// File: contracts/strategies/FlashStrategyAAVEv2.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "../interfaces/AAVE/ILendingPool.sol";
import "../interfaces/AAVE/IAaveIncentivesController.sol";
import "../interfaces/IFlashStrategy.sol";
import "../interfaces/IUserIncentive.sol";
import "../interfaces/IFlashFToken.sol";

contract FlashStrategyAAVEv2 is IFlashStrategy, Ownable, ReentrancyGuard {
    using SafeERC20 for IERC20;

    address immutable flashProtocolAddress;
    address immutable lendingPoolAddress; // The AAVE V2 lending pool address
    address immutable principalTokenAddress; // The Principal token address (eg DAI)
    address immutable interestBearingTokenAddress; // The AAVE V2 interest bearing token address
    uint8 immutable principalDecimals;

    address fTokenAddress; // The Flash fERC20 token address
    uint16 referralCode = 0; // The AAVE V2 referral code
    uint256 principalBalance; // The amount of principal in this strategy
    address constant aaveIncentivesAddress = 0xd784927Ff2f95ba542BfC824c8a8a98F3495f6b5;

    address public userIncentiveAddress;
    bool public userIncentiveAddressLocked;

    uint256 maxStakeDuration = 63072000;        // Maximum stake duration for this strategy
    bool public maxStakeDurationLocked = false; // Determines if the above variable is locked (stop future updates)

    constructor(
        address _lendingPoolAddress,
        address _principalTokenAddress,
        address _interestBearingTokenAddress,
        address _flashProtocolAddress
    ) public {
        lendingPoolAddress = _lendingPoolAddress;
        principalTokenAddress = _principalTokenAddress;
        interestBearingTokenAddress = _interestBearingTokenAddress;
        flashProtocolAddress = _flashProtocolAddress;

        // Read the number of decimals from the principal token
        principalDecimals = IFlashFToken(principalTokenAddress).decimals();

        increaseAllowance();
    }

    // Implemented as a separate function just in case the strategy ever runs out of allowance
    function increaseAllowance() public {
        IERC20(principalTokenAddress).safeApprove(lendingPoolAddress, 0);
        IERC20(principalTokenAddress).safeApprove(lendingPoolAddress, type(uint256).max);
    }

    function depositPrincipal(uint256 _tokenAmount) external override onlyAuthorised returns (uint256) {
        // Register how much we are depositing
        principalBalance = principalBalance + _tokenAmount;

        // Deposit into AAVE
        ILendingPool(lendingPoolAddress).deposit(principalTokenAddress, _tokenAmount, address(this), referralCode);

        return _tokenAmount;
    }

    function withdrawYield(uint256 _tokenAmount) private {
        // Withdraw from AAVE
        uint256 returnedTokens = ILendingPool(lendingPoolAddress).withdraw(
            principalTokenAddress,
            _tokenAmount,
            address(this)
        );
        require(returnedTokens >= _tokenAmount);

        uint256 aTokenBalance = IERC20(interestBearingTokenAddress).balanceOf(address(this));
        require(aTokenBalance >= getPrincipalBalance(), "PRINCIPAL BALANCE INVALID");
    }

    function withdrawPrincipal(uint256 _tokenAmount) external override onlyAuthorised {
        // Withdraw from AAVE
        uint256 returnedTokens = ILendingPool(lendingPoolAddress).withdraw(
            principalTokenAddress,
            _tokenAmount,
            address(this)
        );
        require(returnedTokens >= _tokenAmount);

        IERC20(principalTokenAddress).safeTransfer(msg.sender, _tokenAmount);

        principalBalance = principalBalance - _tokenAmount;
    }

    function withdrawERC20(address[] calldata _tokenAddresses, uint256[] calldata _tokenAmounts) external onlyOwner {
        require(_tokenAddresses.length == _tokenAmounts.length, "ARRAY SIZE MISMATCH");

        for (uint256 i = 0; i < _tokenAddresses.length; i++) {
            // Ensure the token being withdrawn is not the interest bearing token
            require(_tokenAddresses[i] != interestBearingTokenAddress, "TOKEN ADDRESS PROHIBITED");

            // Transfer the token to the caller
            IERC20(_tokenAddresses[i]).safeTransfer(msg.sender, _tokenAmounts[i]);
        }
    }

    function getPrincipalBalance() public view override returns (uint256) {
        return principalBalance;
    }

    function getYieldBalance() public view override returns (uint256) {
        uint256 interestBearingTokenBalance = IERC20(interestBearingTokenAddress).balanceOf(address(this));

        return (interestBearingTokenBalance - getPrincipalBalance());
    }

    function getPrincipalAddress() external view override returns (address) {
        return principalTokenAddress;
    }

    function getFTokenAddress() external view returns (address) {
        return fTokenAddress;
    }

    function setFTokenAddress(address _fTokenAddress) external override onlyAuthorised {
        require(fTokenAddress == address(0), "FTOKEN ADDRESS ALREADY SET");
        fTokenAddress = _fTokenAddress;
    }

    function quoteMintFToken(uint256 _tokenAmount, uint256 _duration) external view override returns (uint256) {
        // Enforce minimum _duration
        require(_duration >= 60, "DURATION TOO LOW");

        // 1 ERC20 for 365 DAYS = 1 fERC20
        // 1 second = 0.000000031709792000
        // eg (100000000000000000 * (1 second * 31709792000)) / 10**18
        // eg (1000000 * (1 second * 31709792000)) / 10**6
        uint256 amountToMint = (_tokenAmount * (_duration * 31709792000)) / (10**principalDecimals);

        require(amountToMint > 0, "INSUFFICIENT OUTPUT");

        return amountToMint;
    }

    function quoteBurnFToken(uint256 _tokenAmount) public view override returns (uint256) {
        uint256 totalSupply = IERC20(fTokenAddress).totalSupply();
        require(totalSupply > 0, "INSUFFICIENT fERC20 TOKEN SUPPLY");

        if (_tokenAmount > totalSupply) {
            _tokenAmount = totalSupply;
        }

        // Calculate the percentage of _tokenAmount vs totalSupply provided
        // and multiply by total yield
        return (getYieldBalance() * _tokenAmount) / totalSupply;
    }

    function burnFToken(
        uint256 _tokenAmount,
        uint256 _minimumReturned,
        address _yieldTo
    ) external override nonReentrant returns (uint256) {
        // Calculate how much yield to give back
        uint256 tokensOwed = quoteBurnFToken(_tokenAmount);
        require(tokensOwed >= _minimumReturned && tokensOwed > 0, "INSUFFICIENT OUTPUT");

        // Transfer fERC20 (from caller) tokens to contract so we can burn them
        IFlashFToken(fTokenAddress).burnFrom(msg.sender, _tokenAmount);

        withdrawYield(tokensOwed);
        IERC20(principalTokenAddress).safeTransfer(_yieldTo, tokensOwed);

        // Distribute rewards if there is a reward balance within contract
        if (userIncentiveAddress != address(0)) {
            IUserIncentive(userIncentiveAddress).claimReward(_tokenAmount, _yieldTo);
        }

        emit BurnedFToken(msg.sender, _tokenAmount, tokensOwed);

        return tokensOwed;
    }

    modifier onlyAuthorised() {
        require(msg.sender == flashProtocolAddress || msg.sender == address(this), "NOT FLASH PROTOCOL");
        _;
    }

    function getMaxStakeDuration() public view override returns (uint256) {
        return maxStakeDuration;
    }

    function claimAAVEv2Rewards(address[] calldata _assets, uint256 _amount) external onlyOwner {
        IAaveIncentivesController(aaveIncentivesAddress).claimRewards(_assets, _amount, address(this));
    }

    // @notice sets the new maximum stake duration
    // @dev this can only be called by the strategy owner
    function setMaxStakeDuration(uint256 _newMaxStakeDuration) external onlyOwner {
        require(maxStakeDurationLocked == false);
        maxStakeDuration = _newMaxStakeDuration;
    }

    // @notice permanently locks the max stake duration
    // @dev this can only be called by the strategy owner
    function lockMaxStakeDuration() external onlyOwner {
        maxStakeDurationLocked = true;
    }

    // @notice set the new user incentive address
    // @dev this can only be called by the strategy owner
    function setUserIncentiveAddress(address _userIncentiveAddress) external onlyOwner {
        require(userIncentiveAddressLocked == false);
        userIncentiveAddress = _userIncentiveAddress;
    }

    // @notice permanently locks the user incentive address
    // @dev this can only be called by the strategy owner
    function lockSetUserIncentiveAddress() external onlyOwner {
        userIncentiveAddressLocked = true;
    }
}

// File: contracts/interfaces/IFlashStrategy.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface IFlashStrategy {
    event BurnedFToken(address indexed _address, uint256 _tokenAmount, uint256 _yieldReturned);

    // This is how principal will be deposited into the contract
    // The Flash protocol allows the strategy to specify how much
    // should be registered. This allows the strategy to manipulate (eg take fee)
    // on the principal if the strategy requires
    function depositPrincipal(uint256 _tokenAmount) external returns (uint256);

    // This is how principal will be returned from the contract
    function withdrawPrincipal(uint256 _tokenAmount) external;

    // Responsible for instant upfront yield. Takes fERC20 tokens specific to this
    // strategy. The strategy is responsible for returning some amount of principal tokens
    function burnFToken(
        uint256 _tokenAmount,
        uint256 _minimumReturned,
        address _yieldTo
    ) external returns (uint256);

    // This should return the current total of all principal within the contract
    function getPrincipalBalance() external view returns (uint256);

    // This should return the current total of all yield generated to date (including bootstrapped tokens)
    function getYieldBalance() external view returns (uint256);

    // This should return the principal token address (eg DAI)
    function getPrincipalAddress() external view returns (address);

    // View function which quotes how many principal tokens would be returned if x
    // fERC20 tokens are burned
    function quoteMintFToken(uint256 _tokenAmount, uint256 duration) external view returns (uint256);

    // View function which quotes how many principal tokens would be returned if x
    // fERC20 tokens are burned
    // IMPORTANT NOTE: This should utilise bootstrap tokens if they exist
    // bootstrapped tokens are any principal tokens that exist within the smart contract
    function quoteBurnFToken(uint256 _tokenAmount) external view returns (uint256);

    // The function to set the fERC20 address within the strategy
    function setFTokenAddress(address _fTokenAddress) external;

    // This should return what the maximum stake duration is
    function getMaxStakeDuration() external view returns (uint256);
}

// File: contracts/interfaces/IUserIncentive.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface IUserIncentive {
    event RewardClaimed(address _rewardToken, address indexed _address);

    // This will be called by the Strategy to claim rewards for the user
    // This should be permissioned such that only the Strategy address can call
    function claimReward(uint256 _fERC20Burned, address _yieldTo) external;

    // This is a view function to determine how many reward tokens will be paid out
    // providing ??? fERC20 tokens are burned
    function quoteReward(uint256 _fERC20Burned) external view returns (uint256);

    // Administrator: setting the reward ratio
    function setRewardRatio(uint256 _ratio) external;

    // Administrator: adding the reward tokens
    function addRewardTokens(uint256 _tokenAmount) external;

    // Administrator: depositing the reward tokens
    function depositReward(
        address _rewardTokenAddress,
        uint256 _tokenAmount,
        uint256 _ratio
    ) external;
}

// File: contracts/interfaces/IFlashFToken.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface IFlashFToken {
    function mint(address account, uint256 amount) external;

    function burnFrom(address from, uint256 amount) external;

    function decimals() external returns (uint8);
}

// File: contracts/interfaces/AAVE/IAaveIncentivesController.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.4;
pragma experimental ABIEncoderV2;

interface IAaveIncentivesController {
    event RewardsAccrued(address indexed user, uint256 amount);

    event RewardsClaimed(address indexed user, address indexed to, uint256 amount);

    event RewardsClaimed(address indexed user, address indexed to, address indexed claimer, uint256 amount);

    event ClaimerSet(address indexed user, address indexed claimer);

    /*
     * @dev Returns the configuration of the distribution for a certain asset
     * @param asset The address of the reference asset of the distribution
     * @return The asset index, the emission per second and the last updated timestamp
     **/
    function getAssetData(address asset)
        external
        view
        returns (
            uint256,
            uint256,
            uint256
        );

    /*
     * LEGACY **************************
     * @dev Returns the configuration of the distribution for a certain asset
     * @param asset The address of the reference asset of the distribution
     * @return The asset index, the emission per second and the last updated timestamp
     **/
    function assets(address asset)
        external
        view
        returns (
            uint128,
            uint128,
            uint256
        );

    /**
     * @dev Whitelists an address to claim the rewards on behalf of another address
     * @param user The address of the user
     * @param claimer The address of the claimer
     */
    function setClaimer(address user, address claimer) external;

    /**
     * @dev Returns the whitelisted claimer for a certain address (0x0 if not set)
     * @param user The address of the user
     * @return The claimer address
     */
    function getClaimer(address user) external view returns (address);

    /**
     * @dev Configure assets for a certain rewards emission
     * @param assets The assets to incentivize
     * @param emissionsPerSecond The emission for each asset
     */
    function configureAssets(address[] calldata assets, uint256[] calldata emissionsPerSecond) external;

    /**
     * @dev Called by the corresponding asset on any update that affects the rewards distribution
     * @param asset The address of the user
     * @param userBalance The balance of the user of the asset in the lending pool
     * @param totalSupply The total supply of the asset in the lending pool
     **/
    function handleAction(
        address asset,
        uint256 userBalance,
        uint256 totalSupply
    ) external;

    /**
     * @dev Returns the total of rewards of an user, already accrued + not yet accrued
     * @param user The address of the user
     * @return The rewards
     **/
    function getRewardsBalance(address[] calldata assets, address user) external view returns (uint256);

    /**
     * @dev Claims reward for an user, on all the assets of the lending pool, accumulating the pending rewards
     * @param amount Amount of rewards to claim
     * @param to Address that will be receiving the rewards
     * @return Rewards claimed
     **/
    function claimRewards(
        address[] calldata assets,
        uint256 amount,
        address to
    ) external returns (uint256);

    /**
     * @dev Claims reward for an user on behalf, on all the assets of the lending pool, accumulating the pending rewards. The caller must
     * be whitelisted via "allowClaimOnBehalf" function by the RewardsAdmin role manager
     * @param amount Amount of rewards to claim
     * @param user Address to check and claim rewards
     * @param to Address that will be receiving the rewards
     * @return Rewards claimed
     **/
    function claimRewardsOnBehalf(
        address[] calldata assets,
        uint256 amount,
        address user,
        address to
    ) external returns (uint256);

    /**
     * @dev returns the unclaimed rewards of the user
     * @param user the address of the user
     * @return the unclaimed user rewards
     */
    function getUserUnclaimedRewards(address user) external view returns (uint256);

    /**
     * @dev returns the unclaimed rewards of the user
     * @param user the address of the user
     * @param asset The asset to incentivize
     * @return the user index for the asset
     */
    function getUserAssetData(address user, address asset) external view returns (uint256);

    /**
     * @dev for backward compatibility with previous implementation of the Incentives controller
     */
    function REWARD_TOKEN() external view returns (address);

    /**
     * @dev for backward compatibility with previous implementation of the Incentives controller
     */
    function PRECISION() external view returns (uint8);

    /**
     * @dev Gets the distribution end timestamp of the emissions
     */
    function DISTRIBUTION_END() external view returns (uint256);
}

// File: contracts/interfaces/AAVE/ILendingPool.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.4;
pragma experimental ABIEncoderV2;

import { ILendingPoolAddressesProvider } from "./ILendingPoolAddressesProvider.sol";
import { DataTypes } from "./DataTypes.sol";

interface ILendingPool {
    /**
     * @dev Emitted on deposit()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The address initiating the deposit
     * @param onBehalfOf The beneficiary of the deposit, receiving the aTokens
     * @param amount The amount deposited
     * @param referral The referral code used
     **/
    event Deposit(
        address indexed reserve,
        address user,
        address indexed onBehalfOf,
        uint256 amount,
        uint16 indexed referral
    );

    /**
     * @dev Emitted on withdraw()
     * @param reserve The address of the underlyng asset being withdrawn
     * @param user The address initiating the withdrawal, owner of aTokens
     * @param to Address that will receive the underlying
     * @param amount The amount to be withdrawn
     **/
    event Withdraw(address indexed reserve, address indexed user, address indexed to, uint256 amount);

    /**
     * @dev Emitted on borrow() and flashLoan() when debt needs to be opened
     * @param reserve The address of the underlying asset being borrowed
     * @param user The address of the user initiating the borrow(), receiving the funds on borrow() or just
     * initiator of the transaction on flashLoan()
     * @param onBehalfOf The address that will be getting the debt
     * @param amount The amount borrowed out
     * @param borrowRateMode The rate mode: 1 for Stable, 2 for Variable
     * @param borrowRate The numeric rate at which the user has borrowed
     * @param referral The referral code used
     **/
    event Borrow(
        address indexed reserve,
        address user,
        address indexed onBehalfOf,
        uint256 amount,
        uint256 borrowRateMode,
        uint256 borrowRate,
        uint16 indexed referral
    );

    /**
     * @dev Emitted on repay()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The beneficiary of the repayment, getting his debt reduced
     * @param repayer The address of the user initiating the repay(), providing the funds
     * @param amount The amount repaid
     **/
    event Repay(address indexed reserve, address indexed user, address indexed repayer, uint256 amount);

    /**
     * @dev Emitted on swapBorrowRateMode()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The address of the user swapping his rate mode
     * @param rateMode The rate mode that the user wants to swap to
     **/
    event Swap(address indexed reserve, address indexed user, uint256 rateMode);

    /**
     * @dev Emitted on setUserUseReserveAsCollateral()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The address of the user enabling the usage as collateral
     **/
    event ReserveUsedAsCollateralEnabled(address indexed reserve, address indexed user);

    /**
     * @dev Emitted on setUserUseReserveAsCollateral()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The address of the user enabling the usage as collateral
     **/
    event ReserveUsedAsCollateralDisabled(address indexed reserve, address indexed user);

    /**
     * @dev Emitted on rebalanceStableBorrowRate()
     * @param reserve The address of the underlying asset of the reserve
     * @param user The address of the user for which the rebalance has been executed
     **/
    event RebalanceStableBorrowRate(address indexed reserve, address indexed user);

    /**
     * @dev Emitted on flashLoan()
     * @param target The address of the flash loan receiver contract
     * @param initiator The address initiating the flash loan
     * @param asset The address of the asset being flash borrowed
     * @param amount The amount flash borrowed
     * @param premium The fee flash borrowed
     * @param referralCode The referral code used
     **/
    event FlashLoan(
        address indexed target,
        address indexed initiator,
        address indexed asset,
        uint256 amount,
        uint256 premium,
        uint16 referralCode
    );

    /**
     * @dev Emitted when the pause is triggered.
     */
    event Paused();

    /**
     * @dev Emitted when the pause is lifted.
     */
    event Unpaused();

    /**
     * @dev Emitted when a borrower is liquidated. This event is emitted by the LendingPool via
     * LendingPoolCollateral manager using a DELEGATECALL
     * This allows to have the events in the generated ABI for LendingPool.
     * @param collateralAsset The address of the underlying asset used as collateral, to receive as result of the liquidation
     * @param debtAsset The address of the underlying borrowed asset to be repaid with the liquidation
     * @param user The address of the borrower getting liquidated
     * @param debtToCover The debt amount of borrowed `asset` the liquidator wants to cover
     * @param liquidatedCollateralAmount The amount of collateral received by the liiquidator
     * @param liquidator The address of the liquidator
     * @param receiveAToken `true` if the liquidators wants to receive the collateral aTokens, `false` if he wants
     * to receive the underlying collateral asset directly
     **/
    event LiquidationCall(
        address indexed collateralAsset,
        address indexed debtAsset,
        address indexed user,
        uint256 debtToCover,
        uint256 liquidatedCollateralAmount,
        address liquidator,
        bool receiveAToken
    );

    /**
     * @dev Emitted when the state of a reserve is updated. NOTE: This event is actually declared
     * in the ReserveLogic library and emitted in the updateInterestRates() function. Since the function is internal,
     * the event will actually be fired by the LendingPool contract. The event is therefore replicated here so it
     * gets added to the LendingPool ABI
     * @param reserve The address of the underlying asset of the reserve
     * @param liquidityRate The new liquidity rate
     * @param stableBorrowRate The new stable borrow rate
     * @param variableBorrowRate The new variable borrow rate
     * @param liquidityIndex The new liquidity index
     * @param variableBorrowIndex The new variable borrow index
     **/
    event ReserveDataUpdated(
        address indexed reserve,
        uint256 liquidityRate,
        uint256 stableBorrowRate,
        uint256 variableBorrowRate,
        uint256 liquidityIndex,
        uint256 variableBorrowIndex
    );

    /**
     * @dev Deposits an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
     * - E.g. User deposits 100 USDC and gets in return 100 aUSDC
     * @param asset The address of the underlying asset to deposit
     * @param amount The amount to be deposited
     * @param onBehalfOf The address that will receive the aTokens, same as msg.sender if the user
     *   wants to receive them on his own wallet, or a different address if the beneficiary of aTokens
     *   is a different wallet
     * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
     *   0 if the action is executed directly by the user, without any middle-man
     **/
    function deposit(
        address asset,
        uint256 amount,
        address onBehalfOf,
        uint16 referralCode
    ) external;

    /**
     * @dev Withdraws an `amount` of underlying asset from the reserve, burning the equivalent aTokens owned
     * E.g. User has 100 aUSDC, calls withdraw() and receives 100 USDC, burning the 100 aUSDC
     * @param asset The address of the underlying asset to withdraw
     * @param amount The underlying amount to be withdrawn
     *   - Send the value type(uint256).max in order to withdraw the whole aToken balance
     * @param to Address that will receive the underlying, same as msg.sender if the user
     *   wants to receive it on his own wallet, or a different address if the beneficiary is a
     *   different wallet
     * @return The final amount withdrawn
     **/
    function withdraw(
        address asset,
        uint256 amount,
        address to
    ) external returns (uint256);

    /**
     * @dev Allows users to borrow a specific `amount` of the reserve underlying asset, provided that the borrower
     * already deposited enough collateral, or he was given enough allowance by a credit delegator on the
     * corresponding debt token (StableDebtToken or VariableDebtToken)
     * - E.g. User borrows 100 USDC passing as `onBehalfOf` his own address, receiving the 100 USDC in his wallet
     *   and 100 stable/variable debt tokens, depending on the `interestRateMode`
     * @param asset The address of the underlying asset to borrow
     * @param amount The amount to be borrowed
     * @param interestRateMode The interest rate mode at which the user wants to borrow: 1 for Stable, 2 for Variable
     * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
     *   0 if the action is executed directly by the user, without any middle-man
     * @param onBehalfOf Address of the user who will receive the debt. Should be the address of the borrower itself
     * calling the function if he wants to borrow against his own collateral, or the address of the credit delegator
     * if he has been given credit delegation allowance
     **/
    function borrow(
        address asset,
        uint256 amount,
        uint256 interestRateMode,
        uint16 referralCode,
        address onBehalfOf
    ) external;

    /**
     * @notice Repays a borrowed `amount` on a specific reserve, burning the equivalent debt tokens owned
     * - E.g. User repays 100 USDC, burning 100 variable/stable debt tokens of the `onBehalfOf` address
     * @param asset The address of the borrowed underlying asset previously borrowed
     * @param amount The amount to repay
     * - Send the value type(uint256).max in order to repay the whole debt for `asset` on the specific `debtMode`
     * @param rateMode The interest rate mode at of the debt the user wants to repay: 1 for Stable, 2 for Variable
     * @param onBehalfOf Address of the user who will get his debt reduced/removed. Should be the address of the
     * user calling the function if he wants to reduce/remove his own debt, or the address of any other
     * other borrower whose debt should be removed
     * @return The final amount repaid
     **/
    function repay(
        address asset,
        uint256 amount,
        uint256 rateMode,
        address onBehalfOf
    ) external returns (uint256);

    /**
     * @dev Allows a borrower to swap his debt between stable and variable mode, or viceversa
     * @param asset The address of the underlying asset borrowed
     * @param rateMode The rate mode that the user wants to swap to
     **/
    function swapBorrowRateMode(address asset, uint256 rateMode) external;

    /**
     * @dev Rebalances the stable interest rate of a user to the current stable rate defined on the reserve.
     * - Users can be rebalanced if the following conditions are satisfied:
     *     1. Usage ratio is above 95%
     *     2. the current deposit APY is below REBALANCE_UP_THRESHOLD * maxVariableBorrowRate, which means that too much has been
     *        borrowed at a stable rate and depositors are not earning enough
     * @param asset The address of the underlying asset borrowed
     * @param user The address of the user to be rebalanced
     **/
    function rebalanceStableBorrowRate(address asset, address user) external;

    /**
     * @dev Allows depositors to enable/disable a specific deposited asset as collateral
     * @param asset The address of the underlying asset deposited
     * @param useAsCollateral `true` if the user wants to use the deposit as collateral, `false` otherwise
     **/
    function setUserUseReserveAsCollateral(address asset, bool useAsCollateral) external;

    /**
     * @dev Function to liquidate a non-healthy position collateral-wise, with Health Factor below 1
     * - The caller (liquidator) covers `debtToCover` amount of debt of the user getting liquidated, and receives
     *   a proportionally amount of the `collateralAsset` plus a bonus to cover market risk
     * @param collateralAsset The address of the underlying asset used as collateral, to receive as result of the liquidation
     * @param debtAsset The address of the underlying borrowed asset to be repaid with the liquidation
     * @param user The address of the borrower getting liquidated
     * @param debtToCover The debt amount of borrowed `asset` the liquidator wants to cover
     * @param receiveAToken `true` if the liquidators wants to receive the collateral aTokens, `false` if he wants
     * to receive the underlying collateral asset directly
     **/
    function liquidationCall(
        address collateralAsset,
        address debtAsset,
        address user,
        uint256 debtToCover,
        bool receiveAToken
    ) external;

    /**
     * @dev Allows smartcontracts to access the liquidity of the pool within one transaction,
     * as long as the amount taken plus a fee is returned.
     * IMPORTANT There are security concerns for developers of flashloan receiver contracts that must be kept into consideration.
     * For further details please visit https://developers.aave.com
     * @param receiverAddress The address of the contract receiving the funds, implementing the IFlashLoanReceiver interface
     * @param assets The addresses of the assets being flash-borrowed
     * @param amounts The amounts amounts being flash-borrowed
     * @param modes Types of the debt to open if the flash loan is not returned:
     *   0 -> Don't open any debt, just revert if funds can't be transferred from the receiver
     *   1 -> Open debt at stable rate for the value of the amount flash-borrowed to the `onBehalfOf` address
     *   2 -> Open debt at variable rate for the value of the amount flash-borrowed to the `onBehalfOf` address
     * @param onBehalfOf The address  that will receive the debt in the case of using on `modes` 1 or 2
     * @param params Variadic packed params to pass to the receiver as extra information
     * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
     *   0 if the action is executed directly by the user, without any middle-man
     **/
    function flashLoan(
        address receiverAddress,
        address[] calldata assets,
        uint256[] calldata amounts,
        uint256[] calldata modes,
        address onBehalfOf,
        bytes calldata params,
        uint16 referralCode
    ) external;

    /**
     * @dev Returns the user account data across all the reserves
     * @param user The address of the user
     * @return totalCollateralETH the total collateral in ETH of the user
     * @return totalDebtETH the total debt in ETH of the user
     * @return availableBorrowsETH the borrowing power left of the user
     * @return currentLiquidationThreshold the liquidation threshold of the user
     * @return ltv the loan to value of the user
     * @return healthFactor the current health factor of the user
     **/
    function getUserAccountData(address user)
        external
        view
        returns (
            uint256 totalCollateralETH,
            uint256 totalDebtETH,
            uint256 availableBorrowsETH,
            uint256 currentLiquidationThreshold,
            uint256 ltv,
            uint256 healthFactor
        );

    function initReserve(
        address reserve,
        address aTokenAddress,
        address stableDebtAddress,
        address variableDebtAddress,
        address interestRateStrategyAddress
    ) external;

    function setReserveInterestRateStrategyAddress(address reserve, address rateStrategyAddress) external;

    function setConfiguration(address reserve, uint256 configuration) external;

    /**
     * @dev Returns the configuration of the reserve
     * @param asset The address of the underlying asset of the reserve
     * @return The configuration of the reserve
     **/
    function getConfiguration(address asset) external view returns (DataTypes.ReserveConfigurationMap memory);

    /**
     * @dev Returns the configuration of the user across all the reserves
     * @param user The user address
     * @return The configuration of the user
     **/
    function getUserConfiguration(address user) external view returns (DataTypes.UserConfigurationMap memory);

    /**
     * @dev Returns the normalized income normalized income of the reserve
     * @param asset The address of the underlying asset of the reserve
     * @return The reserve's normalized income
     */
    function getReserveNormalizedIncome(address asset) external view returns (uint256);

    /**
     * @dev Returns the normalized variable debt per unit of asset
     * @param asset The address of the underlying asset of the reserve
     * @return The reserve normalized variable debt
     */
    function getReserveNormalizedVariableDebt(address asset) external view returns (uint256);

    /**
     * @dev Returns the state and configuration of the reserve
     * @param asset The address of the underlying asset of the reserve
     * @return The state of the reserve
     **/
    function getReserveData(address asset) external view returns (DataTypes.ReserveData memory);

    function finalizeTransfer(
        address asset,
        address from,
        address to,
        uint256 amount,
        uint256 balanceFromAfter,
        uint256 balanceToBefore
    ) external;

    function getReservesList() external view returns (address[] memory);

    function getAddressesProvider() external view returns (ILendingPoolAddressesProvider);

    function setPause(bool val) external;

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

// 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/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @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: @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: contracts/interfaces/AAVE/DataTypes.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.4;

library DataTypes {
    // refer to the whitepaper, section 1.1 basic concepts for a formal description of these properties.
    struct ReserveData {
        //stores the reserve configuration
        ReserveConfigurationMap configuration;
        //the liquidity index. Expressed in ray
        uint128 liquidityIndex;
        //variable borrow index. Expressed in ray
        uint128 variableBorrowIndex;
        //the current supply rate. Expressed in ray
        uint128 currentLiquidityRate;
        //the current variable borrow rate. Expressed in ray
        uint128 currentVariableBorrowRate;
        //the current stable borrow rate. Expressed in ray
        uint128 currentStableBorrowRate;
        uint40 lastUpdateTimestamp;
        //tokens addresses
        address aTokenAddress;
        address stableDebtTokenAddress;
        address variableDebtTokenAddress;
        //address of the interest rate strategy
        address interestRateStrategyAddress;
        //the id of the reserve. Represents the position in the list of the active reserves
        uint8 id;
    }

    struct ReserveConfigurationMap {
        //bit 0-15: LTV
        //bit 16-31: Liq. threshold
        //bit 32-47: Liq. bonus
        //bit 48-55: Decimals
        //bit 56: Reserve is active
        //bit 57: reserve is frozen
        //bit 58: borrowing is enabled
        //bit 59: stable rate borrowing enabled
        //bit 60-63: reserved
        //bit 64-79: reserve factor
        uint256 data;
    }

    struct UserConfigurationMap {
        uint256 data;
    }

    enum InterestRateMode {
        NONE,
        STABLE,
        VARIABLE
    }
}

// File: contracts/interfaces/AAVE/ILendingPoolAddressesProvider.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.4;

/**
 * @title LendingPoolAddressesProvider contract
 * @dev Main registry of addresses part of or connected to the protocol, including permissioned roles
 * - Acting also as factory of proxies and admin of those, so with right to change its implementations
 * - Owned by the Aave Governance
 * @author Aave
 **/
interface ILendingPoolAddressesProvider {
    event MarketIdSet(string newMarketId);
    event LendingPoolUpdated(address indexed newAddress);
    event ConfigurationAdminUpdated(address indexed newAddress);
    event EmergencyAdminUpdated(address indexed newAddress);
    event LendingPoolConfiguratorUpdated(address indexed newAddress);
    event LendingPoolCollateralManagerUpdated(address indexed newAddress);
    event PriceOracleUpdated(address indexed newAddress);
    event LendingRateOracleUpdated(address indexed newAddress);
    event ProxyCreated(bytes32 id, address indexed newAddress);
    event AddressSet(bytes32 id, address indexed newAddress, bool hasProxy);

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

    function setMarketId(string calldata marketId) external;

    function setAddress(bytes32 id, address newAddress) external;

    function setAddressAsProxy(bytes32 id, address impl) external;

    function getAddress(bytes32 id) external view returns (address);

    function getLendingPool() external view returns (address);

    function setLendingPoolImpl(address pool) external;

    function getLendingPoolConfigurator() external view returns (address);

    function setLendingPoolConfiguratorImpl(address configurator) external;

    function getLendingPoolCollateralManager() external view returns (address);

    function setLendingPoolCollateralManager(address manager) external;

    function getPoolAdmin() external view returns (address);

    function setPoolAdmin(address admin) external;

    function getEmergencyAdmin() external view returns (address);

    function setEmergencyAdmin(address admin) external;

    function getPriceOracle() external view returns (address);

    function setPriceOracle(address priceOracle) external;

    function getLendingRateOracle() external view returns (address);

    function setLendingRateOracle(address lendingRateOracle) external;
}

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



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

pragma solidity ^0.8.0;

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

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

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



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

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

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

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

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

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

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

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

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

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

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

// File: @openzeppelin/contracts/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);
}