returns (uint256) {
        address voter = ECDSA.recover(
            _hashTypedDataV4(
                keccak256(
                    abi.encode(
                        EXTENDED_BALLOT_TYPEHASH,
                        proposalId,
                        support,
                        keccak256(bytes(reason)),
                        keccak256(params)
                    )
                )
            ),
            v,
            r,
            s
        );

        return _castVote(proposalId, voter, support, reason, params);
    }

    /**
     * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
     * voting weight using {IGovernor-getVotes} and call the {_countVote} internal function. Uses the _defaultParams().
     *
     * Emits a {IGovernor-VoteCast} event.
     */
    function _castVote(
        uint256 proposalId,
        address account,
        uint8 support,
        string memory reason
    ) internal virtual returns (uint256) {
        return _castVote(proposalId, account, support, reason, _defaultParams());
    }

    /**
     * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
     * voting weight using {IGovernor-getVotes} and call the {_countVote} internal function.
     *
     * Emits a {IGovernor-VoteCast} event.
     */
    function _castVote(
        uint256 proposalId,
        address account,
        uint8 support,
        string memory reason,
        bytes memory params
    ) internal virtual returns (uint256) {
        ProposalCore storage proposal = _proposals[proposalId];
        require(state(proposalId) == ProposalState.Active, "Governor: vote not currently active");

        uint256 weight = _getVotes(account, proposal.voteStart.getDeadline(), params);
        _countVote(proposalId, account, support, weight, params);

        if (params.length == 0) {
            emit VoteCast(account, proposalId, support, weight, reason);
        } else {
            emit VoteCastWithParams(account, proposalId, support, weight, reason, params);
        }

        return weight;
    }

    /**
     * @dev Relays a transaction or function call to an arbitrary target. In cases where the governance executor
     * is some contract other than the governor itself, like when using a timelock, this function can be invoked
     * in a governance proposal to recover tokens or Ether that was sent to the governor contract by mistake.
     * Note that if the executor is simply the governor itself, use of `relay` is redundant.
     */
    function relay(
        address target,
        uint256 value,
        bytes calldata data
    ) external virtual onlyGovernance {
        Address.functionCallWithValue(target, data, value);
    }

    /**
     * @dev Address through which the governor executes action. Will be overloaded by module that execute actions
     * through another contract such as a timelock.
     */
    function _executor() internal view virtual returns (address) {
        return address(this);
    }

    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }

    /**
     * @dev See {IERC1155Receiver-onERC1155Received}.
     */
    function onERC1155Received(
        address,
        address,
        uint256,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    /**
     * @dev See {IERC1155Receiver-onERC1155BatchReceived}.
     */
    function onERC1155BatchReceived(
        address,
        address,
        uint256[] memory,
        uint256[] memory,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}

// File: @openzeppelin/contracts/governance/extensions/GovernorCountingSimple.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (governance/extensions/GovernorCountingSimple.sol)

pragma solidity ^0.8.0;

import "../Governor.sol";

/**
 * @dev Extension of {Governor} for simple, 3 options, vote counting.
 *
 * _Available since v4.3._
 */
abstract contract GovernorCountingSimple is Governor {
    /**
     * @dev Supported vote types. Matches Governor Bravo ordering.
     */
    enum VoteType {
        Against,
        For,
        Abstain
    }

    struct ProposalVote {
        uint256 againstVotes;
        uint256 forVotes;
        uint256 abstainVotes;
        mapping(address => bool) hasVoted;
    }

    mapping(uint256 => ProposalVote) private _proposalVotes;

    /**
     * @dev See {IGovernor-COUNTING_MODE}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function COUNTING_MODE() public pure virtual override returns (string memory) {
        return "support=bravo&quorum=for,abstain";
    }

    /**
     * @dev See {IGovernor-hasVoted}.
     */
    function hasVoted(uint256 proposalId, address account) public view virtual override returns (bool) {
        return _proposalVotes[proposalId].hasVoted[account];
    }

    /**
     * @dev Accessor to the internal vote counts.
     */
    function proposalVotes(uint256 proposalId)
        public
        view
        virtual
        returns (
            uint256 againstVotes,
            uint256 forVotes,
            uint256 abstainVotes
        )
    {
        ProposalVote storage proposalvote = _proposalVotes[proposalId];
        return (proposalvote.againstVotes, proposalvote.forVotes, proposalvote.abstainVotes);
    }

    /**
     * @dev See {Governor-_quorumReached}.
     */
    function _quorumReached(uint256 proposalId) internal view virtual override returns (bool) {
        ProposalVote storage proposalvote = _proposalVotes[proposalId];

        return quorum(proposalSnapshot(proposalId)) <= proposalvote.forVotes + proposalvote.abstainVotes;
    }

    /**
     * @dev See {Governor-_voteSucceeded}. In this module, the forVotes must be strictly over the againstVotes.
     */
    function _voteSucceeded(uint256 proposalId) internal view virtual override returns (bool) {
        ProposalVote storage proposalvote = _proposalVotes[proposalId];

        return proposalvote.forVotes > proposalvote.againstVotes;
    }

    /**
     * @dev See {Governor-_countVote}. In this module, the support follows the `VoteType` enum (from Governor Bravo).
     */
    function _countVote(
        uint256 proposalId,
        address account,
        uint8 support,
        uint256 weight,
        bytes memory // params
    ) internal virtual override {
        ProposalVote storage proposalvote = _proposalVotes[proposalId];

        require(!proposalvote.hasVoted[account], "GovernorVotingSimple: vote already cast");
        proposalvote.hasVoted[account] = true;

        if (support == uint8(VoteType.Against)) {
            proposalvote.againstVotes += weight;
        } else if (support == uint8(VoteType.For)) {
            proposalvote.forVotes += weight;
        } else if (support == uint8(VoteType.Abstain)) {
            proposalvote.abstainVotes += weight;
        } else {
            revert("GovernorVotingSimple: invalid value for enum VoteType");
        }
    }
}

// File: @openzeppelin/contracts/governance/extensions/GovernorSettings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (governance/extensions/GovernorSettings.sol)

pragma solidity ^0.8.0;

import "../Governor.sol";

/**
 * @dev Extension of {Governor} for settings updatable through governance.
 *
 * _Available since v4.4._
 */
abstract contract GovernorSettings is Governor {
    uint256 private _votingDelay;
    uint256 private _votingPeriod;
    uint256 private _proposalThreshold;

    event VotingDelaySet(uint256 oldVotingDelay, uint256 newVotingDelay);
    event VotingPeriodSet(uint256 oldVotingPeriod, uint256 newVotingPeriod);
    event ProposalThresholdSet(uint256 oldProposalThreshold, uint256 newProposalThreshold);

    /**
     * @dev Initialize the governance parameters.
     */
    constructor(
        uint256 initialVotingDelay,
        uint256 initialVotingPeriod,
        uint256 initialProposalThreshold
    ) {
        _setVotingDelay(initialVotingDelay);
        _setVotingPeriod(initialVotingPeriod);
        _setProposalThreshold(initialProposalThreshold);
    }

    /**
     * @dev See {IGovernor-votingDelay}.
     */
    function votingDelay() public view virtual override returns (uint256) {
        return _votingDelay;
    }

    /**
     * @dev See {IGovernor-votingPeriod}.
     */
    function votingPeriod() public view virtual override returns (uint256) {
        return _votingPeriod;
    }

    /**
     * @dev See {Governor-proposalThreshold}.
     */
    function proposalThreshold() public view virtual override returns (uint256) {
        return _proposalThreshold;
    }

    /**
     * @dev Update the voting delay. This operation can only be performed through a governance proposal.
     *
     * Emits a {VotingDelaySet} event.
     */
    function setVotingDelay(uint256 newVotingDelay) public virtual onlyGovernance {
        _setVotingDelay(newVotingDelay);
    }

    /**
     * @dev Update the voting period. This operation can only be performed through a governance proposal.
     *
     * Emits a {VotingPeriodSet} event.
     */
    function setVotingPeriod(uint256 newVotingPeriod) public virtual onlyGovernance {
        _setVotingPeriod(newVotingPeriod);
    }

    /**
     * @dev Update the proposal threshold. This operation can only be performed through a governance proposal.
     *
     * Emits a {ProposalThresholdSet} event.
     */
    function setProposalThreshold(uint256 newProposalThreshold) public virtual onlyGovernance {
        _setProposalThreshold(newProposalThreshold);
    }

    /**
     * @dev Internal setter for the voting delay.
     *
     * Emits a {VotingDelaySet} event.
     */
    function _setVotingDelay(uint256 newVotingDelay) internal virtual {
        emit VotingDelaySet(_votingDelay, newVotingDelay);
        _votingDelay = newVotingDelay;
    }

    /**
     * @dev Internal setter for the voting period.
     *
     * Emits a {VotingPeriodSet} event.
     */
    function _setVotingPeriod(uint256 newVotingPeriod) internal virtual {
        // voting period must be at least one block long
        require(newVotingPeriod > 0, "GovernorSettings: voting period too low");
        emit VotingPeriodSet(_votingPeriod, newVotingPeriod);
        _votingPeriod = newVotingPeriod;
    }

    /**
     * @dev Internal setter for the proposal threshold.
     *
     * Emits a {ProposalThresholdSet} event.
     */
    function _setProposalThreshold(uint256 newProposalThreshold) internal virtual {
        emit ProposalThresholdSet(_proposalThreshold, newProposalThreshold);
        _proposalThreshold = newProposalThreshold;
    }
}

// File: @openzeppelin/contracts/governance/extensions/GovernorTimelockControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (governance/extensions/GovernorTimelockControl.sol)

pragma solidity ^0.8.0;

import "./IGovernorTimelock.sol";
import "../Governor.sol";
import "../TimelockController.sol";

/**
 * @dev Extension of {Governor} that binds the execution process to an instance of {TimelockController}. This adds a
 * delay, enforced by the {TimelockController} to all successful proposal (in addition to the voting duration). The
 * {Governor} needs the proposer (and ideally the executor) roles for the {Governor} to work properly.
 *
 * Using this model means the proposal will be operated by the {TimelockController} and not by the {Governor}. Thus,
 * the assets and permissions must be attached to the {TimelockController}. Any asset sent to the {Governor} will be
 * inaccessible.
 *
 * WARNING: Setting up the TimelockController to have additional proposers besides the governor is very risky, as it
 * grants them powers that they must be trusted or known not to use: 1) {onlyGovernance} functions like {relay} are
 * available to them through the timelock, and 2) approved governance proposals can be blocked by them, effectively
 * executing a Denial of Service attack. This risk will be mitigated in a future release.
 *
 * _Available since v4.3._
 */
abstract contract GovernorTimelockControl is IGovernorTimelock, Governor {
    TimelockController private _timelock;
    mapping(uint256 => bytes32) private _timelockIds;

    /**
     * @dev Emitted when the timelock controller used for proposal execution is modified.
     */
    event TimelockChange(address oldTimelock, address newTimelock);

    /**
     * @dev Set the timelock.
     */
    constructor(TimelockController timelockAddress) {
        _updateTimelock(timelockAddress);
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, Governor) returns (bool) {
        return interfaceId == type(IGovernorTimelock).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Overridden version of the {Governor-state} function with added support for the `Queued` status.
     */
    function state(uint256 proposalId) public view virtual override(IGovernor, Governor) returns (ProposalState) {
        ProposalState status = super.state(proposalId);

        if (status != ProposalState.Succeeded) {
            return status;
        }

        // core tracks execution, so we just have to check if successful proposal have been queued.
        bytes32 queueid = _timelockIds[proposalId];
        if (queueid == bytes32(0)) {
            return status;
        } else if (_timelock.isOperationDone(queueid)) {
            return ProposalState.Executed;
        } else if (_timelock.isOperationPending(queueid)) {
            return ProposalState.Queued;
        } else {
            return ProposalState.Canceled;
        }
    }

    /**
     * @dev Public accessor to check the address of the timelock
     */
    function timelock() public view virtual override returns (address) {
        return address(_timelock);
    }

    /**
     * @dev Public accessor to check the eta of a queued proposal
     */
    function proposalEta(uint256 proposalId) public view virtual override returns (uint256) {
        uint256 eta = _timelock.getTimestamp(_timelockIds[proposalId]);
        return eta == 1 ? 0 : eta; // _DONE_TIMESTAMP (1) should be replaced with a 0 value
    }

    /**
     * @dev Function to queue a proposal to the timelock.
     */
    function queue(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public virtual override returns (uint256) {
        uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);

        require(state(proposalId) == ProposalState.Succeeded, "Governor: proposal not successful");

        uint256 delay = _timelock.getMinDelay();
        _timelockIds[proposalId] = _timelock.hashOperationBatch(targets, values, calldatas, 0, descriptionHash);
        _timelock.scheduleBatch(targets, values, calldatas, 0, descriptionHash, delay);

        emit ProposalQueued(proposalId, block.timestamp + delay);

        return proposalId;
    }

    /**
     * @dev Overridden execute function that run the already queued proposal through the timelock.
     */
    function _execute(
        uint256, /* proposalId */
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) internal virtual override {
        _timelock.executeBatch{value: msg.value}(targets, values, calldatas, 0, descriptionHash);
    }

    /**
     * @dev Overridden version of the {Governor-_cancel} function to cancel the timelocked proposal if it as already
     * been queued.
     */
    // This function can reenter through the external call to the timelock, but we assume the timelock is trusted and
    // well behaved (according to TimelockController) and this will not happen.
    // slither-disable-next-line reentrancy-no-eth
    function _cancel(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) internal virtual override returns (uint256) {
        uint256 proposalId = super._cancel(targets, values, calldatas, descriptionHash);

        if (_timelockIds[proposalId] != 0) {
            _timelock.cancel(_timelockIds[proposalId]);
            delete _timelockIds[proposalId];
        }

        return proposalId;
    }

    /**
     * @dev Address through which the governor executes action. In this case, the timelock.
     */
    function _executor() internal view virtual override returns (address) {
        return address(_timelock);
    }

    /**
     * @dev Public endpoint to update the underlying timelock instance. Restricted to the timelock itself, so updates
     * must be proposed, scheduled, and executed through governance proposals.
     *
     * CAUTION: It is not recommended to change the timelock while there are other queued governance proposals.
     */
    function updateTimelock(TimelockController newTimelock) external virtual onlyGovernance {
        _updateTimelock(newTimelock);
    }

    function _updateTimelock(TimelockController newTimelock) private {
        emit TimelockChange(address(_timelock), address(newTimelock));
        _timelock = newTimelock;
    }
}

// File: @openzeppelin/contracts/governance/extensions/GovernorVotes.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (governance/extensions/GovernorVotes.sol)

pragma solidity ^0.8.0;

import "../Governor.sol";
import "../utils/IVotes.sol";

/**
 * @dev Extension of {Governor} for voting weight extraction from an {ERC20Votes} token, or since v4.5 an {ERC721Votes} token.
 *
 * _Available since v4.3._
 */
abstract contract GovernorVotes is Governor {
    IVotes public immutable token;

    constructor(IVotes tokenAddress) {
        token = tokenAddress;
    }

    /**
     * Read the voting weight from the token's built in snapshot mechanism (see {Governor-_getVotes}).
     */
    function _getVotes(
        address account,
        uint256 blockNumber,
        bytes memory /*params*/
    ) internal view virtual override returns (uint256) {
        return token.getPastVotes(account, blockNumber);
    }
}

// File: @openzeppelin/contracts/governance/extensions/GovernorVotesQuorumFraction.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (governance/extensions/GovernorVotesQuorumFraction.sol)

pragma solidity ^0.8.0;

import "./GovernorVotes.sol";
import "../../utils/Checkpoints.sol";
import "../../utils/math/SafeCast.sol";

/**
 * @dev Extension of {Governor} for voting weight extraction from an {ERC20Votes} token and a quorum expressed as a
 * fraction of the total supply.
 *
 * _Available since v4.3._
 */
abstract contract GovernorVotesQuorumFraction is GovernorVotes {
    using Checkpoints for Checkpoints.History;

    uint256 private _quorumNumerator; // DEPRECATED
    Checkpoints.History private _quorumNumeratorHistory;

    event QuorumNumeratorUpdated(uint256 oldQuorumNumerator, uint256 newQuorumNumerator);

    /**
     * @dev Initialize quorum as a fraction of the token's total supply.
     *
     * The fraction is specified as `numerator / denominator`. By default the denominator is 100, so quorum is
     * specified as a percent: a numerator of 10 corresponds to quorum being 10% of total supply. The denominator can be
     * customized by overriding {quorumDenominator}.
     */
    constructor(uint256 quorumNumeratorValue) {
        _updateQuorumNumerator(quorumNumeratorValue);
    }

    /**
     * @dev Returns the current quorum numerator. See {quorumDenominator}.
     */
    function quorumNumerator() public view virtual returns (uint256) {
        return _quorumNumeratorHistory._checkpoints.length == 0 ? _quorumNumerator : _quorumNumeratorHistory.latest();
    }

    /**
     * @dev Returns the quorum numerator at a specific block number. See {quorumDenominator}.
     */
    function quorumNumerator(uint256 blockNumber) public view virtual returns (uint256) {
        // If history is empty, fallback to old storage
        uint256 length = _quorumNumeratorHistory._checkpoints.length;
        if (length == 0) {
            return _quorumNumerator;
        }

        // Optimistic search, check the latest checkpoint
        Checkpoints.Checkpoint memory latest = _quorumNumeratorHistory._checkpoints[length - 1];
        if (latest._blockNumber <= blockNumber) {
            return latest._value;
        }

        // Otherwize, do the binary search
        return _quorumNumeratorHistory.getAtBlock(blockNumber);
    }

    /**
     * @dev Returns the quorum denominator. Defaults to 100, but may be overridden.
     */
    function quorumDenominator() public view virtual returns (uint256) {
        return 100;
    }

    /**
     * @dev Returns the quorum for a block number, in terms of number of votes: `supply * numerator / denominator`.
     */
    function quorum(uint256 blockNumber) public view virtual override returns (uint256) {
        return (token.getPastTotalSupply(blockNumber) * quorumNumerator(blockNumber)) / quorumDenominator();
    }

    /**
     * @dev Changes the quorum numerator.
     *
     * Emits a {QuorumNumeratorUpdated} event.
     *
     * Requirements:
     *
     * - Must be called through a governance proposal.
     * - New numerator must be smaller or equal to the denominator.
     */
    function updateQuorumNumerator(uint256 newQuorumNumerator) external virtual onlyGovernance {
        _updateQuorumNumerator(newQuorumNumerator);
    }

    /**
     * @dev Changes the quorum numerator.
     *
     * Emits a {QuorumNumeratorUpdated} event.
     *
     * Requirements:
     *
     * - New numerator must be smaller or equal to the denominator.
     */
    function _updateQuorumNumerator(uint256 newQuorumNumerator) internal virtual {
        require(
            newQuorumNumerator <= quorumDenominator(),
            "GovernorVotesQuorumFraction: quorumNumerator over quorumDenominator"
        );

        uint256 oldQuorumNumerator = quorumNumerator();

        // Make sure we keep track of the original numerator in contracts upgraded from a version without checkpoints.
        if (oldQuorumNumerator != 0 && _quorumNumeratorHistory._checkpoints.length == 0) {
            _quorumNumeratorHistory._checkpoints.push(
                Checkpoints.Checkpoint({_blockNumber: 0, _value: SafeCast.toUint224(oldQuorumNumerator)})
            );
        }

        // Set new quorum for future proposals
        _quorumNumeratorHistory.push(newQuorumNumerator);

        emit QuorumNumeratorUpdated(oldQuorumNumerator, newQuorumNumerator);
    }
}

// File: contracts/interfaces/IStRSRVotes.sol



// SPDX-License-Identifier: BlueOak-1.0.0
pragma solidity 0.8.9;

import "@openzeppelin/contracts-upgradeable/governance/utils/IVotesUpgradeable.sol";

interface IStRSRVotes is IVotesUpgradeable {
    /// @return The current era
    function currentEra() external view returns (uint256);

    /// @return The era at a past block number
    function getPastEra(uint256 blockNumber) external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/IERC1155Receiver.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {
    /**
     * @dev Handles the receipt of a single ERC1155 token type. This function is
     * called at the end of a `safeTransferFrom` after the balance has been updated.
     *
     * NOTE: To accept the transfer, this must return
     * `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
     * (i.e. 0xf23a6e61, or its own function selector).
     *
     * @param operator The address which initiated the transfer (i.e. msg.sender)
     * @param from The address which previously owned the token
     * @param id The ID of the token being transferred
     * @param value The amount of tokens being transferred
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
     */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    ) external returns (bytes4);

    /**
     * @dev Handles the receipt of a multiple ERC1155 token types. This function
     * is called at the end of a `safeBatchTransferFrom` after the balances have
     * been updated.
     *
     * NOTE: To accept the transfer(s), this must return
     * `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
     * (i.e. 0xbc197c81, or its own function selector).
     *
     * @param operator The address which initiated the batch transfer (i.e. msg.sender)
     * @param from The address which previously owned the token
     * @param ids An array containing ids of each token being transferred (order and length must match values array)
     * @param values An array containing amounts of each token being transferred (order and length must match ids array)
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
     */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/utils/cryptography/ECDSA.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.3) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        } else if (error == RecoverError.InvalidSignatureV) {
            revert("ECDSA: invalid signature 'v' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }
        if (v != 27 && v != 28) {
            return (address(0), RecoverError.InvalidSignatureV);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
    }
}

// File: @openzeppelin/contracts/utils/cryptography/draft-EIP712.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/cryptography/draft-EIP712.sol)

pragma solidity ^0.8.0;

import "./ECDSA.sol";

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * _Available since v3.4._
 */
abstract contract EIP712 {
    /* solhint-disable var-name-mixedcase */
    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
    // invalidate the cached domain separator if the chain id changes.
    bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
    uint256 private immutable _CACHED_CHAIN_ID;
    address private immutable _CACHED_THIS;

    bytes32 private immutable _HASHED_NAME;
    bytes32 private immutable _HASHED_VERSION;
    bytes32 private immutable _TYPE_HASH;

    /* solhint-enable var-name-mixedcase */

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    constructor(string memory name, string memory version) {
        bytes32 hashedName = keccak256(bytes(name));
        bytes32 hashedVersion = keccak256(bytes(version));
        bytes32 typeHash = keccak256(
            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
        );
        _HASHED_NAME = hashedName;
        _HASHED_VERSION = hashedVersion;
        _CACHED_CHAIN_ID = block.chainid;
        _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);
        _CACHED_THIS = address(this);
        _TYPE_HASH = typeHash;
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view returns (bytes32) {
        if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {
            return _CACHED_DOMAIN_SEPARATOR;
        } else {
            return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);
        }
    }

    function _buildDomainSeparator(
        bytes32 typeHash,
        bytes32 nameHash,
        bytes32 versionHash
    ) private view returns (bytes32) {
        return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/math/SafeCast.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/math/SafeCast.sol)

pragma solidity ^0.8.0;

/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toUint248(uint256 value) internal pure returns (uint248) {
        require(value <= type(uint248).max, "SafeCast: value doesn't fit in 248 bits");
        return uint248(value);
    }

    /**
     * @dev Returns the downcasted uint240 from uint256, reverting on
     * overflow (when the input is greater than largest uint240).
     *
     * Counterpart to Solidity's `uint240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toUint240(uint256 value) internal pure returns (uint240) {
        require(value <= type(uint240).max, "SafeCast: value doesn't fit in 240 bits");
        return uint240(value);
    }

    /**
     * @dev Returns the downcasted uint232 from uint256, reverting on
     * overflow (when the input is greater than largest uint232).
     *
     * Counterpart to Solidity's `uint232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toUint232(uint256 value) internal pure returns (uint232) {
        require(value <= type(uint232).max, "SafeCast: value doesn't fit in 232 bits");
        return uint232(value);
    }

    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.2._
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
        return uint224(value);
    }

    /**
     * @dev Returns the downcasted uint216 from uint256, reverting on
     * overflow (when the input is greater than largest uint216).
     *
     * Counterpart to Solidity's `uint216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toUint216(uint256 value) internal pure returns (uint216) {
        require(value <= type(uint216).max, "SafeCast: value doesn't fit in 216 bits");
        return uint216(value);
    }

    /**
     * @dev Returns the downcasted uint208 from uint256, reverting on
     * overflow (when the input is greater than largest uint208).
     *
     * Counterpart to Solidity's `uint208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toUint208(uint256 value) internal pure returns (uint208) {
        require(value <= type(uint208).max, "SafeCast: value doesn't fit in 208 bits");
        return uint208(value);
    }

    /**
     * @dev Returns the downcasted uint200 from uint256, reverting on
     * overflow (when the input is greater than largest uint200).
     *
     * Counterpart to Solidity's `uint200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toUint200(uint256 value) internal pure returns (uint200) {
        require(value <= type(uint200).max, "SafeCast: value doesn't fit in 200 bits");
        return uint200(value);
    }

    /**
     * @dev Returns the downcasted uint192 from uint256, reverting on
     * overflow (when the input is greater than largest uint192).
     *
     * Counterpart to Solidity's `uint192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toUint192(uint256 value) internal pure returns (uint192) {
        require(value <= type(uint192).max, "SafeCast: value doesn't fit in 192 bits");
        return uint192(value);
    }

    /**
     * @dev Returns the downcasted uint184 from uint256, reverting on
     * overflow (when the input is greater than largest uint184).
     *
     * Counterpart to Solidity's `uint184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toUint184(uint256 value) internal pure returns (uint184) {
        require(value <= type(uint184).max, "SafeCast: value doesn't fit in 184 bits");
        return uint184(value);
    }

    /**
     * @dev Returns the downcasted uint176 from uint256, reverting on
     * overflow (when the input is greater than largest uint176).
     *
     * Counterpart to Solidity's `uint176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toUint176(uint256 value) internal pure returns (uint176) {
        require(value <= type(uint176).max, "SafeCast: value doesn't fit in 176 bits");
        return uint176(value);
    }

    /**
     * @dev Returns the downcasted uint168 from uint256, reverting on
     * overflow (when the input is greater than largest uint168).
     *
     * Counterpart to Solidity's `uint168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toUint168(uint256 value) internal pure returns (uint168) {
        require(value <= type(uint168).max, "SafeCast: value doesn't fit in 168 bits");
        return uint168(value);
    }

    /**
     * @dev Returns the downcasted uint160 from uint256, reverting on
     * overflow (when the input is greater than largest uint160).
     *
     * Counterpart to Solidity's `uint160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toUint160(uint256 value) internal pure returns (uint160) {
        require(value <= type(uint160).max, "SafeCast: value doesn't fit in 160 bits");
        return uint160(value);
    }

    /**
     * @dev Returns the downcasted uint152 from uint256, reverting on
     * overflow (when the input is greater than largest uint152).
     *
     * Counterpart to Solidity's `uint152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toUint152(uint256 value) internal pure returns (uint152) {
        require(value <= type(uint152).max, "SafeCast: value doesn't fit in 152 bits");
        return uint152(value);
    }

    /**
     * @dev Returns the downcasted uint144 from uint256, reverting on
     * overflow (when the input is greater than largest uint144).
     *
     * Counterpart to Solidity's `uint144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toUint144(uint256 value) internal pure returns (uint144) {
        require(value <= type(uint144).max, "SafeCast: value doesn't fit in 144 bits");
        return uint144(value);
    }

    /**
     * @dev Returns the downcasted uint136 from uint256, reverting on
     * overflow (when the input is greater than largest uint136).
     *
     * Counterpart to Solidity's `uint136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toUint136(uint256 value) internal pure returns (uint136) {
        require(value <= type(uint136).max, "SafeCast: value doesn't fit in 136 bits");
        return uint136(value);
    }

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v2.5._
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toUint120(uint256 value) internal pure returns (uint120) {
        require(value <= type(uint120).max, "SafeCast: value doesn't fit in 120 bits");
        return uint120(value);
    }

    /**
     * @dev Returns the downcasted uint112 from uint256, reverting on
     * overflow (when the input is greater than largest uint112).
     *
     * Counterpart to Solidity's `uint112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toUint112(uint256 value) internal pure returns (uint112) {
        require(value <= type(uint112).max, "SafeCast: value doesn't fit in 112 bits");
        return uint112(value);
    }

    /**
     * @dev Returns the downcasted uint104 from uint256, reverting on
     * overflow (when the input is greater than largest uint104).
     *
     * Counterpart to Solidity's `uint104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toUint104(uint256 value) internal pure returns (uint104) {
        require(value <= type(uint104).max, "SafeCast: value doesn't fit in 104 bits");
        return uint104(value);
    }

    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.2._
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
        return uint96(value);
    }

    /**
     * @dev Returns the downcasted uint88 from uint256, reverting on
     * overflow (when the input is greater than largest uint88).
     *
     * Counterpart to Solidity's `uint88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toUint88(uint256 value) internal pure returns (uint88) {
        require(value <= type(uint88).max, "SafeCast: value doesn't fit in 88 bits");
        return uint88(value);
    }

    /**
     * @dev Returns the downcasted uint80 from uint256, reverting on
     * overflow (when the input is greater than largest uint80).
     *
     * Counterpart to Solidity's `uint80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toUint80(uint256 value) internal pure returns (uint80) {
        require(value <= type(uint80).max, "SafeCast: value doesn't fit in 80 bits");
        return uint80(value);
    }

    /**
     * @dev Returns the downcasted uint72 from uint256, reverting on
     * overflow (when the input is greater than largest uint72).
     *
     * Counterpart to Solidity's `uint72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toUint72(uint256 value) internal pure returns (uint72) {
        require(value <= type(uint72).max, "SafeCast: value doesn't fit in 72 bits");
        return uint72(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v2.5._
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint56 from uint256, reverting on
     * overflow (when the input is greater than largest uint56).
     *
     * Counterpart to Solidity's `uint56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toUint56(uint256 value) internal pure returns (uint56) {
        require(value <= type(uint56).max, "SafeCast: value doesn't fit in 56 bits");
        return uint56(value);
    }

    /**
     * @dev Returns the downcasted uint48 from uint256, reverting on
     * overflow (when the input is greater than largest uint48).
     *
     * Counterpart to Solidity's `uint48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toUint48(uint256 value) internal pure returns (uint48) {
        require(value <= type(uint48).max, "SafeCast: value doesn't fit in 48 bits");
        return uint48(value);
    }

    /**
     * @dev Returns the downcasted uint40 from uint256, reverting on
     * overflow (when the input is greater than largest uint40).
     *
     * Counterpart to Solidity's `uint40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toUint40(uint256 value) internal pure returns (uint40) {
        require(value <= type(uint40).max, "SafeCast: value doesn't fit in 40 bits");
        return uint40(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v2.5._
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint24 from uint256, reverting on
     * overflow (when the input is greater than largest uint24).
     *
     * Counterpart to Solidity's `uint24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toUint24(uint256 value) internal pure returns (uint24) {
        require(value <= type(uint24).max, "SafeCast: value doesn't fit in 24 bits");
        return uint24(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v2.5._
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v2.5._
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     *
     * _Available since v3.0._
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int248 from int256, reverting on
     * overflow (when the input is less than smallest int248 or
     * greater than largest int248).
     *
     * Counterpart to Solidity's `int248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toInt248(int256 value) internal pure returns (int248) {
        require(value >= type(int248).min && value <= type(int248).max, "SafeCast: value doesn't fit in 248 bits");
        return int248(value);
    }

    /**
     * @dev Returns the downcasted int240 from int256, reverting on
     * overflow (when the input is less than smallest int240 or
     * greater than largest int240).
     *
     * Counterpart to Solidity's `int240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toInt240(int256 value) internal pure returns (int240) {
        require(value >= type(int240).min && value <= type(int240).max, "SafeCast: value doesn't fit in 240 bits");
        return int240(value);
    }

    /**
     * @dev Returns the downcasted int232 from int256, reverting on
     * overflow (when the input is less than smallest int232 or
     * greater than largest int232).
     *
     * Counterpart to Solidity's `int232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toInt232(int256 value) internal pure returns (int232) {
        require(value >= type(int232).min && value <= type(int232).max, "SafeCast: value doesn't fit in 232 bits");
        return int232(value);
    }

    /**
     * @dev Returns the downcasted int224 from int256, reverting on
     * overflow (when the input is less than smallest int224 or
     * greater than largest int224).
     *
     * Counterpart to Solidity's `int224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.7._
     */
    function toInt224(int256 value) internal pure returns (int224) {
        require(value >= type(int224).min && value <= type(int224).max, "SafeCast: value doesn't fit in 224 bits");
        return int224(value);
    }

    /**
     * @dev Returns the downcasted int216 from int256, reverting on
     * overflow (when the input is less than smallest int216 or
     * greater than largest int216).
     *
     * Counterpart to Solidity's `int216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toInt216(int256 value) internal pure returns (int216) {
        require(value >= type(int216).min && value <= type(int216).max, "SafeCast: value doesn't fit in 216 bits");
        return int216(value);
    }

    /**
     * @dev Returns the downcasted int208 from int256, reverting on
     * overflow (when the input is less than smallest int208 or
     * greater than largest int208).
     *
     * Counterpart to Solidity's `int208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toInt208(int256 value) internal pure returns (int208) {
        require(value >= type(int208).min && value <= type(int208).max, "SafeCast: value doesn't fit in 208 bits");
        return int208(value);
    }

    /**
     * @dev Returns the downcasted int200 from int256, reverting on
     * overflow (when the input is less than smallest int200 or
     * greater than largest int200).
     *
     * Counterpart to Solidity's `int200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toInt200(int256 value) internal pure returns (int200) {
        require(value >= type(int200).min && value <= type(int200).max, "SafeCast: value doesn't fit in 200 bits");
        return int200(value);
    }

    /**
     * @dev Returns the downcasted int192 from int256, reverting on
     * overflow (when the input is less than smallest int192 or
     * greater than largest int192).
     *
     * Counterpart to Solidity's `int192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toInt192(int256 value) internal pure returns (int192) {
        require(value >= type(int192).min && value <= type(int192).max, "SafeCast: value doesn't fit in 192 bits");
        return int192(value);
    }

    /**
     * @dev Returns the downcasted int184 from int256, reverting on
     * overflow (when the input is less than smallest int184 or
     * greater than largest int184).
     *
     * Counterpart to Solidity's `int184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toInt184(int256 value) internal pure returns (int184) {
        require(value >= type(int184).min && value <= type(int184).max, "SafeCast: value doesn't fit in 184 bits");
        return int184(value);
    }

    /**
     * @dev Returns the downcasted int176 from int256, reverting on
     * overflow (when the input is less than smallest int176 or
     * greater than largest int176).
     *
     * Counterpart to Solidity's `int176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toInt176(int256 value) internal pure returns (int176) {
        require(value >= type(int176).min && value <= type(int176).max, "SafeCast: value doesn't fit in 176 bits");
        return int176(value);
    }

    /**
     * @dev Returns the downcasted int168 from int256, reverting on
     * overflow (when the input is less than smallest int168 or
     * greater than largest int168).
     *
     * Counterpart to Solidity's `int168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toInt168(int256 value) internal pure returns (int168) {
        require(value >= type(int168).min && value <= type(int168).max, "SafeCast: value doesn't fit in 168 bits");
        return int168(value);
    }

    /**
     * @dev Returns the downcasted int160 from int256, reverting on
     * overflow (when the input is less than smallest int160 or
     * greater than largest int160).
     *
     * Counterpart to Solidity's `int160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toInt160(int256 value) internal pure returns (int160) {
        require(value >= type(int160).min && value <= type(int160).max, "SafeCast: value doesn't fit in 160 bits");
        return int160(value);
    }

    /**
     * @dev Returns the downcasted int152 from int256, reverting on
     * overflow (when the input is less than smallest int152 or
     * greater than largest int152).
     *
     * Counterpart to Solidity's `int152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toInt152(int256 value) internal pure returns (int152) {
        require(value >= type(int152).min && value <= type(int152).max, "SafeCast: value doesn't fit in 152 bits");
        return int152(value);
    }

    /**
     * @dev Returns the downcasted int144 from int256, reverting on
     * overflow (when the input is less than smallest int144 or
     * greater than largest int144).
     *
     * Counterpart to Solidity's `int144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toInt144(int256 value) internal pure returns (int144) {
        require(value >= type(int144).min && value <= type(int144).max, "SafeCast: value doesn't fit in 144 bits");
        return int144(value);
    }

    /**
     * @dev Returns the downcasted int136 from int256, reverting on
     * overflow (when the input is less than smallest int136 or
     * greater than largest int136).
     *
     * Counterpart to Solidity's `int136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toInt136(int256 value) internal pure returns (int136) {
        require(value >= type(int136).min && value <= type(int136).max, "SafeCast: value doesn't fit in 136 bits");
        return int136(value);
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128) {
        require(value >= type(int128).min && value <= type(int128).max, "SafeCast: value doesn't fit in 128 bits");
        return int128(value);
    }

    /**
     * @dev Returns the downcasted int120 from int256, reverting on
     * overflow (when the input is less than smallest int120 or
     * greater than largest int120).
     *
     * Counterpart to Solidity's `int120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toInt120(int256 value) internal pure returns (int120) {
        require(value >= type(int120).min && value <= type(int120).max, "SafeCast: value doesn't fit in 120 bits");
        return int120(value);
    }

    /**
     * @dev Returns the downcasted int112 from int256, reverting on
     * overflow (when the input is less than smallest int112 or
     * greater than largest int112).
     *
     * Counterpart to Solidity's `int112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toInt112(int256 value) internal pure returns (int112) {
        require(value >= type(int112).min && value <= type(int112).max, "SafeCast: value doesn't fit in 112 bits");
        return int112(value);
    }

    /**
     * @dev Returns the downcasted int104 from int256, reverting on
     * overflow (when the input is less than smallest int104 or
     * greater than largest int104).
     *
     * Counterpart to Solidity's `int104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toInt104(int256 value) internal pure returns (int104) {
        require(value >= type(int104).min && value <= type(int104).max, "SafeCast: value doesn't fit in 104 bits");
        return int104(value);
    }

    /**
     * @dev Returns the downcasted int96 from int256, reverting on
     * overflow (when the input is less than smallest int96 or
     * greater than largest int96).
     *
     * Counterpart to Solidity's `int96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.7._
     */
    function toInt96(int256 value) internal pure returns (int96) {
        require(value >= type(int96).min && value <= type(int96).max, "SafeCast: value doesn't fit in 96 bits");
        return int96(value);
    }

    /**
     * @dev Returns the downcasted int88 from int256, reverting on
     * overflow (when the input is less than smallest int88 or
     * greater than largest int88).
     *
     * Counterpart to Solidity's `int88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toInt88(int256 value) internal pure returns (int88) {
        require(value >= type(int88).min && value <= type(int88).max, "SafeCast: value doesn't fit in 88 bits");
        return int88(value);
    }

    /**
     * @dev Returns the downcasted int80 from int256, reverting on
     * overflow (when the input is less than smallest int80 or
     * greater than largest int80).
     *
     * Counterpart to Solidity's `int80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toInt80(int256 value) internal pure returns (int80) {
        require(value >= type(int80).min && value <= type(int80).max, "SafeCast: value doesn't fit in 80 bits");
        return int80(value);
    }

    /**
     * @dev Returns the downcasted int72 from int256, reverting on
     * overflow (when the input is less than smallest int72 or
     * greater than largest int72).
     *
     * Counterpart to Solidity's `int72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toInt72(int256 value) internal pure returns (int72) {
        require(value >= type(int72).min && value <= type(int72).max, "SafeCast: value doesn't fit in 72 bits");
        return int72(value);
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64) {
        require(value >= type(int64).min && value <= type(int64).max, "SafeCast: value doesn't fit in 64 bits");
        return int64(value);
    }

    /**
     * @dev Returns the downcasted int56 from int256, reverting on
     * overflow (when the input is less than smallest int56 or
     * greater than largest int56).
     *
     * Counterpart to Solidity's `int56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toInt56(int256 value) internal pure returns (int56) {
        require(value >= type(int56).min && value <= type(int56).max, "SafeCast: value doesn't fit in 56 bits");
        return int56(value);
    }

    /**
     * @dev Returns the downcasted int48 from int256, reverting on
     * overflow (when the input is less than smallest int48 or
     * greater than largest int48).
     *
     * Counterpart to Solidity's `int48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toInt48(int256 value) internal pure returns (int48) {
        require(value >= type(int48).min && value <= type(int48).max, "SafeCast: value doesn't fit in 48 bits");
        return int48(value);
    }

    /**
     * @dev Returns the downcasted int40 from int256, reverting on
     * overflow (when the input is less than smallest int40 or
     * greater than largest int40).
     *
     * Counterpart to Solidity's `int40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toInt40(int256 value) internal pure returns (int40) {
        require(value >= type(int40).min && value <= type(int40).max, "SafeCast: value doesn't fit in 40 bits");
        return int40(value);
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32) {
        require(value >= type(int32).min && value <= type(int32).max, "SafeCast: value doesn't fit in 32 bits");
        return int32(value);
    }

    /**
     * @dev Returns the downcasted int24 from int256, reverting on
     * overflow (when the input is less than smallest int24 or
     * greater than largest int24).
     *
     * Counterpart to Solidity's `int24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toInt24(int256 value) internal pure returns (int24) {
        require(value >= type(int24).min && value <= type(int24).max, "SafeCast: value doesn't fit in 24 bits");
        return int24(value);
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16) {
        require(value >= type(int16).min && value <= type(int16).max, "SafeCast: value doesn't fit in 16 bits");
        return int16(value);
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8) {
        require(value >= type(int8).min && value <= type(int8).max, "SafeCast: value doesn't fit in 8 bits");
        return int8(value);
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     *
     * _Available since v3.0._
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}

// File: @openzeppelin/contracts/utils/structs/DoubleEndedQueue.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/structs/DoubleEndedQueue.sol)
pragma solidity ^0.8.4;

import "../math/SafeCast.sol";

/**
 * @dev A sequence of items with the ability to efficiently push and pop items (i.e. insert and remove) on both ends of
 * the sequence (called front and back). Among other access patterns, it can be used to implement efficient LIFO and
 * FIFO queues. Storage use is optimized, and all operations are O(1) constant time. This includes {clear}, given that
 * the existing queue contents are left in storage.
 *
 * The struct is called `Bytes32Deque`. Other types can be cast to and from `bytes32`. This data structure can only be
 * used in storage, and not in memory.
 * ```
 * DoubleEndedQueue.Bytes32Deque queue;
 * ```
 *
 * _Available since v4.6._
 */
library DoubleEndedQueue {
    /**
     * @dev An operation (e.g. {front}) couldn't be completed due to the queue being empty.
     */
    error Empty();

    /**
     * @dev An operation (e.g. {at}) couldn't be completed due to an index being out of bounds.
     */
    error OutOfBounds();

    /**
     * @dev Indices are signed integers because the queue can grow in any direction. They are 128 bits so begin and end
     * are packed in a single storage slot for efficient access. Since the items are added one at a time we can safely
     * assume that these 128-bit indices will not overflow, and use unchecked arithmetic.
     *
     * Struct members have an underscore prefix indicating that they are "private" and should not be read or written to
     * directly. Use the functions provided below instead. Modifying the struct manually may violate assumptions and
     * lead to unexpected behavior.
     *
     * Indices are in the range [begin, end) which means the first item is at data[begin] and the last item is at
     * data[end - 1].
     */
    struct Bytes32Deque {
        int128 _begin;
        int128 _end;
        mapping(int128 => bytes32) _data;
    }

    /**
     * @dev Inserts an item at the end of the queue.
     */
    function pushBack(Bytes32Deque storage deque, bytes32 value) internal {
        int128 backIndex = deque._end;
        deque._data[backIndex] = value;
        unchecked {
            deque._end = backIndex + 1;
        }
    }

    /**
     * @dev Removes the item at the end of the queue and returns it.
     *
     * Reverts with `Empty` if the queue is empty.
     */
    function popBack(Bytes32Deque storage deque) internal returns (bytes32 value) {
        if (empty(deque)) revert Empty();
        int128 backIndex;
        unchecked {
            backIndex = deque._end - 1;
        }
        value = deque._data[backIndex];
        delete deque._data[backIndex];
        deque._end = backIndex;
    }

    /**
     * @dev Inserts an item at the beginning of the queue.
     */
    function pushFront(Bytes32Deque storage deque, bytes32 value) internal {
        int128 frontIndex;
        unchecked {
            frontIndex = deque._begin - 1;
        }
        deque._data[frontIndex] = value;
        deque._begin = frontIndex;
    }

    /**
     * @dev Removes the item at the beginning of the queue and returns it.
     *
     * Reverts with `Empty` if the queue is empty.
     */
    function popFront(Bytes32Deque storage deque) internal returns (bytes32 value) {
        if (empty(deque)) revert Empty();
        int128 frontIndex = deque._begin;
        value = deque._data[frontIndex];
        delete deque._data[frontIndex];
        unchecked {
            deque._begin = frontIndex + 1;
        }
    }

    /**
     * @dev Returns the item at the beginning of the queue.
     *
     * Reverts with `Empty` if the queue is empty.
     */
    function front(Bytes32Deque storage deque) internal view returns (bytes32 value) {
        if (empty(deque)) revert Empty();
        int128 frontIndex = deque._begin;
        return deque._data[frontIndex];
    }

    /**
     * @dev Returns the item at the end of the queue.
     *
     * Reverts with `Empty` if the queue is empty.
     */
    function back(Bytes32Deque storage deque) internal view returns (bytes32 value) {
        if (empty(deque)) revert Empty();
        int128 backIndex;
        unchecked {
            backIndex = deque._end - 1;
        }
        return deque._data[backIndex];
    }

    /**
     * @dev Return the item at a position in the queue given by `index`, with the first item at 0 and last item at
     * `length(deque) - 1`.
     *
     * Reverts with `OutOfBounds` if the index is out of bounds.
     */
    function at(Bytes32Deque storage deque, uint256 index) internal view returns (bytes32 value) {
        // int256(deque._begin) is a safe upcast
        int128 idx = SafeCast.toInt128(int256(deque._begin) + SafeCast.toInt256(index));
        if (idx >= deque._end) revert OutOfBounds();
        return deque._data[idx];
    }

    /**
     * @dev Resets the queue back to being empty.
     *
     * NOTE: The current items are left behind in storage. This does not affect the functioning of the queue, but misses
     * out on potential gas refunds.
     */
    function clear(Bytes32Deque storage deque) internal {
        deque._begin = 0;
        deque._end = 0;
    }

    /**
     * @dev Returns the number of items in the queue.
     */
    function length(Bytes32Deque storage deque) internal view returns (uint256) {
        // The interface preserves the invariant that begin <= end so we assume this will not overflow.
        // We also assume there are at most int256.max items in the queue.
        unchecked {
            return uint256(int256(deque._end) - int256(deque._begin));
        }
    }

    /**
     * @dev Returns true if the queue is empty.
     */
    function empty(Bytes32Deque storage deque) internal view returns (bool) {
        return deque._end <= deque._begin;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/utils/Timers.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Timers.sol)

pragma solidity ^0.8.0;

/**
 * @dev Tooling for timepoints, timers and delays
 */
library Timers {
    struct Timestamp {
        uint64 _deadline;
    }

    function getDeadline(Timestamp memory timer) internal pure returns (uint64) {
        return timer._deadline;
    }

    function setDeadline(Timestamp storage timer, uint64 timestamp) internal {
        timer._deadline = timestamp;
    }

    function reset(Timestamp storage timer) internal {
        timer._deadline = 0;
    }

    function isUnset(Timestamp memory timer) internal pure returns (bool) {
        return timer._deadline == 0;
    }

    function isStarted(Timestamp memory timer) internal pure returns (bool) {
        return timer._deadline > 0;
    }

    function isPending(Timestamp memory timer) internal view returns (bool) {
        return timer._deadline > block.timestamp;
    }

    function isExpired(Timestamp memory timer) internal view returns (bool) {
        return isStarted(timer) && timer._deadline <= block.timestamp;
    }

    struct BlockNumber {
        uint64 _deadline;
    }

    function getDeadline(BlockNumber memory timer) internal pure returns (uint64) {
        return timer._deadline;
    }

    function setDeadline(BlockNumber storage timer, uint64 timestamp) internal {
        timer._deadline = timestamp;
    }

    function reset(BlockNumber storage timer) internal {
        timer._deadline = 0;
    }

    function isUnset(BlockNumber memory timer) internal pure returns (bool) {
        return timer._deadline == 0;
    }

    function isStarted(BlockNumber memory timer) internal pure returns (bool) {
        return timer._deadline > 0;
    }

    function isPending(BlockNumber memory timer) internal view returns (bool) {
        return timer._deadline > block.number;
    }

    function isExpired(BlockNumber memory timer) internal view returns (bool) {
        return isStarted(timer) && timer._deadline <= block.number;
    }
}

// File: @openzeppelin/contracts/governance/IGovernor.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (governance/IGovernor.sol)

pragma solidity ^0.8.0;

import "../utils/introspection/ERC165.sol";

/**
 * @dev Interface of the {Governor} core.
 *
 * _Available since v4.3._
 */
abstract contract IGovernor is IERC165 {
    enum ProposalState {
        Pending,
        Active,
        Canceled,
        Defeated,
        Succeeded,
        Queued,
        Expired,
        Executed
    }

    /**
     * @dev Emitted when a proposal is created.
     */
    event ProposalCreated(
        uint256 proposalId,
        address proposer,
        address[] targets,
        uint256[] values,
        string[] signatures,
        bytes[] calldatas,
        uint256 startBlock,
        uint256 endBlock,
        string description
    );

    /**
     * @dev Emitted when a proposal is canceled.
     */
    event ProposalCanceled(uint256 proposalId);

    /**
     * @dev Emitted when a proposal is executed.
     */
    event ProposalExecuted(uint256 proposalId);

    /**
     * @dev Emitted when a vote is cast without params.
     *
     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
     */
    event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason);

    /**
     * @dev Emitted when a vote is cast with params.
     *
     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
     * `params` are additional encoded parameters. Their intepepretation also depends on the voting module used.
     */
    event VoteCastWithParams(
        address indexed voter,
        uint256 proposalId,
        uint8 support,
        uint256 weight,
        string reason,
        bytes params
    );

    /**
     * @notice module:core
     * @dev Name of the governor instance (used in building the ERC712 domain separator).
     */
    function name() public view virtual returns (string memory);

    /**
     * @notice module:core
     * @dev Version of the governor instance (used in building the ERC712 domain separator). Default: "1"
     */
    function version() public view virtual returns (string memory);

    /**
     * @notice module:voting
     * @dev A description of the possible `support` values for {castVote} and the way these votes are counted, meant to
     * be consumed by UIs to show correct vote options and interpret the results. The string is a URL-encoded sequence of
     * key-value pairs that each describe one aspect, for example `support=bravo&quorum=for,abstain`.
     *
     * There are 2 standard keys: `support` and `quorum`.
     *
     * - `support=bravo` refers to the vote options 0 = Against, 1 = For, 2 = Abstain, as in `GovernorBravo`.
     * - `quorum=bravo` means that only For votes are counted towards quorum.
     * - `quorum=for,abstain` means that both For and Abstain votes are counted towards quorum.
     *
     * If a counting module makes use of encoded `params`, it should  include this under a `params` key with a unique
     * name that describes the behavior. For example:
     *
     * - `params=fractional` might refer to a scheme where votes are divided fractionally between for/against/abstain.
     * - `params=erc721` might refer to a scheme where specific NFTs are delegated to vote.
     *
     * NOTE: The string can be decoded by the standard
     * https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams[`URLSearchParams`]
     * JavaScript class.
     */
    // solhint-disable-next-line func-name-mixedcase
    function COUNTING_MODE() public pure virtual returns (string memory);

    /**
     * @notice module:core
     * @dev Hashing function used to (re)build the proposal id from the proposal details..
     */
    function hashProposal(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public pure virtual returns (uint256);

    /**
     * @notice module:core
     * @dev Current state of a proposal, following Compound's convention
     */
    function state(uint256 proposalId) public view virtual returns (ProposalState);

    /**
     * @notice module:core
     * @dev Block number used to retrieve user's votes and quorum. As per Compound's Comp and OpenZeppelin's
     * ERC20Votes, the snapshot is performed at the end of this block. Hence, voting for this proposal starts at the
     * beginning of the following block.
     */
    function proposalSnapshot(uint256 proposalId) public view virtual returns (uint256);

    /**
     * @notice module:core
     * @dev Block number at which votes close. Votes close at the end of this block, so it is possible to cast a vote
     * during this block.
     */
    function proposalDeadline(uint256 proposalId) public view virtual returns (uint256);

    /**
     * @notice module:user-config
     * @dev Delay, in number of block, between the proposal is created and the vote starts. This can be increassed to
     * leave time for users to buy voting power, or delegate it, before the voting of a proposal starts.
     */
    function votingDelay() public view virtual returns (uint256);

    /**
     * @notice module:user-config
     * @dev Delay, in number of blocks, between the vote start and vote ends.
     *
     * NOTE: The {votingDelay} can delay the start of the vote. This must be considered when setting the voting
     * duration compared to the voting delay.
     */
    function votingPeriod() public view virtual returns (uint256);

    /**
     * @notice module:user-config
     * @dev Minimum number of cast voted required for a proposal to be successful.
     *
     * Note: The `blockNumber` parameter corresponds to the snapshot used for counting vote. This allows to scale the
     * quorum depending on values such as the totalSupply of a token at this block (see {ERC20Votes}).
     */
    function quorum(uint256 blockNumber) public view virtual returns (uint256);

    /**
     * @notice module:reputation
     * @dev Voting power of an `account` at a specific `blockNumber`.
     *
     * Note: this can be implemented in a number of ways, for example by reading the delegated balance from one (or
     * multiple), {ERC20Votes} tokens.
     */
    function getVotes(address account, uint256 blockNumber) public view virtual returns (uint256);

    /**
     * @notice module:reputation
     * @dev Voting power of an `account` at a specific `blockNumber` given additional encoded parameters.
     */
    function getVotesWithParams(
        address account,
        uint256 blockNumber,
        bytes memory params
    ) public view virtual returns (uint256);

    /**
     * @notice module:voting
     * @dev Returns weither `account` has cast a vote on `proposalId`.
     */
    function hasVoted(uint256 proposalId, address account) public view virtual returns (bool);

    /**
     * @dev Create a new proposal. Vote start {IGovernor-votingDelay} blocks after the proposal is created and ends
     * {IGovernor-votingPeriod} blocks after the voting starts.
     *
     * Emits a {ProposalCreated} event.
     */
    function propose(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        string memory description
    ) public virtual returns (uint256 proposalId);

    /**
     * @dev Execute a successful proposal. This requires the quorum to be reached, the vote to be successful, and the
     * deadline to be reached.
     *
     * Emits a {ProposalExecuted} event.
     *
     * Note: some module can modify the requirements for execution, for example by adding an additional timelock.
     */
    function execute(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public payable virtual returns (uint256 proposalId);

    /**
     * @dev Cast a vote
     *
     * Emits a {VoteCast} event.
     */
    function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason
     *
     * Emits a {VoteCast} event.
     */
    function castVoteWithReason(
        uint256 proposalId,
        uint8 support,
        string calldata reason
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason and additional encoded parameters
     *
     * Emits a {VoteCast} or {VoteCastWithParams} event depending on the length of params.
     */
    function castVoteWithReasonAndParams(
        uint256 proposalId,
        uint8 support,
        string calldata reason,
        bytes memory params
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote using the user's cryptographic signature.
     *
     * Emits a {VoteCast} event.
     */
    function castVoteBySig(
        uint256 proposalId,
        uint8 support,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason and additional encoded parameters using the user's cryptographic signature.
     *
     * Emits a {VoteCast} or {VoteCastWithParams} event depending on the length of params.
     */
    function castVoteWithReasonAndParamsBySig(
        uint256 proposalId,
        uint8 support,
        string calldata reason,
        bytes memory params,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual returns (uint256 balance);
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// File: @openzeppelin/contracts/governance/extensions/IGovernorTimelock.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (governance/extensions/IGovernorTimelock.sol)

pragma solidity ^0.8.0;

import "../IGovernor.sol";

/**
 * @dev Extension of the {IGovernor} for timelock supporting modules.
 *
 * _Available since v4.3._
 */
abstract contract IGovernorTimelock is IGovernor {
    event ProposalQueued(uint256 proposalId, uint256 eta);

    function timelock() public view virtual returns (address);

    function proposalEta(uint256 proposalId) public view virtual returns (uint256);

    function queue(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public virtual returns (uint256 proposalId);
}

// File: @openzeppelin/contracts/governance/TimelockController.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (governance/TimelockController.sol)

pragma solidity ^0.8.0;

import "../access/AccessControl.sol";
import "../token/ERC721/IERC721Receiver.sol";
import "../token/ERC1155/IERC1155Receiver.sol";
import "../utils/Address.sol";

/**
 * @dev Contract module which acts as a timelocked controller. When set as the
 * owner of an `Ownable` smart contract, it enforces a timelock on all
 * `onlyOwner` maintenance operations. This gives time for users of the
 * controlled contract to exit before a potentially dangerous maintenance
 * operation is applied.
 *
 * By default, this contract is self administered, meaning administration tasks
 * have to go through the timelock process. The proposer (resp executor) role
 * is in charge of proposing (resp executing) operations. A common use case is
 * to position this {TimelockController} as the owner of a smart contract, with
 * a multisig or a DAO as the sole proposer.
 *
 * _Available since v3.3._
 */
contract TimelockController is AccessControl, IERC721Receiver, IERC1155Receiver {
    bytes32 public constant TIMELOCK_ADMIN_ROLE = keccak256("TIMELOCK_ADMIN_ROLE");
    bytes32 public constant PROPOSER_ROLE = keccak256("PROPOSER_ROLE");
    bytes32 public constant EXECUTOR_ROLE = keccak256("EXECUTOR_ROLE");
    bytes32 public constant CANCELLER_ROLE = keccak256("CANCELLER_ROLE");
    uint256 internal constant _DONE_TIMESTAMP = uint256(1);

    mapping(bytes32 => uint256) private _timestamps;
    uint256 private _minDelay;

    /**
     * @dev Emitted when a call is scheduled as part of operation `id`.
     */
    event CallScheduled(
        bytes32 indexed id,
        uint256 indexed index,
        address target,
        uint256 value,
        bytes data,
        bytes32 predecessor,
        uint256 delay
    );

    /**
     * @dev Emitted when a call is performed as part of operation `id`.
     */
    event CallExecuted(bytes32 indexed id, uint256 indexed index, address target, uint256 value, bytes data);

    /**
     * @dev Emitted when operation `id` is cancelled.
     */
    event Cancelled(bytes32 indexed id);

    /**
     * @dev Emitted when the minimum delay for future operations is modified.
     */
    event MinDelayChange(uint256 oldDuration, uint256 newDuration);

    /**
     * @dev Initializes the contract with a given `minDelay`, and a list of
     * initial proposers and executors. The proposers receive both the
     * proposer and the canceller role (for backward compatibility). The
     * executors receive the executor role.
     *
     * NOTE: At construction, both the deployer and the timelock itself are
     * administrators. This helps further configuration of the timelock by the
     * deployer. After configuration is done, it is recommended that the
     * deployer renounces its admin position and relies on timelocked
     * operations to perform future maintenance.
     */
    constructor(
        uint256 minDelay,
        address[] memory proposers,
        address[] memory executors
    ) {
        _setRoleAdmin(TIMELOCK_ADMIN_ROLE, TIMELOCK_ADMIN_ROLE);
        _setRoleAdmin(PROPOSER_ROLE, TIMELOCK_ADMIN_ROLE);
        _setRoleAdmin(EXECUTOR_ROLE, TIMELOCK_ADMIN_ROLE);
        _setRoleAdmin(CANCELLER_ROLE, TIMELOCK_ADMIN_ROLE);

        // deployer + self administration
        _setupRole(TIMELOCK_ADMIN_ROLE, _msgSender());
        _setupRole(TIMELOCK_ADMIN_ROLE, address(this));

        // register proposers and cancellers
        for (uint256 i = 0; i < proposers.length; ++i) {
            _setupRole(PROPOSER_ROLE, proposers[i]);
            _setupRole(CANCELLER_ROLE, proposers[i]);
        }

        // register executors
        for (uint256 i = 0; i < executors.length; ++i) {
            _setupRole(EXECUTOR_ROLE, executors[i]);
        }

        _minDelay = minDelay;
        emit MinDelayChange(0, minDelay);
    }

    /**
     * @dev Modifier to make a function callable only by a certain role. In
     * addition to checking the sender's role, `address(0)` 's role is also
     * considered. Granting a role to `address(0)` is equivalent to enabling
     * this role for everyone.
     */
    modifier onlyRoleOrOpenRole(bytes32 role) {
        if (!hasRole(role, address(0))) {
            _checkRole(role, _msgSender());
        }
        _;
    }

    /**
     * @dev Contract might receive/hold ETH as part of the maintenance process.
     */
    receive() external payable {}

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, AccessControl) returns (bool) {
        return interfaceId == type(IERC1155Receiver).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns whether an id correspond to a registered operation. This
     * includes both Pending, Ready and Done operations.
     */
    function isOperation(bytes32 id) public view virtual returns (bool registered) {
        return getTimestamp(id) > 0;
    }

    /**
     * @dev Returns whether an operation is pending or not.
     */
    function isOperationPending(bytes32 id) public view virtual returns (bool pending) {
        return getTimestamp(id) > _DONE_TIMESTAMP;
    }

    /**
     * @dev Returns whether an operation is ready or not.
     */
    function isOperationReady(bytes32 id) public view virtual returns (bool ready) {
        uint256 timestamp = getTimestamp(id);
        return timestamp > _DONE_TIMESTAMP && timestamp <= block.timestamp;
    }

    /**
     * @dev Returns whether an operation is done or not.
     */
    function isOperationDone(bytes32 id) public view virtual returns (bool done) {
        return getTimestamp(id) == _DONE_TIMESTAMP;
    }

    /**
     * @dev Returns the timestamp at with an operation becomes ready (0 for
     * unset operations, 1 for done operations).
     */
    function getTimestamp(bytes32 id) public view virtual returns (uint256 timestamp) {
        return _timestamps[id];
    }

    /**
     * @dev Returns the minimum delay for an operation to become valid.
     *
     * This value can be changed by executing an operation that calls `updateDelay`.
     */
    function getMinDelay() public view virtual returns (uint256 duration) {
        return _minDelay;
    }

    /**
     * @dev Returns the identifier of an operation containing a single
     * transaction.
     */
    function hashOperation(
        address target,
        uint256 value,
        bytes calldata data,
        bytes32 predecessor,
        bytes32 salt
    ) public pure virtual returns (bytes32 hash) {
        return keccak256(abi.encode(target, value, data, predecessor, salt));
    }

    /**
     * @dev Returns the identifier of an operation containing a batch of
     * transactions.
     */
    function hashOperationBatch(
        address[] calldata targets,
        uint256[] calldata values,
        bytes[] calldata payloads,
        bytes32 predecessor,
        bytes32 salt
    ) public pure virtual returns (bytes32 hash) {
        return keccak256(abi.encode(targets, values, payloads, predecessor, salt));
    }

    /**
     * @dev Schedule an operation containing a single transaction.
     *
     * Emits a {CallScheduled} event.
     *
     * Requirements:
     *
     * - the caller must have the 'proposer' role.
     */
    function schedule(
        address target,
        uint256 value,
        bytes calldata data,
        bytes32 predecessor,
        bytes32 salt,
        uint256 delay
    ) public virtual onlyRole(PROPOSER_ROLE) {
        bytes32 id = hashOperation(target, value, data, predecessor, salt);
        _schedule(id, delay);
        emit CallScheduled(id, 0, target, value, data, predecessor, delay);
    }

    /**
     * @dev Schedule an operation containing a batch of transactions.
     *
     * Emits one {CallScheduled} event per transaction in the batch.
     *
     * Requirements:
     *
     * - the caller must have the 'proposer' role.
     */
    function scheduleBatch(
        address[] calldata targets,
        uint256[] calldata values,
        bytes[] calldata payloads,
        bytes32 predecessor,
        bytes32 salt,
        uint256 delay
    ) public virtual onlyRole(PROPOSER_ROLE) {
        require(targets.length == values.length, "TimelockController: length mismatch");
        require(targets.length == payloads.length, "TimelockController: length mismatch");

        bytes32 id = hashOperationBatch(targets, values, payloads, predecessor, salt);
        _schedule(id, delay);
        for (uint256 i = 0; i < targets.length; ++i) {
            emit CallScheduled(id, i, targets[i], values[i], payloads[i], predecessor, delay);
        }
    }

    /**
     * @dev Schedule an operation that is to becomes valid after a given delay.
     */
    function _schedule(bytes32 id, uint256 delay) private {
        require(!isOperation(id), "TimelockController: operation already scheduled");
        require(delay >= getMinDelay(), "TimelockController: insufficient delay");
        _timestamps[id] = block.timestamp + delay;
    }

    /**
     * @dev Cancel an operation.
     *
     * Requirements:
     *
     * - the caller must have the 'canceller' role.
     */
    function cancel(bytes32 id) public virtual onlyRole(CANCELLER_ROLE) {
        require(isOperationPending(id), "TimelockController: operation cannot be cancelled");
        delete _timestamps[id];

        emit Cancelled(id);
    }

    /**
     * @dev Execute an (ready) operation containing a single transaction.
     *
     * Emits a {CallExecuted} event.
     *
     * Requirements:
     *
     * - the caller must have the 'executor' role.
     */
    // This function can reenter, but it doesn't pose a risk because _afterCall checks that the proposal is pending,
    // thus any modifications to the operation during reentrancy should be caught.
    // slither-disable-next-line reentrancy-eth
    function execute(
        address target,
        uint256 value,
        bytes calldata payload,
        bytes32 predecessor,
        bytes32 salt
    ) public payable virtual onlyRoleOrOpenRole(EXECUTOR_ROLE) {
        bytes32 id = hashOperation(target, value, payload, predecessor, salt);

        _beforeCall(id, predecessor);
        _execute(target, value, payload);
        emit CallExecuted(id, 0, target, value, payload);
        _afterCall(id);
    }

    /**
     * @dev Execute an (ready) operation containing a batch of transactions.
     *
     * Emits one {CallExecuted} event per transaction in the batch.
     *
     * Requirements:
     *
     * - the caller must have the 'executor' role.
     */
    function executeBatch(
        address[] calldata targets,
        uint256[] calldata values,
        bytes[] calldata payloads,
        bytes32 predecessor,
        bytes32 salt
    ) public payable virtual onlyRoleOrOpenRole(EXECUTOR_ROLE) {
        require(targets.length == values.length, "TimelockController: length mismatch");
        require(targets.length == payloads.length, "TimelockController: length mismatch");

        bytes32 id = hashOperationBatch(targets, values, payloads, predecessor, salt);

        _beforeCall(id, predecessor);
        for (uint256 i = 0; i < targets.length; ++i) {
            address target = targets[i];
            uint256 value = values[i];
            bytes calldata payload = payloads[i];
            _execute(target, value, payload);
            emit CallExecuted(id, i, target, value, payload);
        }
        _afterCall(id);
    }

    /**
     * @dev Execute an operation's call.
     */
    function _execute(
        address target,
        uint256 value,
        bytes calldata data
    ) internal virtual {
        (bool success, ) = target.call{value: value}(data);
        require(success, "TimelockController: underlying transaction reverted");
    }

    /**
     * @dev Checks before execution of an operation's calls.
     */
    function _beforeCall(bytes32 id, bytes32 predecessor) private view {
        require(isOperationReady(id), "TimelockController: operation is not ready");
        require(predecessor == bytes32(0) || isOperationDone(predecessor), "TimelockController: missing dependency");
    }

    /**
     * @dev Checks after execution of an operation's calls.
     */
    function _afterCall(bytes32 id) private {
        require(isOperationReady(id), "TimelockController: operation is not ready");
        _timestamps[id] = _DONE_TIMESTAMP;
    }

    /**
     * @dev Changes the minimum timelock duration for future operations.
     *
     * Emits a {MinDelayChange} event.
     *
     * Requirements:
     *
     * - the caller must be the timelock itself. This can only be achieved by scheduling and later executing
     * an operation where the timelock is the target and the data is the ABI-encoded call to this function.
     */
    function updateDelay(uint256 newDelay) external virtual {
        require(msg.sender == address(this), "TimelockController: caller must be timelock");
        emit MinDelayChange(_minDelay, newDelay);
        _minDelay = newDelay;
    }

    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }

    /**
     * @dev See {IERC1155Receiver-onERC1155Received}.
     */
    function onERC1155Received(
        address,
        address,
        uint256,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    /**
     * @dev See {IERC1155Receiver-onERC1155BatchReceived}.
     */
    function onERC1155BatchReceived(
        address,
        address,
        uint256[] memory,
        uint256[] memory,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}

// File: @openzeppelin/contracts/access/AccessControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(uint160(account), 20),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleGranted} event.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleRevoked} event.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * May emit a {RoleGranted} event.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: @openzeppelin/contracts/access/IAccessControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

// File: @openzeppelin/contracts/governance/utils/IVotes.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (governance/utils/IVotes.sol)
pragma solidity ^0.8.0;

/**
 * @dev Common interface for {ERC20Votes}, {ERC721Votes}, and other {Votes}-enabled contracts.
 *
 * _Available since v4.5._
 */
interface IVotes {
    /**
     * @dev Emitted when an account changes their delegate.
     */
    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);

    /**
     * @dev Emitted when a token transfer or delegate change results in changes to a delegate's number of votes.
     */
    event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);

    /**
     * @dev Returns the current amount of votes that `account` has.
     */
    function getVotes(address account) external view returns (uint256);

    /**
     * @dev Returns the amount of votes that `account` had at the end of a past block (`blockNumber`).
     */
    function getPastVotes(address account, uint256 blockNumber) external view returns (uint256);

    /**
     * @dev Returns the total supply of votes available at the end of a past block (`blockNumber`).
     *
     * NOTE: This value is the sum of all available votes, which is not necessarily the sum of all delegated votes.
     * Votes that have not been delegated are still part of total supply, even though they would not participate in a
     * vote.
     */
    function getPastTotalSupply(uint256 blockNumber) external view returns (uint256);

    /**
     * @dev Returns the delegate that `account` has chosen.
     */
    function delegates(address account) external view returns (address);

    /**
     * @dev Delegates votes from the sender to `delegatee`.
     */
    function delegate(address delegatee) external;

    /**
     * @dev Delegates votes from signer to `delegatee`.
     */
    function delegateBySig(
        address delegatee,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}

// File: @openzeppelin/contracts/utils/Checkpoints.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Checkpoints.sol)
pragma solidity ^0.8.0;

import "./math/Math.sol";
import "./math/SafeCast.sol";

/**
 * @dev This library defines the `History` struct, for checkpointing values as they change at different points in
 * time, and later looking up past values by block number. See {Votes} as an example.
 *
 * To create a history of checkpoints define a variable type `Checkpoints.History` in your contract, and store a new
 * checkpoint for the current transaction block using the {push} function.
 *
 * _Available since v4.5._
 */
library Checkpoints {
    struct Checkpoint {
        uint32 _blockNumber;
        uint224 _value;
    }

    struct History {
        Checkpoint[] _checkpoints;
    }

    /**
     * @dev Returns the value in the latest checkpoint, or zero if there are no checkpoints.
     */
    function latest(History storage self) internal view returns (uint256) {
        uint256 pos = self._checkpoints.length;
        return pos == 0 ? 0 : self._checkpoints[pos - 1]._value;
    }

    /**
     * @dev Returns the value at a given block number. If a checkpoint is not available at that block, the closest one
     * before it is returned, or zero otherwise.
     */
    function getAtBlock(History storage self, uint256 blockNumber) internal view returns (uint256) {
        require(blockNumber < block.number, "Checkpoints: block not yet mined");

        uint256 high = self._checkpoints.length;
        uint256 low = 0;
        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (self._checkpoints[mid]._blockNumber > blockNumber) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return high == 0 ? 0 : self._checkpoints[high - 1]._value;
    }

    /**
     * @dev Pushes a value onto a History so that it is stored as the checkpoint for the current block.
     *
     * Returns previous value and new value.
     */
    function push(History storage self, uint256 value) internal returns (uint256, uint256) {
        uint256 pos = self._checkpoints.length;
        uint256 old = latest(self);
        if (pos > 0 && self._checkpoints[pos - 1]._blockNumber == block.number) {
            self._checkpoints[pos - 1]._value = SafeCast.toUint224(value);
        } else {
            self._checkpoints.push(
                Checkpoint({_blockNumber: SafeCast.toUint32(block.number), _value: SafeCast.toUint224(value)})
            );
        }
        return (old, value);
    }

    /**
     * @dev Pushes a value onto a History, by updating the latest value using binary operation `op`. The new value will
     * be set to `op(latest, delta)`.
     *
     * Returns previous value and new value.
     */
    function push(
        History storage self,
        function(uint256, uint256) view returns (uint256) op,
        uint256 delta
    ) internal returns (uint256, uint256) {
        return push(self, op(latest(self), delta));
    }
}

// File: @openzeppelin/contracts/utils/math/Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. It the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`.
        // We also know that `k`, the position of the most significant bit, is such that `msb(a) = 2**k`.
        // This gives `2**k < a <= 2**(k+1)` → `2**(k/2) <= sqrt(a) < 2 ** (k/2+1)`.
        // Using an algorithm similar to the msb conmputation, we are able to compute `result = 2**(k/2)` which is a
        // good first aproximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1;
        uint256 x = a;
        if (x >> 128 > 0) {
            x >>= 128;
            result <<= 64;
        }
        if (x >> 64 > 0) {
            x >>= 64;
            result <<= 32;
        }
        if (x >> 32 > 0) {
            x >>= 32;
            result <<= 16;
        }
        if (x >> 16 > 0) {
            x >>= 16;
            result <<= 8;
        }
        if (x >> 8 > 0) {
            x >>= 8;
            result <<= 4;
        }
        if (x >> 4 > 0) {
            x >>= 4;
            result <<= 2;
        }
        if (x >> 2 > 0) {
            result <<= 1;
        }

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        uint256 result = sqrt(a);
        if (rounding == Rounding.Up && result * result < a) {
            result += 1;
        }
        return result;
    }
}

// File: @openzeppelin/contracts-upgradeable/governance/utils/IVotesUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (governance/utils/IVotes.sol)
pragma solidity ^0.8.0;

/**
 * @dev Common interface for {ERC20Votes}, {ERC721Votes}, and other {Votes}-enabled contracts.
 *
 * _Available since v4.5._
 */
interface IVotesUpgradeable {
    /**
     * @dev Emitted when an account changes their delegate.
     */
    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);

    /**
     * @dev Emitted when a token transfer or delegate change results in changes to a delegate's number of votes.
     */
    event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);

    /**
     * @dev Returns the current amount of votes that `account` has.
     */
    function getVotes(address account) external view returns (uint256);

    /**
     * @dev Returns the amount of votes that `account` had at the end of a past block (`blockNumber`).
     */
    function getPastVotes(address account, uint256 blockNumber) external view returns (uint256);

    /**
     * @dev Returns the total supply of votes available at the end of a past block (`blockNumber`).
     *
     * NOTE: This value is the sum of all available votes, which is not necessarily the sum of all delegated votes.
     * Votes that have not been delegated are still part of total supply, even though they would not participate in a
     * vote.
     */
    function getPastTotalSupply(uint256 blockNumber) external view returns (uint256);

    /**
     * @dev Returns the delegate that `account` has chosen.
     */
    function delegates(address account) external view returns (address);

    /**
     * @dev Delegates votes from the sender to `delegatee`.
     */
    function delegate(address delegatee) external;

    /**
     * @dev Delegates votes from signer to `delegatee`.
     */
    function delegateBySig(
        address delegatee,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}