// File: src/contracts/FraxlendPairDeployer.sol



// SPDX-License-Identifier: ISC
pragma solidity ^0.8.17;

// ====================================================================
// |     ______                   _______                             |
// |    / _____________ __  __   / ____(_____  ____ _____  ________   |
// |   / /_  / ___/ __ `| |/_/  / /_  / / __ \/ __ `/ __ \/ ___/ _ \  |
// |  / __/ / /  / /_/ _>  <   / __/ / / / / / /_/ / / / / /__/  __/  |
// | /_/   /_/   \__,_/_/|_|  /_/   /_/_/ /_/\__,_/_/ /_/\___/\___/   |
// |                                                                  |
// ====================================================================
// ====================== FraxlendPairDeployer ========================
// ====================================================================
// Frax Finance: https://github.com/FraxFinance

// Primary Author
// Drake Evans: https://github.com/DrakeEvans

// Reviewers
// Dennis: https://github.com/denett
// Sam Kazemian: https://github.com/samkazemian
// Travis Moore: https://github.com/FortisFortuna
// Jack Corddry: https://github.com/corddry
// Rich Gee: https://github.com/zer0blockchain

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

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@rari-capital/solmate/src/utils/SSTORE2.sol";
import "solidity-bytes-utils/contracts/BytesLib.sol";
import "./interfaces/IRateCalculator.sol";
import "./interfaces/IFraxlendWhitelist.sol";
import "./interfaces/IFraxlendPair.sol";
import "./interfaces/IFraxlendPairRegistry.sol";
import "./libraries/SafeERC20.sol";

// solhint-disable no-inline-assembly

/// @title FraxlendPairDeployer
/// @author Drake Evans (Frax Finance) https://github.com/drakeevans
/// @notice Deploys and initializes new FraxlendPairs
/// @dev Uses create2 to deploy the pairs, logs an event, and records a list of all deployed pairs
contract FraxlendPairDeployer is Ownable {
    using Strings for uint256;
    using SafeERC20 for IERC20;

    // Storage
    address public contractAddress1;
    address public contractAddress2;

    // Admin contracts
    address public CIRCUIT_BREAKER_ADDRESS;
    address public COMPTROLLER_ADDRESS;
    address public TIMELOCK_ADDRESS;
    address public FRAXLEND_PAIR_REGISTRY_ADDRESS;
    address public FRAXLEND_WHITELIST_ADDRESS;

    // Default swappers
    address[] public defaultSwappers;

    /// @notice Emits when a new pair is deployed
    /// @notice The ```LogDeploy``` event is emitted when a new Pair is deployed
    /// @param _address The address of the pair
    /// @param _asset The address of the Asset Token contract
    /// @param _collateral The address of the Collateral Token contract
    /// @param _name The name of the Pair
    event LogDeploy(address indexed _address, address indexed _asset, address indexed _collateral, string _name);

    /// @notice List of the names of all deployed Pairs
    address[] public deployedPairsArray;

    constructor(
        address _circuitBreaker,
        address _comptroller,
        address _timelock,
        address _fraxlendWhitelist,
        address _fraxlendPairRegistry
    ) Ownable() {
        CIRCUIT_BREAKER_ADDRESS = _circuitBreaker;
        COMPTROLLER_ADDRESS = _comptroller;
        TIMELOCK_ADDRESS = _timelock;
        FRAXLEND_WHITELIST_ADDRESS = _fraxlendWhitelist;
        FRAXLEND_PAIR_REGISTRY_ADDRESS = _fraxlendPairRegistry;
    }

    function version() external pure returns (uint256 _major, uint256 _minor, uint256 _patch) {
        return (3, 0, 0);
    }

    // ============================================================================================
    // Functions: View Functions
    // ============================================================================================

    /// @notice The ```deployedPairsLength``` function returns the length of the deployedPairsArray
    /// @return length of array
    function deployedPairsLength() external view returns (uint256) {
        return deployedPairsArray.length;
    }

    /// @notice The ```getAllPairAddresses``` function returns all pair addresses in deployedPairsArray
    /// @return _deployedPairs memory All deployed pair addresses
    function getAllPairAddresses() external view returns (address[] memory _deployedPairs) {
        _deployedPairs = deployedPairsArray;
    }

    function getNextNameSymbol(address _asset, address _collateral)
        public
        view
        returns (string memory _name, string memory _symbol)
    {
        uint256 _length = IFraxlendPairRegistry(FRAXLEND_PAIR_REGISTRY_ADDRESS).deployedPairsLength();
        _name = string(
            abi.encodePacked(
                "Fraxlend Interest Bearing ",
                IERC20(_asset).safeSymbol(),
                " (",
                IERC20(_collateral).safeName(),
                ")",
                " - ",
                (_length + 1).toString()
            )
        );
        _symbol = string(
            abi.encodePacked(
                "f",
                IERC20(_asset).safeSymbol(),
                "(",
                IERC20(_collateral).safeSymbol(),
                ")",
                "-",
                (_length + 1).toString()
            )
        );
    }

    // ============================================================================================
    // Functions: Setters
    // ============================================================================================

    /// @notice The ```setCreationCode``` function sets the bytecode for the fraxlendPair
    /// @dev splits the data if necessary to accommodate creation code that is slightly larger than 24kb
    /// @param _creationCode The creationCode for the Fraxlend Pair
    function setCreationCode(bytes calldata _creationCode) external onlyOwner {
        bytes memory _firstHalf = BytesLib.slice(_creationCode, 0, 13000);
        contractAddress1 = SSTORE2.write(_firstHalf);
        if (_creationCode.length > 13000) {
            bytes memory _secondHalf = BytesLib.slice(_creationCode, 13000, _creationCode.length - 13000);
            contractAddress2 = SSTORE2.write(_secondHalf);
        }
    }

    /// @notice The ```setDefaultSwappers``` function is used to set default list of approved swappers
    /// @param _swappers The list of swappers to set as default allowed
    function setDefaultSwappers(address[] memory _swappers) external onlyOwner {
        defaultSwappers = _swappers;
    }

    /// @notice The ```SetTimelock``` event is emitted when the TIMELOCK_ADDRESS is set
    /// @param _oldAddress The original address
    /// @param _newAddress The new address
    event SetTimelock(address _oldAddress, address _newAddress);

    /// @notice The ```setTimelock``` function sets the TIMELOCK_ADDRESS
    /// @param _newAddress the new time lock address
    function setTimelock(address _newAddress) external onlyOwner {
        emit SetTimelock(TIMELOCK_ADDRESS, _newAddress);
        TIMELOCK_ADDRESS = _newAddress;
    }

    /// @notice The ```SetRegistry``` event is emitted when the FRAXLEND_PAIR_REGISTRY_ADDRESS is set
    /// @param _oldAddress The old address
    /// @param _newAddress The new address
    event SetRegistry(address _oldAddress, address _newAddress);

    /// @notice The ```setRegistry``` function sets the FRAXLEND_PAIR_REGISTRY_ADDRESS
    /// @param _newAddress The new address
    function setRegistry(address _newAddress) external onlyOwner {
        emit SetRegistry(FRAXLEND_PAIR_REGISTRY_ADDRESS, _newAddress);
        FRAXLEND_PAIR_REGISTRY_ADDRESS = _newAddress;
    }

    /// @notice The ```SetComptroller``` event is emitted when the COMPTROLLER_ADDRESS is set
    /// @param _oldAddress The old address
    /// @param _newAddress The new address
    event SetComptroller(address _oldAddress, address _newAddress);

    /// @notice The ```setComptroller``` function sets the COMPTROLLER_ADDRESS
    /// @param _newAddress The new address
    function setComptroller(address _newAddress) external onlyOwner {
        emit SetComptroller(COMPTROLLER_ADDRESS, _newAddress);
        COMPTROLLER_ADDRESS = _newAddress;
    }

    /// @notice The ```SetWhitelist``` event is emitted when the FRAXLEND_WHITELIST_ADDRESS is set
    /// @param _oldAddress The old address
    /// @param _newAddress The new address
    event SetWhitelist(address _oldAddress, address _newAddress);

    /// @notice The ```setWhitelist``` function sets the FRAXLEND_WHITELIST_ADDRESS
    /// @param _newAddress The new address
    function setWhitelist(address _newAddress) external onlyOwner {
        emit SetWhitelist(FRAXLEND_WHITELIST_ADDRESS, _newAddress);
        FRAXLEND_WHITELIST_ADDRESS = _newAddress;
    }

    /// @notice The ```SetCircuitBreaker``` event is emitted when the CIRCUIT_BREAKER_ADDRESS is set
    /// @param _oldAddress The old address
    /// @param _newAddress The new address
    event SetCircuitBreaker(address _oldAddress, address _newAddress);

    /// @notice The ```setCircuitBreaker``` function sets the CIRCUIT_BREAKER_ADDRESS
    /// @param _newAddress The new address
    function setCircuitBreaker(address _newAddress) external onlyOwner {
        emit SetCircuitBreaker(CIRCUIT_BREAKER_ADDRESS, _newAddress);
        CIRCUIT_BREAKER_ADDRESS = _newAddress;
    }

    // ============================================================================================
    // Functions: Internal Methods
    // ============================================================================================

    /// @notice The ```_deploy``` function is an internal function with deploys the pair
    /// @param _configData abi.encode(address _asset, address _collateral, address _oracleMultiply, address _oracleDivide, uint144 _oracleNormalization, address _rateContract, uint64 _fullUtilizationRate)
    /// @param _immutables abi.encode(address _circuitBreaker, address _comptrollerAddress, address _timeLockAddress, address _fraxlendWhitelistAddress)
    /// @param _customConfigData abi.encode(string _nameOfContract, string _symbolOfContract, uint8 _decimalsOfContract, uint256 _maxLTV, uint256 _liquidationFee, uint256 _maturityDate, uint256 _penaltyRate, address[] _approvedBorrowers, address[] _approvedLenders)
    /// @return _pairAddress The address to which the Pair was deployed
    function _deploy(bytes memory _configData, bytes memory _immutables, bytes memory _customConfigData)
        private
        returns (address _pairAddress)
    {
        // Get creation code
        bytes memory _creationCode = BytesLib.concat(SSTORE2.read(contractAddress1), SSTORE2.read(contractAddress2));

        // Get bytecode
        bytes memory bytecode = abi.encodePacked(
            _creationCode,
            abi.encode(_configData, _immutables, _customConfigData)
        );

        // Generate salt using constructor params
        bytes32 salt = keccak256(abi.encodePacked(_configData, _immutables, _customConfigData));

        /// @solidity memory-safe-assembly
        assembly {
            _pairAddress := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        if (_pairAddress == address(0)) revert Create2Failed();

        deployedPairsArray.push(_pairAddress);

        // Set additional values for FraxlendPair
        IFraxlendPair _fraxlendPair = IFraxlendPair(_pairAddress);
        address[] memory _defaultSwappers = defaultSwappers;
        for (uint256 i = 0; i < _defaultSwappers.length; i++) {
            _fraxlendPair.setSwapper(_defaultSwappers[i], true);
        }

        return _pairAddress;
    }

    /// @notice The ```_logDeploy``` function emits a LogDeploy event
    /// @param _name The name of the Pair
    /// @param _pairAddress The address of the Pair
    /// @param _configData abi.encode(address _asset, address _collateral, address _oracleMultiply, address _oracleDivide, uint144 _oracleNormalization, address _rateContract, uint64 _fullUtilizationRate)
    function _logDeploy(string memory _name, address _pairAddress, bytes memory _configData) private {
        (address _asset, address _collateral, , , , , ) = abi.decode(
            _configData,
            (address, address, address, address, uint144, address, uint64)
        );
        emit LogDeploy(_pairAddress, _asset, _collateral, _name);
    }

    // ============================================================================================
    // Functions: External Deploy Methods
    // ============================================================================================

    /// @notice The ```deployWithDefaults``` function allows the deployment of a FraxlendPair with default values
    /// @param _configData abi.encode(address _asset, address _collateral, address _oracleMultiply, address _oracleDivide, uint144 _oracleNormalization, address _rateContract, uint64 _fullUtilizationRate)
    /// @return _pairAddress The address to which the Pair was deployed
    function deploy(bytes memory _configData) external returns (address _pairAddress) {
        if (!IFraxlendWhitelist(FRAXLEND_WHITELIST_ADDRESS).fraxlendDeployerWhitelist(msg.sender))
            revert WhitelistedDeployersOnly();

        (address _asset, address _collateral, , , , , , , ) = abi.decode(
            _configData,
            (address, address, address, uint32, address, uint64, uint256, uint256, uint256)
        );

        (string memory _name, string memory _symbol) = getNextNameSymbol(_asset, _collateral);

        _pairAddress = _deploy(
            _configData,
            abi.encode(CIRCUIT_BREAKER_ADDRESS, COMPTROLLER_ADDRESS, TIMELOCK_ADDRESS),
            abi.encode(_name, _symbol, IERC20(_asset).safeDecimals())
        );

        IFraxlendPairRegistry(FRAXLEND_PAIR_REGISTRY_ADDRESS).addPair(_pairAddress);

        emit LogDeploy(_pairAddress, _asset, _collateral, _name);
    }

    // ============================================================================================
    // Functions: Admin
    // ============================================================================================

    /// @notice The ```globalPause``` function calls the pause() function on a given set of pair addresses
    /// @dev Ignores reverts when calling pause()
    /// @param _addresses Addresses to attempt to pause()
    /// @return _updatedAddresses Addresses for which pause() was successful
    function globalPause(address[] memory _addresses) external returns (address[] memory _updatedAddresses) {
        if (msg.sender != CIRCUIT_BREAKER_ADDRESS) revert CircuitBreakerOnly();

        address _pairAddress;
        uint256 _lengthOfArray = _addresses.length;
        _updatedAddresses = new address[](_lengthOfArray);
        for (uint256 i = 0; i < _lengthOfArray; ) {
            _pairAddress = _addresses[i];
            try IFraxlendPair(_pairAddress).pause() {
                _updatedAddresses[i] = _addresses[i];
            } catch {}
            unchecked {
                i = i + 1;
            }
        }
    }

    // ============================================================================================
    // Errors
    // ============================================================================================

    error CircuitBreakerOnly();
    error WhitelistedDeployersOnly();
    error Create2Failed();
}

// File: src/contracts/interfaces/IRateCalculator.sol



// SPDX-License-Identifier: ISC
pragma solidity >=0.8.17;

interface IRateCalculator {
    function name() external pure returns (string memory);

    function requireValidInitData(bytes calldata _initData) external pure;

    function getConstants() external pure returns (bytes memory _calldata);

    function getNewRate(bytes calldata _data, bytes calldata _initData) external pure returns (uint64 _newRatePerSec);
}

// File: src/contracts/interfaces/IFraxlendPairRegistry.sol



// SPDX-License-Identifier: ISC
pragma solidity ^0.8.17;

interface IFraxlendPairRegistry {
    function addPair(address _pairAddress) external;

    function addSalt(address _pairAddress, bytes32 _salt) external;

    function deployedPairsArray(uint256) external view returns (address);

    function deployedPairsByName(string memory) external view returns (address);

    function deployedPairsBySalt(bytes32) external view returns (address);

    function deployedPairsLength() external view returns (uint256);

    function deployedSaltsArray(uint256) external view returns (address);

    function deployedSaltsLength() external view returns (uint256);

    function deployers(address) external view returns (bool);

    function getAllPairAddresses() external view returns (address[] memory _deployedPairsArray);

    function getAllPairSalts() external view returns (address[] memory _deployedSaltsArray);

    function owner() external view returns (address);

    function renounceOwnership() external;

    function setDeployers(address[] memory _deployers, bool _bool) external;

    function transferOwnership(address newOwner) external;
}

// File: src/contracts/interfaces/IFraxlendPair.sol



// SPDX-License-Identifier: ISC
pragma solidity >=0.8.17;

interface IFraxlendPair {
    function CIRCUIT_BREAKER_ADDRESS() external view returns (address);

    function COMPTROLLER_ADDRESS() external view returns (address);

    function DEPLOYER_ADDRESS() external view returns (address);

    function FRAXLEND_WHITELIST_ADDRESS() external view returns (address);

    function timelockAddress() external view returns (address);

    function addCollateral(uint256 _collateralAmount, address _borrower) external;

    function addInterest()
        external
        returns (uint256 _interestEarned, uint256 _feesAmount, uint256 _feesShare, uint64 _newRate);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function approvedBorrowers(address) external view returns (bool);

    function approvedLenders(address) external view returns (bool);

    function asset() external view returns (address);

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

    function borrowAsset(uint256 _borrowAmount, uint256 _collateralAmount, address _receiver)
        external
        returns (uint256 _shares);

    function borrowerWhitelistActive() external view returns (bool);

    function changeFee(uint32 _newFee) external;

    function cleanLiquidationFee() external view returns (uint256);

    function collateralContract() external view returns (address);

    function currentRateInfo()
        external
        view
        returns (
            uint32 lastBlock,
            uint32 feeToProtocolRate,
            uint64 lastTimestamp,
            uint64 ratePerSec,
            uint64 fullUtilizationRate
        );

    function decimals() external view returns (uint8);

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

    function deposit(uint256 _amount, address _receiver) external returns (uint256 _sharesReceived);

    function dirtyLiquidationFee() external view returns (uint256);

    function exchangeRateInfo() external view returns (uint32 lastTimestamp, uint224 exchangeRate);

    function getConstants()
        external
        pure
        returns (
            uint256 _LTV_PRECISION,
            uint256 _LIQ_PRECISION,
            uint256 _UTIL_PREC,
            uint256 _FEE_PRECISION,
            uint256 _EXCHANGE_PRECISION,
            uint64 _DEFAULT_INT,
            uint16 _DEFAULT_PROTOCOL_FEE,
            uint256 _MAX_PROTOCOL_FEE
        );

    function getImmutableAddressBool()
        external
        view
        returns (
            address _assetContract,
            address _collateralContract,
            address _oracleMultiply,
            address _oracleDivide,
            address _rateContract,
            address _DEPLOYER_CONTRACT,
            address _COMPTROLLER_ADDRESS,
            address _FRAXLEND_WHITELIST,
            bool _borrowerWhitelistActive,
            bool _lenderWhitelistActive
        );

    function getImmutableUint256()
        external
        view
        returns (
            uint256 _oracleNormalization,
            uint256 _maxLTV,
            uint256 _cleanLiquidationFee,
            uint256 _maturityDate,
            uint256 _penaltyRate
        );

    function getPairAccounting()
        external
        view
        returns (
            uint128 _totalAssetAmount,
            uint128 _totalAssetShares,
            uint128 _totalBorrowAmount,
            uint128 _totalBorrowShares,
            uint256 _totalCollateral
        );

    function getUserSnapshot(address _address)
        external
        view
        returns (uint256 _userAssetShares, uint256 _userBorrowShares, uint256 _userCollateralBalance);

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

    function lenderWhitelistActive() external view returns (bool);

    function leveragedPosition(
        address _swapperAddress,
        uint256 _borrowAmount,
        uint256 _initialCollateralAmount,
        uint256 _amountCollateralOutMin,
        address[] memory _path
    ) external returns (uint256 _totalCollateralBalance);

    function liquidate(uint128 _sharesToLiquidate, uint256 _deadline, address _borrower)
        external
        returns (uint256 _collateralForLiquidator);

    function maturityDate() external view returns (uint256);

    function maxLTV() external view returns (uint256);

    function maxOracleDelay() external view returns (uint256);

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

    function oracleDivide() external view returns (address);

    function oracleMultiply() external view returns (address);

    function oracleNormalization() external view returns (uint256);

    function owner() external view returns (address);

    function pause() external;

    function paused() external view returns (bool);

    function penaltyRate() external view returns (uint256);

    function rateContract() external view returns (address);

    function redeem(uint256 _shares, address _receiver, address _owner) external returns (uint256 _amountToReturn);

    function removeCollateral(uint256 _collateralAmount, address _receiver) external;

    function renounceOwnership() external;

    function repayAsset(uint256 _shares, address _borrower) external returns (uint256 _amountToRepay);

    function repayAssetWithCollateral(
        address _swapperAddress,
        uint256 _collateralToSwap,
        uint256 _amountAssetOutMin,
        address[] memory _path
    ) external returns (uint256 _amountAssetOut);

    function setApprovedBorrowers(address[] memory _borrowers, bool _approval) external;

    function setApprovedLenders(address[] memory _lenders, bool _approval) external;

    function setMaxOracleDelay(uint256 _newDelay) external;

    function setSwapper(address _swapper, bool _approval) external;

    function setTimelock(address _newAddress) external;

    function swappers(address) external view returns (bool);

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

    function toAssetAmount(uint256 _shares, bool _roundUp) external view returns (uint256);

    function toAssetShares(uint256 _amount, bool _roundUp) external view returns (uint256);

    function toBorrowAmount(uint256 _shares, bool _roundUp) external view returns (uint256);

    function toBorrowShares(uint256 _amount, bool _roundUp) external view returns (uint256);

    function totalAsset() external view returns (uint128 amount, uint128 shares);

    function totalBorrow() external view returns (uint128 amount, uint128 shares);

    function totalCollateral() external view returns (uint256);

    function totalSupply() external view returns (uint256);

    function transfer(address to, uint256 amount) external returns (bool);

    function transferFrom(address from, address to, uint256 amount) external returns (bool);

    function transferOwnership(address newOwner) external;

    function unpause() external;

    function updateExchangeRate() external returns (uint256 _exchangeRate);

    function userBorrowShares(address) external view returns (uint256);

    function userCollateralBalance(address) external view returns (uint256);

    function version() external pure returns (uint256 _major, uint256 _minor, uint256 _patch);

    function withdrawFees(uint128 _shares, address _recipient) external returns (uint256 _amountToTransfer);
}

// File: src/contracts/interfaces/IFraxlendWhitelist.sol



// SPDX-License-Identifier: ISC
pragma solidity >=0.8.17;

interface IFraxlendWhitelist {
    function fraxlendDeployerWhitelist(address) external view returns (bool);

    function oracleContractWhitelist(address) external view returns (bool);

    function owner() external view returns (address);

    function rateContractWhitelist(address) external view returns (bool);

    function renounceOwnership() external;

    function setFraxlendDeployerWhitelist(address[] calldata _addresses, bool _bool) external;

    function setOracleContractWhitelist(address[] calldata _addresses, bool _bool) external;

    function setRateContractWhitelist(address[] calldata _addresses, bool _bool) external;

    function transferOwnership(address newOwner) external;
}

// File: src/contracts/libraries/SafeERC20.sol



// SPDX-License-Identifier: ISC
pragma solidity ^0.8.17;

import "@openzeppelin/contracts/interfaces/IERC20.sol";
import { SafeERC20 as OZSafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

// solhint-disable avoid-low-level-calls
// solhint-disable max-line-length

/// @title SafeERC20 provides helper functions for safe transfers as well as safe metadata access
/// @author Library originally written by @Boring_Crypto github.com/boring_crypto, modified by Drake Evans (Frax Finance) github.com/drakeevans
/// @dev original: https://github.com/boringcrypto/BoringSolidity/blob/fed25c5d43cb7ce20764cd0b838e21a02ea162e9/contracts/libraries/BoringERC20.sol
library SafeERC20 {
    bytes4 private constant SIG_SYMBOL = 0x95d89b41; // symbol()
    bytes4 private constant SIG_NAME = 0x06fdde03; // name()
    bytes4 private constant SIG_DECIMALS = 0x313ce567; // decimals()

    function returnDataToString(bytes memory data) internal pure returns (string memory) {
        if (data.length >= 64) {
            return abi.decode(data, (string));
        } else if (data.length == 32) {
            uint8 i = 0;
            while (i < 32 && data[i] != 0) {
                i++;
            }
            bytes memory bytesArray = new bytes(i);
            for (i = 0; i < 32 && data[i] != 0; i++) {
                bytesArray[i] = data[i];
            }
            return string(bytesArray);
        } else {
            return "???";
        }
    }

    /// @notice Provides a safe ERC20.symbol version which returns '???' as fallback string.
    /// @param token The address of the ERC-20 token contract.
    /// @return (string) Token symbol.
    function safeSymbol(IERC20 token) internal view returns (string memory) {
        (bool success, bytes memory data) = address(token).staticcall(abi.encodeWithSelector(SIG_SYMBOL));
        return success ? returnDataToString(data) : "???";
    }

    /// @notice Provides a safe ERC20.name version which returns '???' as fallback string.
    /// @param token The address of the ERC-20 token contract.
    /// @return (string) Token name.
    function safeName(IERC20 token) internal view returns (string memory) {
        (bool success, bytes memory data) = address(token).staticcall(abi.encodeWithSelector(SIG_NAME));
        return success ? returnDataToString(data) : "???";
    }

    /// @notice Provides a safe ERC20.decimals version which returns '18' as fallback value.
    /// @param token The address of the ERC-20 token contract.
    /// @return (uint8) Token decimals.
    function safeDecimals(IERC20 token) internal view returns (uint8) {
        (bool success, bytes memory data) = address(token).staticcall(abi.encodeWithSelector(SIG_DECIMALS));
        return success && data.length == 32 ? abi.decode(data, (uint8)) : 18;
    }

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        OZSafeERC20.safeTransfer(token, to, value);
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        OZSafeERC20.safeTransferFrom(token, from, to, value);
    }
}

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

import "./math/Math.sol";

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _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) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @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] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

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

// File: @openzeppelin/contracts/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: @rari-capital/solmate/src/utils/SSTORE2.sol



// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Read and write to persistent storage at a fraction of the cost.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SSTORE2.sol)
/// @author Modified from 0xSequence (https://github.com/0xSequence/sstore2/blob/master/contracts/SSTORE2.sol)
library SSTORE2 {
    uint256 internal constant DATA_OFFSET = 1; // We skip the first byte as it's a STOP opcode to ensure the contract can't be called.

    /*//////////////////////////////////////////////////////////////
                               WRITE LOGIC
    //////////////////////////////////////////////////////////////*/

    function write(bytes memory data) internal returns (address pointer) {
        // Prefix the bytecode with a STOP opcode to ensure it cannot be called.
        bytes memory runtimeCode = abi.encodePacked(hex"00", data);

        bytes memory creationCode = abi.encodePacked(
            //---------------------------------------------------------------------------------------------------------------//
            // Opcode  | Opcode + Arguments  | Description  | Stack View                                                     //
            //---------------------------------------------------------------------------------------------------------------//
            // 0x60    |  0x600B             | PUSH1 11     | codeOffset                                                     //
            // 0x59    |  0x59               | MSIZE        | 0 codeOffset                                                   //
            // 0x81    |  0x81               | DUP2         | codeOffset 0 codeOffset                                        //
            // 0x38    |  0x38               | CODESIZE     | codeSize codeOffset 0 codeOffset                               //
            // 0x03    |  0x03               | SUB          | (codeSize - codeOffset) 0 codeOffset                           //
            // 0x80    |  0x80               | DUP          | (codeSize - codeOffset) (codeSize - codeOffset) 0 codeOffset   //
            // 0x92    |  0x92               | SWAP3        | codeOffset (codeSize - codeOffset) 0 (codeSize - codeOffset)   //
            // 0x59    |  0x59               | MSIZE        | 0 codeOffset (codeSize - codeOffset) 0 (codeSize - codeOffset) //
            // 0x39    |  0x39               | CODECOPY     | 0 (codeSize - codeOffset)                                      //
            // 0xf3    |  0xf3               | RETURN       |                                                                //
            //---------------------------------------------------------------------------------------------------------------//
            hex"60_0B_59_81_38_03_80_92_59_39_F3", // Returns all code in the contract except for the first 11 (0B in hex) bytes.
            runtimeCode // The bytecode we want the contract to have after deployment. Capped at 1 byte less than the code size limit.
        );

        assembly {
            // Deploy a new contract with the generated creation code.
            // We start 32 bytes into the code to avoid copying the byte length.
            pointer := create(0, add(creationCode, 32), mload(creationCode))
        }

        require(pointer != address(0), "DEPLOYMENT_FAILED");
    }

    /*//////////////////////////////////////////////////////////////
                               READ LOGIC
    //////////////////////////////////////////////////////////////*/

    function read(address pointer) internal view returns (bytes memory) {
        return readBytecode(pointer, DATA_OFFSET, pointer.code.length - DATA_OFFSET);
    }

    function read(address pointer, uint256 start) internal view returns (bytes memory) {
        start += DATA_OFFSET;

        return readBytecode(pointer, start, pointer.code.length - start);
    }

    function read(
        address pointer,
        uint256 start,
        uint256 end
    ) internal view returns (bytes memory) {
        start += DATA_OFFSET;
        end += DATA_OFFSET;

        require(pointer.code.length >= end, "OUT_OF_BOUNDS");

        return readBytecode(pointer, start, end - start);
    }

    /*//////////////////////////////////////////////////////////////
                          INTERNAL HELPER LOGIC
    //////////////////////////////////////////////////////////////*/

    function readBytecode(
        address pointer,
        uint256 start,
        uint256 size
    ) private view returns (bytes memory data) {
        assembly {
            // Get a pointer to some free memory.
            data := mload(0x40)

            // Update the free memory pointer to prevent overriding our data.
            // We use and(x, not(31)) as a cheaper equivalent to sub(x, mod(x, 32)).
            // Adding 31 to size and running the result through the logic above ensures
            // the memory pointer remains word-aligned, following the Solidity convention.
            mstore(0x40, add(data, and(add(add(size, 32), 31), not(31))))

            // Store the size of the data in the first 32 byte chunk of free memory.
            mstore(data, size)

            // Copy the code into memory right after the 32 bytes we used to store the size.
            extcodecopy(pointer, add(data, 32), start, size)
        }
    }
}

// File: solidity-bytes-utils/contracts/BytesLib.sol



// SPDX-License-Identifier: Unlicense
/*
 * @title Solidity Bytes Arrays Utils
 * @author Gonçalo Sá <goncalo.sa@consensys.net>
 *
 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
 */
pragma solidity >=0.8.0 <0.9.0;


library BytesLib {
    function concat(
        bytes memory _preBytes,
        bytes memory _postBytes
    )
        internal
        pure
        returns (bytes memory)
    {
        bytes memory tempBytes;

        assembly {
            // Get a location of some free memory and store it in tempBytes as
            // Solidity does for memory variables.
            tempBytes := mload(0x40)

            // Store the length of the first bytes array at the beginning of
            // the memory for tempBytes.
            let length := mload(_preBytes)
            mstore(tempBytes, length)

            // Maintain a memory counter for the current write location in the
            // temp bytes array by adding the 32 bytes for the array length to
            // the starting location.
            let mc := add(tempBytes, 0x20)
            // Stop copying when the memory counter reaches the length of the
            // first bytes array.
            let end := add(mc, length)

            for {
                // Initialize a copy counter to the start of the _preBytes data,
                // 32 bytes into its memory.
                let cc := add(_preBytes, 0x20)
            } lt(mc, end) {
                // Increase both counters by 32 bytes each iteration.
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
                // Write the _preBytes data into the tempBytes memory 32 bytes
                // at a time.
                mstore(mc, mload(cc))
            }

            // Add the length of _postBytes to the current length of tempBytes
            // and store it as the new length in the first 32 bytes of the
            // tempBytes memory.
            length := mload(_postBytes)
            mstore(tempBytes, add(length, mload(tempBytes)))

            // Move the memory counter back from a multiple of 0x20 to the
            // actual end of the _preBytes data.
            mc := end
            // Stop copying when the memory counter reaches the new combined
            // length of the arrays.
            end := add(mc, length)

            for {
                let cc := add(_postBytes, 0x20)
            } lt(mc, end) {
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
                mstore(mc, mload(cc))
            }

            // Update the free-memory pointer by padding our last write location
            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
            // next 32 byte block, then round down to the nearest multiple of
            // 32. If the sum of the length of the two arrays is zero then add
            // one before rounding down to leave a blank 32 bytes (the length block with 0).
            mstore(0x40, and(
              add(add(end, iszero(add(length, mload(_preBytes)))), 31),
              not(31) // Round down to the nearest 32 bytes.
            ))
        }

        return tempBytes;
    }

    function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
        assembly {
            // Read the first 32 bytes of _preBytes storage, which is the length
            // of the array. (We don't need to use the offset into the slot
            // because arrays use the entire slot.)
            let fslot := sload(_preBytes.slot)
            // Arrays of 31 bytes or less have an even value in their slot,
            // while longer arrays have an odd value. The actual length is
            // the slot divided by two for odd values, and the lowest order
            // byte divided by two for even values.
            // If the slot is even, bitwise and the slot with 255 and divide by
            // two to get the length. If the slot is odd, bitwise and the slot
            // with -1 and divide by two.
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)
            let newlength := add(slength, mlength)
            // slength can contain both the length and contents of the array
            // if length < 32 bytes so let's prepare for that
            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
            switch add(lt(slength, 32), lt(newlength, 32))
            case 2 {
                // Since the new array still fits in the slot, we just need to
                // update the contents of the slot.
                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                sstore(
                    _preBytes.slot,
                    // all the modifications to the slot are inside this
                    // next block
                    add(
                        // we can just add to the slot contents because the
                        // bytes we want to change are the LSBs
                        fslot,
                        add(
                            mul(
                                div(
                                    // load the bytes from memory
                                    mload(add(_postBytes, 0x20)),
                                    // zero all bytes to the right
                                    exp(0x100, sub(32, mlength))
                                ),
                                // and now shift left the number of bytes to
                                // leave space for the length in the slot
                                exp(0x100, sub(32, newlength))
                            ),
                            // increase length by the double of the memory
                            // bytes length
                            mul(mlength, 2)
                        )
                    )
                )
            }
            case 1 {
                // The stored value fits in the slot, but the combined value
                // will exceed it.
                // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

                // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

                // The contents of the _postBytes array start 32 bytes into
                // the structure. Our first read should obtain the `submod`
                // bytes that can fit into the unused space in the last word
                // of the stored array. To get this, we read 32 bytes starting
                // from `submod`, so the data we read overlaps with the array
                // contents by `submod` bytes. Masking the lowest-order
                // `submod` bytes allows us to add that value directly to the
                // stored value.

                let submod := sub(32, slength)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(
                    sc,
                    add(
                        and(
                            fslot,
                            0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                        ),
                        and(mload(mc), mask)
                    )
                )

                for {
                    mc := add(mc, 0x20)
                    sc := add(sc, 1)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
            default {
                // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
                // Start copying to the last used word of the stored array.
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

                // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

                // Copy over the first `submod` bytes of the new data as in
                // case 1 above.
                let slengthmod := mod(slength, 32)
                let mlengthmod := mod(mlength, 32)
                let submod := sub(32, slengthmod)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(sc, add(sload(sc), and(mload(mc), mask)))

                for {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
        }
    }

    function slice(
        bytes memory _bytes,
        uint256 _start,
        uint256 _length
    )
        internal
        pure
        returns (bytes memory)
    {
        require(_length + 31 >= _length, "slice_overflow");
        require(_bytes.length >= _start + _length, "slice_outOfBounds");

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
            case 0 {
                // Get a location of some free memory and store it in tempBytes as
                // Solidity does for memory variables.
                tempBytes := mload(0x40)

                // The first word of the slice result is potentially a partial
                // word read from the original array. To read it, we calculate
                // the length of that partial word and start copying that many
                // bytes into the array. The first word we copy will start with
                // data we don't care about, but the last `lengthmod` bytes will
                // land at the beginning of the contents of the new array. When
                // we're done copying, we overwrite the full first word with
                // the actual length of the slice.
                let lengthmod := and(_length, 31)

                // The multiplication in the next line is necessary
                // because when slicing multiples of 32 bytes (lengthmod == 0)
                // the following copy loop was copying the origin's length
                // and then ending prematurely not copying everything it should.
                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                let end := add(mc, _length)

                for {
                    // The multiplication in the next line has the same exact purpose
                    // as the one above.
                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    mstore(mc, mload(cc))
                }

                mstore(tempBytes, _length)

                //update free-memory pointer
                //allocating the array padded to 32 bytes like the compiler does now
                mstore(0x40, and(add(mc, 31), not(31)))
            }
            //if we want a zero-length slice let's just return a zero-length array
            default {
                tempBytes := mload(0x40)
                //zero out the 32 bytes slice we are about to return
                //we need to do it because Solidity does not garbage collect
                mstore(tempBytes, 0)

                mstore(0x40, add(tempBytes, 0x20))
            }
        }

        return tempBytes;
    }

    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
        require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
        address tempAddress;

        assembly {
            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
        }

        return tempAddress;
    }

    function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
        require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
        uint8 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x1), _start))
        }

        return tempUint;
    }

    function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
        require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
        uint16 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x2), _start))
        }

        return tempUint;
    }

    function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
        require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
        uint32 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x4), _start))
        }

        return tempUint;
    }

    function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
        require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
        uint64 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x8), _start))
        }

        return tempUint;
    }

    function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
        require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
        uint96 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0xc), _start))
        }

        return tempUint;
    }

    function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
        require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
        uint128 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x10), _start))
        }

        return tempUint;
    }

    function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
        require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
        uint256 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x20), _start))
        }

        return tempUint;
    }

    function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
        require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
        bytes32 tempBytes32;

        assembly {
            tempBytes32 := mload(add(add(_bytes, 0x20), _start))
        }

        return tempBytes32;
    }

    function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
        bool success = true;

        assembly {
            let length := mload(_preBytes)

            // if lengths don't match the arrays are not equal
            switch eq(length, mload(_postBytes))
            case 1 {
                // cb is a circuit breaker in the for loop since there's
                //  no said feature for inline assembly loops
                // cb = 1 - don't breaker
                // cb = 0 - break
                let cb := 1

                let mc := add(_preBytes, 0x20)
                let end := add(mc, length)

                for {
                    let cc := add(_postBytes, 0x20)
                // the next line is the loop condition:
                // while(uint256(mc < end) + cb == 2)
                } eq(add(lt(mc, end), cb), 2) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    // if any of these checks fails then arrays are not equal
                    if iszero(eq(mload(mc), mload(cc))) {
                        // unsuccess:
                        success := 0
                        cb := 0
                    }
                }
            }
            default {
                // unsuccess:
                success := 0
            }
        }

        return success;
    }

    function equalStorage(
        bytes storage _preBytes,
        bytes memory _postBytes
    )
        internal
        view
        returns (bool)
    {
        bool success = true;

        assembly {
            // we know _preBytes_offset is 0
            let fslot := sload(_preBytes.slot)
            // Decode the length of the stored array like in concatStorage().
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)

            // if lengths don't match the arrays are not equal
            switch eq(slength, mlength)
            case 1 {
                // slength can contain both the length and contents of the array
                // if length < 32 bytes so let's prepare for that
                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                if iszero(iszero(slength)) {
                    switch lt(slength, 32)
                    case 1 {
                        // blank the last byte which is the length
                        fslot := mul(div(fslot, 0x100), 0x100)

                        if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                            // unsuccess:
                            success := 0
                        }
                    }
                    default {
                        // cb is a circuit breaker in the for loop since there's
                        //  no said feature for inline assembly loops
                        // cb = 1 - don't breaker
                        // cb = 0 - break
                        let cb := 1

                        // get the keccak hash to get the contents of the array
                        mstore(0x0, _preBytes.slot)
                        let sc := keccak256(0x0, 0x20)

                        let mc := add(_postBytes, 0x20)
                        let end := add(mc, mlength)

                        // the next line is the loop condition:
                        // while(uint256(mc < end) + cb == 2)
                        for {} eq(add(lt(mc, end), cb), 2) {
                            sc := add(sc, 1)
                            mc := add(mc, 0x20)
                        } {
                            if iszero(eq(sload(sc), mload(mc))) {
                                // unsuccess:
                                success := 0
                                cb := 0
                            }
                        }
                    }
                }
            }
            default {
                // unsuccess:
                success := 0
            }
        }

        return success;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/interfaces/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20.sol)

pragma solidity ^0.8.0;

import "../token/ERC20/IERC20.sol";

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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: @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: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

// File: @openzeppelin/contracts/utils/math/Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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. If 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)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 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) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10**64) {
                value /= 10**64;
                result += 64;
            }
            if (value >= 10**32) {
                value /= 10**32;
                result += 32;
            }
            if (value >= 10**16) {
                value /= 10**16;
                result += 16;
            }
            if (value >= 10**8) {
                value /= 10**8;
                result += 8;
            }
            if (value >= 10**4) {
                value /= 10**4;
                result += 4;
            }
            if (value >= 10**2) {
                value /= 10**2;
                result += 2;
            }
            if (value >= 10**1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



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

pragma solidity ^0.8.0;

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

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