// File: contracts/L1/L1StandardBridge.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Predeploys } from "../libraries/Predeploys.sol";
import { StandardBridge } from "../universal/StandardBridge.sol";
import { Semver } from "../universal/Semver.sol";

/**
 * @custom:proxied
 * @title L1StandardBridge
 * @notice The L1StandardBridge is responsible for transfering ETH and ERC20 tokens between L1 and
 *         L2. In the case that an ERC20 token is native to L1, it will be escrowed within this
 *         contract. If the ERC20 token is native to L2, it will be burnt. Before Bedrock, ETH was
 *         stored within this contract. After Bedrock, ETH is instead stored inside the
 *         OptimismPortal contract.
 *         NOTE: this contract is not intended to support all variations of ERC20 tokens. Examples
 *         of some token types that may not be properly supported by this contract include, but are
 *         not limited to: tokens with transfer fees, rebasing tokens, and tokens with blocklists.
 */
contract L1StandardBridge is StandardBridge, Semver {
    /**
     * @custom:legacy
     * @notice Emitted whenever a deposit of ETH from L1 into L2 is initiated.
     *
     * @param from      Address of the depositor.
     * @param to        Address of the recipient on L2.
     * @param amount    Amount of ETH deposited.
     * @param extraData Extra data attached to the deposit.
     */
    event ETHDepositInitiated(
        address indexed from,
        address indexed to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @custom:legacy
     * @notice Emitted whenever a withdrawal of ETH from L2 to L1 is finalized.
     *
     * @param from      Address of the withdrawer.
     * @param to        Address of the recipient on L1.
     * @param amount    Amount of ETH withdrawn.
     * @param extraData Extra data attached to the withdrawal.
     */
    event ETHWithdrawalFinalized(
        address indexed from,
        address indexed to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @custom:legacy
     * @notice Emitted whenever an ERC20 deposit is initiated.
     *
     * @param l1Token   Address of the token on L1.
     * @param l2Token   Address of the corresponding token on L2.
     * @param from      Address of the depositor.
     * @param to        Address of the recipient on L2.
     * @param amount    Amount of the ERC20 deposited.
     * @param extraData Extra data attached to the deposit.
     */
    event ERC20DepositInitiated(
        address indexed l1Token,
        address indexed l2Token,
        address indexed from,
        address to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @custom:legacy
     * @notice Emitted whenever an ERC20 withdrawal is finalized.
     *
     * @param l1Token   Address of the token on L1.
     * @param l2Token   Address of the corresponding token on L2.
     * @param from      Address of the withdrawer.
     * @param to        Address of the recipient on L1.
     * @param amount    Amount of the ERC20 withdrawn.
     * @param extraData Extra data attached to the withdrawal.
     */
    event ERC20WithdrawalFinalized(
        address indexed l1Token,
        address indexed l2Token,
        address indexed from,
        address to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @custom:semver 1.1.0
     *
     * @param _messenger Address of the L1CrossDomainMessenger.
     */
    constructor(address payable _messenger)
        Semver(1, 1, 0)
        StandardBridge(_messenger, payable(Predeploys.L2_STANDARD_BRIDGE))
    {}

    /**
     * @notice Allows EOAs to bridge ETH by sending directly to the bridge.
     */
    receive() external payable override onlyEOA {
        _initiateETHDeposit(msg.sender, msg.sender, RECEIVE_DEFAULT_GAS_LIMIT, bytes(""));
    }

    /**
     * @custom:legacy
     * @notice Deposits some amount of ETH into the sender's account on L2.
     *
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2. Data supplied here will not be used to
     *                     execute any code on L2 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function depositETH(uint32 _minGasLimit, bytes calldata _extraData) external payable onlyEOA {
        _initiateETHDeposit(msg.sender, msg.sender, _minGasLimit, _extraData);
    }

    /**
     * @custom:legacy
     * @notice Deposits some amount of ETH into a target account on L2.
     *         Note that if ETH is sent to a contract on L2 and the call fails, then that ETH will
     *         be locked in the L2StandardBridge. ETH may be recoverable if the call can be
     *         successfully replayed by increasing the amount of gas supplied to the call. If the
     *         call will fail for any amount of gas, then the ETH will be locked permanently.
     *
     * @param _to          Address of the recipient on L2.
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2. Data supplied here will not be used to
     *                     execute any code on L2 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function depositETHTo(
        address _to,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) external payable {
        _initiateETHDeposit(msg.sender, _to, _minGasLimit, _extraData);
    }

    /**
     * @custom:legacy
     * @notice Deposits some amount of ERC20 tokens into the sender's account on L2.
     *
     * @param _l1Token     Address of the L1 token being deposited.
     * @param _l2Token     Address of the corresponding token on L2.
     * @param _amount      Amount of the ERC20 to deposit.
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2. Data supplied here will not be used to
     *                     execute any code on L2 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function depositERC20(
        address _l1Token,
        address _l2Token,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) external virtual onlyEOA {
        _initiateERC20Deposit(
            _l1Token,
            _l2Token,
            msg.sender,
            msg.sender,
            _amount,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @custom:legacy
     * @notice Deposits some amount of ERC20 tokens into a target account on L2.
     *
     * @param _l1Token     Address of the L1 token being deposited.
     * @param _l2Token     Address of the corresponding token on L2.
     * @param _to          Address of the recipient on L2.
     * @param _amount      Amount of the ERC20 to deposit.
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2. Data supplied here will not be used to
     *                     execute any code on L2 and is only emitted as extra data for the
     *                     convenience of off-chain tooling.
     */
    function depositERC20To(
        address _l1Token,
        address _l2Token,
        address _to,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) external virtual {
        _initiateERC20Deposit(
            _l1Token,
            _l2Token,
            msg.sender,
            _to,
            _amount,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @custom:legacy
     * @notice Finalizes a withdrawal of ETH from L2.
     *
     * @param _from      Address of the withdrawer on L2.
     * @param _to        Address of the recipient on L1.
     * @param _amount    Amount of ETH to withdraw.
     * @param _extraData Optional data forwarded from L2.
     */
    function finalizeETHWithdrawal(
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _extraData
    ) external payable {
        finalizeBridgeETH(_from, _to, _amount, _extraData);
    }

    /**
     * @custom:legacy
     * @notice Finalizes a withdrawal of ERC20 tokens from L2.
     *
     * @param _l1Token   Address of the token on L1.
     * @param _l2Token   Address of the corresponding token on L2.
     * @param _from      Address of the withdrawer on L2.
     * @param _to        Address of the recipient on L1.
     * @param _amount    Amount of the ERC20 to withdraw.
     * @param _extraData Optional data forwarded from L2.
     */
    function finalizeERC20Withdrawal(
        address _l1Token,
        address _l2Token,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _extraData
    ) external {
        finalizeBridgeERC20(_l1Token, _l2Token, _from, _to, _amount, _extraData);
    }

    /**
     * @custom:legacy
     * @notice Retrieves the access of the corresponding L2 bridge contract.
     *
     * @return Address of the corresponding L2 bridge contract.
     */
    function l2TokenBridge() external view returns (address) {
        return address(OTHER_BRIDGE);
    }

    /**
     * @notice Internal function for initiating an ETH deposit.
     *
     * @param _from        Address of the sender on L1.
     * @param _to          Address of the recipient on L2.
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2.
     */
    function _initiateETHDeposit(
        address _from,
        address _to,
        uint32 _minGasLimit,
        bytes memory _extraData
    ) internal {
        _initiateBridgeETH(_from, _to, msg.value, _minGasLimit, _extraData);
    }

    /**
     * @notice Internal function for initiating an ERC20 deposit.
     *
     * @param _l1Token     Address of the L1 token being deposited.
     * @param _l2Token     Address of the corresponding token on L2.
     * @param _from        Address of the sender on L1.
     * @param _to          Address of the recipient on L2.
     * @param _amount      Amount of the ERC20 to deposit.
     * @param _minGasLimit Minimum gas limit for the deposit message on L2.
     * @param _extraData   Optional data to forward to L2.
     */
    function _initiateERC20Deposit(
        address _l1Token,
        address _l2Token,
        address _from,
        address _to,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes memory _extraData
    ) internal {
        _initiateBridgeERC20(_l1Token, _l2Token, _from, _to, _amount, _minGasLimit, _extraData);
    }

    /**
     * @notice Emits the legacy ETHDepositInitiated event followed by the ETHBridgeInitiated event.
     *         This is necessary for backwards compatibility with the legacy bridge.
     *
     * @inheritdoc StandardBridge
     */
    function _emitETHBridgeInitiated(
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal override {
        emit ETHDepositInitiated(_from, _to, _amount, _extraData);
        super._emitETHBridgeInitiated(_from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the legacy ETHWithdrawalFinalized event followed by the ETHBridgeFinalized
     *         event. This is necessary for backwards compatibility with the legacy bridge.
     *
     * @inheritdoc StandardBridge
     */
    function _emitETHBridgeFinalized(
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal override {
        emit ETHWithdrawalFinalized(_from, _to, _amount, _extraData);
        super._emitETHBridgeFinalized(_from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the legacy ERC20DepositInitiated event followed by the ERC20BridgeInitiated
     *         event. This is necessary for backwards compatibility with the legacy bridge.
     *
     * @inheritdoc StandardBridge
     */
    function _emitERC20BridgeInitiated(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal override {
        emit ERC20DepositInitiated(_localToken, _remoteToken, _from, _to, _amount, _extraData);
        super._emitERC20BridgeInitiated(_localToken, _remoteToken, _from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the legacy ERC20WithdrawalFinalized event followed by the ERC20BridgeFinalized
     *         event. This is necessary for backwards compatibility with the legacy bridge.
     *
     * @inheritdoc StandardBridge
     */
    function _emitERC20BridgeFinalized(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal override {
        emit ERC20WithdrawalFinalized(_localToken, _remoteToken, _from, _to, _amount, _extraData);
        super._emitERC20BridgeFinalized(_localToken, _remoteToken, _from, _to, _amount, _extraData);
    }
}

// File: contracts/L1/ResourceMetering.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Burn } from "../libraries/Burn.sol";
import { Arithmetic } from "../libraries/Arithmetic.sol";

/**
 * @custom:upgradeable
 * @title ResourceMetering
 * @notice ResourceMetering implements an EIP-1559 style resource metering system where pricing
 *         updates automatically based on current demand.
 */
abstract contract ResourceMetering is Initializable {
    /**
     * @notice Represents the various parameters that control the way in which resources are
     *         metered. Corresponds to the EIP-1559 resource metering system.
     *
     * @custom:field prevBaseFee   Base fee from the previous block(s).
     * @custom:field prevBoughtGas Amount of gas bought so far in the current block.
     * @custom:field prevBlockNum  Last block number that the base fee was updated.
     */
    struct ResourceParams {
        uint128 prevBaseFee;
        uint64 prevBoughtGas;
        uint64 prevBlockNum;
    }

    /**
     * @notice Represents the configuration for the EIP-1559 based curve for the deposit gas
     *         market. These values should be set with care as it is possible to set them in
     *         a way that breaks the deposit gas market. The target resource limit is defined as
     *         maxResourceLimit / elasticityMultiplier. This struct was designed to fit within a
     *         single word. There is additional space for additions in the future.
     *
     * @custom:field maxResourceLimit             Represents the maximum amount of deposit gas that
     *                                            can be purchased per block.
     * @custom:field elasticityMultiplier         Determines the target resource limit along with
     *                                            the resource limit.
     * @custom:field baseFeeMaxChangeDenominator  Determines max change on fee per block.
     * @custom:field minimumBaseFee               The min deposit base fee, it is clamped to this
     *                                            value.
     * @custom:field systemTxMaxGas               The amount of gas supplied to the system
     *                                            transaction. This should be set to the same number
     *                                            that the op-node sets as the gas limit for the
     *                                            system transaction.
     * @custom:field maximumBaseFee               The max deposit base fee, it is clamped to this
     *                                            value.
     */
    struct ResourceConfig {
        uint32 maxResourceLimit;
        uint8 elasticityMultiplier;
        uint8 baseFeeMaxChangeDenominator;
        uint32 minimumBaseFee;
        uint32 systemTxMaxGas;
        uint128 maximumBaseFee;
    }

    /**
     * @notice EIP-1559 style gas parameters.
     */
    ResourceParams public params;

    /**
     * @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
     */
    uint256[48] private __gap;

    /**
     * @notice Meters access to a function based an amount of a requested resource.
     *
     * @param _amount Amount of the resource requested.
     */
    modifier metered(uint64 _amount) {
        // Record initial gas amount so we can refund for it later.
        uint256 initialGas = gasleft();

        // Run the underlying function.
        _;

        // Run the metering function.
        _metered(_amount, initialGas);
    }

    /**
     * @notice An internal function that holds all of the logic for metering a resource.
     *
     * @param _amount     Amount of the resource requested.
     * @param _initialGas The amount of gas before any modifier execution.
     */
    function _metered(uint64 _amount, uint256 _initialGas) internal {
        // Update block number and base fee if necessary.
        uint256 blockDiff = block.number - params.prevBlockNum;

        ResourceConfig memory config = _resourceConfig();
        int256 targetResourceLimit = int256(uint256(config.maxResourceLimit)) /
            int256(uint256(config.elasticityMultiplier));

        if (blockDiff > 0) {
            // Handle updating EIP-1559 style gas parameters. We use EIP-1559 to restrict the rate
            // at which deposits can be created and therefore limit the potential for deposits to
            // spam the L2 system. Fee scheme is very similar to EIP-1559 with minor changes.
            int256 gasUsedDelta = int256(uint256(params.prevBoughtGas)) - targetResourceLimit;
            int256 baseFeeDelta = (int256(uint256(params.prevBaseFee)) * gasUsedDelta) /
                (targetResourceLimit * int256(uint256(config.baseFeeMaxChangeDenominator)));

            // Update base fee by adding the base fee delta and clamp the resulting value between
            // min and max.
            int256 newBaseFee = Arithmetic.clamp({
                _value: int256(uint256(params.prevBaseFee)) + baseFeeDelta,
                _min: int256(uint256(config.minimumBaseFee)),
                _max: int256(uint256(config.maximumBaseFee))
            });

            // If we skipped more than one block, we also need to account for every empty block.
            // Empty block means there was no demand for deposits in that block, so we should
            // reflect this lack of demand in the fee.
            if (blockDiff > 1) {
                // Update the base fee by repeatedly applying the exponent 1-(1/change_denominator)
                // blockDiff - 1 times. Simulates multiple empty blocks. Clamp the resulting value
                // between min and max.
                newBaseFee = Arithmetic.clamp({
                    _value: Arithmetic.cdexp({
                        _coefficient: newBaseFee,
                        _denominator: int256(uint256(config.baseFeeMaxChangeDenominator)),
                        _exponent: int256(blockDiff - 1)
                    }),
                    _min: int256(uint256(config.minimumBaseFee)),
                    _max: int256(uint256(config.maximumBaseFee))
                });
            }

            // Update new base fee, reset bought gas, and update block number.
            params.prevBaseFee = uint128(uint256(newBaseFee));
            params.prevBoughtGas = 0;
            params.prevBlockNum = uint64(block.number);
        }

        // Make sure we can actually buy the resource amount requested by the user.
        params.prevBoughtGas += _amount;
        require(
            int256(uint256(params.prevBoughtGas)) <= int256(uint256(config.maxResourceLimit)),
            "ResourceMetering: cannot buy more gas than available gas limit"
        );

        // Determine the amount of ETH to be paid.
        uint256 resourceCost = uint256(_amount) * uint256(params.prevBaseFee);

        // We currently charge for this ETH amount as an L1 gas burn, so we convert the ETH amount
        // into gas by dividing by the L1 base fee. We assume a minimum base fee of 1 gwei to avoid
        // division by zero for L1s that don't support 1559 or to avoid excessive gas burns during
        // periods of extremely low L1 demand. One-day average gas fee hasn't dipped below 1 gwei
        // during any 1 day period in the last 5 years, so should be fine.
        uint256 gasCost = resourceCost / Math.max(block.basefee, 1 gwei);

        // Give the user a refund based on the amount of gas they used to do all of the work up to
        // this point. Since we're at the end of the modifier, this should be pretty accurate. Acts
        // effectively like a dynamic stipend (with a minimum value).
        uint256 usedGas = _initialGas - gasleft();
        if (gasCost > usedGas) {
            Burn.gas(gasCost - usedGas);
        }
    }

    /**
     * @notice Virtual function that returns the resource config. Contracts that inherit this
     *         contract must implement this function.
     *
     * @return ResourceConfig
     */
    function _resourceConfig() internal virtual returns (ResourceConfig memory);

    /**
     * @notice Sets initial resource parameter values. This function must either be called by the
     *         initializer function of an upgradeable child contract.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __ResourceMetering_init() internal onlyInitializing {
        params = ResourceParams({
            prevBaseFee: 1 gwei,
            prevBoughtGas: 0,
            prevBlockNum: uint64(block.number)
        });
    }
}

// File: contracts/libraries/Arithmetic.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { SignedMath } from "@openzeppelin/contracts/utils/math/SignedMath.sol";
import { FixedPointMathLib } from "@rari-capital/solmate/src/utils/FixedPointMathLib.sol";

/**
 * @title Arithmetic
 * @notice Even more math than before.
 */
library Arithmetic {
    /**
     * @notice Clamps a value between a minimum and maximum.
     *
     * @param _value The value to clamp.
     * @param _min   The minimum value.
     * @param _max   The maximum value.
     *
     * @return The clamped value.
     */
    function clamp(
        int256 _value,
        int256 _min,
        int256 _max
    ) internal pure returns (int256) {
        return SignedMath.min(SignedMath.max(_value, _min), _max);
    }

    /**
     * @notice (c)oefficient (d)enominator (exp)onentiation function.
     *         Returns the result of: c * (1 - 1/d)^exp.
     *
     * @param _coefficient Coefficient of the function.
     * @param _denominator Fractional denominator.
     * @param _exponent    Power function exponent.
     *
     * @return Result of c * (1 - 1/d)^exp.
     */
    function cdexp(
        int256 _coefficient,
        int256 _denominator,
        int256 _exponent
    ) internal pure returns (int256) {
        return
            (_coefficient *
                (FixedPointMathLib.powWad(1e18 - (1e18 / _denominator), _exponent * 1e18))) / 1e18;
    }
}

// File: contracts/libraries/Burn.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/**
 * @title Burn
 * @notice Utilities for burning stuff.
 */
library Burn {
    /**
     * Burns a given amount of ETH.
     *
     * @param _amount Amount of ETH to burn.
     */
    function eth(uint256 _amount) internal {
        new Burner{ value: _amount }();
    }

    /**
     * Burns a given amount of gas.
     *
     * @param _amount Amount of gas to burn.
     */
    function gas(uint256 _amount) internal view {
        uint256 i = 0;
        uint256 initialGas = gasleft();
        while (initialGas - gasleft() < _amount) {
            ++i;
        }
    }
}

/**
 * @title Burner
 * @notice Burner self-destructs on creation and sends all ETH to itself, removing all ETH given to
 *         the contract from the circulating supply. Self-destructing is the only way to remove ETH
 *         from the circulating supply.
 */
contract Burner {
    constructor() payable {
        selfdestruct(payable(address(this)));
    }
}

// File: contracts/libraries/Constants.sol



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

import { ResourceMetering } from "../L1/ResourceMetering.sol";

/**
 * @title Constants
 * @notice Constants is a library for storing constants. Simple! Don't put everything in here, just
 *         the stuff used in multiple contracts. Constants that only apply to a single contract
 *         should be defined in that contract instead.
 */
library Constants {
    /**
     * @notice Special address to be used as the tx origin for gas estimation calls in the
     *         OptimismPortal and CrossDomainMessenger calls. You only need to use this address if
     *         the minimum gas limit specified by the user is not actually enough to execute the
     *         given message and you're attempting to estimate the actual necessary gas limit. We
     *         use address(1) because it's the ecrecover precompile and therefore guaranteed to
     *         never have any code on any EVM chain.
     */
    address internal constant ESTIMATION_ADDRESS = address(1);

    /**
     * @notice Value used for the L2 sender storage slot in both the OptimismPortal and the
     *         CrossDomainMessenger contracts before an actual sender is set. This value is
     *         non-zero to reduce the gas cost of message passing transactions.
     */
    address internal constant DEFAULT_L2_SENDER = 0x000000000000000000000000000000000000dEaD;

    /**
     * @notice Returns the default values for the ResourceConfig. These are the recommended values
     *         for a production network.
     */
    function DEFAULT_RESOURCE_CONFIG()
        internal
        pure
        returns (ResourceMetering.ResourceConfig memory)
    {
        ResourceMetering.ResourceConfig memory config = ResourceMetering.ResourceConfig({
            maxResourceLimit: 20_000_000,
            elasticityMultiplier: 10,
            baseFeeMaxChangeDenominator: 8,
            minimumBaseFee: 1 gwei,
            systemTxMaxGas: 1_000_000,
            maximumBaseFee: type(uint128).max
        });
        return config;
    }
}

// File: contracts/libraries/Encoding.sol



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

import { Types } from "./Types.sol";
import { Hashing } from "./Hashing.sol";
import { RLPWriter } from "./rlp/RLPWriter.sol";

/**
 * @title Encoding
 * @notice Encoding handles Optimism's various different encoding schemes.
 */
library Encoding {
    /**
     * @notice RLP encodes the L2 transaction that would be generated when a given deposit is sent
     *         to the L2 system. Useful for searching for a deposit in the L2 system. The
     *         transaction is prefixed with 0x7e to identify its EIP-2718 type.
     *
     * @param _tx User deposit transaction to encode.
     *
     * @return RLP encoded L2 deposit transaction.
     */
    function encodeDepositTransaction(Types.UserDepositTransaction memory _tx)
        internal
        pure
        returns (bytes memory)
    {
        bytes32 source = Hashing.hashDepositSource(_tx.l1BlockHash, _tx.logIndex);
        bytes[] memory raw = new bytes[](8);
        raw[0] = RLPWriter.writeBytes(abi.encodePacked(source));
        raw[1] = RLPWriter.writeAddress(_tx.from);
        raw[2] = _tx.isCreation ? RLPWriter.writeBytes("") : RLPWriter.writeAddress(_tx.to);
        raw[3] = RLPWriter.writeUint(_tx.mint);
        raw[4] = RLPWriter.writeUint(_tx.value);
        raw[5] = RLPWriter.writeUint(uint256(_tx.gasLimit));
        raw[6] = RLPWriter.writeBool(false);
        raw[7] = RLPWriter.writeBytes(_tx.data);
        return abi.encodePacked(uint8(0x7e), RLPWriter.writeList(raw));
    }

    /**
     * @notice Encodes the cross domain message based on the version that is encoded into the
     *         message nonce.
     *
     * @param _nonce    Message nonce with version encoded into the first two bytes.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes memory) {
        (, uint16 version) = decodeVersionedNonce(_nonce);
        if (version == 0) {
            return encodeCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return encodeCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Encoding: unknown cross domain message version");
        }
    }

    /**
     * @notice Encodes a cross domain message based on the V0 (legacy) encoding.
     *
     * @param _target Address of the target of the message.
     * @param _sender Address of the sender of the message.
     * @param _data   Data to send with the message.
     * @param _nonce  Message nonce.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    ) internal pure returns (bytes memory) {
        return
            abi.encodeWithSignature(
                "relayMessage(address,address,bytes,uint256)",
                _target,
                _sender,
                _data,
                _nonce
            );
    }

    /**
     * @notice Encodes a cross domain message based on the V1 (current) encoding.
     *
     * @param _nonce    Message nonce.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Encoded cross domain message.
     */
    function encodeCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes memory) {
        return
            abi.encodeWithSignature(
                "relayMessage(uint256,address,address,uint256,uint256,bytes)",
                _nonce,
                _sender,
                _target,
                _value,
                _gasLimit,
                _data
            );
    }

    /**
     * @notice Adds a version number into the first two bytes of a message nonce.
     *
     * @param _nonce   Message nonce to encode into.
     * @param _version Version number to encode into the message nonce.
     *
     * @return Message nonce with version encoded into the first two bytes.
     */
    function encodeVersionedNonce(uint240 _nonce, uint16 _version) internal pure returns (uint256) {
        uint256 nonce;
        assembly {
            nonce := or(shl(240, _version), _nonce)
        }
        return nonce;
    }

    /**
     * @notice Pulls the version out of a version-encoded nonce.
     *
     * @param _nonce Message nonce with version encoded into the first two bytes.
     *
     * @return Nonce without encoded version.
     * @return Version of the message.
     */
    function decodeVersionedNonce(uint256 _nonce) internal pure returns (uint240, uint16) {
        uint240 nonce;
        uint16 version;
        assembly {
            nonce := and(_nonce, 0x0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
            version := shr(240, _nonce)
        }
        return (nonce, version);
    }
}

// File: contracts/libraries/Hashing.sol



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

import { Types } from "./Types.sol";
import { Encoding } from "./Encoding.sol";

/**
 * @title Hashing
 * @notice Hashing handles Optimism's various different hashing schemes.
 */
library Hashing {
    /**
     * @notice Computes the hash of the RLP encoded L2 transaction that would be generated when a
     *         given deposit is sent to the L2 system. Useful for searching for a deposit in the L2
     *         system.
     *
     * @param _tx User deposit transaction to hash.
     *
     * @return Hash of the RLP encoded L2 deposit transaction.
     */
    function hashDepositTransaction(Types.UserDepositTransaction memory _tx)
        internal
        pure
        returns (bytes32)
    {
        return keccak256(Encoding.encodeDepositTransaction(_tx));
    }

    /**
     * @notice Computes the deposit transaction's "source hash", a value that guarantees the hash
     *         of the L2 transaction that corresponds to a deposit is unique and is
     *         deterministically generated from L1 transaction data.
     *
     * @param _l1BlockHash Hash of the L1 block where the deposit was included.
     * @param _logIndex    The index of the log that created the deposit transaction.
     *
     * @return Hash of the deposit transaction's "source hash".
     */
    function hashDepositSource(bytes32 _l1BlockHash, uint256 _logIndex)
        internal
        pure
        returns (bytes32)
    {
        bytes32 depositId = keccak256(abi.encode(_l1BlockHash, _logIndex));
        return keccak256(abi.encode(bytes32(0), depositId));
    }

    /**
     * @notice Hashes the cross domain message based on the version that is encoded into the
     *         message nonce.
     *
     * @param _nonce    Message nonce with version encoded into the first two bytes.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes32) {
        (, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
        if (version == 0) {
            return hashCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return hashCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Hashing: unknown cross domain message version");
        }
    }

    /**
     * @notice Hashes a cross domain message based on the V0 (legacy) encoding.
     *
     * @param _target Address of the target of the message.
     * @param _sender Address of the sender of the message.
     * @param _data   Data to send with the message.
     * @param _nonce  Message nonce.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    ) internal pure returns (bytes32) {
        return keccak256(Encoding.encodeCrossDomainMessageV0(_target, _sender, _data, _nonce));
    }

    /**
     * @notice Hashes a cross domain message based on the V1 (current) encoding.
     *
     * @param _nonce    Message nonce.
     * @param _sender   Address of the sender of the message.
     * @param _target   Address of the target of the message.
     * @param _value    ETH value to send to the target.
     * @param _gasLimit Gas limit to use for the message.
     * @param _data     Data to send with the message.
     *
     * @return Hashed cross domain message.
     */
    function hashCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    ) internal pure returns (bytes32) {
        return
            keccak256(
                Encoding.encodeCrossDomainMessageV1(
                    _nonce,
                    _sender,
                    _target,
                    _value,
                    _gasLimit,
                    _data
                )
            );
    }

    /**
     * @notice Derives the withdrawal hash according to the encoding in the L2 Withdrawer contract
     *
     * @param _tx Withdrawal transaction to hash.
     *
     * @return Hashed withdrawal transaction.
     */
    function hashWithdrawal(Types.WithdrawalTransaction memory _tx)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(_tx.nonce, _tx.sender, _tx.target, _tx.value, _tx.gasLimit, _tx.data)
            );
    }

    /**
     * @notice Hashes the various elements of an output root proof into an output root hash which
     *         can be used to check if the proof is valid.
     *
     * @param _outputRootProof Output root proof which should hash to an output root.
     *
     * @return Hashed output root proof.
     */
    function hashOutputRootProof(Types.OutputRootProof memory _outputRootProof)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(
                    _outputRootProof.version,
                    _outputRootProof.stateRoot,
                    _outputRootProof.messagePasserStorageRoot,
                    _outputRootProof.latestBlockhash
                )
            );
    }
}

// File: contracts/libraries/Predeploys.sol



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

/**
 * @title Predeploys
 * @notice Contains constant addresses for contracts that are pre-deployed to the L2 system.
 */
library Predeploys {
    /**
     * @notice Address of the L2ToL1MessagePasser predeploy.
     */
    address internal constant L2_TO_L1_MESSAGE_PASSER = 0x4200000000000000000000000000000000000016;

    /**
     * @notice Address of the L2CrossDomainMessenger predeploy.
     */
    address internal constant L2_CROSS_DOMAIN_MESSENGER =
        0x4200000000000000000000000000000000000007;

    /**
     * @notice Address of the L2StandardBridge predeploy.
     */
    address internal constant L2_STANDARD_BRIDGE = 0x4200000000000000000000000000000000000010;

    /**
     * @notice Address of the L2ERC721Bridge predeploy.
     */
    address internal constant L2_ERC721_BRIDGE = 0x4200000000000000000000000000000000000014;

    /**
     * @notice Address of the SequencerFeeWallet predeploy.
     */
    address internal constant SEQUENCER_FEE_WALLET = 0x4200000000000000000000000000000000000011;

    /**
     * @notice Address of the OptimismMintableERC20Factory predeploy.
     */
    address internal constant OPTIMISM_MINTABLE_ERC20_FACTORY =
        0x4200000000000000000000000000000000000012;

    /**
     * @notice Address of the OptimismMintableERC721Factory predeploy.
     */
    address internal constant OPTIMISM_MINTABLE_ERC721_FACTORY =
        0x4200000000000000000000000000000000000017;

    /**
     * @notice Address of the L1Block predeploy.
     */
    address internal constant L1_BLOCK_ATTRIBUTES = 0x4200000000000000000000000000000000000015;

    /**
     * @notice Address of the GasPriceOracle predeploy. Includes fee information
     *         and helpers for computing the L1 portion of the transaction fee.
     */
    address internal constant GAS_PRICE_ORACLE = 0x420000000000000000000000000000000000000F;

    /**
     * @custom:legacy
     * @notice Address of the L1MessageSender predeploy. Deprecated. Use L2CrossDomainMessenger
     *         or access tx.origin (or msg.sender) in a L1 to L2 transaction instead.
     */
    address internal constant L1_MESSAGE_SENDER = 0x4200000000000000000000000000000000000001;

    /**
     * @custom:legacy
     * @notice Address of the DeployerWhitelist predeploy. No longer active.
     */
    address internal constant DEPLOYER_WHITELIST = 0x4200000000000000000000000000000000000002;

    /**
     * @custom:legacy
     * @notice Address of the LegacyERC20ETH predeploy. Deprecated. Balances are migrated to the
     *         state trie as of the Bedrock upgrade. Contract has been locked and write functions
     *         can no longer be accessed.
     */
    address internal constant LEGACY_ERC20_ETH = 0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000;

    /**
     * @custom:legacy
     * @notice Address of the L1BlockNumber predeploy. Deprecated. Use the L1Block predeploy
     *         instead, which exposes more information about the L1 state.
     */
    address internal constant L1_BLOCK_NUMBER = 0x4200000000000000000000000000000000000013;

    /**
     * @custom:legacy
     * @notice Address of the LegacyMessagePasser predeploy. Deprecate. Use the updated
     *         L2ToL1MessagePasser contract instead.
     */
    address internal constant LEGACY_MESSAGE_PASSER = 0x4200000000000000000000000000000000000000;

    /**
     * @notice Address of the ProxyAdmin predeploy.
     */
    address internal constant PROXY_ADMIN = 0x4200000000000000000000000000000000000018;

    /**
     * @notice Address of the BaseFeeVault predeploy.
     */
    address internal constant BASE_FEE_VAULT = 0x4200000000000000000000000000000000000019;

    /**
     * @notice Address of the L1FeeVault predeploy.
     */
    address internal constant L1_FEE_VAULT = 0x420000000000000000000000000000000000001A;

    /**
     * @notice Address of the GovernanceToken predeploy.
     */
    address internal constant GOVERNANCE_TOKEN = 0x4200000000000000000000000000000000000042;
}

// File: contracts/libraries/SafeCall.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/**
 * @title SafeCall
 * @notice Perform low level safe calls
 */
library SafeCall {
    /**
     * @notice Perform a low level call without copying any returndata
     *
     * @param _target   Address to call
     * @param _gas      Amount of gas to pass to the call
     * @param _value    Amount of value to pass to the call
     * @param _calldata Calldata to pass to the call
     */
    function call(
        address _target,
        uint256 _gas,
        uint256 _value,
        bytes memory _calldata
    ) internal returns (bool) {
        bool _success;
        assembly {
            _success := call(
                _gas, // gas
                _target, // recipient
                _value, // ether value
                add(_calldata, 32), // inloc
                mload(_calldata), // inlen
                0, // outloc
                0 // outlen
            )
        }
        return _success;
    }

    /**
     * @notice Perform a low level call without copying any returndata. This function
     *         will revert if the call cannot be performed with the specified minimum
     *         gas.
     *
     * @param _target   Address to call
     * @param _minGas   The minimum amount of gas that may be passed to the call
     * @param _value    Amount of value to pass to the call
     * @param _calldata Calldata to pass to the call
     */
    function callWithMinGas(
        address _target,
        uint256 _minGas,
        uint256 _value,
        bytes memory _calldata
    ) internal returns (bool) {
        bool _success;
        assembly {
            // Assertion: gasleft() >= ((_minGas + 200) * 64) / 63
            //
            // Because EIP-150 ensures that, a maximum of 63/64ths of the remaining gas in the call
            // frame may be passed to a subcontext, we need to ensure that the gas will not be
            // truncated to hold this function's invariant: "If a call is performed by
            // `callWithMinGas`, it must receive at least the specified minimum gas limit." In
            // addition, exactly 51 gas is consumed between the below `GAS` opcode and the `CALL`
            // opcode, so it is factored in with some extra room for error.
            if lt(gas(), div(mul(64, add(_minGas, 200)), 63)) {
                // Store the "Error(string)" selector in scratch space.
                mstore(0, 0x08c379a0)
                // Store the pointer to the string length in scratch space.
                mstore(32, 32)
                // Store the string.
                //
                // SAFETY:
                // - We pad the beginning of the string with two zero bytes as well as the
                // length (24) to ensure that we override the free memory pointer at offset
                // 0x40. This is necessary because the free memory pointer is likely to
                // be greater than 1 byte when this function is called, but it is incredibly
                // unlikely that it will be greater than 3 bytes. As for the data within
                // 0x60, it is ensured that it is 0 due to 0x60 being the zero offset.
                // - It's fine to clobber the free memory pointer, we're reverting.
                mstore(88, 0x0000185361666543616c6c3a204e6f7420656e6f75676820676173)

                // Revert with 'Error("SafeCall: Not enough gas")'
                revert(28, 100)
            }

            // The call will be supplied at least (((_minGas + 200) * 64) / 63) - 49 gas due to the
            // above assertion. This ensures that, in all circumstances, the call will
            // receive at least the minimum amount of gas specified.
            // We can prove this property by solving the inequalities:
            // ((((_minGas + 200) * 64) / 63) - 49) >= _minGas
            // ((((_minGas + 200) * 64) / 63) - 51) * (63 / 64) >= _minGas
            // Both inequalities hold true for all possible values of `_minGas`.
            _success := call(
                gas(), // gas
                _target, // recipient
                _value, // ether value
                add(_calldata, 32), // inloc
                mload(_calldata), // inlen
                0x00, // outloc
                0x00 // outlen
            )
        }
        return _success;
    }
}

// File: contracts/libraries/Types.sol



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

/**
 * @title Types
 * @notice Contains various types used throughout the Optimism contract system.
 */
library Types {
    /**
     * @notice OutputProposal represents a commitment to the L2 state. The timestamp is the L1
     *         timestamp that the output root is posted. This timestamp is used to verify that the
     *         finalization period has passed since the output root was submitted.
     *
     * @custom:field outputRoot    Hash of the L2 output.
     * @custom:field timestamp     Timestamp of the L1 block that the output root was submitted in.
     * @custom:field l2BlockNumber L2 block number that the output corresponds to.
     */
    struct OutputProposal {
        bytes32 outputRoot;
        uint128 timestamp;
        uint128 l2BlockNumber;
    }

    /**
     * @notice Struct representing the elements that are hashed together to generate an output root
     *         which itself represents a snapshot of the L2 state.
     *
     * @custom:field version                  Version of the output root.
     * @custom:field stateRoot                Root of the state trie at the block of this output.
     * @custom:field messagePasserStorageRoot Root of the message passer storage trie.
     * @custom:field latestBlockhash          Hash of the block this output was generated from.
     */
    struct OutputRootProof {
        bytes32 version;
        bytes32 stateRoot;
        bytes32 messagePasserStorageRoot;
        bytes32 latestBlockhash;
    }

    /**
     * @notice Struct representing a deposit transaction (L1 => L2 transaction) created by an end
     *         user (as opposed to a system deposit transaction generated by the system).
     *
     * @custom:field from        Address of the sender of the transaction.
     * @custom:field to          Address of the recipient of the transaction.
     * @custom:field isCreation  True if the transaction is a contract creation.
     * @custom:field value       Value to send to the recipient.
     * @custom:field mint        Amount of ETH to mint.
     * @custom:field gasLimit    Gas limit of the transaction.
     * @custom:field data        Data of the transaction.
     * @custom:field l1BlockHash Hash of the block the transaction was submitted in.
     * @custom:field logIndex    Index of the log in the block the transaction was submitted in.
     */
    struct UserDepositTransaction {
        address from;
        address to;
        bool isCreation;
        uint256 value;
        uint256 mint;
        uint64 gasLimit;
        bytes data;
        bytes32 l1BlockHash;
        uint256 logIndex;
    }

    /**
     * @notice Struct representing a withdrawal transaction.
     *
     * @custom:field nonce    Nonce of the withdrawal transaction
     * @custom:field sender   Address of the sender of the transaction.
     * @custom:field target   Address of the recipient of the transaction.
     * @custom:field value    Value to send to the recipient.
     * @custom:field gasLimit Gas limit of the transaction.
     * @custom:field data     Data of the transaction.
     */
    struct WithdrawalTransaction {
        uint256 nonce;
        address sender;
        address target;
        uint256 value;
        uint256 gasLimit;
        bytes data;
    }
}

// File: contracts/libraries/rlp/RLPWriter.sol



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

/**
 * @custom:attribution https://github.com/bakaoh/solidity-rlp-encode
 * @title RLPWriter
 * @author RLPWriter is a library for encoding Solidity types to RLP bytes. Adapted from Bakaoh's
 *         RLPEncode library (https://github.com/bakaoh/solidity-rlp-encode) with minor
 *         modifications to improve legibility.
 */
library RLPWriter {
    /**
     * @notice RLP encodes a byte string.
     *
     * @param _in The byte string to encode.
     *
     * @return The RLP encoded string in bytes.
     */
    function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
        bytes memory encoded;

        if (_in.length == 1 && uint8(_in[0]) < 128) {
            encoded = _in;
        } else {
            encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
        }

        return encoded;
    }

    /**
     * @notice RLP encodes a list of RLP encoded byte byte strings.
     *
     * @param _in The list of RLP encoded byte strings.
     *
     * @return The RLP encoded list of items in bytes.
     */
    function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
        bytes memory list = _flatten(_in);
        return abi.encodePacked(_writeLength(list.length, 192), list);
    }

    /**
     * @notice RLP encodes a string.
     *
     * @param _in The string to encode.
     *
     * @return The RLP encoded string in bytes.
     */
    function writeString(string memory _in) internal pure returns (bytes memory) {
        return writeBytes(bytes(_in));
    }

    /**
     * @notice RLP encodes an address.
     *
     * @param _in The address to encode.
     *
     * @return The RLP encoded address in bytes.
     */
    function writeAddress(address _in) internal pure returns (bytes memory) {
        return writeBytes(abi.encodePacked(_in));
    }

    /**
     * @notice RLP encodes a uint.
     *
     * @param _in The uint256 to encode.
     *
     * @return The RLP encoded uint256 in bytes.
     */
    function writeUint(uint256 _in) internal pure returns (bytes memory) {
        return writeBytes(_toBinary(_in));
    }

    /**
     * @notice RLP encodes a bool.
     *
     * @param _in The bool to encode.
     *
     * @return The RLP encoded bool in bytes.
     */
    function writeBool(bool _in) internal pure returns (bytes memory) {
        bytes memory encoded = new bytes(1);
        encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
        return encoded;
    }

    /**
     * @notice Encode the first byte and then the `len` in binary form if `length` is more than 55.
     *
     * @param _len    The length of the string or the payload.
     * @param _offset 128 if item is string, 192 if item is list.
     *
     * @return RLP encoded bytes.
     */
    function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
        bytes memory encoded;

        if (_len < 56) {
            encoded = new bytes(1);
            encoded[0] = bytes1(uint8(_len) + uint8(_offset));
        } else {
            uint256 lenLen;
            uint256 i = 1;
            while (_len / i != 0) {
                lenLen++;
                i *= 256;
            }

            encoded = new bytes(lenLen + 1);
            encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
            for (i = 1; i <= lenLen; i++) {
                encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
            }
        }

        return encoded;
    }

    /**
     * @notice Encode integer in big endian binary form with no leading zeroes.
     *
     * @param _x The integer to encode.
     *
     * @return RLP encoded bytes.
     */
    function _toBinary(uint256 _x) private pure returns (bytes memory) {
        bytes memory b = abi.encodePacked(_x);

        uint256 i = 0;
        for (; i < 32; i++) {
            if (b[i] != 0) {
                break;
            }
        }

        bytes memory res = new bytes(32 - i);
        for (uint256 j = 0; j < res.length; j++) {
            res[j] = b[i++];
        }

        return res;
    }

    /**
     * @custom:attribution https://github.com/Arachnid/solidity-stringutils
     * @notice Copies a piece of memory to another location.
     *
     * @param _dest Destination location.
     * @param _src  Source location.
     * @param _len  Length of memory to copy.
     */
    function _memcpy(
        uint256 _dest,
        uint256 _src,
        uint256 _len
    ) private pure {
        uint256 dest = _dest;
        uint256 src = _src;
        uint256 len = _len;

        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        uint256 mask;
        unchecked {
            mask = 256**(32 - len) - 1;
        }
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /**
     * @custom:attribution https://github.com/sammayo/solidity-rlp-encoder
     * @notice Flattens a list of byte strings into one byte string.
     *
     * @param _list List of byte strings to flatten.
     *
     * @return The flattened byte string.
     */
    function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
        if (_list.length == 0) {
            return new bytes(0);
        }

        uint256 len;
        uint256 i = 0;
        for (; i < _list.length; i++) {
            len += _list[i].length;
        }

        bytes memory flattened = new bytes(len);
        uint256 flattenedPtr;
        assembly {
            flattenedPtr := add(flattened, 0x20)
        }

        for (i = 0; i < _list.length; i++) {
            bytes memory item = _list[i];

            uint256 listPtr;
            assembly {
                listPtr := add(item, 0x20)
            }

            _memcpy(flattenedPtr, listPtr, item.length);
            flattenedPtr += _list[i].length;
        }

        return flattened;
    }
}

// File: contracts/universal/CrossDomainMessenger.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { Hashing } from "../libraries/Hashing.sol";
import { Encoding } from "../libraries/Encoding.sol";
import { Constants } from "../libraries/Constants.sol";

/**
 * @custom:legacy
 * @title CrossDomainMessengerLegacySpacer0
 * @notice Contract only exists to add a spacer to the CrossDomainMessenger where the
 *         libAddressManager variable used to exist. Must be the first contract in the inheritance
 *         tree of the CrossDomainMessenger.
 */
contract CrossDomainMessengerLegacySpacer0 {
    /**
     * @custom:legacy
     * @custom:spacer libAddressManager
     * @notice Spacer for backwards compatibility.
     */
    address private spacer_0_0_20;
}

/**
 * @custom:legacy
 * @title CrossDomainMessengerLegacySpacer1
 * @notice Contract only exists to add a spacer to the CrossDomainMessenger where the
 *         PausableUpgradable and OwnableUpgradeable variables used to exist. Must be
 *         the third contract in the inheritance tree of the CrossDomainMessenger.
 */
contract CrossDomainMessengerLegacySpacer1 {
    /**
     * @custom:legacy
     * @custom:spacer __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         ContextUpgradable via OwnableUpgradeable.
     *
     */
    uint256[50] private spacer_1_0_1600;

    /**
     * @custom:legacy
     * @custom:spacer _owner
     * @notice Spacer for backwards compatibility.
     *         Come from OpenZeppelin OwnableUpgradeable.
     */
    address private spacer_51_0_20;

    /**
     * @custom:legacy
     * @custom:spacer __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         ContextUpgradable via PausableUpgradable.
     */
    uint256[49] private spacer_52_0_1568;

    /**
     * @custom:legacy
     * @custom:spacer _paused
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         PausableUpgradable.
     */
    bool private spacer_101_0_1;

    /**
     * @custom:legacy
     * @custom:spacer __gap
     * @notice Spacer for backwards compatibility. Comes from OpenZeppelin
     *         PausableUpgradable.
     */
    uint256[49] private spacer_102_0_1568;

    /**
     * @custom:legacy
     * @custom:spacer ReentrancyGuardUpgradeable's `_status` field.
     * @notice Spacer for backwards compatibility
     */
    uint256 private spacer_151_0_32;

    /**
     * @custom:spacer ReentrancyGuardUpgradeable
     * @notice Spacer for backwards compatibility
     */
    uint256[49] private __gap_reentrancy_guard;

    /**
     * @custom:legacy
     * @custom:spacer blockedMessages
     * @notice Spacer for backwards compatibility.
     */
    mapping(bytes32 => bool) private spacer_201_0_32;

    /**
     * @custom:legacy
     * @custom:spacer relayedMessages
     * @notice Spacer for backwards compatibility.
     */
    mapping(bytes32 => bool) private spacer_202_0_32;
}

/**
 * @custom:upgradeable
 * @title CrossDomainMessenger
 * @notice CrossDomainMessenger is a base contract that provides the core logic for the L1 and L2
 *         cross-chain messenger contracts. It's designed to be a universal interface that only
 *         needs to be extended slightly to provide low-level message passing functionality on each
 *         chain it's deployed on. Currently only designed for message passing between two paired
 *         chains and does not support one-to-many interactions.
 *
 *         Any changes to this contract MUST result in a semver bump for contracts that inherit it.
 */
abstract contract CrossDomainMessenger is
    CrossDomainMessengerLegacySpacer0,
    Initializable,
    CrossDomainMessengerLegacySpacer1
{
    /**
     * @notice Current message version identifier.
     */
    uint16 public constant MESSAGE_VERSION = 1;

    /**
     * @notice Constant overhead added to the base gas for a message.
     */
    uint64 public constant MIN_GAS_CONSTANT_OVERHEAD = 200_000;

    /**
     * @notice Numerator for dynamic overhead added to the base gas for a message.
     */
    uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR = 1016;

    /**
     * @notice Denominator for dynamic overhead added to the base gas for a message.
     */
    uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR = 1000;

    /**
     * @notice Extra gas added to base gas for each byte of calldata in a message.
     */
    uint64 public constant MIN_GAS_CALLDATA_OVERHEAD = 16;

    /**
     * @notice Address of the paired CrossDomainMessenger contract on the other chain.
     */
    address public immutable OTHER_MESSENGER;

    /**
     * @notice Mapping of message hashes to boolean receipt values. Note that a message will only
     *         be present in this mapping if it has successfully been relayed on this chain, and
     *         can therefore not be relayed again.
     */
    mapping(bytes32 => bool) public successfulMessages;

    /**
     * @notice Address of the sender of the currently executing message on the other chain. If the
     *         value of this variable is the default value (0x00000000...dead) then no message is
     *         currently being executed. Use the xDomainMessageSender getter which will throw an
     *         error if this is the case.
     */
    address internal xDomainMsgSender;

    /**
     * @notice Nonce for the next message to be sent, without the message version applied. Use the
     *         messageNonce getter which will insert the message version into the nonce to give you
     *         the actual nonce to be used for the message.
     */
    uint240 internal msgNonce;

    /**
     * @notice Mapping of message hashes to a boolean if and only if the message has failed to be
     *         executed at least once. A message will not be present in this mapping if it
     *         successfully executed on the first attempt.
     */
    mapping(bytes32 => bool) public failedMessages;

    /**
     * @notice A mapping of hashes to reentrancy locks.
     */
    mapping(bytes32 => bool) internal reentrancyLocks;

    /**
     * @notice Reserve extra slots in the storage layout for future upgrades.
     *         A gap size of 41 was chosen here, so that the first slot used in a child contract
     *         would be a multiple of 50.
     */
    uint256[41] private __gap;

    /**
     * @notice Emitted whenever a message is sent to the other chain.
     *
     * @param target       Address of the recipient of the message.
     * @param sender       Address of the sender of the message.
     * @param message      Message to trigger the recipient address with.
     * @param messageNonce Unique nonce attached to the message.
     * @param gasLimit     Minimum gas limit that the message can be executed with.
     */
    event SentMessage(
        address indexed target,
        address sender,
        bytes message,
        uint256 messageNonce,
        uint256 gasLimit
    );

    /**
     * @notice Additional event data to emit, required as of Bedrock. Cannot be merged with the
     *         SentMessage event without breaking the ABI of this contract, this is good enough.
     *
     * @param sender Address of the sender of the message.
     * @param value  ETH value sent along with the message to the recipient.
     */
    event SentMessageExtension1(address indexed sender, uint256 value);

    /**
     * @notice Emitted whenever a message is successfully relayed on this chain.
     *
     * @param msgHash Hash of the message that was relayed.
     */
    event RelayedMessage(bytes32 indexed msgHash);

    /**
     * @notice Emitted whenever a message fails to be relayed on this chain.
     *
     * @param msgHash Hash of the message that failed to be relayed.
     */
    event FailedRelayedMessage(bytes32 indexed msgHash);

    /**
     * @param _otherMessenger Address of the messenger on the paired chain.
     */
    constructor(address _otherMessenger) {
        OTHER_MESSENGER = _otherMessenger;
    }

    /**
     * @notice Sends a message to some target address on the other chain. Note that if the call
     *         always reverts, then the message will be unrelayable, and any ETH sent will be
     *         permanently locked. The same will occur if the target on the other chain is
     *         considered unsafe (see the _isUnsafeTarget() function).
     *
     * @param _target      Target contract or wallet address.
     * @param _message     Message to trigger the target address with.
     * @param _minGasLimit Minimum gas limit that the message can be executed with.
     */
    function sendMessage(
        address _target,
        bytes calldata _message,
        uint32 _minGasLimit
    ) external payable {
        // Triggers a message to the other messenger. Note that the amount of gas provided to the
        // message is the amount of gas requested by the user PLUS the base gas value. We want to
        // guarantee the property that the call to the target contract will always have at least
        // the minimum gas limit specified by the user.
        _sendMessage(
            OTHER_MESSENGER,
            baseGas(_message, _minGasLimit),
            msg.value,
            abi.encodeWithSelector(
                this.relayMessage.selector,
                messageNonce(),
                msg.sender,
                _target,
                msg.value,
                _minGasLimit,
                _message
            )
        );

        emit SentMessage(_target, msg.sender, _message, messageNonce(), _minGasLimit);
        emit SentMessageExtension1(msg.sender, msg.value);

        unchecked {
            ++msgNonce;
        }
    }

    /**
     * @notice Relays a message that was sent by the other CrossDomainMessenger contract. Can only
     *         be executed via cross-chain call from the other messenger OR if the message was
     *         already received once and is currently being replayed.
     *
     * @param _nonce       Nonce of the message being relayed.
     * @param _sender      Address of the user who sent the message.
     * @param _target      Address that the message is targeted at.
     * @param _value       ETH value to send with the message.
     * @param _minGasLimit Minimum amount of gas that the message can be executed with.
     * @param _message     Message to send to the target.
     */
    function relayMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _minGasLimit,
        bytes calldata _message
    ) external payable {
        (, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
        require(
            version < 2,
            "CrossDomainMessenger: only version 0 or 1 messages are supported at this time"
        );

        // If the message is version 0, then it's a migrated legacy withdrawal. We therefore need
        // to check that the legacy version of the message has not already been relayed.
        if (version == 0) {
            bytes32 oldHash = Hashing.hashCrossDomainMessageV0(_target, _sender, _message, _nonce);
            require(
                successfulMessages[oldHash] == false,
                "CrossDomainMessenger: legacy withdrawal already relayed"
            );
        }

        // We use the v1 message hash as the unique identifier for the message because it commits
        // to the value and minimum gas limit of the message.
        bytes32 versionedHash = Hashing.hashCrossDomainMessageV1(
            _nonce,
            _sender,
            _target,
            _value,
            _minGasLimit,
            _message
        );

        // Check if the reentrancy lock for the `versionedHash` is already set.
        if (reentrancyLocks[versionedHash]) {
            revert("ReentrancyGuard: reentrant call");
        }
        // Trigger the reentrancy lock for `versionedHash`
        reentrancyLocks[versionedHash] = true;

        if (_isOtherMessenger()) {
            // These properties should always hold when the message is first submitted (as
            // opposed to being replayed).
            assert(msg.value == _value);
            assert(!failedMessages[versionedHash]);
        } else {
            require(
                msg.value == 0,
                "CrossDomainMessenger: value must be zero unless message is from a system address"
            );

            require(
                failedMessages[versionedHash],
                "CrossDomainMessenger: message cannot be replayed"
            );
        }

        require(
            _isUnsafeTarget(_target) == false,
            "CrossDomainMessenger: cannot send message to blocked system address"
        );

        require(
            successfulMessages[versionedHash] == false,
            "CrossDomainMessenger: message has already been relayed"
        );

        xDomainMsgSender = _sender;
        bool success = SafeCall.callWithMinGas(_target, _minGasLimit, _value, _message);
        xDomainMsgSender = Constants.DEFAULT_L2_SENDER;

        if (success) {
            successfulMessages[versionedHash] = true;
            emit RelayedMessage(versionedHash);
        } else {
            failedMessages[versionedHash] = true;
            emit FailedRelayedMessage(versionedHash);

            // Revert in this case if the transaction was triggered by the estimation address. This
            // should only be possible during gas estimation or we have bigger problems. Reverting
            // here will make the behavior of gas estimation change such that the gas limit
            // computed will be the amount required to relay the message, even if that amount is
            // greater than the minimum gas limit specified by the user.
            if (tx.origin == Constants.ESTIMATION_ADDRESS) {
                revert("CrossDomainMessenger: failed to relay message");
            }
        }

        // Clear the reentrancy lock for `versionedHash`
        reentrancyLocks[versionedHash] = false;
    }

    /**
     * @notice Retrieves the address of the contract or wallet that initiated the currently
     *         executing message on the other chain. Will throw an error if there is no message
     *         currently being executed. Allows the recipient of a call to see who triggered it.
     *
     * @return Address of the sender of the currently executing message on the other chain.
     */
    function xDomainMessageSender() external view returns (address) {
        require(
            xDomainMsgSender != Constants.DEFAULT_L2_SENDER,
            "CrossDomainMessenger: xDomainMessageSender is not set"
        );

        return xDomainMsgSender;
    }

    /**
     * @notice Retrieves the next message nonce. Message version will be added to the upper two
     *         bytes of the message nonce. Message version allows us to treat messages as having
     *         different structures.
     *
     * @return Nonce of the next message to be sent, with added message version.
     */
    function messageNonce() public view returns (uint256) {
        return Encoding.encodeVersionedNonce(msgNonce, MESSAGE_VERSION);
    }

    /**
     * @notice Computes the amount of gas required to guarantee that a given message will be
     *         received on the other chain without running out of gas. Guaranteeing that a message
     *         will not run out of gas is important because this ensures that a message can always
     *         be replayed on the other chain if it fails to execute completely.
     *
     * @param _message     Message to compute the amount of required gas for.
     * @param _minGasLimit Minimum desired gas limit when message goes to target.
     *
     * @return Amount of gas required to guarantee message receipt.
     */
    function baseGas(bytes calldata _message, uint32 _minGasLimit) public pure returns (uint64) {
        // We peform the following math on uint64s to avoid overflow errors. Multiplying the
        // by MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR would otherwise limit the _minGasLimit to
        // type(uint32).max / MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR ~= 4.2m.
        return
            // Dynamic overhead
            ((uint64(_minGasLimit) * MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR) /
                MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR) +
            // Calldata overhead
            (uint64(_message.length) * MIN_GAS_CALLDATA_OVERHEAD) +
            // Constant overhead
            MIN_GAS_CONSTANT_OVERHEAD;
    }

    /**
     * @notice Intializer.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __CrossDomainMessenger_init() internal onlyInitializing {
        xDomainMsgSender = Constants.DEFAULT_L2_SENDER;
    }

    /**
     * @notice Sends a low-level message to the other messenger. Needs to be implemented by child
     *         contracts because the logic for this depends on the network where the messenger is
     *         being deployed.
     *
     * @param _to       Recipient of the message on the other chain.
     * @param _gasLimit Minimum gas limit the message can be executed with.
     * @param _value    Amount of ETH to send with the message.
     * @param _data     Message data.
     */
    function _sendMessage(
        address _to,
        uint64 _gasLimit,
        uint256 _value,
        bytes memory _data
    ) internal virtual;

    /**
     * @notice Checks whether the message is coming from the other messenger. Implemented by child
     *         contracts because the logic for this depends on the network where the messenger is
     *         being deployed.
     *
     * @return Whether the message is coming from the other messenger.
     */
    function _isOtherMessenger() internal view virtual returns (bool);

    /**
     * @notice Checks whether a given call target is a system address that could cause the
     *         messenger to peform an unsafe action. This is NOT a mechanism for blocking user
     *         addresses. This is ONLY used to prevent the execution of messages to specific
     *         system addresses that could cause security issues, e.g., having the
     *         CrossDomainMessenger send messages to itself.
     *
     * @param _target Address of the contract to check.
     *
     * @return Whether or not the address is an unsafe system address.
     */
    function _isUnsafeTarget(address _target) internal view virtual returns (bool);
}

// File: contracts/universal/IOptimismMintableERC20.sol



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

import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";

/**
 * @title IOptimismMintableERC20
 * @notice This interface is available on the OptimismMintableERC20 contract. We declare it as a
 *         separate interface so that it can be used in custom implementations of
 *         OptimismMintableERC20.
 */
interface IOptimismMintableERC20 is IERC165 {
    function remoteToken() external view returns (address);

    function bridge() external returns (address);

    function mint(address _to, uint256 _amount) external;

    function burn(address _from, uint256 _amount) external;
}

/**
 * @custom:legacy
 * @title ILegacyMintableERC20
 * @notice This interface was available on the legacy L2StandardERC20 contract. It remains available
 *         on the OptimismMintableERC20 contract for backwards compatibility.
 */
interface ILegacyMintableERC20 is IERC165 {
    function l1Token() external view returns (address);

    function mint(address _to, uint256 _amount) external;

    function burn(address _from, uint256 _amount) external;
}

// File: contracts/universal/OptimismMintableERC20.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
import { ILegacyMintableERC20, IOptimismMintableERC20 } from "./IOptimismMintableERC20.sol";
import { Semver } from "../universal/Semver.sol";

/**
 * @title OptimismMintableERC20
 * @notice OptimismMintableERC20 is a standard extension of the base ERC20 token contract designed
 *         to allow the StandardBridge contracts to mint and burn tokens. This makes it possible to
 *         use an OptimismMintablERC20 as the L2 representation of an L1 token, or vice-versa.
 *         Designed to be backwards compatible with the older StandardL2ERC20 token which was only
 *         meant for use on L2.
 */
contract OptimismMintableERC20 is IOptimismMintableERC20, ILegacyMintableERC20, ERC20, Semver {
    /**
     * @notice Address of the corresponding version of this token on the remote chain.
     */
    address public immutable REMOTE_TOKEN;

    /**
     * @notice Address of the StandardBridge on this network.
     */
    address public immutable BRIDGE;

    /**
     * @notice Emitted whenever tokens are minted for an account.
     *
     * @param account Address of the account tokens are being minted for.
     * @param amount  Amount of tokens minted.
     */
    event Mint(address indexed account, uint256 amount);

    /**
     * @notice Emitted whenever tokens are burned from an account.
     *
     * @param account Address of the account tokens are being burned from.
     * @param amount  Amount of tokens burned.
     */
    event Burn(address indexed account, uint256 amount);

    /**
     * @notice A modifier that only allows the bridge to call
     */
    modifier onlyBridge() {
        require(msg.sender == BRIDGE, "OptimismMintableERC20: only bridge can mint and burn");
        _;
    }

    /**
     * @custom:semver 1.0.0
     *
     * @param _bridge      Address of the L2 standard bridge.
     * @param _remoteToken Address of the corresponding L1 token.
     * @param _name        ERC20 name.
     * @param _symbol      ERC20 symbol.
     */
    constructor(
        address _bridge,
        address _remoteToken,
        string memory _name,
        string memory _symbol
    ) ERC20(_name, _symbol) Semver(1, 0, 0) {
        REMOTE_TOKEN = _remoteToken;
        BRIDGE = _bridge;
    }

    /**
     * @notice Allows the StandardBridge on this network to mint tokens.
     *
     * @param _to     Address to mint tokens to.
     * @param _amount Amount of tokens to mint.
     */
    function mint(address _to, uint256 _amount)
        external
        virtual
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _mint(_to, _amount);
        emit Mint(_to, _amount);
    }

    /**
     * @notice Allows the StandardBridge on this network to burn tokens.
     *
     * @param _from   Address to burn tokens from.
     * @param _amount Amount of tokens to burn.
     */
    function burn(address _from, uint256 _amount)
        external
        virtual
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _burn(_from, _amount);
        emit Burn(_from, _amount);
    }

    /**
     * @notice ERC165 interface check function.
     *
     * @param _interfaceId Interface ID to check.
     *
     * @return Whether or not the interface is supported by this contract.
     */
    function supportsInterface(bytes4 _interfaceId) external pure returns (bool) {
        bytes4 iface1 = type(IERC165).interfaceId;
        // Interface corresponding to the legacy L2StandardERC20.
        bytes4 iface2 = type(ILegacyMintableERC20).interfaceId;
        // Interface corresponding to the updated OptimismMintableERC20 (this contract).
        bytes4 iface3 = type(IOptimismMintableERC20).interfaceId;
        return _interfaceId == iface1 || _interfaceId == iface2 || _interfaceId == iface3;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for the remote token. Use REMOTE_TOKEN going forward.
     */
    function l1Token() public view returns (address) {
        return REMOTE_TOKEN;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for the bridge. Use BRIDGE going forward.
     */
    function l2Bridge() public view returns (address) {
        return BRIDGE;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for REMOTE_TOKEN.
     */
    function remoteToken() public view returns (address) {
        return REMOTE_TOKEN;
    }

    /**
     * @custom:legacy
     * @notice Legacy getter for BRIDGE.
     */
    function bridge() public view returns (address) {
        return BRIDGE;
    }
}

// File: contracts/universal/Semver.sol



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

import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";

/**
 * @title Semver
 * @notice Semver is a simple contract for managing contract versions.
 */
contract Semver {
    /**
     * @notice Contract version number (major).
     */
    uint256 private immutable MAJOR_VERSION;

    /**
     * @notice Contract version number (minor).
     */
    uint256 private immutable MINOR_VERSION;

    /**
     * @notice Contract version number (patch).
     */
    uint256 private immutable PATCH_VERSION;

    /**
     * @param _major Version number (major).
     * @param _minor Version number (minor).
     * @param _patch Version number (patch).
     */
    constructor(
        uint256 _major,
        uint256 _minor,
        uint256 _patch
    ) {
        MAJOR_VERSION = _major;
        MINOR_VERSION = _minor;
        PATCH_VERSION = _patch;
    }

    /**
     * @notice Returns the full semver contract version.
     *
     * @return Semver contract version as a string.
     */
    function version() public view returns (string memory) {
        return
            string(
                abi.encodePacked(
                    Strings.toString(MAJOR_VERSION),
                    ".",
                    Strings.toString(MINOR_VERSION),
                    ".",
                    Strings.toString(PATCH_VERSION)
                )
            );
    }
}

// File: contracts/universal/StandardBridge.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { IOptimismMintableERC20, ILegacyMintableERC20 } from "./IOptimismMintableERC20.sol";
import { CrossDomainMessenger } from "./CrossDomainMessenger.sol";
import { OptimismMintableERC20 } from "./OptimismMintableERC20.sol";

/**
 * @custom:upgradeable
 * @title StandardBridge
 * @notice StandardBridge is a base contract for the L1 and L2 standard ERC20 bridges. It handles
 *         the core bridging logic, including escrowing tokens that are native to the local chain
 *         and minting/burning tokens that are native to the remote chain.
 */
abstract contract StandardBridge {
    using SafeERC20 for IERC20;

    /**
     * @notice The L2 gas limit set when eth is depoisited using the receive() function.
     */
    uint32 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 200_000;

    /**
     * @notice Messenger contract on this domain.
     */
    CrossDomainMessenger public immutable MESSENGER;

    /**
     * @notice Corresponding bridge on the other domain.
     */
    StandardBridge public immutable OTHER_BRIDGE;

    /**
     * @custom:legacy
     * @custom:spacer messenger
     * @notice Spacer for backwards compatibility.
     */
    address private spacer_0_0_20;

    /**
     * @custom:legacy
     * @custom:spacer l2TokenBridge
     * @notice Spacer for backwards compatibility.
     */
    address private spacer_1_0_20;

    /**
     * @notice Mapping that stores deposits for a given pair of local and remote tokens.
     */
    mapping(address => mapping(address => uint256)) public deposits;

    /**
     * @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
     *         A gap size of 47 was chosen here, so that the first slot used in a child contract
     *         would be a multiple of 50.
     */
    uint256[47] private __gap;

    /**
     * @notice Emitted when an ETH bridge is initiated to the other chain.
     *
     * @param from      Address of the sender.
     * @param to        Address of the receiver.
     * @param amount    Amount of ETH sent.
     * @param extraData Extra data sent with the transaction.
     */
    event ETHBridgeInitiated(
        address indexed from,
        address indexed to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @notice Emitted when an ETH bridge is finalized on this chain.
     *
     * @param from      Address of the sender.
     * @param to        Address of the receiver.
     * @param amount    Amount of ETH sent.
     * @param extraData Extra data sent with the transaction.
     */
    event ETHBridgeFinalized(
        address indexed from,
        address indexed to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @notice Emitted when an ERC20 bridge is initiated to the other chain.
     *
     * @param localToken  Address of the ERC20 on this chain.
     * @param remoteToken Address of the ERC20 on the remote chain.
     * @param from        Address of the sender.
     * @param to          Address of the receiver.
     * @param amount      Amount of the ERC20 sent.
     * @param extraData   Extra data sent with the transaction.
     */
    event ERC20BridgeInitiated(
        address indexed localToken,
        address indexed remoteToken,
        address indexed from,
        address to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @notice Emitted when an ERC20 bridge is finalized on this chain.
     *
     * @param localToken  Address of the ERC20 on this chain.
     * @param remoteToken Address of the ERC20 on the remote chain.
     * @param from        Address of the sender.
     * @param to          Address of the receiver.
     * @param amount      Amount of the ERC20 sent.
     * @param extraData   Extra data sent with the transaction.
     */
    event ERC20BridgeFinalized(
        address indexed localToken,
        address indexed remoteToken,
        address indexed from,
        address to,
        uint256 amount,
        bytes extraData
    );

    /**
     * @notice Only allow EOAs to call the functions. Note that this is not safe against contracts
     *         calling code within their constructors, but also doesn't really matter since we're
     *         just trying to prevent users accidentally depositing with smart contract wallets.
     */
    modifier onlyEOA() {
        require(
            !Address.isContract(msg.sender),
            "StandardBridge: function can only be called from an EOA"
        );
        _;
    }

    /**
     * @notice Ensures that the caller is a cross-chain message from the other bridge.
     */
    modifier onlyOtherBridge() {
        require(
            msg.sender == address(MESSENGER) &&
                MESSENGER.xDomainMessageSender() == address(OTHER_BRIDGE),
            "StandardBridge: function can only be called from the other bridge"
        );
        _;
    }

    /**
     * @param _messenger   Address of CrossDomainMessenger on this network.
     * @param _otherBridge Address of the other StandardBridge contract.
     */
    constructor(address payable _messenger, address payable _otherBridge) {
        MESSENGER = CrossDomainMessenger(_messenger);
        OTHER_BRIDGE = StandardBridge(_otherBridge);
    }

    /**
     * @notice Allows EOAs to bridge ETH by sending directly to the bridge.
     *         Must be implemented by contracts that inherit.
     */
    receive() external payable virtual;

    /**
     * @custom:legacy
     * @notice Legacy getter for messenger contract.
     *
     * @return Messenger contract on this domain.
     */
    function messenger() external view returns (CrossDomainMessenger) {
        return MESSENGER;
    }

    /**
     * @notice Sends ETH to the sender's address on the other chain.
     *
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function bridgeETH(uint32 _minGasLimit, bytes calldata _extraData) public payable onlyEOA {
        _initiateBridgeETH(msg.sender, msg.sender, msg.value, _minGasLimit, _extraData);
    }

    /**
     * @notice Sends ETH to a receiver's address on the other chain. Note that if ETH is sent to a
     *         smart contract and the call fails, the ETH will be temporarily locked in the
     *         StandardBridge on the other chain until the call is replayed. If the call cannot be
     *         replayed with any amount of gas (call always reverts), then the ETH will be
     *         permanently locked in the StandardBridge on the other chain. ETH will also
     *         be locked if the receiver is the other bridge, because finalizeBridgeETH will revert
     *         in that case.
     *
     * @param _to          Address of the receiver.
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function bridgeETHTo(
        address _to,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) public payable {
        _initiateBridgeETH(msg.sender, _to, msg.value, _minGasLimit, _extraData);
    }

    /**
     * @notice Sends ERC20 tokens to the sender's address on the other chain. Note that if the
     *         ERC20 token on the other chain does not recognize the local token as the correct
     *         pair token, the ERC20 bridge will fail and the tokens will be returned to sender on
     *         this chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the corresponding token on the remote chain.
     * @param _amount      Amount of local tokens to deposit.
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function bridgeERC20(
        address _localToken,
        address _remoteToken,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) public virtual onlyEOA {
        _initiateBridgeERC20(
            _localToken,
            _remoteToken,
            msg.sender,
            msg.sender,
            _amount,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @notice Sends ERC20 tokens to a receiver's address on the other chain. Note that if the
     *         ERC20 token on the other chain does not recognize the local token as the correct
     *         pair token, the ERC20 bridge will fail and the tokens will be returned to sender on
     *         this chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the corresponding token on the remote chain.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of local tokens to deposit.
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function bridgeERC20To(
        address _localToken,
        address _remoteToken,
        address _to,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes calldata _extraData
    ) public virtual {
        _initiateBridgeERC20(
            _localToken,
            _remoteToken,
            msg.sender,
            _to,
            _amount,
            _minGasLimit,
            _extraData
        );
    }

    /**
     * @notice Finalizes an ETH bridge on this chain. Can only be triggered by the other
     *         StandardBridge contract on the remote chain.
     *
     * @param _from      Address of the sender.
     * @param _to        Address of the receiver.
     * @param _amount    Amount of ETH being bridged.
     * @param _extraData Extra data to be sent with the transaction. Note that the recipient will
     *                   not be triggered with this data, but it will be emitted and can be used
     *                   to identify the transaction.
     */
    function finalizeBridgeETH(
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _extraData
    ) public payable onlyOtherBridge {
        require(msg.value == _amount, "StandardBridge: amount sent does not match amount required");
        require(_to != address(this), "StandardBridge: cannot send to self");
        require(_to != address(MESSENGER), "StandardBridge: cannot send to messenger");

        // Emit the correct events. By default this will be _amount, but child
        // contracts may override this function in order to emit legacy events as well.
        _emitETHBridgeFinalized(_from, _to, _amount, _extraData);

        bool success = SafeCall.call(_to, gasleft(), _amount, hex"");
        require(success, "StandardBridge: ETH transfer failed");
    }

    /**
     * @notice Finalizes an ERC20 bridge on this chain. Can only be triggered by the other
     *         StandardBridge contract on the remote chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the corresponding token on the remote chain.
     * @param _from        Address of the sender.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of the ERC20 being bridged.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function finalizeBridgeERC20(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _extraData
    ) public onlyOtherBridge {
        if (_isOptimismMintableERC20(_localToken)) {
            require(
                _isCorrectTokenPair(_localToken, _remoteToken),
                "StandardBridge: wrong remote token for Optimism Mintable ERC20 local token"
            );

            OptimismMintableERC20(_localToken).mint(_to, _amount);
        } else {
            deposits[_localToken][_remoteToken] = deposits[_localToken][_remoteToken] - _amount;
            IERC20(_localToken).safeTransfer(_to, _amount);
        }

        // Emit the correct events. By default this will be ERC20BridgeFinalized, but child
        // contracts may override this function in order to emit legacy events as well.
        _emitERC20BridgeFinalized(_localToken, _remoteToken, _from, _to, _amount, _extraData);
    }

    /**
     * @notice Initiates a bridge of ETH through the CrossDomainMessenger.
     *
     * @param _from        Address of the sender.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of ETH being bridged.
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function _initiateBridgeETH(
        address _from,
        address _to,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes memory _extraData
    ) internal {
        require(
            msg.value == _amount,
            "StandardBridge: bridging ETH must include sufficient ETH value"
        );

        // Emit the correct events. By default this will be _amount, but child
        // contracts may override this function in order to emit legacy events as well.
        _emitETHBridgeInitiated(_from, _to, _amount, _extraData);

        MESSENGER.sendMessage{ value: _amount }(
            address(OTHER_BRIDGE),
            abi.encodeWithSelector(
                this.finalizeBridgeETH.selector,
                _from,
                _to,
                _amount,
                _extraData
            ),
            _minGasLimit
        );
    }

    /**
     * @notice Sends ERC20 tokens to a receiver's address on the other chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the corresponding token on the remote chain.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of local tokens to deposit.
     * @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
     * @param _extraData   Extra data to be sent with the transaction. Note that the recipient will
     *                     not be triggered with this data, but it will be emitted and can be used
     *                     to identify the transaction.
     */
    function _initiateBridgeERC20(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        uint32 _minGasLimit,
        bytes memory _extraData
    ) internal {
        if (_isOptimismMintableERC20(_localToken)) {
            require(
                _isCorrectTokenPair(_localToken, _remoteToken),
                "StandardBridge: wrong remote token for Optimism Mintable ERC20 local token"
            );

            OptimismMintableERC20(_localToken).burn(_from, _amount);
        } else {
            IERC20(_localToken).safeTransferFrom(_from, address(this), _amount);
            deposits[_localToken][_remoteToken] = deposits[_localToken][_remoteToken] + _amount;
        }

        // Emit the correct events. By default this will be ERC20BridgeInitiated, but child
        // contracts may override this function in order to emit legacy events as well.
        _emitERC20BridgeInitiated(_localToken, _remoteToken, _from, _to, _amount, _extraData);

        MESSENGER.sendMessage(
            address(OTHER_BRIDGE),
            abi.encodeWithSelector(
                this.finalizeBridgeERC20.selector,
                // Because this call will be executed on the remote chain, we reverse the order of
                // the remote and local token addresses relative to their order in the
                // finalizeBridgeERC20 function.
                _remoteToken,
                _localToken,
                _from,
                _to,
                _amount,
                _extraData
            ),
            _minGasLimit
        );
    }

    /**
     * @notice Checks if a given address is an OptimismMintableERC20. Not perfect, but good enough.
     *         Just the way we like it.
     *
     * @param _token Address of the token to check.
     *
     * @return True if the token is an OptimismMintableERC20.
     */
    function _isOptimismMintableERC20(address _token) internal view returns (bool) {
        return
            ERC165Checker.supportsInterface(_token, type(ILegacyMintableERC20).interfaceId) ||
            ERC165Checker.supportsInterface(_token, type(IOptimismMintableERC20).interfaceId);
    }

    /**
     * @notice Checks if the "other token" is the correct pair token for the OptimismMintableERC20.
     *         Calls can be saved in the future by combining this logic with
     *         `_isOptimismMintableERC20`.
     *
     * @param _mintableToken OptimismMintableERC20 to check against.
     * @param _otherToken    Pair token to check.
     *
     * @return True if the other token is the correct pair token for the OptimismMintableERC20.
     */
    function _isCorrectTokenPair(address _mintableToken, address _otherToken)
        internal
        view
        returns (bool)
    {
        if (
            ERC165Checker.supportsInterface(_mintableToken, type(ILegacyMintableERC20).interfaceId)
        ) {
            return _otherToken == ILegacyMintableERC20(_mintableToken).l1Token();
        } else {
            return _otherToken == IOptimismMintableERC20(_mintableToken).remoteToken();
        }
    }

    /** @notice Emits the ETHBridgeInitiated event and if necessary the appropriate legacy event
     *          when an ETH bridge is finalized on this chain.
     *
     * @param _from      Address of the sender.
     * @param _to        Address of the receiver.
     * @param _amount    Amount of ETH sent.
     * @param _extraData Extra data sent with the transaction.
     */
    function _emitETHBridgeInitiated(
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal virtual {
        emit ETHBridgeInitiated(_from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the ETHBridgeFinalized and if necessary the appropriate legacy event when an
     *         ETH bridge is finalized on this chain.
     *
     * @param _from      Address of the sender.
     * @param _to        Address of the receiver.
     * @param _amount    Amount of ETH sent.
     * @param _extraData Extra data sent with the transaction.
     */
    function _emitETHBridgeFinalized(
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal virtual {
        emit ETHBridgeFinalized(_from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the ERC20BridgeInitiated event and if necessary the appropriate legacy
     *         event when an ERC20 bridge is initiated to the other chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the ERC20 on the remote chain.
     * @param _from        Address of the sender.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of the ERC20 sent.
     * @param _extraData   Extra data sent with the transaction.
     */
    function _emitERC20BridgeInitiated(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal virtual {
        emit ERC20BridgeInitiated(_localToken, _remoteToken, _from, _to, _amount, _extraData);
    }

    /**
     * @notice Emits the ERC20BridgeFinalized event and if necessary the appropriate legacy
     *         event when an ERC20 bridge is initiated to the other chain.
     *
     * @param _localToken  Address of the ERC20 on this chain.
     * @param _remoteToken Address of the ERC20 on the remote chain.
     * @param _from        Address of the sender.
     * @param _to          Address of the receiver.
     * @param _amount      Amount of the ERC20 sent.
     * @param _extraData   Extra data sent with the transaction.
     */
    function _emitERC20BridgeFinalized(
        address _localToken,
        address _remoteToken,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _extraData
    ) internal virtual {
        emit ERC20BridgeFinalized(_localToken, _remoteToken, _from, _to, _amount, _extraData);
    }
}

// File: node_modules/@openzeppelin/contracts/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/Address.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) || (!Address.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: node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol



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

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.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 ERC20 is Context, IERC20, IERC20Metadata {
    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.
     */
    constructor(string memory name_, string memory symbol_) {
        _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 {}
}

// File: node_modules/@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: node_modules/@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: node_modules/@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.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 IERC20Permit {
    /**
     * @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: node_modules/@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



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

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.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 SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 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(
        IERC20 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(
        IERC20 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(
        IERC20 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(
        IERC20Permit 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(IERC20 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: node_modules/@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: node_modules/@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: node_modules/@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: node_modules/@openzeppelin/contracts/utils/introspection/ERC165Checker.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (utils/introspection/ERC165Checker.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Library used to query support of an interface declared via {IERC165}.
 *
 * Note that these functions return the actual result of the query: they do not
 * `revert` if an interface is not supported. It is up to the caller to decide
 * what to do in these cases.
 */
library ERC165Checker {
    // As per the EIP-165 spec, no interface should ever match 0xffffffff
    bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;

    /**
     * @dev Returns true if `account` supports the {IERC165} interface,
     */
    function supportsERC165(address account) internal view returns (bool) {
        // Any contract that implements ERC165 must explicitly indicate support of
        // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
        return
            _supportsERC165Interface(account, type(IERC165).interfaceId) &&
            !_supportsERC165Interface(account, _INTERFACE_ID_INVALID);
    }

    /**
     * @dev Returns true if `account` supports the interface defined by
     * `interfaceId`. Support for {IERC165} itself is queried automatically.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
        // query support of both ERC165 as per the spec and support of _interfaceId
        return supportsERC165(account) && _supportsERC165Interface(account, interfaceId);
    }

    /**
     * @dev Returns a boolean array where each value corresponds to the
     * interfaces passed in and whether they're supported or not. This allows
     * you to batch check interfaces for a contract where your expectation
     * is that some interfaces may not be supported.
     *
     * See {IERC165-supportsInterface}.
     *
     * _Available since v3.4._
     */
    function getSupportedInterfaces(address account, bytes4[] memory interfaceIds)
        internal
        view
        returns (bool[] memory)
    {
        // an array of booleans corresponding to interfaceIds and whether they're supported or not
        bool[] memory interfaceIdsSupported = new bool[](interfaceIds.length);

        // query support of ERC165 itself
        if (supportsERC165(account)) {
            // query support of each interface in interfaceIds
            for (uint256 i = 0; i < interfaceIds.length; i++) {
                interfaceIdsSupported[i] = _supportsERC165Interface(account, interfaceIds[i]);
            }
        }

        return interfaceIdsSupported;
    }

    /**
     * @dev Returns true if `account` supports all the interfaces defined in
     * `interfaceIds`. Support for {IERC165} itself is queried automatically.
     *
     * Batch-querying can lead to gas savings by skipping repeated checks for
     * {IERC165} support.
     *
     * See {IERC165-supportsInterface}.
     */
    function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
        // query support of ERC165 itself
        if (!supportsERC165(account)) {
            return false;
        }

        // query support of each interface in _interfaceIds
        for (uint256 i = 0; i < interfaceIds.length; i++) {
            if (!_supportsERC165Interface(account, interfaceIds[i])) {
                return false;
            }
        }

        // all interfaces supported
        return true;
    }

    /**
     * @notice Query if a contract implements an interface, does not check ERC165 support
     * @param account The address of the contract to query for support of an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @return true if the contract at account indicates support of the interface with
     * identifier interfaceId, false otherwise
     * @dev Assumes that account contains a contract that supports ERC165, otherwise
     * the behavior of this method is undefined. This precondition can be checked
     * with {supportsERC165}.
     * Interface identification is specified in ERC-165.
     */
    function _supportsERC165Interface(address account, bytes4 interfaceId) private view returns (bool) {
        // prepare call
        bytes memory encodedParams = abi.encodeWithSelector(IERC165.supportsInterface.selector, interfaceId);

        // perform static call
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly {
            success := staticcall(30000, account, add(encodedParams, 0x20), mload(encodedParams), 0x00, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0x00)
        }

        return success && returnSize >= 0x20 && returnValue > 0;
    }
}

// File: node_modules/@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: node_modules/@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: node_modules/@openzeppelin/contracts/utils/math/SignedMath.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

// File: node_modules/@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: node_modules/@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: node_modules/@rari-capital/solmate/src/utils/FixedPointMathLib.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/FixedPointMathLib.sol)
library FixedPointMathLib {
    /*//////////////////////////////////////////////////////////////
                    SIMPLIFIED FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.

    function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
    }

    function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
    }

    function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
    }

    function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
    }

    function powWad(int256 x, int256 y) internal pure returns (int256) {
        // Equivalent to x to the power of y because x ** y = (e ** ln(x)) ** y = e ** (ln(x) * y)
        return expWad((lnWad(x) * y) / int256(WAD)); // Using ln(x) means x must be greater than 0.
    }

    function expWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            // When the result is < 0.5 we return zero. This happens when
            // x <= floor(log(0.5e18) * 1e18) ~ -42e18
            if (x <= -42139678854452767551) return 0;

            // When the result is > (2**255 - 1) / 1e18 we can not represent it as an
            // int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
            if (x >= 135305999368893231589) revert("EXP_OVERFLOW");

            // x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
            // for more intermediate precision and a binary basis. This base conversion
            // is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
            x = (x << 78) / 5**18;

            // Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
            // of two such that exp(x) = exp(x') * 2**k, where k is an integer.
            // Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
            int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
            x = x - k * 54916777467707473351141471128;

            // k is in the range [-61, 195].

            // Evaluate using a (6, 7)-term rational approximation.
            // p is made monic, we'll multiply by a scale factor later.
            int256 y = x + 1346386616545796478920950773328;
            y = ((y * x) >> 96) + 57155421227552351082224309758442;
            int256 p = y + x - 94201549194550492254356042504812;
            p = ((p * y) >> 96) + 28719021644029726153956944680412240;
            p = p * x + (4385272521454847904659076985693276 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            int256 q = x - 2855989394907223263936484059900;
            q = ((q * x) >> 96) + 50020603652535783019961831881945;
            q = ((q * x) >> 96) - 533845033583426703283633433725380;
            q = ((q * x) >> 96) + 3604857256930695427073651918091429;
            q = ((q * x) >> 96) - 14423608567350463180887372962807573;
            q = ((q * x) >> 96) + 26449188498355588339934803723976023;

            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial won't have zeros in the domain as all its roots are complex.
                // No scaling is necessary because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r should be in the range (0.09, 0.25) * 2**96.

            // We now need to multiply r by:
            // * the scale factor s = ~6.031367120.
            // * the 2**k factor from the range reduction.
            // * the 1e18 / 2**96 factor for base conversion.
            // We do this all at once, with an intermediate result in 2**213
            // basis, so the final right shift is always by a positive amount.
            r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
        }
    }

    function lnWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            require(x > 0, "UNDEFINED");

            // We want to convert x from 10**18 fixed point to 2**96 fixed point.
            // We do this by multiplying by 2**96 / 10**18. But since
            // ln(x * C) = ln(x) + ln(C), we can simply do nothing here
            // and add ln(2**96 / 10**18) at the end.

            // Reduce range of x to (1, 2) * 2**96
            // ln(2^k * x) = k * ln(2) + ln(x)
            int256 k = int256(log2(uint256(x))) - 96;
            x <<= uint256(159 - k);
            x = int256(uint256(x) >> 159);

            // Evaluate using a (8, 8)-term rational approximation.
            // p is made monic, we will multiply by a scale factor later.
            int256 p = x + 3273285459638523848632254066296;
            p = ((p * x) >> 96) + 24828157081833163892658089445524;
            p = ((p * x) >> 96) + 43456485725739037958740375743393;
            p = ((p * x) >> 96) - 11111509109440967052023855526967;
            p = ((p * x) >> 96) - 45023709667254063763336534515857;
            p = ((p * x) >> 96) - 14706773417378608786704636184526;
            p = p * x - (795164235651350426258249787498 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            // q is monic by convention.
            int256 q = x + 5573035233440673466300451813936;
            q = ((q * x) >> 96) + 71694874799317883764090561454958;
            q = ((q * x) >> 96) + 283447036172924575727196451306956;
            q = ((q * x) >> 96) + 401686690394027663651624208769553;
            q = ((q * x) >> 96) + 204048457590392012362485061816622;
            q = ((q * x) >> 96) + 31853899698501571402653359427138;
            q = ((q * x) >> 96) + 909429971244387300277376558375;
            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial is known not to have zeros in the domain.
                // No scaling required because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r is in the range (0, 0.125) * 2**96

            // Finalization, we need to:
            // * multiply by the scale factor s = 5.549…
            // * add ln(2**96 / 10**18)
            // * add k * ln(2)
            // * multiply by 10**18 / 2**96 = 5**18 >> 78

            // mul s * 5e18 * 2**96, base is now 5**18 * 2**192
            r *= 1677202110996718588342820967067443963516166;
            // add ln(2) * k * 5e18 * 2**192
            r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
            // add ln(2**96 / 10**18) * 5e18 * 2**192
            r += 600920179829731861736702779321621459595472258049074101567377883020018308;
            // base conversion: mul 2**18 / 2**192
            r >>= 174;
        }
    }

    /*//////////////////////////////////////////////////////////////
                    LOW LEVEL FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // Divide z by the denominator.
            z := div(z, denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // First, divide z - 1 by the denominator and add 1.
            // We allow z - 1 to underflow if z is 0, because we multiply the
            // end result by 0 if z is zero, ensuring we return 0 if z is zero.
            z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
        }
    }

    function rpow(
        uint256 x,
        uint256 n,
        uint256 scalar
    ) internal pure returns (uint256 z) {
        assembly {
            switch x
            case 0 {
                switch n
                case 0 {
                    // 0 ** 0 = 1
                    z := scalar
                }
                default {
                    // 0 ** n = 0
                    z := 0
                }
            }
            default {
                switch mod(n, 2)
                case 0 {
                    // If n is even, store scalar in z for now.
                    z := scalar
                }
                default {
                    // If n is odd, store x in z for now.
                    z := x
                }

                // Shifting right by 1 is like dividing by 2.
                let half := shr(1, scalar)

                for {
                    // Shift n right by 1 before looping to halve it.
                    n := shr(1, n)
                } n {
                    // Shift n right by 1 each iteration to halve it.
                    n := shr(1, n)
                } {
                    // Revert immediately if x ** 2 would overflow.
                    // Equivalent to iszero(eq(div(xx, x), x)) here.
                    if shr(128, x) {
                        revert(0, 0)
                    }

                    // Store x squared.
                    let xx := mul(x, x)

                    // Round to the nearest number.
                    let xxRound := add(xx, half)

                    // Revert if xx + half overflowed.
                    if lt(xxRound, xx) {
                        revert(0, 0)
                    }

                    // Set x to scaled xxRound.
                    x := div(xxRound, scalar)

                    // If n is even:
                    if mod(n, 2) {
                        // Compute z * x.
                        let zx := mul(z, x)

                        // If z * x overflowed:
                        if iszero(eq(div(zx, x), z)) {
                            // Revert if x is non-zero.
                            if iszero(iszero(x)) {
                                revert(0, 0)
                            }
                        }

                        // Round to the nearest number.
                        let zxRound := add(zx, half)

                        // Revert if zx + half overflowed.
                        if lt(zxRound, zx) {
                            revert(0, 0)
                        }

                        // Return properly scaled zxRound.
                        z := div(zxRound, scalar)
                    }
                }
            }
        }
    }

    /*//////////////////////////////////////////////////////////////
                        GENERAL NUMBER UTILITIES
    //////////////////////////////////////////////////////////////*/

    function sqrt(uint256 x) internal pure returns (uint256 z) {
        assembly {
            let y := x // We start y at x, which will help us make our initial estimate.

            z := 181 // The "correct" value is 1, but this saves a multiplication later.

            // This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
            // start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.

            // We check y >= 2^(k + 8) but shift right by k bits
            // each branch to ensure that if x >= 256, then y >= 256.
            if iszero(lt(y, 0x10000000000000000000000000000000000)) {
                y := shr(128, y)
                z := shl(64, z)
            }
            if iszero(lt(y, 0x1000000000000000000)) {
                y := shr(64, y)
                z := shl(32, z)
            }
            if iszero(lt(y, 0x10000000000)) {
                y := shr(32, y)
                z := shl(16, z)
            }
            if iszero(lt(y, 0x1000000)) {
                y := shr(16, y)
                z := shl(8, z)
            }

            // Goal was to get z*z*y within a small factor of x. More iterations could
            // get y in a tighter range. Currently, we will have y in [256, 256*2^16).
            // We ensured y >= 256 so that the relative difference between y and y+1 is small.
            // That's not possible if x < 256 but we can just verify those cases exhaustively.

            // Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
            // Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
            // Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.

            // For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
            // (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.

            // Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
            // sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.

            // There is no overflow risk here since y < 2^136 after the first branch above.
            z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.

            // Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))

            // If x+1 is a perfect square, the Babylonian method cycles between
            // floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
            // See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
            // Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
            // If you don't care whether the floor or ceil square root is returned, you can remove this statement.
            z := sub(z, lt(div(x, z), z))
        }
    }

    function log2(uint256 x) internal pure returns (uint256 r) {
        require(x > 0, "UNDEFINED");

        assembly {
            r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
            r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
            r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
            r := or(r, shl(4, lt(0xffff, shr(r, x))))
            r := or(r, shl(3, lt(0xff, shr(r, x))))
            r := or(r, shl(2, lt(0xf, shr(r, x))))
            r := or(r, shl(1, lt(0x3, shr(r, x))))
            r := or(r, lt(0x1, shr(r, x)))
        }
    }
}