// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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);
        }
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

/**
 * @title Careful Math
 * @author Moonwell
 * @notice Derived from OpenZeppelin's SafeMath library
 *         https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/math/SafeMath.sol
 */
contract CarefulMath {
    /**
     * @dev Possible error codes that we can return
     */
    enum MathError {
        NO_ERROR,
        DIVISION_BY_ZERO,
        INTEGER_OVERFLOW,
        INTEGER_UNDERFLOW
    }

    /**
     * @dev Multiplies two numbers, returns an error on overflow.
     */
    function mulUInt(uint a, uint b) internal pure returns (MathError, uint) {
        if (a == 0) {
            return (MathError.NO_ERROR, 0);
        }

        uint c = a * b;

        if (c / a != b) {
            return (MathError.INTEGER_OVERFLOW, 0);
        } else {
            return (MathError.NO_ERROR, c);
        }
    }

    /**
     * @dev Integer division of two numbers, truncating the quotient.
     */
    function divUInt(uint a, uint b) internal pure returns (MathError, uint) {
        if (b == 0) {
            return (MathError.DIVISION_BY_ZERO, 0);
        }

        return (MathError.NO_ERROR, a / b);
    }

    /**
     * @dev Subtracts two numbers, returns an error on overflow (i.e. if subtrahend is greater than minuend).
     */
    function subUInt(uint a, uint b) internal pure returns (MathError, uint) {
        if (b <= a) {
            return (MathError.NO_ERROR, a - b);
        } else {
            return (MathError.INTEGER_UNDERFLOW, 0);
        }
    }

    /**
     * @dev Adds two numbers, returns an error on overflow.
     */
    function addUInt(uint a, uint b) internal pure returns (MathError, uint) {
        uint c = a + b;

        if (c >= a) {
            return (MathError.NO_ERROR, c);
        } else {
            return (MathError.INTEGER_OVERFLOW, 0);
        }
    }

    /**
     * @dev add a and b and then subtract c
     */
    function addThenSubUInt(
        uint a,
        uint b,
        uint c
    ) internal pure returns (MathError, uint) {
        (MathError err0, uint sum) = addUInt(a, b);

        if (err0 != MathError.NO_ERROR) {
            return (err0, 0);
        }

        return subUInt(sum, c);
    }
}

// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.19;

import {SafeTransferLib} from "solmate/utils/SafeTransferLib.sol";
import {ERC4626} from "solmate/mixins/ERC4626.sol";
import {ERC20} from "solmate/tokens/ERC20.sol";

import {MErc20} from "@protocol/MErc20.sol";
import {MToken} from "@protocol/MToken.sol";
import {LibCompound} from "@protocol/4626/LibCompound.sol";
import {Comptroller as IComptroller} from "@protocol/Comptroller.sol";
import {MultiRewardDistributor, MultiRewardDistributorCommon} from "@protocol/rewards/MultiRewardDistributor.sol";

/// @title CompoundERC4626
/// @author zefram.eth
/// @notice ERC4626 wrapper for Moonwell Finance
contract CompoundERC4626 is ERC4626 {
    /// -----------------------------------------------------------------------
    /// Libraries usage
    /// -----------------------------------------------------------------------

    using LibCompound for MErc20;
    using SafeTransferLib for ERC20;

    /// -----------------------------------------------------------------------
    /// Events
    /// -----------------------------------------------------------------------

    event ClaimRewards(uint256 amount, address token);

    /// -----------------------------------------------------------------------
    /// Errors
    /// -----------------------------------------------------------------------

    /// @notice Thrown when a call to Compound returned an error.
    /// @param errorCode The error code returned by Compound
    error CompoundERC4626__CompoundError(uint256 errorCode);

    /// -----------------------------------------------------------------------
    /// Constants
    /// -----------------------------------------------------------------------

    uint256 internal constant NO_ERROR = 0;

    /// -----------------------------------------------------------------------
    /// Immutable params
    /// -----------------------------------------------------------------------

    /// @notice The Moonwell mToken contract
    MErc20 public immutable mToken;

    /// @notice The address that will receive the liquidity mining rewards (if any)
    address public immutable rewardRecipient;

    /// @notice The Compound comptroller contract
    IComptroller public immutable comptroller;

    /// -----------------------------------------------------------------------
    /// Constructor
    /// -----------------------------------------------------------------------

    constructor(
        ERC20 asset_,
        MErc20 mToken_,
        address rewardRecipient_,
        IComptroller comptroller_
    ) ERC4626(asset_, _vaultName(asset_), _vaultSymbol(asset_)) {
        mToken = mToken_;
        comptroller = comptroller_;
        rewardRecipient = rewardRecipient_;
    }

    /// -----------------------------------------------------------------------
    /// Compound liquidity mining
    /// -----------------------------------------------------------------------

    /// @notice Claims liquidity mining rewards from Compound and sends it to rewardRecipient
    function claimRewards() external {
        address[] memory holders = new address[](1);
        holders[0] = address(this);

        MToken[] memory mTokens = new MToken[](1);
        mTokens[0] = MToken(address(mToken));

        comptroller.claimReward(holders, mTokens, false, true);

        MultiRewardDistributor mrd = comptroller.rewardDistributor();

        if (address(mrd) != address(0)) {
            MultiRewardDistributorCommon.MarketConfig[] memory configs = mrd
                .getAllMarketConfigs(MToken(address(mToken)));

            unchecked {
                for (uint256 i = 0; i < configs.length; i++) {
                    uint256 amount = ERC20(configs[i].emissionToken).balanceOf(
                        address(this)
                    );

                    if (amount != 0) {
                        /// gas opti, skip transfer and event emission if no rewards
                        ERC20(configs[i].emissionToken).safeTransfer(
                            rewardRecipient,
                            amount
                        );

                        emit ClaimRewards(amount, configs[i].emissionToken);
                    }
                }
            }
        }
    }

    /// @notice Claims liquidity mining rewards from Compound and sends it to rewardRecipient
    /// used for edgecase where reward distribution is not yet configured or was removed
    /// the tokens were swept into the vault.
    /// @param tokens The list of tokens to sweep
    function sweepRewards(address[] calldata tokens) external {
        require(msg.sender == rewardRecipient, "CompoundERC4626: forbidden");
        for (uint256 i = 0; i < tokens.length; i++) {
            require(
                tokens[i] != address(mToken),
                "CompoundERC4626: cannot sweep mToken"
            );

            ERC20 token = ERC20(tokens[i]);
            uint256 amount = token.balanceOf(address(this));
            token.safeTransfer(rewardRecipient, amount);

            emit ClaimRewards(amount, address(token));
        }
    }

    /// -----------------------------------------------------------------------
    /// ERC4626 override
    /// -----------------------------------------------------------------------

    function totalAssets() public view virtual override returns (uint256) {
        return mToken.viewUnderlyingBalanceOf(address(this));
    }

    function beforeWithdraw(
        uint256 assets,
        uint256 /*shares*/
    ) internal virtual override {
        /// -----------------------------------------------------------------------
        /// Withdraw assets from Compound
        /// -----------------------------------------------------------------------

        uint256 errorCode = mToken.redeemUnderlying(assets);
        if (errorCode != NO_ERROR) {
            revert CompoundERC4626__CompoundError(errorCode);
        }
    }

    function afterDeposit(
        uint256 assets,
        uint256 /*shares*/
    ) internal virtual override {
        /// -----------------------------------------------------------------------
        /// Deposit assets into Compound
        /// -----------------------------------------------------------------------

        // approve to mToken
        asset.safeApprove(address(mToken), assets);

        // deposit into mToken
        uint256 errorCode = mToken.mint(assets);
        if (errorCode != NO_ERROR) {
            revert CompoundERC4626__CompoundError(errorCode);
        }
    }

    /// @notice maximum amount of underlying tokens that can be deposited into the underlying protocol
    function maxDeposit(address) public view override returns (uint256) {
        return maxMint(address(0));
    }

    /// @notice Returns the maximum amount of tokens that can be supplied
    /// no way for this function to ever revert unless comptroller or mToken is broken
    /// @dev accrue interest must be called before this function is called, otherwise
    /// an outdated value will be fetched, and the returned value will be incorrect
    /// (greater than actual amount available to be minted will be returned)
    function maxMint(address) public view override returns (uint256) {
        if (comptroller.mintGuardianPaused(address(mToken))) {
            return 0;
        }

        uint256 supplyCap = comptroller.supplyCaps(address(mToken));
        if (supplyCap != 0) {
            uint256 currentExchangeRate = mToken.viewExchangeRate();
            uint256 _totalSupply = MToken(address(mToken)).totalSupply();
            uint256 totalSupplies = (_totalSupply * currentExchangeRate) / 1e18; /// exchange rate is scaled up by 1e18, so needs to be divided off to get accurate total supply

            // uint256 totalCash = MToken(address(mToken)).getCash();
            // uint256 totalBorrows = MToken(address(mToken)).totalBorrows();
            // uint256 totalReserves = MToken(address(mToken)).totalReserves();

            // // (Pseudocode) totalSupplies = totalCash + totalBorrows - totalReserves
            // uint256 totalSupplies = (totalCash + totalBorrows) - totalReserves;

            // supply cap is      3
            // total supplies is  1
            /// no room for additional supplies

            // supply cap is      3
            // total supplies is  0
            /// room for 1 additional supplies

            // supply cap is      4
            // total supplies is  1
            /// room for 1 additional supplies

            /// total supplies could exceed supply cap as interest accrues, need to handle this edge case
            /// going to subtract 2 from supply cap to account for rounding errors
            if (totalSupplies + 2 >= supplyCap) {
                return 0;
            }

            return supplyCap - totalSupplies - 2;
        }

        return type(uint256).max;
    }

    /// @notice maximum amount of underlying tokens that can be withdrawn
    /// @param owner The address that owns the shares
    function maxWithdraw(address owner) public view override returns (uint256) {
        uint256 cash = mToken.getCash();
        uint256 assetsBalance = convertToAssets(balanceOf[owner]);
        return cash < assetsBalance ? cash : assetsBalance;
    }

    /// @notice maximum amount of shares that can be withdrawn
    /// @param owner The address that owns the shares
    function maxRedeem(address owner) public view override returns (uint256) {
        uint256 cash = mToken.getCash();
        uint256 cashInShares = convertToShares(cash);
        uint256 shareBalance = balanceOf[owner];
        return cashInShares < shareBalance ? cashInShares : shareBalance;
    }

    /// -----------------------------------------------------------------------
    /// ERC20 metadata generation
    /// -----------------------------------------------------------------------

    function _vaultName(
        ERC20 asset_
    ) internal view virtual returns (string memory vaultName) {
        vaultName = string.concat("ERC4626-Wrapped Moonwell ", asset_.symbol());
    }

    function _vaultSymbol(
        ERC20 asset_
    ) internal view virtual returns (string memory vaultSymbol) {
        vaultSymbol = string.concat("wm", asset_.symbol());
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

import "./MToken.sol";
import "./ErrorReporter.sol";
import "./oracles/PriceOracle.sol";
import "./ComptrollerInterface.sol";
import "./ComptrollerStorage.sol";
import "./Unitroller.sol";

/**
 * @title Moonwell's Comptroller Contract
 * @author Moonwell
 */
contract Comptroller is
    ComptrollerV2Storage,
    ComptrollerInterface,
    ComptrollerErrorReporter,
    ExponentialNoError
{
    /// @notice Emitted when an admin supports a market
    event MarketListed(MToken mToken);

    /// @notice Emitted when an account enters a market
    event MarketEntered(MToken mToken, address account);

    /// @notice Emitted when an account exits a market
    event MarketExited(MToken mToken, address account);

    /// @notice Emitted when close factor is changed by admin
    event NewCloseFactor(
        uint oldCloseFactorMantissa,
        uint newCloseFactorMantissa
    );

    /// @notice Emitted when a collateral factor is changed by admin
    event NewCollateralFactor(
        MToken mToken,
        uint oldCollateralFactorMantissa,
        uint newCollateralFactorMantissa
    );

    /// @notice Emitted when liquidation incentive is changed by admin
    event NewLiquidationIncentive(
        uint oldLiquidationIncentiveMantissa,
        uint newLiquidationIncentiveMantissa
    );

    /// @notice Emitted when price oracle is changed
    event NewPriceOracle(
        PriceOracle oldPriceOracle,
        PriceOracle newPriceOracle
    );

    /// @notice Emitted when pause guardian is changed
    event NewPauseGuardian(address oldPauseGuardian, address newPauseGuardian);

    /// @notice Emitted when an action is paused globally
    event ActionPaused(string action, bool pauseState);

    /// @notice Emitted when an action is paused on a market
    event ActionPaused(MToken mToken, string action, bool pauseState);

    /// @notice Emitted when borrow cap for a mToken is changed
    event NewBorrowCap(MToken indexed mToken, uint newBorrowCap);

    /// @notice Emitted when borrow cap guardian is changed
    event NewBorrowCapGuardian(
        address oldBorrowCapGuardian,
        address newBorrowCapGuardian
    );

    /// @notice Emitted when supply cap for a mToken is changed
    event NewSupplyCap(MToken indexed mToken, uint newSupplyCap);

    /// @notice Emitted when supply cap guardian is changed
    event NewSupplyCapGuardian(
        address oldSupplyCapGuardian,
        address newSupplyCapGuardian
    );

    /// @notice Emitted when reward distributor is changed
    event NewRewardDistributor(
        MultiRewardDistributor oldRewardDistributor,
        MultiRewardDistributor newRewardDistributor
    );

    // closeFactorMantissa must be strictly greater than this value
    uint internal constant closeFactorMinMantissa = 0.05e18; // 0.05

    // closeFactorMantissa must not exceed this value
    uint internal constant closeFactorMaxMantissa = 0.9e18; // 0.9

    // No collateralFactorMantissa may exceed this value
    uint internal constant collateralFactorMaxMantissa = 0.9e18; // 0.9

    constructor() {
        admin = msg.sender;
    }

    /*** Assets You Are In ***/

    /**
     * @notice Returns the assets an account has entered
     * @param account The address of the account to pull assets for
     * @return A dynamic list with the assets the account has entered
     */
    function getAssetsIn(
        address account
    ) external view returns (MToken[] memory) {
        MToken[] memory assetsIn = accountAssets[account];

        return assetsIn;
    }

    /**
     * @notice Returns whether the given account is entered in the given asset
     * @param account The address of the account to check
     * @param mToken The mToken to check
     * @return True if the account is in the asset, otherwise false.
     */
    function checkMembership(
        address account,
        MToken mToken
    ) external view returns (bool) {
        return markets[address(mToken)].accountMembership[account];
    }

    /**
     * @notice Add assets to be included in account liquidity calculation
     * @param mTokens The list of addresses of the mToken markets to be enabled
     * @return Success indicator for whether each corresponding market was entered
     */
    function enterMarkets(
        address[] memory mTokens
    ) public override returns (uint[] memory) {
        uint len = mTokens.length;

        uint[] memory results = new uint[](len);
        for (uint i = 0; i < len; i++) {
            MToken mToken = MToken(mTokens[i]);

            results[i] = uint(addToMarketInternal(mToken, msg.sender));
        }

        return results;
    }

    /**
     * @notice Add the market to the borrower's "assets in" for liquidity calculations
     * @param mToken The market to enter
     * @param borrower The address of the account to modify
     * @return Success indicator for whether the market was entered
     */
    function addToMarketInternal(
        MToken mToken,
        address borrower
    ) internal returns (Error) {
        Market storage marketToJoin = markets[address(mToken)];

        if (!marketToJoin.isListed) {
            // market is not listed, cannot join
            return Error.MARKET_NOT_LISTED;
        }

        if (marketToJoin.accountMembership[borrower] == true) {
            // already joined
            return Error.NO_ERROR;
        }

        // survived the gauntlet, add to list
        // NOTE: we store these somewhat redundantly as a significant optimization
        //  this avoids having to iterate through the list for the most common use cases
        //  that is, only when we need to perform liquidity checks
        //  and not whenever we want to check if an account is in a particular market
        marketToJoin.accountMembership[borrower] = true;
        accountAssets[borrower].push(mToken);

        emit MarketEntered(mToken, borrower);

        return Error.NO_ERROR;
    }

    /**
     * @notice Removes asset from sender's account liquidity calculation
     * @dev Sender must not have an outstanding borrow balance in the asset,
     *  or be providing necessary collateral for an outstanding borrow.
     * @param mTokenAddress The address of the asset to be removed
     * @return Whether or not the account successfully exited the market
     */
    function exitMarket(
        address mTokenAddress
    ) external override returns (uint) {
        MToken mToken = MToken(mTokenAddress);
        /* Get sender tokensHeld and amountOwed underlying from the mToken */
        (uint oErr, uint tokensHeld, uint amountOwed, ) = mToken
            .getAccountSnapshot(msg.sender);
        require(oErr == 0, "exitMarket: getAccountSnapshot failed"); // semi-opaque error code

        /* Fail if the sender has a borrow balance */
        if (amountOwed != 0) {
            return
                fail(
                    Error.NONZERO_BORROW_BALANCE,
                    FailureInfo.EXIT_MARKET_BALANCE_OWED
                );
        }

        /* Fail if the sender is not permitted to redeem all of their tokens */
        uint allowed = redeemAllowedInternal(
            mTokenAddress,
            msg.sender,
            tokensHeld
        );
        if (allowed != 0) {
            return
                failOpaque(
                    Error.REJECTION,
                    FailureInfo.EXIT_MARKET_REJECTION,
                    allowed
                );
        }

        Market storage marketToExit = markets[address(mToken)];

        /* Return true if the sender is not already ‘in’ the market */
        if (!marketToExit.accountMembership[msg.sender]) {
            return uint(Error.NO_ERROR);
        }

        /* Set mToken account membership to false */
        delete marketToExit.accountMembership[msg.sender];

        /* Delete mToken from the account’s list of assets */
        // load into memory for faster iteration
        MToken[] memory userAssetList = accountAssets[msg.sender];
        uint len = userAssetList.length;
        uint assetIndex = len;
        for (uint i = 0; i < len; i++) {
            if (userAssetList[i] == mToken) {
                assetIndex = i;
                break;
            }
        }

        // We *must* have found the asset in the list or our redundant data structure is broken
        assert(assetIndex < len);

        // copy last item in list to location of item to be removed, reduce length by 1
        MToken[] storage storedList = accountAssets[msg.sender];
        storedList[assetIndex] = storedList[storedList.length - 1];
        storedList.pop();

        emit MarketExited(mToken, msg.sender);

        return uint(Error.NO_ERROR);
    }

    /*** Policy Hooks ***/

    /**
     * @notice Checks if the account should be allowed to mint tokens in the given market
     * @param mToken The market to verify the mint against
     * @param minter The account which would get the minted tokens
     * @param mintAmount The amount of underlying being supplied to the market in exchange for tokens
     * @return 0 if the mint is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
     */
    function mintAllowed(
        address mToken,
        address minter,
        uint mintAmount
    ) external override returns (uint) {
        // Pausing is a very serious situation - we revert to sound the alarms
        require(!mintGuardianPaused[mToken], "mint is paused");

        // Shh - currently unused
        mintAmount;

        if (!markets[mToken].isListed) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        uint supplyCap = supplyCaps[mToken];
        // Supply cap of 0 corresponds to unlimited supplying
        if (supplyCap != 0) {
            uint totalCash = MToken(mToken).getCash();
            uint totalBorrows = MToken(mToken).totalBorrows();
            uint totalReserves = MToken(mToken).totalReserves();
            // totalSupplies = totalCash + totalBorrows - totalReserves
            uint totalSupplies = sub_(
                add_(totalCash, totalBorrows),
                totalReserves
            );

            uint nextTotalSupplies = add_(totalSupplies, mintAmount);
            require(nextTotalSupplies < supplyCap, "market supply cap reached");
        }

        // Keep the flywheel moving
        updateAndDistributeSupplierRewardsForToken(mToken, minter);
        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Checks if the account should be allowed to redeem tokens in the given market
     * @param mToken The market to verify the redeem against
     * @param redeemer The account which would redeem the tokens
     * @param redeemTokens The number of mTokens to exchange for the underlying asset in the market
     * @return 0 if the redeem is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
     */
    function redeemAllowed(
        address mToken,
        address redeemer,
        uint redeemTokens
    ) external override returns (uint) {
        uint allowed = redeemAllowedInternal(mToken, redeemer, redeemTokens);
        if (allowed != uint(Error.NO_ERROR)) {
            return allowed;
        }

        // Keep the flywheel moving
        updateAndDistributeSupplierRewardsForToken(mToken, redeemer);

        return uint(Error.NO_ERROR);
    }

    function redeemAllowedInternal(
        address mToken,
        address redeemer,
        uint redeemTokens
    ) internal view returns (uint) {
        if (!markets[mToken].isListed) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        /* If the redeemer is not 'in' the market, then we can bypass the liquidity check */
        if (!markets[mToken].accountMembership[redeemer]) {
            return uint(Error.NO_ERROR);
        }

        /* Otherwise, perform a hypothetical liquidity check to guard against shortfall */
        (Error err, , uint shortfall) = getHypotheticalAccountLiquidityInternal(
            redeemer,
            MToken(mToken),
            redeemTokens,
            0
        );
        if (err != Error.NO_ERROR) {
            return uint(err);
        }
        if (shortfall > 0) {
            return uint(Error.INSUFFICIENT_LIQUIDITY);
        }

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Validates redeem and reverts on rejection. May emit logs.
     * @param mToken Asset being redeemed
     * @param redeemer The address redeeming the tokens
     * @param redeemAmount The amount of the underlying asset being redeemed
     * @param redeemTokens The number of tokens being redeemed
     */
    function redeemVerify(
        address mToken,
        address redeemer,
        uint redeemAmount,
        uint redeemTokens
    ) external pure override {
        // Shh - currently unused
        mToken;
        redeemer;

        // Require tokens is zero or amount is also zero
        if (redeemTokens == 0 && redeemAmount > 0) {
            revert("redeemTokens zero");
        }
    }

    /**
     * @notice Checks if the account should be allowed to borrow the underlying asset of the given market
     * @param mToken The market to verify the borrow against
     * @param borrower The account which would borrow the asset
     * @param borrowAmount The amount of underlying the account would borrow
     * @return 0 if the borrow is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
     */
    function borrowAllowed(
        address mToken,
        address borrower,
        uint borrowAmount
    ) external override returns (uint) {
        // Pausing is a very serious situation - we revert to sound the alarms
        require(!borrowGuardianPaused[mToken], "borrow is paused");

        if (!markets[mToken].isListed) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        if (!markets[mToken].accountMembership[borrower]) {
            // only mTokens may call borrowAllowed if borrower not in market
            require(msg.sender == mToken, "sender must be mToken");

            // attempt to add borrower to the market
            Error addToMarketErr = addToMarketInternal(
                MToken(msg.sender),
                borrower
            );
            if (addToMarketErr != Error.NO_ERROR) {
                return uint(addToMarketErr);
            }

            // it should be impossible to break the important invariant
            assert(markets[mToken].accountMembership[borrower]);
        }

        if (oracle.getUnderlyingPrice(MToken(mToken)) == 0) {
            return uint(Error.PRICE_ERROR);
        }

        uint borrowCap = borrowCaps[mToken];
        // Borrow cap of 0 corresponds to unlimited borrowing
        if (borrowCap != 0) {
            uint totalBorrows = MToken(mToken).totalBorrows();
            uint nextTotalBorrows = add_(totalBorrows, borrowAmount);
            require(nextTotalBorrows < borrowCap, "market borrow cap reached");
        }

        (Error err, , uint shortfall) = getHypotheticalAccountLiquidityInternal(
            borrower,
            MToken(mToken),
            0,
            borrowAmount
        );
        if (err != Error.NO_ERROR) {
            return uint(err);
        }
        if (shortfall > 0) {
            return uint(Error.INSUFFICIENT_LIQUIDITY);
        }

        // Keep the flywheel moving
        updateAndDistributeBorrowerRewardsForToken(mToken, borrower);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Checks if the account should be allowed to repay a borrow in the given market
     * @param mToken The market to verify the repay against
     * @param payer The account which would repay the asset
     * @param borrower The account which would borrowed the asset
     * @param repayAmount The amount of the underlying asset the account would repay
     * @return 0 if the repay is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
     */
    function repayBorrowAllowed(
        address mToken,
        address payer,
        address borrower,
        uint repayAmount
    ) external override returns (uint) {
        // Shh - currently unused
        payer;
        borrower;
        repayAmount;

        if (!markets[mToken].isListed) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        // Keep the flywheel moving
        updateAndDistributeBorrowerRewardsForToken(mToken, borrower);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Checks if the liquidation should be allowed to occur
     * @param mTokenBorrowed Asset which was borrowed by the borrower
     * @param mTokenCollateral Asset which was used as collateral and will be seized
     * @param liquidator The address repaying the borrow and seizing the collateral
     * @param borrower The address of the borrower
     * @param repayAmount The amount of underlying being repaid
     */
    function liquidateBorrowAllowed(
        address mTokenBorrowed,
        address mTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount
    ) external view override returns (uint) {
        // Shh - currently unused
        liquidator;

        if (
            !markets[mTokenBorrowed].isListed ||
            !markets[mTokenCollateral].isListed
        ) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        /* The borrower must have shortfall in order to be liquidatable */
        (Error err, , uint shortfall) = getAccountLiquidityInternal(borrower);
        if (err != Error.NO_ERROR) {
            return uint(err);
        }
        if (shortfall == 0) {
            return uint(Error.INSUFFICIENT_SHORTFALL);
        }

        /* The liquidator may not repay more than what is allowed by the closeFactor */
        uint borrowBalance = MToken(mTokenBorrowed).borrowBalanceStored(
            borrower
        );
        uint maxClose = mul_ScalarTruncate(
            Exp({mantissa: closeFactorMantissa}),
            borrowBalance
        );
        if (repayAmount > maxClose) {
            return uint(Error.TOO_MUCH_REPAY);
        }

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Checks if the seizing of assets should be allowed to occur
     * @param mTokenCollateral Asset which was used as collateral and will be seized
     * @param mTokenBorrowed Asset which was borrowed by the borrower
     * @param liquidator The address repaying the borrow and seizing the collateral
     * @param borrower The address of the borrower
     * @param seizeTokens The number of collateral tokens to seize
     */
    function seizeAllowed(
        address mTokenCollateral,
        address mTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens
    ) external override returns (uint) {
        // Pausing is a very serious situation - we revert to sound the alarms
        require(!seizeGuardianPaused, "seize is paused");

        // Shh - currently unused
        seizeTokens;

        if (
            !markets[mTokenCollateral].isListed ||
            !markets[mTokenBorrowed].isListed
        ) {
            return uint(Error.MARKET_NOT_LISTED);
        }

        if (
            MToken(mTokenCollateral).comptroller() !=
            MToken(mTokenBorrowed).comptroller()
        ) {
            return uint(Error.COMPTROLLER_MISMATCH);
        }

        // Keep the flywheel moving
        // Note: We don't update borrower indices here because as part of liquidations
        //       repayBorrowFresh is called, which in turn calls `borrowAllow`, which updates
        //       the liquidated borrower's indices.
        updateAndDistributeSupplierRewardsForToken(mTokenCollateral, borrower);
        updateAndDistributeSupplierRewardsForToken(
            mTokenCollateral,
            liquidator
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Checks if the account should be allowed to transfer tokens in the given market
     * @param mToken The market to verify the transfer against
     * @param src The account which sources the tokens
     * @param dst The account which receives the tokens
     * @param transferTokens The number of mTokens to transfer
     * @return 0 if the transfer is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
     */
    function transferAllowed(
        address mToken,
        address src,
        address dst,
        uint transferTokens
    ) external override returns (uint) {
        // Pausing is a very serious situation - we revert to sound the alarms
        require(!transferGuardianPaused, "transfer is paused");

        // Currently the only consideration is whether or not
        //  the src is allowed to redeem this many tokens
        uint allowed = redeemAllowedInternal(mToken, src, transferTokens);
        if (allowed != uint(Error.NO_ERROR)) {
            return allowed;
        }

        // Keep the flywheel moving
        updateAndDistributeSupplierRewardsForToken(mToken, src);
        updateAndDistributeSupplierRewardsForToken(mToken, dst);

        return uint(Error.NO_ERROR);
    }

    /*** Liquidity/Liquidation Calculations ***/

    /**
     * @dev Local vars for avoiding stack-depth limits in calculating account liquidity.
     *  Note that `mTokenBalance` is the number of mTokens the account owns in the market,
     *  whereas `borrowBalance` is the amount of underlying that the account has borrowed.
     */
    struct AccountLiquidityLocalVars {
        uint sumCollateral;
        uint sumBorrowPlusEffects;
        uint mTokenBalance;
        uint borrowBalance;
        uint exchangeRateMantissa;
        uint oraclePriceMantissa;
        Exp collateralFactor;
        Exp exchangeRate;
        Exp oraclePrice;
        Exp tokensToDenom;
    }

    /**
     * @notice Determine the current account liquidity wrt collateral requirements
     * @return (possible error code (semi-opaque),
                account liquidity in excess of collateral requirements,
     *          account shortfall below collateral requirements)
     */
    function getAccountLiquidity(
        address account
    ) public view returns (uint, uint, uint) {
        (
            Error err,
            uint liquidity,
            uint shortfall
        ) = getHypotheticalAccountLiquidityInternal(
                account,
                MToken(address(0)),
                0,
                0
            );

        return (uint(err), liquidity, shortfall);
    }

    /**
     * @notice Determine the current account liquidity wrt collateral requirements
     * @return (possible error code,
                account liquidity in excess of collateral requirements,
     *          account shortfall below collateral requirements)
     */
    function getAccountLiquidityInternal(
        address account
    ) internal view returns (Error, uint, uint) {
        return
            getHypotheticalAccountLiquidityInternal(
                account,
                MToken(address(0)),
                0,
                0
            );
    }

    /**
     * @notice Determine what the account liquidity would be if the given amounts were redeemed/borrowed
     * @param mTokenModify The market to hypothetically redeem/borrow in
     * @param account The account to determine liquidity for
     * @param redeemTokens The number of tokens to hypothetically redeem
     * @param borrowAmount The amount of underlying to hypothetically borrow
     * @return (possible error code (semi-opaque),
                hypothetical account liquidity in excess of collateral requirements,
     *          hypothetical account shortfall below collateral requirements)
     */
    function getHypotheticalAccountLiquidity(
        address account,
        address mTokenModify,
        uint redeemTokens,
        uint borrowAmount
    ) public view returns (uint, uint, uint) {
        (
            Error err,
            uint liquidity,
            uint shortfall
        ) = getHypotheticalAccountLiquidityInternal(
                account,
                MToken(mTokenModify),
                redeemTokens,
                borrowAmount
            );
        return (uint(err), liquidity, shortfall);
    }

    /**
     * @notice Determine what the account liquidity would be if the given amounts were redeemed/borrowed
     * @param mTokenModify The market to hypothetically redeem/borrow in
     * @param account The account to determine liquidity for
     * @param redeemTokens The number of tokens to hypothetically redeem
     * @param borrowAmount The amount of underlying to hypothetically borrow
     * @dev Note that we calculate the exchangeRateStored for each collateral mToken using stored data,
     *  without calculating accumulated interest.
     * @return (possible error code,
                hypothetical account liquidity in excess of collateral requirements,
     *          hypothetical account shortfall below collateral requirements)
     */
    function getHypotheticalAccountLiquidityInternal(
        address account,
        MToken mTokenModify,
        uint redeemTokens,
        uint borrowAmount
    ) internal view returns (Error, uint, uint) {
        AccountLiquidityLocalVars memory vars; // Holds all our calculation results
        uint oErr;

        // For each asset the account is in
        MToken[] memory assets = accountAssets[account];
        for (uint i = 0; i < assets.length; i++) {
            MToken asset = assets[i];

            // Read the balances and exchange rate from the mToken
            (
                oErr,
                vars.mTokenBalance,
                vars.borrowBalance,
                vars.exchangeRateMantissa
            ) = asset.getAccountSnapshot(account);
            if (oErr != 0) {
                // semi-opaque error code, we assume NO_ERROR == 0 is invariant between upgrades
                return (Error.SNAPSHOT_ERROR, 0, 0);
            }
            vars.collateralFactor = Exp({
                mantissa: markets[address(asset)].collateralFactorMantissa
            });
            vars.exchangeRate = Exp({mantissa: vars.exchangeRateMantissa});

            // Get the normalized price of the asset
            vars.oraclePriceMantissa = oracle.getUnderlyingPrice(asset);
            if (vars.oraclePriceMantissa == 0) {
                return (Error.PRICE_ERROR, 0, 0);
            }
            vars.oraclePrice = Exp({mantissa: vars.oraclePriceMantissa});

            // Pre-compute a conversion factor from tokens -> glmr (normalized price value)
            vars.tokensToDenom = mul_(
                mul_(vars.collateralFactor, vars.exchangeRate),
                vars.oraclePrice
            );

            // sumCollateral += tokensToDenom * mTokenBalance
            vars.sumCollateral = mul_ScalarTruncateAddUInt(
                vars.tokensToDenom,
                vars.mTokenBalance,
                vars.sumCollateral
            );

            // sumBorrowPlusEffects += oraclePrice * borrowBalance
            vars.sumBorrowPlusEffects = mul_ScalarTruncateAddUInt(
                vars.oraclePrice,
                vars.borrowBalance,
                vars.sumBorrowPlusEffects
            );

            // Calculate effects of interacting with mTokenModify
            if (asset == mTokenModify) {
                // redeem effect
                // sumBorrowPlusEffects += tokensToDenom * redeemTokens
                vars.sumBorrowPlusEffects = mul_ScalarTruncateAddUInt(
                    vars.tokensToDenom,
                    redeemTokens,
                    vars.sumBorrowPlusEffects
                );

                // borrow effect
                // sumBorrowPlusEffects += oraclePrice * borrowAmount
                vars.sumBorrowPlusEffects = mul_ScalarTruncateAddUInt(
                    vars.oraclePrice,
                    borrowAmount,
                    vars.sumBorrowPlusEffects
                );
            }
        }

        // These are safe, as the underflow condition is checked first
        if (vars.sumCollateral > vars.sumBorrowPlusEffects) {
            return (
                Error.NO_ERROR,
                vars.sumCollateral - vars.sumBorrowPlusEffects,
                0
            );
        } else {
            return (
                Error.NO_ERROR,
                0,
                vars.sumBorrowPlusEffects - vars.sumCollateral
            );
        }
    }

    /**
     * @notice Calculate number of tokens of collateral asset to seize given an underlying amount
     * @dev Used in liquidation (called in mToken.liquidateBorrowFresh)
     * @param mTokenBorrowed The address of the borrowed mToken
     * @param mTokenCollateral The address of the collateral mToken
     * @param actualRepayAmount The amount of mTokenBorrowed underlying to convert into mTokenCollateral tokens
     * @return (errorCode, number of mTokenCollateral tokens to be seized in a liquidation)
     */
    function liquidateCalculateSeizeTokens(
        address mTokenBorrowed,
        address mTokenCollateral,
        uint actualRepayAmount
    ) external view override returns (uint, uint) {
        /* Read oracle prices for borrowed and collateral markets */
        uint priceBorrowedMantissa = oracle.getUnderlyingPrice(
            MToken(mTokenBorrowed)
        );
        uint priceCollateralMantissa = oracle.getUnderlyingPrice(
            MToken(mTokenCollateral)
        );
        if (priceBorrowedMantissa == 0 || priceCollateralMantissa == 0) {
            return (uint(Error.PRICE_ERROR), 0);
        }

        /*
         * Get the exchange rate and calculate the number of collateral tokens to seize:
         *  seizeAmount = actualRepayAmount * liquidationIncentive * priceBorrowed / priceCollateral
         *  seizeTokens = seizeAmount / exchangeRate
         *   = actualRepayAmount * (liquidationIncentive * priceBorrowed) / (priceCollateral * exchangeRate)
         */
        uint exchangeRateMantissa = MToken(mTokenCollateral)
            .exchangeRateStored(); // Note: reverts on error
        uint seizeTokens;
        Exp memory numerator;
        Exp memory denominator;
        Exp memory ratio;

        numerator = mul_(
            Exp({mantissa: liquidationIncentiveMantissa}),
            Exp({mantissa: priceBorrowedMantissa})
        );
        denominator = mul_(
            Exp({mantissa: priceCollateralMantissa}),
            Exp({mantissa: exchangeRateMantissa})
        );
        ratio = div_(numerator, denominator);

        seizeTokens = mul_ScalarTruncate(ratio, actualRepayAmount);

        return (uint(Error.NO_ERROR), seizeTokens);
    }

    /*** Admin Functions ***/

    /**
     * @notice Sets a new price oracle for the comptroller
     * @dev Admin function to set a new price oracle
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setPriceOracle(PriceOracle newOracle) public returns (uint) {
        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_PRICE_ORACLE_OWNER_CHECK
                );
        }

        // Track the old oracle for the comptroller
        PriceOracle oldOracle = oracle;

        // Set comptroller's oracle to newOracle
        oracle = newOracle;

        // Emit NewPriceOracle(oldOracle, newOracle)
        emit NewPriceOracle(oldOracle, newOracle);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sets the closeFactor used when liquidating borrows
     * @dev Admin function to set closeFactor
     * @param newCloseFactorMantissa New close factor, scaled by 1e18
     * @return uint 0=success, otherwise a failure
     */
    function _setCloseFactor(
        uint newCloseFactorMantissa
    ) external returns (uint) {
        // Check caller is admin
        require(msg.sender == admin, "only admin can set close factor");

        uint oldCloseFactorMantissa = closeFactorMantissa;
        closeFactorMantissa = newCloseFactorMantissa;
        emit NewCloseFactor(oldCloseFactorMantissa, closeFactorMantissa);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sets the collateralFactor for a market
     * @dev Admin function to set per-market collateralFactor
     * @param mToken The market to set the factor on
     * @param newCollateralFactorMantissa The new collateral factor, scaled by 1e18
     * @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
     */
    function _setCollateralFactor(
        MToken mToken,
        uint newCollateralFactorMantissa
    ) external returns (uint) {
        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_COLLATERAL_FACTOR_OWNER_CHECK
                );
        }

        // Verify market is listed
        Market storage market = markets[address(mToken)];
        if (!market.isListed) {
            return
                fail(
                    Error.MARKET_NOT_LISTED,
                    FailureInfo.SET_COLLATERAL_FACTOR_NO_EXISTS
                );
        }

        Exp memory newCollateralFactorExp = Exp({
            mantissa: newCollateralFactorMantissa
        });

        // Check collateral factor <= 0.9
        Exp memory highLimit = Exp({mantissa: collateralFactorMaxMantissa});
        if (lessThanExp(highLimit, newCollateralFactorExp)) {
            return
                fail(
                    Error.INVALID_COLLATERAL_FACTOR,
                    FailureInfo.SET_COLLATERAL_FACTOR_VALIDATION
                );
        }

        // If collateral factor != 0, fail if price == 0
        if (
            newCollateralFactorMantissa != 0 &&
            oracle.getUnderlyingPrice(mToken) == 0
        ) {
            return
                fail(
                    Error.PRICE_ERROR,
                    FailureInfo.SET_COLLATERAL_FACTOR_WITHOUT_PRICE
                );
        }

        // Set market's collateral factor to new collateral factor, remember old value
        uint oldCollateralFactorMantissa = market.collateralFactorMantissa;
        market.collateralFactorMantissa = newCollateralFactorMantissa;

        // Emit event with asset, old collateral factor, and new collateral factor
        emit NewCollateralFactor(
            mToken,
            oldCollateralFactorMantissa,
            newCollateralFactorMantissa
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sets liquidationIncentive
     * @dev Admin function to set liquidationIncentive
     * @param newLiquidationIncentiveMantissa New liquidationIncentive scaled by 1e18
     * @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
     */
    function _setLiquidationIncentive(
        uint newLiquidationIncentiveMantissa
    ) external returns (uint) {
        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_LIQUIDATION_INCENTIVE_OWNER_CHECK
                );
        }

        // Save current value for use in log
        uint oldLiquidationIncentiveMantissa = liquidationIncentiveMantissa;

        // Set liquidation incentive to new incentive
        liquidationIncentiveMantissa = newLiquidationIncentiveMantissa;

        // Emit event with old incentive, new incentive
        emit NewLiquidationIncentive(
            oldLiquidationIncentiveMantissa,
            newLiquidationIncentiveMantissa
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Add the market to the markets mapping and set it as listed
     * @dev Admin function to set isListed and add support for the market
     * @param mToken The address of the market (token) to list
     * @return uint 0=success, otherwise a failure. (See enum Error for details)
     */
    function _supportMarket(MToken mToken) external returns (uint) {
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SUPPORT_MARKET_OWNER_CHECK
                );
        }

        if (markets[address(mToken)].isListed) {
            return
                fail(
                    Error.MARKET_ALREADY_LISTED,
                    FailureInfo.SUPPORT_MARKET_EXISTS
                );
        }

        require(mToken.isMToken(), "Must be an MToken"); // Sanity check to make sure its really a MToken

        Market storage newMarket = markets[address(mToken)];
        newMarket.isListed = true;
        newMarket.collateralFactorMantissa = 0;

        _addMarketInternal(address(mToken));

        emit MarketListed(mToken);

        return uint(Error.NO_ERROR);
    }

    function _addMarketInternal(address mToken) internal {
        for (uint i = 0; i < allMarkets.length; i++) {
            require(allMarkets[i] != MToken(mToken), "market already added");
        }
        allMarkets.push(MToken(mToken));
    }

    /**
     * @notice Set the given borrow caps for the given mToken markets. Borrowing that brings total borrows to or above borrow cap will revert.
     * @dev Admin or borrowCapGuardian function to set the borrow caps. A borrow cap of 0 corresponds to unlimited borrowing.
     * @param mTokens The addresses of the markets (tokens) to change the borrow caps for
     * @param newBorrowCaps The new borrow cap values in underlying to be set. A value of 0 corresponds to unlimited borrowing.
     */
    function _setMarketBorrowCaps(
        MToken[] calldata mTokens,
        uint[] calldata newBorrowCaps
    ) external {
        require(
            msg.sender == admin || msg.sender == borrowCapGuardian,
            "only admin or borrow cap guardian can set borrow caps"
        );

        uint numMarkets = mTokens.length;
        uint numBorrowCaps = newBorrowCaps.length;

        require(
            numMarkets != 0 && numMarkets == numBorrowCaps,
            "invalid input"
        );

        for (uint i = 0; i < numMarkets; i++) {
            borrowCaps[address(mTokens[i])] = newBorrowCaps[i];
            emit NewBorrowCap(mTokens[i], newBorrowCaps[i]);
        }
    }

    /**
     * @notice Admin function to change the Borrow Cap Guardian
     * @param newBorrowCapGuardian The address of the new Borrow Cap Guardian
     */
    function _setBorrowCapGuardian(address newBorrowCapGuardian) external {
        require(msg.sender == admin, "only admin can set borrow cap guardian");

        // Save current value for inclusion in log
        address oldBorrowCapGuardian = borrowCapGuardian;

        // Store borrowCapGuardian with value newBorrowCapGuardian
        borrowCapGuardian = newBorrowCapGuardian;

        // Emit NewBorrowCapGuardian(OldBorrowCapGuardian, NewBorrowCapGuardian)
        emit NewBorrowCapGuardian(oldBorrowCapGuardian, newBorrowCapGuardian);
    }

    /**
     * @notice Set the given supply caps for the given mToken markets. Supplying that brings total supplies to or above supply cap will revert.
     * @dev Admin or supplyCapGuardian function to set the supply caps. A supply cap of 0 corresponds to unlimited supplying.
     * @param mTokens The addresses of the markets (tokens) to change the supply caps for
     * @param newSupplyCaps The new supply cap values in underlying to be set. A value of 0 corresponds to unlimited supplying.
     */
    function _setMarketSupplyCaps(
        MToken[] calldata mTokens,
        uint[] calldata newSupplyCaps
    ) external {
        require(
            msg.sender == admin || msg.sender == supplyCapGuardian,
            "only admin or supply cap guardian can set supply caps"
        );

        uint numMarkets = mTokens.length;
        uint numSupplyCaps = newSupplyCaps.length;

        require(
            numMarkets != 0 && numMarkets == numSupplyCaps,
            "invalid input"
        );

        for (uint i = 0; i < numMarkets; i++) {
            supplyCaps[address(mTokens[i])] = newSupplyCaps[i];
            emit NewSupplyCap(mTokens[i], newSupplyCaps[i]);
        }
    }

    /**
     * @notice Admin function to change the Supply Cap Guardian
     * @param newSupplyCapGuardian The address of the new Supply Cap Guardian
     */
    function _setSupplyCapGuardian(address newSupplyCapGuardian) external {
        require(msg.sender == admin, "only admin can set supply cap guardian");

        // Save current value for inclusion in log
        address oldSupplyCapGuardian = supplyCapGuardian;

        // Store supplyCapGuardian with value newSupplyCapGuardian
        supplyCapGuardian = newSupplyCapGuardian;

        // Emit NewSupplyCapGuardian(OldSupplyCapGuardian, NewSupplyCapGuardian)
        emit NewSupplyCapGuardian(oldSupplyCapGuardian, newSupplyCapGuardian);
    }

    /**
     * @notice Admin function to change the Pause Guardian
     * @param newPauseGuardian The address of the new Pause Guardian
     * @return uint 0=success, otherwise a failure. (See enum Error for details)
     */
    function _setPauseGuardian(address newPauseGuardian) public returns (uint) {
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_PAUSE_GUARDIAN_OWNER_CHECK
                );
        }

        // Save current value for inclusion in log
        address oldPauseGuardian = pauseGuardian;

        // Store pauseGuardian with value newPauseGuardian
        pauseGuardian = newPauseGuardian;

        // Emit NewPauseGuardian(OldPauseGuardian, NewPauseGuardian)
        emit NewPauseGuardian(oldPauseGuardian, pauseGuardian);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Admin function to change the Reward Distributor
     * @param newRewardDistributor The address of the new Reward Distributor
     */
    function _setRewardDistributor(
        MultiRewardDistributor newRewardDistributor
    ) public {
        require(msg.sender == admin, "Unauthorized");

        MultiRewardDistributor oldRewardDistributor = rewardDistributor;

        rewardDistributor = newRewardDistributor;

        emit NewRewardDistributor(oldRewardDistributor, newRewardDistributor);
    }

    function _setMintPaused(MToken mToken, bool state) public returns (bool) {
        require(
            markets[address(mToken)].isListed,
            "cannot pause a market that is not listed"
        );
        require(
            msg.sender == pauseGuardian || msg.sender == admin,
            "only pause guardian and admin can pause"
        );
        require(msg.sender == admin || state == true, "only admin can unpause");

        mintGuardianPaused[address(mToken)] = state;
        emit ActionPaused(mToken, "Mint", state);
        return state;
    }

    function _setBorrowPaused(MToken mToken, bool state) public returns (bool) {
        require(
            markets[address(mToken)].isListed,
            "cannot pause a market that is not listed"
        );
        require(
            msg.sender == pauseGuardian || msg.sender == admin,
            "only pause guardian and admin can pause"
        );
        require(msg.sender == admin || state == true, "only admin can unpause");

        borrowGuardianPaused[address(mToken)] = state;
        emit ActionPaused(mToken, "Borrow", state);
        return state;
    }

    function _setTransferPaused(bool state) public returns (bool) {
        require(
            msg.sender == pauseGuardian || msg.sender == admin,
            "only pause guardian and admin can pause"
        );
        require(msg.sender == admin || state == true, "only admin can unpause");

        transferGuardianPaused = state;
        emit ActionPaused("Transfer", state);
        return state;
    }

    function _setSeizePaused(bool state) public returns (bool) {
        require(
            msg.sender == pauseGuardian || msg.sender == admin,
            "only pause guardian and admin can pause"
        );
        require(msg.sender == admin || state == true, "only admin can unpause");

        seizeGuardianPaused = state;
        emit ActionPaused("Seize", state);
        return state;
    }

    function _become(Unitroller unitroller) public {
        require(
            msg.sender == unitroller.admin(),
            "only unitroller admin can change brains"
        );
        require(
            unitroller._acceptImplementation() == 0,
            "change not authorized"
        );
    }

    /**
     * @notice Sweep ERC-20 tokens from the comptroller to the admin
     * @param _tokenAddress The address of the token to transfer
     * @param _amount The amount of tokens to sweep, uint.max means everything
     */
    function _rescueFunds(address _tokenAddress, uint _amount) external {
        require(msg.sender == admin, "Unauthorized");

        IERC20 token = IERC20(_tokenAddress);
        // Similar to mTokens, if this is uint.max that means "transfer everything"
        if (_amount == type(uint).max) {
            token.transfer(admin, token.balanceOf(address(this)));
        } else {
            token.transfer(admin, _amount);
        }
    }

    /*** WELL Distribution ***/

    /**
     * @notice Call out to the reward distributor to update its supply index and this user's index too
     * @param mToken The market to synchronize indexes for
     * @param supplier The supplier to whom rewards are going
     */
    function updateAndDistributeSupplierRewardsForToken(
        address mToken,
        address supplier
    ) internal {
        if (address(rewardDistributor) != address(0)) {
            rewardDistributor.updateMarketSupplyIndexAndDisburseSupplierRewards(
                MToken(mToken),
                supplier,
                false
            );
        }
    }

    /**
     * @notice Call out to the reward distributor to update its borrow index and this user's index too
     * @param mToken The market to synchronize indexes for
     * @param borrower The borrower to whom rewards are going
     */
    function updateAndDistributeBorrowerRewardsForToken(
        address mToken,
        address borrower
    ) internal {
        if (address(rewardDistributor) != address(0)) {
            rewardDistributor.updateMarketBorrowIndexAndDisburseBorrowerRewards(
                MToken(mToken),
                borrower,
                false
            );
        }
    }

    /**
     * @notice Claim all the WELL accrued by holder in all markets
     */
    function claimReward() public {
        claimReward(msg.sender, allMarkets);
    }

    /**
     * @notice Claim all the rewards accrued by specified holder in all markets
     * @param holder The address to claim rewards for
     */
    function claimReward(address holder) public {
        claimReward(holder, allMarkets);
    }

    /**
     * @notice Claim all the rewards accrued by holder in the specified markets
     * @param holder The address to claim rewards for
     * @param mTokens The list of markets to claim rewards in
     */
    function claimReward(address holder, MToken[] memory mTokens) public {
        address[] memory holders = new address[](1);
        holders[0] = holder;
        claimReward(holders, mTokens, true, true);
    }

    /**
     * @notice Claim all rewards for a specified group of users, tokens, and market sides
     * @param holders The addresses to claim for
     * @param mTokens The list of markets to claim in
     * @param borrowers Whether or not to claim earned by borrowing
     * @param suppliers Whether or not to claim earned by supplying
     */
    function claimReward(
        address[] memory holders,
        MToken[] memory mTokens,
        bool borrowers,
        bool suppliers
    ) public {
        require(
            address(rewardDistributor) != address(0),
            "No reward distributor configured!"
        );

        for (uint i = 0; i < mTokens.length; i++) {
            // Safety check that the supplied mTokens are active/listed
            MToken mToken = mTokens[i];
            require(markets[address(mToken)].isListed, "market must be listed");

            // Disburse supply side
            if (suppliers == true) {
                rewardDistributor.updateMarketSupplyIndex(mToken);
                for (
                    uint holderIndex = 0;
                    holderIndex < holders.length;
                    holderIndex++
                ) {
                    rewardDistributor.disburseSupplierRewards(
                        mToken,
                        holders[holderIndex],
                        true
                    );
                }
            }

            // Disburse borrow side
            if (borrowers == true) {
                rewardDistributor.updateMarketBorrowIndex(mToken);
                for (
                    uint holderIndex = 0;
                    holderIndex < holders.length;
                    holderIndex++
                ) {
                    rewardDistributor.disburseBorrowerRewards(
                        mToken,
                        holders[holderIndex],
                        true
                    );
                }
            }
        }
    }

    /**
     * @notice Return all of the markets
     * @dev The automatic getter may be used to access an individual market.
     * @return The list of market addresses
     */
    function getAllMarkets() public view returns (MToken[] memory) {
        return allMarkets;
    }

    function getBlockTimestamp() public view returns (uint) {
        return block.timestamp;
    }

    /**
     * @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 make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_locked != 1, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _locked = 1;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _locked = 0;
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

abstract contract ComptrollerInterface {
    /// @notice Indicator that this is a Comptroller contract (for inspection)
    bool public constant isComptroller = true;

    /*** Assets You Are In ***/

    function enterMarkets(
        address[] calldata mTokens
    ) external virtual returns (uint[] memory);
    function exitMarket(address mToken) external virtual returns (uint);

    /*** Policy Hooks ***/

    function mintAllowed(
        address mToken,
        address minter,
        uint mintAmount
    ) external virtual returns (uint);

    function redeemAllowed(
        address mToken,
        address redeemer,
        uint redeemTokens
    ) external virtual returns (uint);

    // Do not remove, still used by MToken
    function redeemVerify(
        address mToken,
        address redeemer,
        uint redeemAmount,
        uint redeemTokens
    ) external pure virtual;

    function borrowAllowed(
        address mToken,
        address borrower,
        uint borrowAmount
    ) external virtual returns (uint);

    function repayBorrowAllowed(
        address mToken,
        address payer,
        address borrower,
        uint repayAmount
    ) external virtual returns (uint);

    function liquidateBorrowAllowed(
        address mTokenBorrowed,
        address mTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount
    ) external view virtual returns (uint);

    function seizeAllowed(
        address mTokenCollateral,
        address mTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens
    ) external virtual returns (uint);

    function transferAllowed(
        address mToken,
        address src,
        address dst,
        uint transferTokens
    ) external virtual returns (uint);

    /*** Liquidity/Liquidation Calculations ***/

    function liquidateCalculateSeizeTokens(
        address mTokenBorrowed,
        address mTokenCollateral,
        uint repayAmount
    ) external view virtual returns (uint, uint);
}

// The hooks that were patched out of the comptroller to make room for the supply caps, if we need them
abstract contract ComptrollerInterfaceWithAllVerificationHooks is
    ComptrollerInterface
{
    function mintVerify(
        address mToken,
        address minter,
        uint mintAmount,
        uint mintTokens
    ) external virtual;

    // Included in ComptrollerInterface already
    // function redeemVerify(address mToken, address redeemer, uint redeemAmount, uint redeemTokens) virtual external;

    function borrowVerify(
        address mToken,
        address borrower,
        uint borrowAmount
    ) external virtual;

    function repayBorrowVerify(
        address mToken,
        address payer,
        address borrower,
        uint repayAmount,
        uint borrowerIndex
    ) external virtual;

    function liquidateBorrowVerify(
        address mTokenBorrowed,
        address mTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount,
        uint seizeTokens
    ) external virtual;

    function seizeVerify(
        address mTokenCollateral,
        address mTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens
    ) external virtual;

    function transferVerify(
        address mToken,
        address src,
        address dst,
        uint transferTokens
    ) external virtual;
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

import "./MToken.sol";
import "./oracles/PriceOracle.sol";
import "./rewards/MultiRewardDistributor.sol";

contract UnitrollerAdminStorage {
    /**
     * @notice Administrator for this contract
     */
    address public admin;

    /**
     * @notice Pending administrator for this contract
     */
    address public pendingAdmin;

    /**
     * @notice Active brains of Unitroller
     */
    address public comptrollerImplementation;

    /**
     * @notice Pending brains of Unitroller
     */
    address public pendingComptrollerImplementation;
}

contract ComptrollerVXStorage is UnitrollerAdminStorage {
    /**
     * @notice Oracle which gives the price of any given asset
     */
    PriceOracle public oracle;

    /**
     * @notice Multiplier used to calculate the maximum repayAmount when liquidating a borrow
     */
    uint public closeFactorMantissa;

    /**
     * @notice Multiplier representing the discount on collateral that a liquidator receives
     */
    uint public liquidationIncentiveMantissa;

    /**
     * @notice Per-account mapping of "assets you are in", capped by maxAssets
     */
    mapping(address => MToken[]) public accountAssets;

    struct Market {
        /// @notice Whether or not this market is listed
        bool isListed;
        /**
         * @notice Multiplier representing the most one can borrow against their collateral in this market.
         *  For instance, 0.9 to allow borrowing 90% of collateral value.
         *  Must be between 0 and 1, and stored as a mantissa.
         */
        uint collateralFactorMantissa;
        /// @notice Per-market mapping of "accounts in this asset"
        mapping(address => bool) accountMembership;
    }

    /**
     * @notice Official mapping of mTokens -> Market metadata
     * @dev Used e.g. to determine if a market is supported
     */
    mapping(address => Market) public markets;

    /**
     * @notice The Pause Guardian can pause certain actions as a safety mechanism.
     *  Actions which allow users to remove their own assets cannot be paused.
     *  Liquidation / seizing / transfer can only be paused globally, not by market.
     */
    address public pauseGuardian;
    bool public transferGuardianPaused;
    bool public seizeGuardianPaused;
    mapping(address => bool) public mintGuardianPaused;
    mapping(address => bool) public borrowGuardianPaused;

    /// @notice A list of all markets
    MToken[] public allMarkets;

    // @notice The borrowCapGuardian can set borrowCaps to any number for any market. Lowering the borrow cap could disable borrowing on the given market.
    address public borrowCapGuardian;

    // @notice Borrow caps enforced by borrowAllowed for each mToken address. Defaults to zero which corresponds to unlimited borrowing.
    mapping(address => uint) public borrowCaps;

    struct RewardMarketState {
        /// @notice The market's last updated rewardBorrowIndex or rewardSupplyIndex
        uint224 index;
        /// @notice The block timestamp the index was last updated at
        uint32 timestamp;
    }

    /// @notice Reentrant status, 0: not entered, 1: entered
    uint256 internal _locked;
}

contract ComptrollerV2Storage is ComptrollerVXStorage {
    /// @notice The supplyCapGuardian can set supplyCaps to any number for any market. Lowering the supply cap could disable supplying to the given market.
    address public supplyCapGuardian;

    /// @notice Supply caps enforced by mintAllowed for each cToken address. Defaults to zero which corresponds to unlimited supplying.
    mapping(address => uint) public supplyCaps;

    /// @notice The Reward distributor used to emit protocol rewards
    MultiRewardDistributor public rewardDistributor;
}

// 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;
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

/**
 * @title ERC 20 Token Standard Interface
 *  https://eips.ethereum.org/EIPS/eip-20
 */
interface EIP20Interface {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);

    /**
     * @notice Get the total number of tokens in circulation
     * @return The supply of tokens
     */
    function totalSupply() external view returns (uint256);

    /**
     * @notice Gets the balance of the specified address
     * @param owner The address from which the balance will be retrieved
     * @return balance The balance
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @notice Transfer `amount` tokens from `msg.sender` to `dst`
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     * @return success Whether or not the transfer succeeded
     */
    function transfer(
        address dst,
        uint256 amount
    ) external returns (bool success);

    /**
     * @notice Transfer `amount` tokens from `src` to `dst`
     * @param src The address of the source account
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     * @return success Whether or not the transfer succeeded
     */
    function transferFrom(
        address src,
        address dst,
        uint256 amount
    ) external returns (bool success);

    /**
     * @notice Approve `spender` to transfer up to `amount` from `src`
     * @dev This will overwrite the approval amount for `spender`
     *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
     * @param spender The address of the account which may transfer tokens
     * @param amount The number of tokens that are approved (-1 means infinite)
     * @return success Whether or not the approval succeeded
     */
    function approve(
        address spender,
        uint256 amount
    ) external returns (bool success);

    /**
     * @notice Get the current allowance from `owner` for `spender`
     * @param owner The address of the account which owns the tokens to be spent
     * @param spender The address of the account which may transfer tokens
     * @return remaining The number of tokens allowed to be spent (-1 means infinite)
     */
    function allowance(
        address owner,
        address spender
    ) external view returns (uint256 remaining);

    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 amount
    );
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

/**
 * @title EIP20NonStandardInterface
 * @dev Version of ERC20 with no return values for `transfer` and `transferFrom`
 *  See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
 */
interface EIP20NonStandardInterface {
    /**
     * @notice Get the total number of tokens in circulation
     * @return The supply of tokens
     */
    function totalSupply() external view returns (uint256);

    /**
     * @notice Gets the balance of the specified address
     * @param owner The address from which the balance will be retrieved
     * @return balance The balance
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    ///
    /// !!!!!!!!!!!!!!
    /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification
    /// !!!!!!!!!!!!!!
    ///

    /**
     * @notice Transfer `amount` tokens from `msg.sender` to `dst`
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     */
    function transfer(address dst, uint256 amount) external;

    ///
    /// !!!!!!!!!!!!!!
    /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification
    /// !!!!!!!!!!!!!!
    ///

    /**
     * @notice Transfer `amount` tokens from `src` to `dst`
     * @param src The address of the source account
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     */
    function transferFrom(address src, address dst, uint256 amount) external;

    /**
     * @notice Approve `spender` to transfer up to `amount` from `src`
     * @dev This will overwrite the approval amount for `spender`
     *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
     * @param spender The address of the account which may transfer tokens
     * @param amount The number of tokens that are approved
     * @return success Whether or not the approval succeeded
     */
    function approve(
        address spender,
        uint256 amount
    ) external returns (bool success);

    /**
     * @notice Get the current allowance from `owner` for `spender`
     * @param owner The address of the account which owns the tokens to be spent
     * @param spender The address of the account which may transfer tokens
     * @return remaining The number of tokens allowed to be spent
     */
    function allowance(
        address owner,
        address spender
    ) external view returns (uint256 remaining);

    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 amount
    );
}

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

/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /*//////////////////////////////////////////////////////////////
                            METADATA STORAGE
    //////////////////////////////////////////////////////////////*/

    string public name;

    string public symbol;

    uint8 public immutable decimals;

    /*//////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;

    mapping(address => mapping(address => uint256)) public allowance;

    /*//////////////////////////////////////////////////////////////
                            EIP-2612 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 internal immutable INITIAL_CHAIN_ID;

    bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;

    mapping(address => uint256) public nonces;

    /*//////////////////////////////////////////////////////////////
                               CONSTRUCTOR
    //////////////////////////////////////////////////////////////*/

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        INITIAL_CHAIN_ID = block.chainid;
        INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
    }

    /*//////////////////////////////////////////////////////////////
                               ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/

    function approve(address spender, uint256 amount) public virtual returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transfer(address to, uint256 amount) public virtual returns (bool) {
        balanceOf[msg.sender] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(msg.sender, to, amount);

        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.

        if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

        return true;
    }

    /*//////////////////////////////////////////////////////////////
                             EIP-2612 LOGIC
    //////////////////////////////////////////////////////////////*/

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");

        // Unchecked because the only math done is incrementing
        // the owner's nonce which cannot realistically overflow.
        unchecked {
            address recoveredAddress = ecrecover(
                keccak256(
                    abi.encodePacked(
                        "\x19\x01",
                        DOMAIN_SEPARATOR(),
                        keccak256(
                            abi.encode(
                                keccak256(
                                    "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
                                ),
                                owner,
                                spender,
                                value,
                                nonces[owner]++,
                                deadline
                            )
                        )
                    )
                ),
                v,
                r,
                s
            );

            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");

            allowance[recoveredAddress][spender] = value;
        }

        emit Approval(owner, spender, value);
    }

    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
        return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
    }

    function computeDomainSeparator() internal view virtual returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                    keccak256(bytes(name)),
                    keccak256("1"),
                    block.chainid,
                    address(this)
                )
            );
    }

    /*//////////////////////////////////////////////////////////////
                        INTERNAL MINT/BURN LOGIC
    //////////////////////////////////////////////////////////////*/

    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(address(0), to, amount);
    }

    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;

        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }

        emit Transfer(from, address(0), amount);
    }
}

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

import {ERC20} from "../tokens/ERC20.sol";
import {SafeTransferLib} from "../utils/SafeTransferLib.sol";
import {FixedPointMathLib} from "../utils/FixedPointMathLib.sol";

/// @notice Minimal ERC4626 tokenized Vault implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/mixins/ERC4626.sol)
abstract contract ERC4626 is ERC20 {
    using SafeTransferLib for ERC20;
    using FixedPointMathLib for uint256;

    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Deposit(address indexed caller, address indexed owner, uint256 assets, uint256 shares);

    event Withdraw(
        address indexed caller,
        address indexed receiver,
        address indexed owner,
        uint256 assets,
        uint256 shares
    );

    /*//////////////////////////////////////////////////////////////
                               IMMUTABLES
    //////////////////////////////////////////////////////////////*/

    ERC20 public immutable asset;

    constructor(
        ERC20 _asset,
        string memory _name,
        string memory _symbol
    ) ERC20(_name, _symbol, _asset.decimals()) {
        asset = _asset;
    }

    /*//////////////////////////////////////////////////////////////
                        DEPOSIT/WITHDRAWAL LOGIC
    //////////////////////////////////////////////////////////////*/

    function deposit(uint256 assets, address receiver) public virtual returns (uint256 shares) {
        // Check for rounding error since we round down in previewDeposit.
        require((shares = previewDeposit(assets)) != 0, "ZERO_SHARES");

        // Need to transfer before minting or ERC777s could reenter.
        asset.safeTransferFrom(msg.sender, address(this), assets);

        _mint(receiver, shares);

        emit Deposit(msg.sender, receiver, assets, shares);

        afterDeposit(assets, shares);
    }

    function mint(uint256 shares, address receiver) public virtual returns (uint256 assets) {
        assets = previewMint(shares); // No need to check for rounding error, previewMint rounds up.

        // Need to transfer before minting or ERC777s could reenter.
        asset.safeTransferFrom(msg.sender, address(this), assets);

        _mint(receiver, shares);

        emit Deposit(msg.sender, receiver, assets, shares);

        afterDeposit(assets, shares);
    }

    function withdraw(
        uint256 assets,
        address receiver,
        address owner
    ) public virtual returns (uint256 shares) {
        shares = previewWithdraw(assets); // No need to check for rounding error, previewWithdraw rounds up.

        if (msg.sender != owner) {
            uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.

            if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;
        }

        beforeWithdraw(assets, shares);

        _burn(owner, shares);

        emit Withdraw(msg.sender, receiver, owner, assets, shares);

        asset.safeTransfer(receiver, assets);
    }

    function redeem(
        uint256 shares,
        address receiver,
        address owner
    ) public virtual returns (uint256 assets) {
        if (msg.sender != owner) {
            uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.

            if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;
        }

        // Check for rounding error since we round down in previewRedeem.
        require((assets = previewRedeem(shares)) != 0, "ZERO_ASSETS");

        beforeWithdraw(assets, shares);

        _burn(owner, shares);

        emit Withdraw(msg.sender, receiver, owner, assets, shares);

        asset.safeTransfer(receiver, assets);
    }

    /*//////////////////////////////////////////////////////////////
                            ACCOUNTING LOGIC
    //////////////////////////////////////////////////////////////*/

    function totalAssets() public view virtual returns (uint256);

    function convertToShares(uint256 assets) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? assets : assets.mulDivDown(supply, totalAssets());
    }

    function convertToAssets(uint256 shares) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? shares : shares.mulDivDown(totalAssets(), supply);
    }

    function previewDeposit(uint256 assets) public view virtual returns (uint256) {
        return convertToShares(assets);
    }

    function previewMint(uint256 shares) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? shares : shares.mulDivUp(totalAssets(), supply);
    }

    function previewWithdraw(uint256 assets) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? assets : assets.mulDivUp(supply, totalAssets());
    }

    function previewRedeem(uint256 shares) public view virtual returns (uint256) {
        return convertToAssets(shares);
    }

    /*//////////////////////////////////////////////////////////////
                     DEPOSIT/WITHDRAWAL LIMIT LOGIC
    //////////////////////////////////////////////////////////////*/

    function maxDeposit(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    function maxMint(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    function maxWithdraw(address owner) public view virtual returns (uint256) {
        return convertToAssets(balanceOf[owner]);
    }

    function maxRedeem(address owner) public view virtual returns (uint256) {
        return balanceOf[owner];
    }

    /*//////////////////////////////////////////////////////////////
                          INTERNAL HOOKS LOGIC
    //////////////////////////////////////////////////////////////*/

    function beforeWithdraw(uint256 assets, uint256 shares) internal virtual {}

    function afterDeposit(uint256 assets, uint256 shares) internal virtual {}
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

contract ComptrollerErrorReporter {
    enum Error {
        NO_ERROR,
        UNAUTHORIZED,
        COMPTROLLER_MISMATCH,
        INSUFFICIENT_SHORTFALL,
        INSUFFICIENT_LIQUIDITY,
        INVALID_CLOSE_FACTOR,
        INVALID_COLLATERAL_FACTOR,
        INVALID_LIQUIDATION_INCENTIVE,
        MARKET_NOT_ENTERED, // no longer possible
        MARKET_NOT_LISTED,
        MARKET_ALREADY_LISTED,
        MATH_ERROR,
        NONZERO_BORROW_BALANCE,
        PRICE_ERROR,
        REJECTION,
        SNAPSHOT_ERROR,
        TOO_MANY_ASSETS,
        TOO_MUCH_REPAY
    }

    enum FailureInfo {
        ACCEPT_ADMIN_PENDING_ADMIN_CHECK,
        ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK,
        EXIT_MARKET_BALANCE_OWED,
        EXIT_MARKET_REJECTION,
        SET_CLOSE_FACTOR_OWNER_CHECK,
        SET_CLOSE_FACTOR_VALIDATION,
        SET_COLLATERAL_FACTOR_OWNER_CHECK,
        SET_COLLATERAL_FACTOR_NO_EXISTS,
        SET_COLLATERAL_FACTOR_VALIDATION,
        SET_COLLATERAL_FACTOR_WITHOUT_PRICE,
        SET_IMPLEMENTATION_OWNER_CHECK,
        SET_LIQUIDATION_INCENTIVE_OWNER_CHECK,
        SET_LIQUIDATION_INCENTIVE_VALIDATION,
        SET_MAX_ASSETS_OWNER_CHECK,
        SET_PENDING_ADMIN_OWNER_CHECK,
        SET_PENDING_IMPLEMENTATION_OWNER_CHECK,
        SET_PRICE_ORACLE_OWNER_CHECK,
        SUPPORT_MARKET_EXISTS,
        SUPPORT_MARKET_OWNER_CHECK,
        SET_PAUSE_GUARDIAN_OWNER_CHECK,
        SET_GAS_AMOUNT_OWNER_CHECK
    }

    /**
     * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary
     * contract-specific code that enables us to report opaque error codes from upgradeable contracts.
     **/
    event Failure(uint error, uint info, uint detail);

    /**
     * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator
     */
    function fail(Error err, FailureInfo info) internal returns (uint) {
        emit Failure(uint(err), uint(info), 0);

        return uint(err);
    }

    /**
     * @dev use this when reporting an opaque error from an upgradeable collaborator contract
     */
    function failOpaque(
        Error err,
        FailureInfo info,
        uint opaqueError
    ) internal returns (uint) {
        emit Failure(uint(err), uint(info), opaqueError);

        return uint(err);
    }
}

contract TokenErrorReporter {
    enum Error {
        NO_ERROR,
        UNAUTHORIZED,
        BAD_INPUT,
        COMPTROLLER_REJECTION,
        COMPTROLLER_CALCULATION_ERROR,
        INTEREST_RATE_MODEL_ERROR,
        INVALID_ACCOUNT_PAIR,
        INVALID_CLOSE_AMOUNT_REQUESTED,
        INVALID_COLLATERAL_FACTOR,
        MATH_ERROR,
        MARKET_NOT_FRESH,
        MARKET_NOT_LISTED,
        TOKEN_INSUFFICIENT_ALLOWANCE,
        TOKEN_INSUFFICIENT_BALANCE,
        TOKEN_INSUFFICIENT_CASH,
        TOKEN_TRANSFER_IN_FAILED,
        TOKEN_TRANSFER_OUT_FAILED
    }

    /*
     * Note: FailureInfo (but not Error) is kept in alphabetical order
     *       This is because FailureInfo grows significantly faster, and
     *       the order of Error has some meaning, while the order of FailureInfo
     *       is entirely arbitrary.
     */
    enum FailureInfo {
        ACCEPT_ADMIN_PENDING_ADMIN_CHECK,
        ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED,
        ACCRUE_INTEREST_BORROW_RATE_CALCULATION_FAILED,
        ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED,
        ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED,
        ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED,
        ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED,
        BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
        BORROW_ACCRUE_INTEREST_FAILED,
        BORROW_CASH_NOT_AVAILABLE,
        BORROW_FRESHNESS_CHECK,
        BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
        BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
        BORROW_MARKET_NOT_LISTED,
        BORROW_COMPTROLLER_REJECTION,
        LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED,
        LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED,
        LIQUIDATE_COLLATERAL_FRESHNESS_CHECK,
        LIQUIDATE_COMPTROLLER_REJECTION,
        LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED,
        LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX,
        LIQUIDATE_CLOSE_AMOUNT_IS_ZERO,
        LIQUIDATE_FRESHNESS_CHECK,
        LIQUIDATE_LIQUIDATOR_IS_BORROWER,
        LIQUIDATE_REPAY_BORROW_FRESH_FAILED,
        LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED,
        LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED,
        LIQUIDATE_SEIZE_COMPTROLLER_REJECTION,
        LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER,
        LIQUIDATE_SEIZE_TOO_MUCH,
        MINT_ACCRUE_INTEREST_FAILED,
        MINT_COMPTROLLER_REJECTION,
        MINT_EXCHANGE_CALCULATION_FAILED,
        MINT_EXCHANGE_RATE_READ_FAILED,
        MINT_FRESHNESS_CHECK,
        MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
        MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
        MINT_TRANSFER_IN_FAILED,
        MINT_TRANSFER_IN_NOT_POSSIBLE,
        REDEEM_ACCRUE_INTEREST_FAILED,
        REDEEM_COMPTROLLER_REJECTION,
        REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED,
        REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED,
        REDEEM_EXCHANGE_RATE_READ_FAILED,
        REDEEM_FRESHNESS_CHECK,
        REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
        REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
        REDEEM_TRANSFER_OUT_NOT_POSSIBLE,
        REDUCE_RESERVES_ACCRUE_INTEREST_FAILED,
        REDUCE_RESERVES_ADMIN_CHECK,
        REDUCE_RESERVES_CASH_NOT_AVAILABLE,
        REDUCE_RESERVES_FRESH_CHECK,
        REDUCE_RESERVES_VALIDATION,
        REPAY_BEHALF_ACCRUE_INTEREST_FAILED,
        REPAY_BORROW_ACCRUE_INTEREST_FAILED,
        REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
        REPAY_BORROW_COMPTROLLER_REJECTION,
        REPAY_BORROW_FRESHNESS_CHECK,
        REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
        REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
        REPAY_BORROW_TRANSFER_IN_NOT_POSSIBLE,
        SET_COLLATERAL_FACTOR_OWNER_CHECK,
        SET_COLLATERAL_FACTOR_VALIDATION,
        SET_COMPTROLLER_OWNER_CHECK,
        SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED,
        SET_INTEREST_RATE_MODEL_FRESH_CHECK,
        SET_INTEREST_RATE_MODEL_OWNER_CHECK,
        SET_MAX_ASSETS_OWNER_CHECK,
        SET_ORACLE_MARKET_NOT_LISTED,
        SET_PENDING_ADMIN_OWNER_CHECK,
        SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED,
        SET_RESERVE_FACTOR_ADMIN_CHECK,
        SET_RESERVE_FACTOR_FRESH_CHECK,
        SET_RESERVE_FACTOR_BOUNDS_CHECK,
        TRANSFER_COMPTROLLER_REJECTION,
        TRANSFER_NOT_ALLOWED,
        TRANSFER_NOT_ENOUGH,
        TRANSFER_TOO_MUCH,
        ADD_RESERVES_ACCRUE_INTEREST_FAILED,
        ADD_RESERVES_FRESH_CHECK,
        ADD_RESERVES_TRANSFER_IN_NOT_POSSIBLE,
        SET_PROTOCOL_SEIZE_SHARE_ACCRUE_INTEREST_FAILED,
        SET_PROTOCOL_SEIZE_SHARE_OWNER_CHECK,
        SET_PROTOCOL_SEIZE_SHARE_FRESH_CHECK
    }

    /**
     * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary
     * contract-specific code that enables us to report opaque error codes from upgradeable contracts.
     **/
    event Failure(uint error, uint info, uint detail);

    /**
     * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator
     */
    function fail(Error err, FailureInfo info) internal returns (uint) {
        emit Failure(uint(err), uint(info), 0);

        return uint(err);
    }

    /**
     * @dev use this when reporting an opaque error from an upgradeable collaborator contract
     */
    function failOpaque(
        Error err,
        FailureInfo info,
        uint opaqueError
    ) internal returns (uint) {
        emit Failure(uint(err), uint(info), opaqueError);

        return uint(err);
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

import "./CarefulMath.sol";
import "./ExponentialNoError.sol";

/**
 * @title Exponential module for storing fixed-precision decimals
 * @author Moonwell
 * @dev Legacy contract for compatibility reasons with existing contracts that still use MathError
 * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places.
 *         Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is:
 *         `Exp({mantissa: 5100000000000000000})`.
 */
contract Exponential is CarefulMath, ExponentialNoError {
    /**
     * @dev Creates an exponential from numerator and denominator values.
     *      Note: Returns an error if (`num` * 10e18) > MAX_INT,
     *            or if `denom` is zero.
     */
    function getExp(
        uint num,
        uint denom
    ) internal pure returns (MathError, Exp memory) {
        (MathError err0, uint scaledNumerator) = mulUInt(num, expScale);
        if (err0 != MathError.NO_ERROR) {
            return (err0, Exp({mantissa: 0}));
        }

        (MathError err1, uint rational) = divUInt(scaledNumerator, denom);
        if (err1 != MathError.NO_ERROR) {
            return (err1, Exp({mantissa: 0}));
        }

        return (MathError.NO_ERROR, Exp({mantissa: rational}));
    }

    /**
     * @dev Adds two exponentials, returning a new exponential.
     */
    function addExp(
        Exp memory a,
        Exp memory b
    ) internal pure returns (MathError, Exp memory) {
        (MathError error, uint result) = addUInt(a.mantissa, b.mantissa);

        return (error, Exp({mantissa: result}));
    }

    /**
     * @dev Subtracts two exponentials, returning a new exponential.
     */
    function subExp(
        Exp memory a,
        Exp memory b
    ) internal pure returns (MathError, Exp memory) {
        (MathError error, uint result) = subUInt(a.mantissa, b.mantissa);

        return (error, Exp({mantissa: result}));
    }

    /**
     * @dev Multiply an Exp by a scalar, returning a new Exp.
     */
    function mulScalar(
        Exp memory a,
        uint scalar
    ) internal pure returns (MathError, Exp memory) {
        (MathError err0, uint scaledMantissa) = mulUInt(a.mantissa, scalar);
        if (err0 != MathError.NO_ERROR) {
            return (err0, Exp({mantissa: 0}));
        }

        return (MathError.NO_ERROR, Exp({mantissa: scaledMantissa}));
    }

    /**
     * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer.
     */
    function mulScalarTruncate(
        Exp memory a,
        uint scalar
    ) internal pure returns (MathError, uint) {
        (MathError err, Exp memory product) = mulScalar(a, scalar);
        if (err != MathError.NO_ERROR) {
            return (err, 0);
        }

        return (MathError.NO_ERROR, truncate(product));
    }

    /**
     * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer.
     */
    function mulScalarTruncateAddUInt(
        Exp memory a,
        uint scalar,
        uint addend
    ) internal pure returns (MathError, uint) {
        (MathError err, Exp memory product) = mulScalar(a, scalar);
        if (err != MathError.NO_ERROR) {
            return (err, 0);
        }

        return addUInt(truncate(product), addend);
    }

    /**
     * @dev Divide an Exp by a scalar, returning a new Exp.
     */
    function divScalar(
        Exp memory a,
        uint scalar
    ) internal pure returns (MathError, Exp memory) {
        (MathError err0, uint descaledMantissa) = divUInt(a.mantissa, scalar);
        if (err0 != MathError.NO_ERROR) {
            return (err0, Exp({mantissa: 0}));
        }

        return (MathError.NO_ERROR, Exp({mantissa: descaledMantissa}));
    }

    /**
     * @dev Divide a scalar by an Exp, returning a new Exp.
     */
    function divScalarByExp(
        uint scalar,
        Exp memory divisor
    ) internal pure returns (MathError, Exp memory) {
        /*
          We are doing this as:
          getExp(mulUInt(expScale, scalar), divisor.mantissa)

          How it works:
          Exp = a / b;
          Scalar = s;
          `s / (a / b)` = `b * s / a` and since for an Exp `a = mantissa, b = expScale`
        */
        (MathError err0, uint numerator) = mulUInt(expScale, scalar);
        if (err0 != MathError.NO_ERROR) {
            return (err0, Exp({mantissa: 0}));
        }
        return getExp(numerator, divisor.mantissa);
    }

    /**
     * @dev Divide a scalar by an Exp, then truncate to return an unsigned integer.
     */
    function divScalarByExpTruncate(
        uint scalar,
        Exp memory divisor
    ) internal pure returns (MathError, uint) {
        (MathError err, Exp memory fraction) = divScalarByExp(scalar, divisor);
        if (err != MathError.NO_ERROR) {
            return (err, 0);
        }

        return (MathError.NO_ERROR, truncate(fraction));
    }

    /**
     * @dev Multiplies two exponentials, returning a new exponential.
     */
    function mulExp(
        Exp memory a,
        Exp memory b
    ) internal pure returns (MathError, Exp memory) {
        (MathError err0, uint doubleScaledProduct) = mulUInt(
            a.mantissa,
            b.mantissa
        );
        if (err0 != MathError.NO_ERROR) {
            return (err0, Exp({mantissa: 0}));
        }

        // We add half the scale before dividing so that we get rounding instead of truncation.
        //  See "Listing 6" and text above it at https://accu.org/index.php/journals/1717
        // Without this change, a result like 6.6...e-19 will be truncated to 0 instead of being rounded to 1e-18.
        (MathError err1, uint doubleScaledProductWithHalfScale) = addUInt(
            halfExpScale,
            doubleScaledProduct
        );
        if (err1 != MathError.NO_ERROR) {
            return (err1, Exp({mantissa: 0}));
        }

        (MathError err2, uint product) = divUInt(
            doubleScaledProductWithHalfScale,
            expScale
        );
        // The only error `div` can return is MathError.DIVISION_BY_ZERO but we control `expScale` and it is not zero.
        assert(err2 == MathError.NO_ERROR);

        return (MathError.NO_ERROR, Exp({mantissa: product}));
    }

    /**
     * @dev Multiplies two exponentials given their mantissas, returning a new exponential.
     */
    function mulExp(
        uint a,
        uint b
    ) internal pure returns (MathError, Exp memory) {
        return mulExp(Exp({mantissa: a}), Exp({mantissa: b}));
    }

    /**
     * @dev Multiplies three exponentials, returning a new exponential.
     */
    function mulExp3(
        Exp memory a,
        Exp memory b,
        Exp memory c
    ) internal pure returns (MathError, Exp memory) {
        (MathError err, Exp memory ab) = mulExp(a, b);
        if (err != MathError.NO_ERROR) {
            return (err, ab);
        }
        return mulExp(ab, c);
    }

    /**
     * @dev Divides two exponentials, returning a new exponential.
     *     (a/scale) / (b/scale) = (a/scale) * (scale/b) = a/b,
     *  which we can scale as an Exp by calling getExp(a.mantissa, b.mantissa)
     */
    function divExp(
        Exp memory a,
        Exp memory b
    ) internal pure returns (MathError, Exp memory) {
        return getExp(a.mantissa, b.mantissa);
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

/**
 * @title Exponential module for storing fixed-precision decimals
 * @author Moonwell
 * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places.
 *         Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is:
 *         `Exp({mantissa: 5100000000000000000})`.
 */
contract ExponentialNoError {
    uint constant expScale = 1e18;
    uint constant doubleScale = 1e36;
    uint constant halfExpScale = expScale / 2;
    uint constant mantissaOne = expScale;

    struct Exp {
        uint mantissa;
    }

    struct Double {
        uint mantissa;
    }

    /**
     * @dev Truncates the given exp to a whole number value.
     *      For example, truncate(Exp{mantissa: 15 * expScale}) = 15
     */
    function truncate(Exp memory exp) internal pure returns (uint) {
        // Note: We are not using careful math here as we're performing a division that cannot fail
        return exp.mantissa / expScale;
    }

    /**
     * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer.
     */
    function mul_ScalarTruncate(
        Exp memory a,
        uint scalar
    ) internal pure returns (uint) {
        Exp memory product = mul_(a, scalar);
        return truncate(product);
    }

    /**
     * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer.
     */
    function mul_ScalarTruncateAddUInt(
        Exp memory a,
        uint scalar,
        uint addend
    ) internal pure returns (uint) {
        Exp memory product = mul_(a, scalar);
        return add_(truncate(product), addend);
    }

    /**
     * @dev Checks if first Exp is less than second Exp.
     */
    function lessThanExp(
        Exp memory left,
        Exp memory right
    ) internal pure returns (bool) {
        return left.mantissa < right.mantissa;
    }

    /**
     * @dev Checks if left Exp <= right Exp.
     */
    function lessThanOrEqualExp(
        Exp memory left,
        Exp memory right
    ) internal pure returns (bool) {
        return left.mantissa <= right.mantissa;
    }

    /**
     * @dev Checks if left Exp > right Exp.
     */
    function greaterThanExp(
        Exp memory left,
        Exp memory right
    ) internal pure returns (bool) {
        return left.mantissa > right.mantissa;
    }

    /**
     * @dev returns true if Exp is exactly zero
     */
    function isZeroExp(Exp memory value) internal pure returns (bool) {
        return value.mantissa == 0;
    }

    function safe224(
        uint n,
        string memory errorMessage
    ) internal pure returns (uint224) {
        require(n < 2 ** 224, errorMessage);
        return uint224(n);
    }

    function safe32(
        uint n,
        string memory errorMessage
    ) internal pure returns (uint32) {
        require(n < 2 ** 32, errorMessage);
        return uint32(n);
    }

    function add_(
        Exp memory a,
        Exp memory b
    ) internal pure returns (Exp memory) {
        return Exp({mantissa: add_(a.mantissa, b.mantissa)});
    }

    function add_(
        Double memory a,
        Double memory b
    ) internal pure returns (Double memory) {
        return Double({mantissa: add_(a.mantissa, b.mantissa)});
    }

    function add_(uint a, uint b) internal pure returns (uint) {
        return add_(a, b, "addition overflow");
    }

    function add_(
        uint a,
        uint b,
        string memory errorMessage
    ) internal pure returns (uint) {
        uint c = a + b;
        require(c >= a, errorMessage);
        return c;
    }

    function sub_(
        Exp memory a,
        Exp memory b
    ) internal pure returns (Exp memory) {
        return Exp({mantissa: sub_(a.mantissa, b.mantissa)});
    }

    function sub_(
        Double memory a,
        Double memory b
    ) internal pure returns (Double memory) {
        return Double({mantissa: sub_(a.mantissa, b.mantissa)});
    }

    function sub_(uint a, uint b) internal pure returns (uint) {
        return sub_(a, b, "subtraction underflow");
    }

    function sub_(
        uint a,
        uint b,
        string memory errorMessage
    ) internal pure returns (uint) {
        require(b <= a, errorMessage);
        return a - b;
    }

    function mul_(
        Exp memory a,
        Exp memory b
    ) internal pure returns (Exp memory) {
        return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale});
    }

    function mul_(Exp memory a, uint b) internal pure returns (Exp memory) {
        return Exp({mantissa: mul_(a.mantissa, b)});
    }

    function mul_(uint a, Exp memory b) internal pure returns (uint) {
        return mul_(a, b.mantissa) / expScale;
    }

    function mul_(
        Double memory a,
        Double memory b
    ) internal pure returns (Double memory) {
        return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale});
    }

    function mul_(
        Double memory a,
        uint b
    ) internal pure returns (Double memory) {
        return Double({mantissa: mul_(a.mantissa, b)});
    }

    function mul_(uint a, Double memory b) internal pure returns (uint) {
        return mul_(a, b.mantissa) / doubleScale;
    }

    function mul_(uint a, uint b) internal pure returns (uint) {
        return mul_(a, b, "multiplication overflow");
    }

    function mul_(
        uint a,
        uint b,
        string memory errorMessage
    ) internal pure returns (uint) {
        if (a == 0 || b == 0) {
            return 0;
        }
        uint c = a * b;
        require(c / a == b, errorMessage);
        return c;
    }

    function div_(
        Exp memory a,
        Exp memory b
    ) internal pure returns (Exp memory) {
        return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)});
    }

    function div_(Exp memory a, uint b) internal pure returns (Exp memory) {
        return Exp({mantissa: div_(a.mantissa, b)});
    }

    function div_(uint a, Exp memory b) internal pure returns (uint) {
        return div_(mul_(a, expScale), b.mantissa);
    }

    function div_(
        Double memory a,
        Double memory b
    ) internal pure returns (Double memory) {
        return
            Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)});
    }

    function div_(
        Double memory a,
        uint b
    ) internal pure returns (Double memory) {
        return Double({mantissa: div_(a.mantissa, b)});
    }

    function div_(uint a, Double memory b) internal pure returns (uint) {
        return div_(mul_(a, doubleScale), b.mantissa);
    }

    function div_(uint a, uint b) internal pure returns (uint) {
        return div_(a, b, "divide by zero");
    }

    function div_(
        uint a,
        uint b,
        string memory errorMessage
    ) internal pure returns (uint) {
        require(b > 0, errorMessage);
        return a / b;
    }

    function fraction(uint a, uint b) internal pure returns (Double memory) {
        return Double({mantissa: div_(mul_(a, doubleScale), b)});
    }
}

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

/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/FixedPointMathLib.sol)
/// @author Inspired by USM (https://github.com/usmfum/USM/blob/master/contracts/WadMath.sol)
library FixedPointMathLib {
    /*//////////////////////////////////////////////////////////////
                    SIMPLIFIED FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    uint256 internal constant MAX_UINT256 = 2**256 - 1;

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

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

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

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

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

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

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        /// @solidity memory-safe-assembly
        assembly {
            // Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
            if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
                revert(0, 0)
            }

            // Divide x * y by the denominator.
            z := div(mul(x, y), denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        /// @solidity memory-safe-assembly
        assembly {
            // Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
            if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
                revert(0, 0)
            }

            // If x * y modulo the denominator is strictly greater than 0,
            // 1 is added to round up the division of x * y by the denominator.
            z := add(gt(mod(mul(x, y), denominator), 0), div(mul(x, y), denominator))
        }
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    function unsafeMod(uint256 x, uint256 y) internal pure returns (uint256 z) {
        /// @solidity memory-safe-assembly
        assembly {
            // Mod x by y. Note this will return
            // 0 instead of reverting if y is zero.
            z := mod(x, y)
        }
    }

    function unsafeDiv(uint256 x, uint256 y) internal pure returns (uint256 r) {
        /// @solidity memory-safe-assembly
        assembly {
            // Divide x by y. Note this will return
            // 0 instead of reverting if y is zero.
            r := div(x, y)
        }
    }

    function unsafeDivUp(uint256 x, uint256 y) internal pure returns (uint256 z) {
        /// @solidity memory-safe-assembly
        assembly {
            // Add 1 to x * y if x % y > 0. Note this will
            // return 0 instead of reverting if y is zero.
            z := add(gt(mod(x, y), 0), div(x, y))
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/Address.sol";

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

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

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

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

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: setting the version to 255 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

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

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

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint8) {
        return _initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _initializing;
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

/**
 * @title Moonwell's InterestRateModel Interface
 * @author Moonwell
 */
abstract contract InterestRateModel {
    /// @notice Indicator that this is an InterestRateModel contract (for inspection)
    bool public constant isInterestRateModel = true;

    /**
     * @notice Calculates the current borrow interest rate per timestamp
     * @param cash The total amount of cash the market has
     * @param borrows The total amount of borrows the market has outstanding
     * @param reserves The total amount of reserves the market has
     * @return The borrow rate per timestamp (as a percentage, and scaled by 1e18)
     */
    function getBorrowRate(
        uint cash,
        uint borrows,
        uint reserves
    ) external view virtual returns (uint);

    /**
     * @notice Calculates the current supply interest rate per timestamp
     * @param cash The total amount of cash the market has
     * @param borrows The total amount of borrows the market has outstanding
     * @param reserves The total amount of reserves the market has
     * @param reserveFactorMantissa The current reserve factor the market has
     * @return The supply rate per timestamp (as a percentage, and scaled by 1e18)
     */
    function getSupplyRate(
        uint cash,
        uint borrows,
        uint reserves,
        uint reserveFactorMantissa
    ) external view virtual returns (uint);
}

// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.19;

import {FixedPointMathLib} from "solmate/utils/FixedPointMathLib.sol";

import {MErc20} from "@protocol/MErc20.sol";
import {MToken} from "@protocol/MToken.sol";

/// @notice Get up to date mToken data without mutating state.
/// @author Transmissions11 (https://github.com/transmissions11/libcompound)
library LibCompound {
    using FixedPointMathLib for uint256;

    function viewUnderlyingBalanceOf(
        MErc20 mToken,
        address user
    ) internal view returns (uint256) {
        return mToken.balanceOf(user).mulWadDown(viewExchangeRate(mToken));
    }

    function viewExchangeRate(MErc20 mToken) internal view returns (uint256) {
        uint256 accrualBlockTimestampPrior = mToken.accrualBlockTimestamp();

        if (accrualBlockTimestampPrior == block.timestamp) {
            return mToken.exchangeRateStored();
        }

        uint256 totalCash = MErc20(mToken.underlying()).balanceOf(
            address(mToken)
        );
        uint256 borrowsPrior = mToken.totalBorrows();
        uint256 reservesPrior = mToken.totalReserves();

        uint256 borrowRateMantissa = mToken.interestRateModel().getBorrowRate(
            totalCash,
            borrowsPrior,
            reservesPrior
        );

        require(borrowRateMantissa <= 0.0005e16, "RATE_TOO_HIGH"); // Same as borrowRateMaxMantissa in CTokenInterfaces.sol

        uint256 interestAccumulated = (borrowRateMantissa *
            (block.timestamp - accrualBlockTimestampPrior)).mulWadDown(
                borrowsPrior
            );

        uint256 totalReserves = mToken.reserveFactorMantissa().mulWadDown(
            interestAccumulated
        ) + reservesPrior;
        uint256 totalBorrows = interestAccumulated + borrowsPrior;
        uint256 totalSupply = mToken.totalSupply();

        return
            totalSupply == 0
                ? MToken(address(mToken)).exchangeRateStored() /// get initial exchange rate if total supply is 0
                : (totalCash + totalBorrows - totalReserves).divWadDown(
                    totalSupply
                );
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

import "@openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
import "./MToken.sol";

/**
 * @title Moonwell's MErc20 Contract
 * @notice MTokens which wrap an EIP-20 underlying
 * @author Moonwell
 */
contract MErc20 is MToken, MErc20Interface {
    /**
     * @notice Initialize the new money market
     * @param underlying_ The address of the underlying asset
     * @param comptroller_ The address of the Comptroller
     * @param interestRateModel_ The address of the interest rate model
     * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18
     * @param name_ ERC-20 name of this token
     * @param symbol_ ERC-20 symbol of this token
     * @param decimals_ ERC-20 decimal precision of this token
     */
    function initialize(
        address underlying_,
        ComptrollerInterface comptroller_,
        InterestRateModel interestRateModel_,
        uint initialExchangeRateMantissa_,
        string memory name_,
        string memory symbol_,
        uint8 decimals_
    ) public {
        // MToken initialize does the bulk of the work
        super.initialize(
            comptroller_,
            interestRateModel_,
            initialExchangeRateMantissa_,
            name_,
            symbol_,
            decimals_
        );

        // Set underlying and sanity check it
        underlying = underlying_;
        EIP20Interface(underlying).totalSupply();
    }

    /*** User Interface ***/

    /**
     * @notice Sender supplies assets into the market and receives mTokens in exchange
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param mintAmount The amount of the underlying asset to supply
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function mint(uint mintAmount) external override returns (uint) {
        (uint err, ) = mintInternal(mintAmount);
        return err;
    }

    /**
     * @notice Supply assets but without a 2-step approval process, EIP-2612
     * @dev Simply calls the underlying token's `permit()` function and then assumes things worked
     * @param mintAmount The amount of the underlying asset to supply
     * @param deadline The amount of the underlying asset to supply
     * @param v ECDSA recovery id for the signature
     * @param r ECDSA r parameter for the signature
     * @param s ECDSA s parameter for the signature
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function mintWithPermit(
        uint mintAmount,
        uint deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external override returns (uint) {
        IERC20Permit token = IERC20Permit(underlying);

        // Go submit our pre-approval signature data to the underlying token, but
        // explicitly fail if there is an issue.
        SafeERC20.safePermit(
            token,
            msg.sender,
            address(this),
            mintAmount,
            deadline,
            v,
            r,
            s
        );

        (uint err, ) = mintInternal(mintAmount);
        return err;
    }

    /**
     * @notice Sender redeems mTokens in exchange for the underlying asset
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param redeemTokens The number of mTokens to redeem into underlying
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function redeem(uint redeemTokens) external override returns (uint) {
        return redeemInternal(redeemTokens);
    }

    /**
     * @notice Sender redeems mTokens in exchange for a specified amount of underlying asset
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param redeemAmount The amount of underlying to redeem
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function redeemUnderlying(
        uint redeemAmount
    ) external override returns (uint) {
        return redeemUnderlyingInternal(redeemAmount);
    }

    /**
     * @notice Sender borrows assets from the protocol to their own address
     * @param borrowAmount The amount of the underlying asset to borrow
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function borrow(uint borrowAmount) external override returns (uint) {
        return borrowInternal(borrowAmount);
    }

    /**
     * @notice Sender repays their own borrow
     * @param repayAmount The amount to repay, or uint.max for the full outstanding amount
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function repayBorrow(uint repayAmount) external override returns (uint) {
        (uint err, ) = repayBorrowInternal(repayAmount);
        return err;
    }

    /**
     * @notice Sender repays a borrow belonging to borrower
     * @param borrower the account with the debt being payed off
     * @param repayAmount The amount to repay, or uint.max for the full outstanding amount
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function repayBorrowBehalf(
        address borrower,
        uint repayAmount
    ) external override returns (uint) {
        (uint err, ) = repayBorrowBehalfInternal(borrower, repayAmount);
        return err;
    }

    /**
     * @notice The sender liquidates the borrowers collateral.
     *  The collateral seized is transferred to the liquidator.
     * @param borrower The borrower of this mToken to be liquidated
     * @param repayAmount The amount of the underlying borrowed asset to repay
     * @param mTokenCollateral The market in which to seize collateral from the borrower
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function liquidateBorrow(
        address borrower,
        uint repayAmount,
        MTokenInterface mTokenCollateral
    ) external override returns (uint) {
        (uint err, ) = liquidateBorrowInternal(
            borrower,
            repayAmount,
            mTokenCollateral
        );
        return err;
    }

    /**
     * @notice A public function to sweep accidental ERC-20 transfers to this contract. Tokens are sent to admin (timelock)
     * @param token The address of the ERC-20 token to sweep
     */
    function sweepToken(EIP20NonStandardInterface token) external override {
        require(
            msg.sender == admin,
            "MErc20::sweepToken: only admin can sweep tokens"
        );
        require(
            address(token) != underlying,
            "MErc20::sweepToken: can not sweep underlying token"
        );
        uint256 balance = token.balanceOf(address(this));
        token.transfer(admin, balance);
    }

    /**
     * @notice The sender adds to reserves.
     * @param addAmount The amount fo underlying token to add as reserves
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _addReserves(uint addAmount) external override returns (uint) {
        return _addReservesInternal(addAmount);
    }

    /*** Safe Token ***/

    /**
     * @notice Gets balance of this contract in terms of the underlying
     * @dev This excludes the value of the current message, if any
     * @return The quantity of underlying tokens owned by this contract
     */
    function getCashPrior() internal view virtual override returns (uint) {
        EIP20Interface token = EIP20Interface(underlying);
        return token.balanceOf(address(this));
    }

    /**
     * @dev Similar to EIP20 transfer, except it handles a False result from `transferFrom` and reverts in that case.
     *      This will revert due to insufficient balance or insufficient allowance.
     *      This function returns the actual amount received,
     *      which may be less than `amount` if there is a fee attached to the transfer.
     *
     *      Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
     *            See here: https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
     */
    function doTransferIn(
        address from,
        uint amount
    ) internal virtual override returns (uint) {
        // Read from storage once
        address underlying_ = underlying;
        EIP20NonStandardInterface token = EIP20NonStandardInterface(
            underlying_
        );
        uint balanceBefore = EIP20Interface(underlying_).balanceOf(
            address(this)
        );
        token.transferFrom(from, address(this), amount);

        bool success;
        assembly {
            switch returndatasize()
            case 0 {
                // This is a non-standard ERC-20
                success := not(0) // set success to true
            }
            case 32 {
                // This is a compliant ERC-20
                returndatacopy(0, 0, 32)
                success := mload(0) // Set `success = returndata` of external call
            }
            default {
                // This is an excessively non-compliant ERC-20, revert.
                revert(0, 0)
            }
        }
        require(success, "TOKEN_TRANSFER_IN_FAILED");

        // Calculate the amount that was *actually* transferred
        uint balanceAfter = EIP20Interface(underlying_).balanceOf(
            address(this)
        );
        require(balanceAfter >= balanceBefore, "TOKEN_TRANSFER_IN_OVERFLOW");
        return balanceAfter - balanceBefore; // underflow already checked above, just subtract
    }

    /**
     * @dev Similar to EIP20 transfer, except it handles a False success from `transfer` and returns an explanatory
     *      error code rather than reverting. If caller has not called checked protocol's balance, this may revert due to
     *      insufficient cash held in this contract. If caller has checked protocol's balance prior to this call, and verified
     *      it is >= amount, this should not revert in normal conditions.
     *
     *      Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
     *            See here: https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
     */
    function doTransferOut(
        address payable to,
        uint amount
    ) internal virtual override {
        EIP20NonStandardInterface token = EIP20NonStandardInterface(underlying);
        token.transfer(to, amount);

        bool success;
        assembly {
            switch returndatasize()
            case 0 {
                // This is a non-standard ERC-20
                success := not(0) // set success to true
            }
            case 32 {
                // This is a compliant ERC-20
                returndatacopy(0, 0, 32)
                success := mload(0) // Set `success = returndata` of override external call
            }
            default {
                // This is an excessively non-compliant ERC-20, revert.
                revert(0, 0)
            }
        }
        require(success, "TOKEN_TRANSFER_OUT_FAILED");
    }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.19;

import "./ComptrollerInterface.sol";
import "./MTokenInterfaces.sol";
import "./ErrorReporter.sol";
import "./Exponential.sol";
import "./EIP20Interface.sol";
import "./irm/InterestRateModel.sol";

/**
 * @title Moonwell's MToken Contract
 * @notice Abstract base for MTokens
 * @author Moonwell
 */
abstract contract MToken is MTokenInterface, Exponential, TokenErrorReporter {
    /**
     * @notice Initialize the money market
     * @param comptroller_ The address of the Comptroller
     * @param interestRateModel_ The address of the interest rate model
     * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18
     * @param name_ EIP-20 name of this token
     * @param symbol_ EIP-20 symbol of this token
     * @param decimals_ EIP-20 decimal precision of this token
     */
    function initialize(
        ComptrollerInterface comptroller_,
        InterestRateModel interestRateModel_,
        uint initialExchangeRateMantissa_,
        string memory name_,
        string memory symbol_,
        uint8 decimals_
    ) public {
        require(msg.sender == admin, "only admin may initialize the market");
        require(
            accrualBlockTimestamp == 0 && borrowIndex == 0,
            "market may only be initialized once"
        );

        // Set initial exchange rate
        initialExchangeRateMantissa = initialExchangeRateMantissa_;
        require(
            initialExchangeRateMantissa > 0,
            "initial exchange rate must be greater than zero."
        );

        // Set the comptroller
        uint err = _setComptroller(comptroller_);
        require(err == uint(Error.NO_ERROR), "setting comptroller failed");

        // Initialize block timestamp and borrow index (block timestamp mocks depend on comptroller being set)
        accrualBlockTimestamp = getBlockTimestamp();
        borrowIndex = mantissaOne;

        // Set the interest rate model (depends on block timestamp / borrow index)
        err = _setInterestRateModelFresh(interestRateModel_);
        require(
            err == uint(Error.NO_ERROR),
            "setting interest rate model failed"
        );

        name = name_;
        symbol = symbol_;
        decimals = decimals_;

        // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund)
        _notEntered = true;
    }

    /**
     * @notice Transfer `tokens` tokens from `src` to `dst` by `spender`
     * @dev Called by both `transfer` and `transferFrom` internally
     * @param spender The address of the account performing the transfer
     * @param src The address of the source account
     * @param dst The address of the destination account
     * @param tokens The number of tokens to transfer
     * @return Whether or not the transfer succeeded
     */
    function transferTokens(
        address spender,
        address src,
        address dst,
        uint tokens
    ) internal returns (uint) {
        /* Fail if transfer not allowed */
        uint allowed = comptroller.transferAllowed(
            address(this),
            src,
            dst,
            tokens
        );
        if (allowed != 0) {
            return
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.TRANSFER_COMPTROLLER_REJECTION,
                    allowed
                );
        }

        /* Do not allow self-transfers */
        if (src == dst) {
            return fail(Error.BAD_INPUT, FailureInfo.TRANSFER_NOT_ALLOWED);
        }

        /* Get the allowance, infinite for the account owner */
        uint startingAllowance = 0;
        if (spender == src) {
            startingAllowance = type(uint).max;
        } else {
            startingAllowance = transferAllowances[src][spender];
        }

        /* Do the calculations, checking for {under,over}flow */
        MathError mathErr;
        uint allowanceNew;
        uint srcTokensNew;
        uint dstTokensNew;

        (mathErr, allowanceNew) = subUInt(startingAllowance, tokens);
        if (mathErr != MathError.NO_ERROR) {
            return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ALLOWED);
        }

        (mathErr, srcTokensNew) = subUInt(accountTokens[src], tokens);
        if (mathErr != MathError.NO_ERROR) {
            return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ENOUGH);
        }

        (mathErr, dstTokensNew) = addUInt(accountTokens[dst], tokens);
        if (mathErr != MathError.NO_ERROR) {
            return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_TOO_MUCH);
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        accountTokens[src] = srcTokensNew;
        accountTokens[dst] = dstTokensNew;

        /* Eat some of the allowance (if necessary) */
        if (startingAllowance != type(uint).max) {
            transferAllowances[src][spender] = allowanceNew;
        }

        /* We emit a Transfer event */
        emit Transfer(src, dst, tokens);

        // unused function
        // comptroller.transferVerify(address(this), src, dst, tokens);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Transfer `amount` tokens from `msg.sender` to `dst`
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     * @return Whether or not the transfer succeeded
     */
    function transfer(
        address dst,
        uint256 amount
    ) external override nonReentrant returns (bool) {
        return
            transferTokens(msg.sender, msg.sender, dst, amount) ==
            uint(Error.NO_ERROR);
    }

    /**
     * @notice Transfer `amount` tokens from `src` to `dst`
     * @param src The address of the source account
     * @param dst The address of the destination account
     * @param amount The number of tokens to transfer
     * @return Whether or not the transfer succeeded
     */
    function transferFrom(
        address src,
        address dst,
        uint256 amount
    ) external override nonReentrant returns (bool) {
        return
            transferTokens(msg.sender, src, dst, amount) ==
            uint(Error.NO_ERROR);
    }

    /**
     * @notice Approve `spender` to transfer up to `amount` from `src`
     * @dev This will overwrite the approval amount for `spender`
     *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
     * @param spender The address of the account which may transfer tokens
     * @param amount The number of tokens that are approved (uint.max means infinite)
     * @return Whether or not the approval succeeded
     */
    function approve(
        address spender,
        uint256 amount
    ) external override returns (bool) {
        address src = msg.sender;
        transferAllowances[src][spender] = amount;
        emit Approval(src, spender, amount);
        return true;
    }

    /**
     * @notice Get the current allowance from `owner` for `spender`
     * @param owner The address of the account which owns the tokens to be spent
     * @param spender The address of the account which may transfer tokens
     * @return The number of tokens allowed to be spent (uint.max means infinite)
     */
    function allowance(
        address owner,
        address spender
    ) external view override returns (uint256) {
        return transferAllowances[owner][spender];
    }

    /**
     * @notice Get the token balance of the `owner`
     * @param owner The address of the account to query
     * @return The number of tokens owned by `owner`
     */
    function balanceOf(address owner) external view override returns (uint256) {
        return accountTokens[owner];
    }

    /**
     * @notice Get the underlying balance of the `owner`
     * @dev This also accrues interest in a transaction
     * @param owner The address of the account to query
     * @return The amount of underlying owned by `owner`
     */
    function balanceOfUnderlying(
        address owner
    ) external override returns (uint) {
        Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()});
        (MathError mErr, uint balance) = mulScalarTruncate(
            exchangeRate,
            accountTokens[owner]
        );
        require(mErr == MathError.NO_ERROR, "balance could not be calculated");
        return balance;
    }

    /**
     * @notice Get a snapshot of the account's balances, and the cached exchange rate
     * @dev This is used by comptroller to more efficiently perform liquidity checks.
     * @param account Address of the account to snapshot
     * @return (possible error, token balance, borrow balance, exchange rate mantissa)
     */
    function getAccountSnapshot(
        address account
    ) external view override returns (uint, uint, uint, uint) {
        uint mTokenBalance = accountTokens[account];
        uint borrowBalance;
        uint exchangeRateMantissa;

        MathError mErr;

        (mErr, borrowBalance) = borrowBalanceStoredInternal(account);
        if (mErr != MathError.NO_ERROR) {
            return (uint(Error.MATH_ERROR), 0, 0, 0);
        }

        (mErr, exchangeRateMantissa) = exchangeRateStoredInternal();
        if (mErr != MathError.NO_ERROR) {
            return (uint(Error.MATH_ERROR), 0, 0, 0);
        }

        return (
            uint(Error.NO_ERROR),
            mTokenBalance,
            borrowBalance,
            exchangeRateMantissa
        );
    }

    /**
     * @dev Function to simply retrieve block timestamp
     *  This exists mainly for inheriting test contracts to stub this result.
     */
    function getBlockTimestamp() internal view virtual returns (uint) {
        return block.timestamp;
    }

    /**
     * @notice Returns the current per-timestamp borrow interest rate for this mToken
     * @return The borrow interest rate per timestamp, scaled by 1e18
     */
    function borrowRatePerTimestamp() external view override returns (uint) {
        return
            interestRateModel.getBorrowRate(
                getCashPrior(),
                totalBorrows,
                totalReserves
            );
    }

    /**
     * @notice Returns the current per-timestamp supply interest rate for this mToken
     * @return The supply interest rate per timestamp, scaled by 1e18
     */
    function supplyRatePerTimestamp() external view override returns (uint) {
        return
            interestRateModel.getSupplyRate(
                getCashPrior(),
                totalBorrows,
                totalReserves,
                reserveFactorMantissa
            );
    }

    /**
     * @notice Returns the current total borrows plus accrued interest
     * @return The total borrows with interest
     */
    function totalBorrowsCurrent()
        external
        override
        nonReentrant
        returns (uint)
    {
        require(
            accrueInterest() == uint(Error.NO_ERROR),
            "accrue interest failed"
        );
        return totalBorrows;
    }

    /**
     * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex
     * @param account The address whose balance should be calculated after updating borrowIndex
     * @return The calculated balance
     */
    function borrowBalanceCurrent(
        address account
    ) external override nonReentrant returns (uint) {
        require(
            accrueInterest() == uint(Error.NO_ERROR),
            "accrue interest failed"
        );
        return borrowBalanceStored(account);
    }

    /**
     * @notice Return the borrow balance of account based on stored data
     * @param account The address whose balance should be calculated
     * @return The calculated balance
     */
    function borrowBalanceStored(
        address account
    ) public view override returns (uint) {
        (MathError err, uint result) = borrowBalanceStoredInternal(account);
        require(
            err == MathError.NO_ERROR,
            "borrowBalanceStored: borrowBalanceStoredInternal failed"
        );
        return result;
    }

    /**
     * @notice Return the borrow balance of account based on stored data
     * @param account The address whose balance should be calculated
     * @return (error code, the calculated balance or 0 if error code is non-zero)
     */
    function borrowBalanceStoredInternal(
        address account
    ) internal view returns (MathError, uint) {
        /* Note: we do not assert that the market is up to date */
        MathError mathErr;
        uint principalTimesIndex;
        uint result;

        /* Get borrowBalance and borrowIndex */
        BorrowSnapshot storage borrowSnapshot = accountBorrows[account];

        /* If borrowBalance = 0 then borrowIndex is likely also 0.
         * Rather than failing the calculation with a division by 0, we immediately return 0 in this case.
         */
        if (borrowSnapshot.principal == 0) {
            return (MathError.NO_ERROR, 0);
        }

        /* Calculate new borrow balance using the interest index:
         *  recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex
         */
        (mathErr, principalTimesIndex) = mulUInt(
            borrowSnapshot.principal,
            borrowIndex
        );
        if (mathErr != MathError.NO_ERROR) {
            return (mathErr, 0);
        }

        (mathErr, result) = divUInt(
            principalTimesIndex,
            borrowSnapshot.interestIndex
        );
        if (mathErr != MathError.NO_ERROR) {
            return (mathErr, 0);
        }

        return (MathError.NO_ERROR, result);
    }

    /**
     * @notice Accrue interest then return the up-to-date exchange rate
     * @return Calculated exchange rate scaled by 1e18
     */
    function exchangeRateCurrent() public override nonReentrant returns (uint) {
        require(
            accrueInterest() == uint(Error.NO_ERROR),
            "accrue interest failed"
        );
        return exchangeRateStored();
    }

    /**
     * @notice Calculates the exchange rate from the underlying to the MToken
     * @dev This function does not accrue interest before calculating the exchange rate
     * @return Calculated exchange rate scaled by 1e18
     */
    function exchangeRateStored() public view override returns (uint) {
        (MathError err, uint result) = exchangeRateStoredInternal();
        require(
            err == MathError.NO_ERROR,
            "exchangeRateStored: exchangeRateStoredInternal failed"
        );
        return result;
    }

    /**
     * @notice Calculates the exchange rate from the underlying to the MToken
     * @dev This function does not accrue interest before calculating the exchange rate
     * @return (error code, calculated exchange rate scaled by 1e18)
     */
    function exchangeRateStoredInternal()
        internal
        view
        virtual
        returns (MathError, uint)
    {
        uint _totalSupply = totalSupply;
        if (_totalSupply == 0) {
            /*
             * If there are no tokens minted:
             *  exchangeRate = initialExchangeRate
             */
            return (MathError.NO_ERROR, initialExchangeRateMantissa);
        } else {
            /*
             * Otherwise:
             *  exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply
             */
            uint totalCash = getCashPrior();
            uint cashPlusBorrowsMinusReserves;
            Exp memory exchangeRate;
            MathError mathErr;

            (mathErr, cashPlusBorrowsMinusReserves) = addThenSubUInt(
                totalCash,
                totalBorrows,
                totalReserves
            );
            if (mathErr != MathError.NO_ERROR) {
                return (mathErr, 0);
            }

            (mathErr, exchangeRate) = getExp(
                cashPlusBorrowsMinusReserves,
                _totalSupply
            );
            if (mathErr != MathError.NO_ERROR) {
                return (mathErr, 0);
            }

            return (MathError.NO_ERROR, exchangeRate.mantissa);
        }
    }

    /**
     * @notice Get cash balance of this mToken in the underlying asset
     * @return The quantity of underlying asset owned by this contract
     */
    function getCash() external view override returns (uint) {
        return getCashPrior();
    }

    /**
     * @notice Applies accrued interest to total borrows and reserves
     * @dev This calculates interest accrued from the last checkpointed block
     *   up to the current block and writes new checkpoint to storage.
     */
    function accrueInterest() public virtual override returns (uint) {
        /* Remember the initial block timestamp */
        uint currentBlockTimestamp = getBlockTimestamp();
        uint accrualBlockTimestampPrior = accrualBlockTimestamp;

        /* Short-circuit accumulating 0 interest */
        if (accrualBlockTimestampPrior == currentBlockTimestamp) {
            return uint(Error.NO_ERROR);
        }

        /* Read the previous values out of storage */
        uint cashPrior = getCashPrior();
        uint borrowsPrior = totalBorrows;
        uint reservesPrior = totalReserves;
        uint borrowIndexPrior = borrowIndex;

        /* Calculate the current borrow interest rate */
        uint borrowRateMantissa = interestRateModel.getBorrowRate(
            cashPrior,
            borrowsPrior,
            reservesPrior
        );
        require(
            borrowRateMantissa <= borrowRateMaxMantissa,
            "borrow rate is absurdly high"
        );

        /* Calculate the number of blocks elapsed since the last accrual */
        (MathError mathErr, uint blockDelta) = subUInt(
            currentBlockTimestamp,
            accrualBlockTimestampPrior
        );
        require(
            mathErr == MathError.NO_ERROR,
            "could not calculate block delta"
        );

        /*
         * Calculate the interest accumulated into borrows and reserves and the new index:
         *  simpleInterestFactor = borrowRate * blockDelta
         *  interestAccumulated = simpleInterestFactor * totalBorrows
         *  totalBorrowsNew = interestAccumulated + totalBorrows
         *  totalReservesNew = interestAccumulated * reserveFactor + totalReserves
         *  borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex
         */

        Exp memory simpleInterestFactor;
        uint interestAccumulated;
        uint totalBorrowsNew;
        uint totalReservesNew;
        uint borrowIndexNew;

        (mathErr, simpleInterestFactor) = mulScalar(
            Exp({mantissa: borrowRateMantissa}),
            blockDelta
        );
        if (mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED,
                    uint(mathErr)
                );
        }

        (mathErr, interestAccumulated) = mulScalarTruncate(
            simpleInterestFactor,
            borrowsPrior
        );
        if (mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED,
                    uint(mathErr)
                );
        }

        (mathErr, totalBorrowsNew) = addUInt(interestAccumulated, borrowsPrior);
        if (mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED,
                    uint(mathErr)
                );
        }

        (mathErr, totalReservesNew) = mulScalarTruncateAddUInt(
            Exp({mantissa: reserveFactorMantissa}),
            interestAccumulated,
            reservesPrior
        );
        if (mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED,
                    uint(mathErr)
                );
        }

        (mathErr, borrowIndexNew) = mulScalarTruncateAddUInt(
            simpleInterestFactor,
            borrowIndexPrior,
            borrowIndexPrior
        );
        if (mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED,
                    uint(mathErr)
                );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /* We write the previously calculated values into storage */
        accrualBlockTimestamp = currentBlockTimestamp;
        borrowIndex = borrowIndexNew;
        totalBorrows = totalBorrowsNew;
        totalReserves = totalReservesNew;

        /* We emit an AccrueInterest event */
        emit AccrueInterest(
            cashPrior,
            interestAccumulated,
            borrowIndexNew,
            totalBorrowsNew
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sender supplies assets into the market and receives mTokens in exchange
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param mintAmount The amount of the underlying asset to supply
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual mint amount.
     */
    function mintInternal(
        uint mintAmount
    ) internal nonReentrant returns (uint, uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
            return (
                fail(Error(error), FailureInfo.MINT_ACCRUE_INTEREST_FAILED),
                0
            );
        }
        // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to
        return mintFresh(msg.sender, mintAmount);
    }

    struct MintLocalVars {
        Error err;
        MathError mathErr;
        uint exchangeRateMantissa;
        uint mintTokens;
        uint totalSupplyNew;
        uint accountTokensNew;
        uint actualMintAmount;
    }

    /**
     * @notice User supplies assets into the market and receives mTokens in exchange
     * @dev Assumes interest has already been accrued up to the current block
     * @param minter The address of the account which is supplying the assets
     * @param mintAmount The amount of the underlying asset to supply
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual mint amount.
     */
    function mintFresh(
        address minter,
        uint mintAmount
    ) internal returns (uint, uint) {
        /* Fail if mint not allowed */
        uint allowed = comptroller.mintAllowed(
            address(this),
            minter,
            mintAmount
        );
        if (allowed != 0) {
            return (
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.MINT_COMPTROLLER_REJECTION,
                    allowed
                ),
                0
            );
        }

        /* Verify market's block timestamp equals current block timestamp */
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return (
                fail(Error.MARKET_NOT_FRESH, FailureInfo.MINT_FRESHNESS_CHECK),
                0
            );
        }

        MintLocalVars memory vars;

        (
            vars.mathErr,
            vars.exchangeRateMantissa
        ) = exchangeRateStoredInternal();
        if (vars.mathErr != MathError.NO_ERROR) {
            return (
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.MINT_EXCHANGE_RATE_READ_FAILED,
                    uint(vars.mathErr)
                ),
                0
            );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /*
         *  We call `doTransferIn` for the minter and the mintAmount.
         *  Note: The mToken must handle variations between ERC-20 and GLMR underlying.
         *  `doTransferIn` reverts if anything goes wrong, since we can't be sure if
         *  side-effects occurred. The function returns the amount actually transferred,
         *  in case of a fee. On success, the mToken holds an additional `actualMintAmount`
         *  of cash.
         */
        vars.actualMintAmount = doTransferIn(minter, mintAmount);

        /*
         * We get the current exchange rate and calculate the number of mTokens to be minted:
         *  mintTokens = actualMintAmount / exchangeRate
         */

        (vars.mathErr, vars.mintTokens) = divScalarByExpTruncate(
            vars.actualMintAmount,
            Exp({mantissa: vars.exchangeRateMantissa})
        );
        require(
            vars.mathErr == MathError.NO_ERROR,
            "MINT_EXCHANGE_CALCULATION_FAILED"
        );

        /*
         * We calculate the new total supply of mTokens and minter token balance, checking for overflow:
         *  totalSupplyNew = totalSupply + mintTokens
         *  accountTokensNew = accountTokens[minter] + mintTokens
         */
        (vars.mathErr, vars.totalSupplyNew) = addUInt(
            totalSupply,
            vars.mintTokens
        );
        require(
            vars.mathErr == MathError.NO_ERROR,
            "MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED"
        );

        (vars.mathErr, vars.accountTokensNew) = addUInt(
            accountTokens[minter],
            vars.mintTokens
        );
        require(
            vars.mathErr == MathError.NO_ERROR,
            "MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED"
        );

        /* We write previously calculated values into storage */
        totalSupply = vars.totalSupplyNew;
        accountTokens[minter] = vars.accountTokensNew;

        /* We emit a Mint event, and a Transfer event */
        emit Mint(minter, vars.actualMintAmount, vars.mintTokens);
        emit Transfer(address(this), minter, vars.mintTokens);

        /* We call the defense hook */
        // unused function
        // comptroller.mintVerify(address(this), minter, vars.actualMintAmount, vars.mintTokens);

        return (uint(Error.NO_ERROR), vars.actualMintAmount);
    }

    /**
     * @notice Sender redeems mTokens in exchange for the underlying asset
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param redeemTokens The number of mTokens to redeem into underlying
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function redeemInternal(
        uint redeemTokens
    ) internal nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
            return
                fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
        }
        // redeemFresh emits redeem-specific logs on errors, so we don't need to
        return redeemFresh(payable(msg.sender), redeemTokens, 0);
    }

    /**
     * @notice Sender redeems mTokens in exchange for a specified amount of underlying asset
     * @dev Accrues interest whether or not the operation succeeds, unless reverted
     * @param redeemAmount The amount of underlying to receive from redeeming mTokens
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function redeemUnderlyingInternal(
        uint redeemAmount
    ) internal nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
            return
                fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
        }
        // redeemFresh emits redeem-specific logs on errors, so we don't need to
        return redeemFresh(payable(msg.sender), 0, redeemAmount);
    }

    struct RedeemLocalVars {
        Error err;
        MathError mathErr;
        uint exchangeRateMantissa;
        uint redeemTokens;
        uint redeemAmount;
        uint totalSupplyNew;
        uint accountTokensNew;
    }

    /**
     * @notice User redeems mTokens in exchange for the underlying asset
     * @dev Assumes interest has already been accrued up to the current block
     * @param redeemer The address of the account which is redeeming the tokens
     * @param redeemTokensIn The number of mTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero)
     * @param redeemAmountIn The number of underlying tokens to receive from redeeming mTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero)
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function redeemFresh(
        address payable redeemer,
        uint redeemTokensIn,
        uint redeemAmountIn
    ) internal returns (uint) {
        require(
            redeemTokensIn == 0 || redeemAmountIn == 0,
            "one of redeemTokensIn or redeemAmountIn must be zero"
        );

        RedeemLocalVars memory vars;

        /* exchangeRate = invoke Exchange Rate Stored() */
        (
            vars.mathErr,
            vars.exchangeRateMantissa
        ) = exchangeRateStoredInternal();
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.REDEEM_EXCHANGE_RATE_READ_FAILED,
                    uint(vars.mathErr)
                );
        }

        /* If redeemTokensIn > 0: */
        if (redeemTokensIn > 0) {
            /*
             * We calculate the exchange rate and the amount of underlying to be redeemed:
             *  redeemTokens = redeemTokensIn
             *  redeemAmount = redeemTokensIn x exchangeRateCurrent
             */
            if (redeemTokensIn == type(uint).max) {
                vars.redeemTokens = accountTokens[redeemer];
            } else {
                vars.redeemTokens = redeemTokensIn;
            }

            (vars.mathErr, vars.redeemAmount) = mulScalarTruncate(
                Exp({mantissa: vars.exchangeRateMantissa}),
                vars.redeemTokens
            );
            if (vars.mathErr != MathError.NO_ERROR) {
                return
                    failOpaque(
                        Error.MATH_ERROR,
                        FailureInfo.REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED,
                        uint(vars.mathErr)
                    );
            }
        } else {
            /*
             * We get the current exchange rate and calculate the amount to be redeemed:
             *  redeemTokens = redeemAmountIn / exchangeRate
             *  redeemAmount = redeemAmountIn
             */
            if (redeemAmountIn == type(uint).max) {
                vars.redeemTokens = accountTokens[redeemer];

                (vars.mathErr, vars.redeemAmount) = mulScalarTruncate(
                    Exp({mantissa: vars.exchangeRateMantissa}),
                    vars.redeemTokens
                );
                if (vars.mathErr != MathError.NO_ERROR) {
                    return
                        failOpaque(
                            Error.MATH_ERROR,
                            FailureInfo
                                .REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED,
                            uint(vars.mathErr)
                        );
                }
            } else {
                vars.redeemAmount = redeemAmountIn;

                (vars.mathErr, vars.redeemTokens) = divScalarByExpTruncate(
                    redeemAmountIn,
                    Exp({mantissa: vars.exchangeRateMantissa})
                );
                if (vars.mathErr != MathError.NO_ERROR) {
                    return
                        failOpaque(
                            Error.MATH_ERROR,
                            FailureInfo
                                .REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED,
                            uint(vars.mathErr)
                        );
                }
            }
        }

        /* Fail if redeem not allowed */
        uint allowed = comptroller.redeemAllowed(
            address(this),
            redeemer,
            vars.redeemTokens
        );
        if (allowed != 0) {
            return
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.REDEEM_COMPTROLLER_REJECTION,
                    allowed
                );
        }

        /* Verify market's block timestamp equals current block timestamp */
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.REDEEM_FRESHNESS_CHECK
                );
        }

        /*
         * We calculate the new total supply and redeemer balance, checking for underflow:
         *  totalSupplyNew = totalSupply - redeemTokens
         *  accountTokensNew = accountTokens[redeemer] - redeemTokens
         */
        (vars.mathErr, vars.totalSupplyNew) = subUInt(
            totalSupply,
            vars.redeemTokens
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
                    uint(vars.mathErr)
                );
        }

        (vars.mathErr, vars.accountTokensNew) = subUInt(
            accountTokens[redeemer],
            vars.redeemTokens
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
                    uint(vars.mathErr)
                );
        }

        /* Fail gracefully if protocol has insufficient cash */
        if (getCashPrior() < vars.redeemAmount) {
            return
                fail(
                    Error.TOKEN_INSUFFICIENT_CASH,
                    FailureInfo.REDEEM_TRANSFER_OUT_NOT_POSSIBLE
                );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /* We write previously calculated values into storage */
        totalSupply = vars.totalSupplyNew;
        accountTokens[redeemer] = vars.accountTokensNew;

        /* We emit a Transfer event, and a Redeem event */
        emit Transfer(redeemer, address(this), vars.redeemTokens);
        emit Redeem(redeemer, vars.redeemAmount, vars.redeemTokens);

        /* We call the defense hook */
        comptroller.redeemVerify(
            address(this),
            redeemer,
            vars.redeemAmount,
            vars.redeemTokens
        );

        /*
         * We invoke doTransferOut for the redeemer and the redeemAmount.
         *  Note: The mToken must handle variations between ERC-20 and GLMR underlying.
         *  On success, the mToken has redeemAmount less of cash.
         *  doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred.
         */
        doTransferOut(redeemer, vars.redeemAmount);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sender borrows assets from the protocol to their own address
     * @param borrowAmount The amount of the underlying asset to borrow
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function borrowInternal(
        uint borrowAmount
    ) internal nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
            return
                fail(Error(error), FailureInfo.BORROW_ACCRUE_INTEREST_FAILED);
        }
        // borrowFresh emits borrow-specific logs on errors, so we don't need to
        return borrowFresh(payable(msg.sender), borrowAmount);
    }

    struct BorrowLocalVars {
        MathError mathErr;
        uint accountBorrows;
        uint accountBorrowsNew;
        uint totalBorrowsNew;
    }

    /**
     * @notice Users borrow assets from the protocol to their own address
     * @param borrowAmount The amount of the underlying asset to borrow
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function borrowFresh(
        address payable borrower,
        uint borrowAmount
    ) internal returns (uint) {
        /* Fail if borrow not allowed */
        uint allowed = comptroller.borrowAllowed(
            address(this),
            borrower,
            borrowAmount
        );
        if (allowed != 0) {
            return
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.BORROW_COMPTROLLER_REJECTION,
                    allowed
                );
        }

        /* Verify market's block timestamp equals current block timestamp */
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.BORROW_FRESHNESS_CHECK
                );
        }

        /* Fail gracefully if protocol has insufficient underlying cash */
        if (getCashPrior() < borrowAmount) {
            return
                fail(
                    Error.TOKEN_INSUFFICIENT_CASH,
                    FailureInfo.BORROW_CASH_NOT_AVAILABLE
                );
        }

        BorrowLocalVars memory vars;

        /*
         * We calculate the new borrower and total borrow balances, failing on overflow:
         *  accountBorrowsNew = accountBorrows + borrowAmount
         *  totalBorrowsNew = totalBorrows + borrowAmount
         */
        (vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(
            borrower
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
                    uint(vars.mathErr)
                );
        }

        (vars.mathErr, vars.accountBorrowsNew) = addUInt(
            vars.accountBorrows,
            borrowAmount
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
                    uint(vars.mathErr)
                );
        }

        (vars.mathErr, vars.totalBorrowsNew) = addUInt(
            totalBorrows,
            borrowAmount
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
                    uint(vars.mathErr)
                );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /* We write the previously calculated values into storage */
        accountBorrows[borrower].principal = vars.accountBorrowsNew;
        accountBorrows[borrower].interestIndex = borrowIndex;
        totalBorrows = vars.totalBorrowsNew;

        /* We emit a Borrow event */
        emit Borrow(
            borrower,
            borrowAmount,
            vars.accountBorrowsNew,
            vars.totalBorrowsNew
        );

        /*
         * We invoke doTransferOut for the borrower and the borrowAmount.
         *  Note: The mToken must handle variations between ERC-20 and GLMR underlying.
         *  On success, the mToken borrowAmount less of cash.
         *  doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred.
         */
        doTransferOut(borrower, borrowAmount);

        /* We call the defense hook */
        // unused function
        // comptroller.borrowVerify(address(this), borrower, borrowAmount);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sender repays their own borrow
     * @param repayAmount The amount to repay
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
     */
    function repayBorrowInternal(
        uint repayAmount
    ) internal nonReentrant returns (uint, uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
            return (
                fail(
                    Error(error),
                    FailureInfo.REPAY_BORROW_ACCRUE_INTEREST_FAILED
                ),
                0
            );
        }
        // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
        return repayBorrowFresh(msg.sender, msg.sender, repayAmount);
    }

    /**
     * @notice Sender repays a borrow belonging to borrower
     * @param borrower the account with the debt being payed off
     * @param repayAmount The amount to repay
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
     */
    function repayBorrowBehalfInternal(
        address borrower,
        uint repayAmount
    ) internal nonReentrant returns (uint, uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
            return (
                fail(
                    Error(error),
                    FailureInfo.REPAY_BEHALF_ACCRUE_INTEREST_FAILED
                ),
                0
            );
        }
        // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
        return repayBorrowFresh(msg.sender, borrower, repayAmount);
    }

    struct RepayBorrowLocalVars {
        Error err;
        MathError mathErr;
        uint repayAmount;
        uint borrowerIndex;
        uint accountBorrows;
        uint accountBorrowsNew;
        uint totalBorrowsNew;
        uint actualRepayAmount;
    }

    /**
     * @notice Borrows are repaid by another user (possibly the borrower).
     * @param payer the account paying off the borrow
     * @param borrower the account with the debt being payed off
     * @param repayAmount the amount of underlying tokens being returned
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
     */
    function repayBorrowFresh(
        address payer,
        address borrower,
        uint repayAmount
    ) internal returns (uint, uint) {
        /* Fail if repayBorrow not allowed */
        uint allowed = comptroller.repayBorrowAllowed(
            address(this),
            payer,
            borrower,
            repayAmount
        );
        if (allowed != 0) {
            return (
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.REPAY_BORROW_COMPTROLLER_REJECTION,
                    allowed
                ),
                0
            );
        }

        /* Verify market's block timestamp equals current block timestamp */
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return (
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.REPAY_BORROW_FRESHNESS_CHECK
                ),
                0
            );
        }

        RepayBorrowLocalVars memory vars;

        /* We remember the original borrowerIndex for verification purposes */
        vars.borrowerIndex = accountBorrows[borrower].interestIndex;

        /* We fetch the amount the borrower owes, with accumulated interest */
        (vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(
            borrower
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return (
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo
                        .REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
                    uint(vars.mathErr)
                ),
                0
            );
        }

        /* If repayAmount == uint.max, repayAmount = accountBorrows */
        if (repayAmount == type(uint).max) {
            vars.repayAmount = vars.accountBorrows;
        } else {
            vars.repayAmount = repayAmount;
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /*
         * We call doTransferIn for the payer and the repayAmount
         *  Note: The mToken must handle variations between ERC-20 and GLMR underlying.
         *  On success, the mToken holds an additional repayAmount of cash.
         *  doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred.
         *   it returns the amount actually transferred, in case of a fee.
         */
        vars.actualRepayAmount = doTransferIn(payer, vars.repayAmount);

        /*
         * We calculate the new borrower and total borrow balances, failing on underflow:
         *  accountBorrowsNew = accountBorrows - actualRepayAmount
         *  totalBorrowsNew = totalBorrows - actualRepayAmount
         */
        (vars.mathErr, vars.accountBorrowsNew) = subUInt(
            vars.accountBorrows,
            vars.actualRepayAmount
        );
        require(
            vars.mathErr == MathError.NO_ERROR,
            "REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED"
        );

        (vars.mathErr, vars.totalBorrowsNew) = subUInt(
            totalBorrows,
            vars.actualRepayAmount
        );
        require(
            vars.mathErr == MathError.NO_ERROR,
            "REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED"
        );

        /* We write the previously calculated values into storage */
        accountBorrows[borrower].principal = vars.accountBorrowsNew;
        accountBorrows[borrower].interestIndex = borrowIndex;
        totalBorrows = vars.totalBorrowsNew;

        /* We emit a RepayBorrow event */
        emit RepayBorrow(
            payer,
            borrower,
            vars.actualRepayAmount,
            vars.accountBorrowsNew,
            vars.totalBorrowsNew
        );

        /* We call the defense hook */
        // unused function
        // comptroller.repayBorrowVerify(address(this), payer, borrower, vars.actualRepayAmount, vars.borrowerIndex);

        return (uint(Error.NO_ERROR), vars.actualRepayAmount);
    }

    /**
     * @notice The sender liquidates the borrowers collateral.
     *  The collateral seized is transferred to the liquidator.
     * @param borrower The borrower of this mToken to be liquidated
     * @param mTokenCollateral The market in which to seize collateral from the borrower
     * @param repayAmount The amount of the underlying borrowed asset to repay
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
     */
    function liquidateBorrowInternal(
        address borrower,
        uint repayAmount,
        MTokenInterface mTokenCollateral
    ) internal nonReentrant returns (uint, uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
            return (
                fail(
                    Error(error),
                    FailureInfo.LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED
                ),
                0
            );
        }

        error = mTokenCollateral.accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
            return (
                fail(
                    Error(error),
                    FailureInfo.LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED
                ),
                0
            );
        }

        // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to
        return
            liquidateBorrowFresh(
                msg.sender,
                borrower,
                repayAmount,
                mTokenCollateral
            );
    }

    /**
     * @notice The liquidator liquidates the borrowers collateral.
     *  The collateral seized is transferred to the liquidator.
     * @param borrower The borrower of this mToken to be liquidated
     * @param liquidator The address repaying the borrow and seizing collateral
     * @param mTokenCollateral The market in which to seize collateral from the borrower
     * @param repayAmount The amount of the underlying borrowed asset to repay
     * @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
     */
    function liquidateBorrowFresh(
        address liquidator,
        address borrower,
        uint repayAmount,
        MTokenInterface mTokenCollateral
    ) internal returns (uint, uint) {
        /* Fail if liquidate not allowed */
        uint allowed = comptroller.liquidateBorrowAllowed(
            address(this),
            address(mTokenCollateral),
            liquidator,
            borrower,
            repayAmount
        );
        if (allowed != 0) {
            return (
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.LIQUIDATE_COMPTROLLER_REJECTION,
                    allowed
                ),
                0
            );
        }

        /* Verify market's block timestamp equals current block timestamp */
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return (
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.LIQUIDATE_FRESHNESS_CHECK
                ),
                0
            );
        }

        /* Verify mTokenCollateral market's block timestamp equals current block timestamp */
        if (mTokenCollateral.accrualBlockTimestamp() != getBlockTimestamp()) {
            return (
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.LIQUIDATE_COLLATERAL_FRESHNESS_CHECK
                ),
                0
            );
        }

        /* Fail if borrower = liquidator */
        if (borrower == liquidator) {
            return (
                fail(
                    Error.INVALID_ACCOUNT_PAIR,
                    FailureInfo.LIQUIDATE_LIQUIDATOR_IS_BORROWER
                ),
                0
            );
        }

        /* Fail if repayAmount = 0 */
        if (repayAmount == 0) {
            return (
                fail(
                    Error.INVALID_CLOSE_AMOUNT_REQUESTED,
                    FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_ZERO
                ),
                0
            );
        }

        /* Fail if repayAmount = uint.max */
        if (repayAmount == type(uint).max) {
            return (
                fail(
                    Error.INVALID_CLOSE_AMOUNT_REQUESTED,
                    FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX
                ),
                0
            );
        }

        /* Fail if repayBorrow fails */
        (uint repayBorrowError, uint actualRepayAmount) = repayBorrowFresh(
            liquidator,
            borrower,
            repayAmount
        );
        if (repayBorrowError != uint(Error.NO_ERROR)) {
            return (
                fail(
                    Error(repayBorrowError),
                    FailureInfo.LIQUIDATE_REPAY_BORROW_FRESH_FAILED
                ),
                0
            );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /* We calculate the number of collateral tokens that will be seized */
        (uint amountSeizeError, uint seizeTokens) = comptroller
            .liquidateCalculateSeizeTokens(
                address(this),
                address(mTokenCollateral),
                actualRepayAmount
            );
        require(
            amountSeizeError == uint(Error.NO_ERROR),
            "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED"
        );

        /* Revert if borrower collateral token balance < seizeTokens */
        require(
            mTokenCollateral.balanceOf(borrower) >= seizeTokens,
            "LIQUIDATE_SEIZE_TOO_MUCH"
        );

        // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call
        uint seizeError;
        if (address(mTokenCollateral) == address(this)) {
            seizeError = seizeInternal(
                address(this),
                liquidator,
                borrower,
                seizeTokens
            );
        } else {
            seizeError = mTokenCollateral.seize(
                liquidator,
                borrower,
                seizeTokens
            );
        }

        /* Revert if seize tokens fails (since we cannot be sure of side effects) */
        require(seizeError == uint(Error.NO_ERROR), "token seizure failed");

        /* We emit a LiquidateBorrow event */
        emit LiquidateBorrow(
            liquidator,
            borrower,
            actualRepayAmount,
            address(mTokenCollateral),
            seizeTokens
        );

        /* We call the defense hook */
        // unused function
        // comptroller.liquidateBorrowVerify(address(this), address(mTokenCollateral), liquidator, borrower, actualRepayAmount, seizeTokens);

        return (uint(Error.NO_ERROR), actualRepayAmount);
    }

    /**
     * @notice Transfers collateral tokens (this market) to the liquidator.
     * @dev Will fail unless called by another mToken during the process of liquidation.
     *  Its absolutely critical to use msg.sender as the borrowed mToken and not a parameter.
     * @param liquidator The account receiving seized collateral
     * @param borrower The account having collateral seized
     * @param seizeTokens The number of mTokens to seize
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function seize(
        address liquidator,
        address borrower,
        uint seizeTokens
    ) external override nonReentrant returns (uint) {
        return seizeInternal(msg.sender, liquidator, borrower, seizeTokens);
    }

    struct SeizeInternalLocalVars {
        MathError mathErr;
        uint borrowerTokensNew;
        uint liquidatorTokensNew;
        uint liquidatorSeizeTokens;
        uint protocolSeizeTokens;
        uint protocolSeizeAmount;
        uint exchangeRateMantissa;
        uint totalReservesNew;
        uint totalSupplyNew;
    }

    /**
     * @notice Transfers collateral tokens (this market) to the liquidator.
     * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another MToken.
     *  Its absolutely critical to use msg.sender as the seizer mToken and not a parameter.
     * @param seizerToken The contract seizing the collateral (i.e. borrowed mToken)
     * @param liquidator The account receiving seized collateral
     * @param borrower The account having collateral seized
     * @param seizeTokens The number of mTokens to seize
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function seizeInternal(
        address seizerToken,
        address liquidator,
        address borrower,
        uint seizeTokens
    ) internal returns (uint) {
        /* Fail if seize not allowed */
        uint allowed = comptroller.seizeAllowed(
            address(this),
            seizerToken,
            liquidator,
            borrower,
            seizeTokens
        );
        if (allowed != 0) {
            return
                failOpaque(
                    Error.COMPTROLLER_REJECTION,
                    FailureInfo.LIQUIDATE_SEIZE_COMPTROLLER_REJECTION,
                    allowed
                );
        }

        /* Fail if borrower = liquidator */
        if (borrower == liquidator) {
            return
                fail(
                    Error.INVALID_ACCOUNT_PAIR,
                    FailureInfo.LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER
                );
        }

        SeizeInternalLocalVars memory vars;

        /*
         * We calculate the new borrower and liquidator token balances, failing on underflow/overflow:
         *  borrowerTokensNew = accountTokens[borrower] - seizeTokens
         *  liquidatorTokensNew = accountTokens[liquidator] + seizeTokens
         */
        (vars.mathErr, vars.borrowerTokensNew) = subUInt(
            accountTokens[borrower],
            seizeTokens
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED,
                    uint(vars.mathErr)
                );
        }

        vars.protocolSeizeTokens = mul_(
            seizeTokens,
            Exp({mantissa: protocolSeizeShareMantissa})
        );
        vars.liquidatorSeizeTokens = sub_(
            seizeTokens,
            vars.protocolSeizeTokens
        );

        (
            vars.mathErr,
            vars.exchangeRateMantissa
        ) = exchangeRateStoredInternal();
        require(vars.mathErr == MathError.NO_ERROR, "exchange rate math error");

        vars.protocolSeizeAmount = mul_ScalarTruncate(
            Exp({mantissa: vars.exchangeRateMantissa}),
            vars.protocolSeizeTokens
        );

        vars.totalReservesNew = add_(totalReserves, vars.protocolSeizeAmount);
        vars.totalSupplyNew = sub_(totalSupply, vars.protocolSeizeTokens);

        (vars.mathErr, vars.liquidatorTokensNew) = addUInt(
            accountTokens[liquidator],
            vars.liquidatorSeizeTokens
        );
        if (vars.mathErr != MathError.NO_ERROR) {
            return
                failOpaque(
                    Error.MATH_ERROR,
                    FailureInfo.LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED,
                    uint(vars.mathErr)
                );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /* We write the previously calculated values into storage */
        totalReserves = vars.totalReservesNew;
        totalSupply = vars.totalSupplyNew;
        accountTokens[borrower] = vars.borrowerTokensNew;
        accountTokens[liquidator] = vars.liquidatorTokensNew;

        /* Emit a Transfer event */
        emit Transfer(borrower, liquidator, vars.liquidatorSeizeTokens);
        emit Transfer(borrower, address(this), vars.protocolSeizeTokens);
        emit ReservesAdded(
            address(this),
            vars.protocolSeizeAmount,
            vars.totalReservesNew
        );

        /* We call the defense hook */
        // unused function
        // comptroller.seizeVerify(address(this), seizerToken, liquidator, borrower, seizeTokens);

        return uint(Error.NO_ERROR);
    }

    /*** Admin Functions ***/

    /**
     * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
     * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
     * @param newPendingAdmin New pending admin.
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setPendingAdmin(
        address payable newPendingAdmin
    ) external override returns (uint) {
        // Check caller = admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_PENDING_ADMIN_OWNER_CHECK
                );
        }

        // Save current value, if any, for inclusion in log
        address oldPendingAdmin = pendingAdmin;

        // Store pendingAdmin with value newPendingAdmin
        pendingAdmin = newPendingAdmin;

        // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin)
        emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin
     * @dev Admin function for pending admin to accept role and update admin
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _acceptAdmin() external override returns (uint) {
        // Check caller is pendingAdmin and pendingAdmin ≠ address(0)
        if (msg.sender != pendingAdmin || msg.sender == address(0)) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.ACCEPT_ADMIN_PENDING_ADMIN_CHECK
                );
        }

        // Save current values for inclusion in log
        address oldAdmin = admin;
        address oldPendingAdmin = pendingAdmin;

        // Store admin with value pendingAdmin
        admin = pendingAdmin;

        // Clear the pending value
        pendingAdmin = payable(address(0));

        emit NewAdmin(oldAdmin, admin);
        emit NewPendingAdmin(oldPendingAdmin, pendingAdmin);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Sets a new comptroller for the market
     * @dev Admin function to set a new comptroller
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setComptroller(
        ComptrollerInterface newComptroller
    ) public override returns (uint) {
        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_COMPTROLLER_OWNER_CHECK
                );
        }

        ComptrollerInterface oldComptroller = comptroller;
        // Ensure invoke comptroller.isComptroller() returns true
        require(newComptroller.isComptroller(), "marker method returned false");

        // Set market's comptroller to newComptroller
        comptroller = newComptroller;

        // Emit NewComptroller(oldComptroller, newComptroller)
        emit NewComptroller(oldComptroller, newComptroller);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh
     * @dev Admin function to accrue interest and set a new reserve factor
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setReserveFactor(
        uint newReserveFactorMantissa
    ) external override nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reserve factor change failed.
            return
                fail(
                    Error(error),
                    FailureInfo.SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED
                );
        }
        // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to.
        return _setReserveFactorFresh(newReserveFactorMantissa);
    }

    /**
     * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual)
     * @dev Admin function to set a new reserve factor
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setReserveFactorFresh(
        uint newReserveFactorMantissa
    ) internal returns (uint) {
        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_RESERVE_FACTOR_ADMIN_CHECK
                );
        }

        // Verify market's block timestamp equals current block timestamp
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.SET_RESERVE_FACTOR_FRESH_CHECK
                );
        }

        // Check newReserveFactor ≤ maxReserveFactor
        if (newReserveFactorMantissa > reserveFactorMaxMantissa) {
            return
                fail(
                    Error.BAD_INPUT,
                    FailureInfo.SET_RESERVE_FACTOR_BOUNDS_CHECK
                );
        }

        uint oldReserveFactorMantissa = reserveFactorMantissa;
        reserveFactorMantissa = newReserveFactorMantissa;

        emit NewReserveFactor(
            oldReserveFactorMantissa,
            newReserveFactorMantissa
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice Accrues interest and reduces reserves by transferring from msg.sender
     * @param addAmount Amount of addition to reserves
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _addReservesInternal(
        uint addAmount
    ) internal nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reduce reserves failed.
            return
                fail(
                    Error(error),
                    FailureInfo.ADD_RESERVES_ACCRUE_INTEREST_FAILED
                );
        }

        // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to.
        (error, ) = _addReservesFresh(addAmount);
        return error;
    }

    /**
     * @notice Add reserves by transferring from caller
     * @dev Requires fresh interest accrual
     * @param addAmount Amount of addition to reserves
     * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees
     */
    function _addReservesFresh(uint addAmount) internal returns (uint, uint) {
        // totalReserves + actualAddAmount
        uint totalReservesNew;
        uint actualAddAmount;

        // We fail gracefully unless market's block timestamp equals current block timestamp
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return (
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.ADD_RESERVES_FRESH_CHECK
                ),
                actualAddAmount
            );
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        /*
         * We call doTransferIn for the caller and the addAmount
         *  Note: The mToken must handle variations between ERC-20 and GLMR underlying.
         *  On success, the mToken holds an additional addAmount of cash.
         *  doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred.
         *  it returns the amount actually transferred, in case of a fee.
         */

        actualAddAmount = doTransferIn(msg.sender, addAmount);

        totalReservesNew = totalReserves + actualAddAmount;

        /* Revert on overflow */
        require(
            totalReservesNew >= totalReserves,
            "add reserves unexpected overflow"
        );

        // Store reserves[n+1] = reserves[n] + actualAddAmount
        totalReserves = totalReservesNew;

        /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */
        emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew);

        /* Return (NO_ERROR, actualAddAmount) */
        return (uint(Error.NO_ERROR), actualAddAmount);
    }

    /**
     * @notice Accrues interest and reduces reserves by transferring to admin
     * @param reduceAmount Amount of reduction to reserves
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _reduceReserves(
        uint reduceAmount
    ) external override nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reduce reserves failed.
            return
                fail(
                    Error(error),
                    FailureInfo.REDUCE_RESERVES_ACCRUE_INTEREST_FAILED
                );
        }
        // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to.
        return _reduceReservesFresh(reduceAmount);
    }

    /**
     * @notice Reduces reserves by transferring to admin
     * @dev Requires fresh interest accrual
     * @param reduceAmount Amount of reduction to reserves
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _reduceReservesFresh(uint reduceAmount) internal returns (uint) {
        // totalReserves - reduceAmount
        uint totalReservesNew;

        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.REDUCE_RESERVES_ADMIN_CHECK
                );
        }

        // We fail gracefully unless market's block timestamp equals current block timestamp
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.REDUCE_RESERVES_FRESH_CHECK
                );
        }

        // Fail gracefully if protocol has insufficient underlying cash
        if (getCashPrior() < reduceAmount) {
            return
                fail(
                    Error.TOKEN_INSUFFICIENT_CASH,
                    FailureInfo.REDUCE_RESERVES_CASH_NOT_AVAILABLE
                );
        }

        // Check reduceAmount ≤ reserves[n] (totalReserves)
        if (reduceAmount > totalReserves) {
            return
                fail(Error.BAD_INPUT, FailureInfo.REDUCE_RESERVES_VALIDATION);
        }

        /////////////////////////
        // EFFECTS & INTERACTIONS
        // (No safe failures beyond this point)

        totalReservesNew = totalReserves - reduceAmount;
        // We checked reduceAmount <= totalReserves above, so this should never revert.
        require(
            totalReservesNew <= totalReserves,
            "reduce reserves unexpected underflow"
        );

        // Store reserves[n+1] = reserves[n] - reduceAmount
        totalReserves = totalReservesNew;

        // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred.
        doTransferOut(admin, reduceAmount);

        emit ReservesReduced(admin, reduceAmount, totalReservesNew);

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh
     * @dev Admin function to accrue interest and update the interest rate model
     * @param newInterestRateModel the new interest rate model to use
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setInterestRateModel(
        InterestRateModel newInterestRateModel
    ) public override returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted change of interest rate model failed
            return
                fail(
                    Error(error),
                    FailureInfo.SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED
                );
        }
        // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to.
        return _setInterestRateModelFresh(newInterestRateModel);
    }

    /**
     * @notice updates the interest rate model (*requires fresh interest accrual)
     * @dev Admin function to update the interest rate model
     * @param newInterestRateModel the new interest rate model to use
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setInterestRateModelFresh(
        InterestRateModel newInterestRateModel
    ) internal returns (uint) {
        // Used to store old model for use in the event that is emitted on success
        InterestRateModel oldInterestRateModel;

        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_INTEREST_RATE_MODEL_OWNER_CHECK
                );
        }

        // We fail gracefully unless market's block timestamp equals current block timestamp
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.SET_INTEREST_RATE_MODEL_FRESH_CHECK
                );
        }

        // Track the market's current interest rate model
        oldInterestRateModel = interestRateModel;

        // Ensure invoke newInterestRateModel.isInterestRateModel() returns true
        require(
            newInterestRateModel.isInterestRateModel(),
            "marker method returned false"
        );

        // Set the interest rate model to newInterestRateModel
        interestRateModel = newInterestRateModel;

        // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel)
        emit NewMarketInterestRateModel(
            oldInterestRateModel,
            newInterestRateModel
        );

        return uint(Error.NO_ERROR);
    }

    /**
     * @notice accrues interest and updates the protocol seize share using _setProtocolSeizeShareFresh
     * @dev Admin function to accrue interest and update the protocol seize share
     * @param newProtocolSeizeShareMantissa the new protocol seize share to use
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setProtocolSeizeShare(
        uint newProtocolSeizeShareMantissa
    ) external override nonReentrant returns (uint) {
        uint error = accrueInterest();
        if (error != uint(Error.NO_ERROR)) {
            // accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted change of protocol seize share failed
            return
                fail(
                    Error(error),
                    FailureInfo.SET_PROTOCOL_SEIZE_SHARE_ACCRUE_INTEREST_FAILED
                );
        }
        // _setProtocolSeizeShareFresh emits protocol-seize-share-update-specific logs on errors, so we don't need to.
        return _setProtocolSeizeShareFresh(newProtocolSeizeShareMantissa);
    }

    /**
     * @notice updates the protocol seize share (*requires fresh interest accrual)
     * @dev Admin function to update the protocol seize share
     * @param newProtocolSeizeShareMantissa the new protocol seize share to use
     * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
     */
    function _setProtocolSeizeShareFresh(
        uint newProtocolSeizeShareMantissa
    ) internal returns (uint) {
        // Used to store old share for use in the event that is emitted on success
        uint oldProtocolSeizeShareMantissa;

        // Check caller is admin
        if (msg.sender != admin) {
            return
                fail(
                    Error.UNAUTHORIZED,
                    FailureInfo.SET_PROTOCOL_SEIZE_SHARE_OWNER_CHECK
                );
        }

        // We fail gracefully unless market's block timestamp equals current block timestamp
        if (accrualBlockTimestamp != getBlockTimestamp()) {
            return
                fail(
                    Error.MARKET_NOT_FRESH,
                    FailureInfo.SET_PROTOCOL_SEIZE_SHARE_FRESH_CHECK
                );
        }

        // Track the market's current protocol seize share
        oldProtocolSeizeShareMantissa = protocolSeizeShareMantissa;

        // Set the protocol seize share to newProtocolSeizeShareMantissa
        protocolSeizeShareMantissa = newProtocolSeizeShareMantissa;

        // Emit NewProtocolSeizeShareMantissa(oldProtocolSeizeShareMantissa, newProtocolSeizeShareMantissa)
        emit NewProtocolSeizeShare(
            oldProtocolSeizeShareMantissa,
            newProtocolSeizeShareMantissa
        );

        return uint(Error.NO_ERROR);
    }

    /*** Safe Token ***/

    /**
     * @notice Gets balance of this contract in terms of the underlying
     * @dev This excludes the value of the current message, if any
     * @return The quantity of underlying owned by this contract
     */
    function getCashPrior() internal view virtual returns (uint);

    /**
     * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee.
     *  This may revert due to insufficient balance or insufficient allowance.
     */
    function doTransferIn(
        address from,
        uint amount
    ) internal virtual returns (uint);

    /**
     * @dev Performs a transfer out, ideally returning an explanatory error code upon failure tather than reverting.
     *  If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract.
     *  If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions.
     */
    function doTransferOut(address payable to, uint amount) internal virtual;

    /*** Reentrancy Guard ***/

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     */
    modifier nonReentrant() {
        require(_notEntered, "re-entered");
        _notEntered = false;
        _;
        _notEntered = true; // get a gas-refund post-Istanbul
    }
}