// File: contracts/Unitroller.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./ErrorReporter.sol";
import "./ComptrollerStorage.sol";

/**
 * @title ComptrollerCore
 * @dev Storage for the comptroller is at this address, while execution is delegated to the `comptrollerImplementation`.
 * CTokens should reference this contract as their comptroller.
 */
contract Unitroller is UnitrollerAdminStorage, ComptrollerErrorReporter {
  /**
   * @notice Emitted when pendingComptrollerImplementation is changed
   */
  event NewPendingImplementation(address oldPendingImplementation, address newPendingImplementation);

  /**
   * @notice Emitted when pendingComptrollerImplementation is accepted, which means comptroller implementation is updated
   */
  event NewImplementation(address oldImplementation, address newImplementation);

  /**
   * @notice Emitted when pendingAdmin is changed
   */
  event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);

  /**
   * @notice Emitted when pendingAdmin is accepted, which means admin is updated
   */
  event NewAdmin(address oldAdmin, address newAdmin);

  /**
   * @notice Emitted _compAddress is initially set (when accepting the first comptroller implementation)
   */
  event NewCompAddress(address oldAddress, address newAddress);

  address private _compAddress;

  constructor() {
    // Set admin to caller
    admin = msg.sender;
  }

  /*** Admin Functions ***/
  function _setPendingImplementation(address newPendingImplementation) public returns (uint256) {
    if (msg.sender != admin) {
      return fail(Error.UNAUTHORIZED, FailureInfo.SET_PENDING_IMPLEMENTATION_OWNER_CHECK);
    }

    address oldPendingImplementation = pendingComptrollerImplementation;

    pendingComptrollerImplementation = newPendingImplementation;

    emit NewPendingImplementation(oldPendingImplementation, pendingComptrollerImplementation);

    return uint256(Error.NO_ERROR);
  }

  /**
   * @notice Accepts new implementation of comptroller. msg.sender must be pendingImplementation
   * @dev Admin function for new implementation to accept it's role as implementation
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _acceptImplementation() public returns (uint256) {
    // Check caller is pendingImplementation and pendingImplementation ≠ address(0)
    if (msg.sender != pendingComptrollerImplementation || pendingComptrollerImplementation == address(0)) {
      return fail(Error.UNAUTHORIZED, FailureInfo.ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK);
    }

    // Save current values for inclusion in log
    address oldImplementation = comptrollerImplementation;
    address oldPendingImplementation = pendingComptrollerImplementation;

    if (_compAddress == address(0)) {
      (bool success, bytes memory compAddress) = pendingComptrollerImplementation.call(abi.encodeWithSignature("getCompAddress()"));
      require(success, "failed at getCompAddress()");
      _compAddress = abi.decode(compAddress, (address));
      emit NewCompAddress(address(0), _compAddress);
    }

    comptrollerImplementation = pendingComptrollerImplementation;

    pendingComptrollerImplementation = address(0);

    emit NewImplementation(oldImplementation, comptrollerImplementation);
    emit NewPendingImplementation(oldPendingImplementation, pendingComptrollerImplementation);

    return uint256(Error.NO_ERROR);
  }

  /**
   * @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 newPendingAdmin) public returns (uint256) {
    // 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 uint256(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() public returns (uint256) {
    // 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 = address(0);

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

    return uint256(Error.NO_ERROR);
  }

  /**
   * @dev Delegates execution to an implementation contract.
   * It returns to the external caller whatever the implementation returns
   * or forwards reverts.
   */
  fallback() external payable {
    // delegate all other functions to current implementation
    (bool success, ) = comptrollerImplementation.delegatecall(msg.data);

    assembly {
      let free_mem_ptr := mload(0x40)
      returndatacopy(free_mem_ptr, 0, returndatasize())

      switch success
      case 0 {
        revert(free_mem_ptr, returndatasize())
      }
      default {
        return(free_mem_ptr, returndatasize())
      }
    }
  }
}

// File: contracts/ErrorReporter.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

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_BORROWER_LIMIT_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(uint256 error, uint256 info, uint256 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 (uint256) {
    emit Failure(uint256(err), uint256(info), 0);

    return uint256(err);
  }

  /**
   * @dev use this when reporting an opaque error from an upgradeable collaborator contract
   */
  function failOpaque(
    Error err,
    FailureInfo info,
    uint256 opaqueError
  ) internal returns (uint256) {
    emit Failure(uint256(err), uint256(info), opaqueError);

    return uint256(err);
  }
}

contract TokenErrorReporter {
  uint256 public constant NO_ERROR = 0; // support legacy return codes

  error TransferComptrollerRejection(uint256 errorCode);
  error TransferNotAllowed();
  error TransferNotEnough();
  error TransferTooMuch();

  error MintComptrollerRejection(uint256 errorCode);
  error MintFreshnessCheck();

  error RedeemComptrollerRejection(uint256 errorCode);
  error RedeemFreshnessCheck();
  error RedeemTransferOutNotPossible();

  error BorrowComptrollerRejection(uint256 errorCode);
  error BorrowFreshnessCheck();
  error BorrowCashNotAvailable();

  error RepayBorrowComptrollerRejection(uint256 errorCode);
  error RepayBorrowFreshnessCheck();

  error LiquidateComptrollerRejection(uint256 errorCode);
  error LiquidateFreshnessCheck();
  error LiquidateCollateralFreshnessCheck();
  error LiquidateAccrueBorrowInterestFailed(uint256 errorCode);
  error LiquidateAccrueCollateralInterestFailed(uint256 errorCode);
  error LiquidateLiquidatorIsBorrower();
  error LiquidateCloseAmountIsZero();
  error LiquidateCloseAmountIsUintMax();
  error LiquidateRepayBorrowFreshFailed(uint256 errorCode);

  error LiquidateSeizeComptrollerRejection(uint256 errorCode);
  error LiquidateSeizeLiquidatorIsBorrower();

  error AcceptAdminPendingAdminCheck();

  error SetComptrollerOwnerCheck();
  error SetPendingAdminOwnerCheck();

  error SetReserveFactorAdminCheck();
  error SetReserveFactorFreshCheck();
  error SetReserveFactorBoundsCheck();

  error AddReservesFactorFreshCheck(uint256 actualAddAmount);

  error ReduceReservesAdminCheck();
  error ReduceReservesFreshCheck();
  error ReduceReservesCashNotAvailable();
  error ReduceReservesCashValidation();

  error SetInterestRateModelOwnerCheck();
  error SetInterestRateModelFreshCheck();
}

// File: contracts/ComptrollerStorage.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./CToken.sol";
import "./PriceOracle.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 ComptrollerV1Storage 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
   */
  uint256 public closeFactorMantissa;

  /**
   * @notice Multiplier representing the discount on collateral that a liquidator receives
   */
  uint256 public liquidationIncentiveMantissa;

  /**
   * @notice Max number of assets a single account can participate in (borrow or use as collateral)
   */
  uint256 public maxAssets;

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

  mapping(address => bool) public borrowerArray;

  mapping(address => uint256) public borrowLimit;
}

contract ComptrollerV2Storage is ComptrollerV1Storage {
  struct Market {
    // Whether or not this market is listed
    bool isListed;
    //  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.
    uint256 collateralFactorMantissa;
    // Per-market mapping of "accounts in this asset"
    mapping(address => bool) accountMembership;
    // Whether or not this market receives COMP
    bool isComped;
  }

  /**
   * @notice Official mapping of cTokens -> 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 _mintGuardianPaused;
  bool public _borrowGuardianPaused;
  bool public transferGuardianPaused;
  bool public seizeGuardianPaused;
  mapping(address => bool) public mintGuardianPaused;
  mapping(address => bool) public borrowGuardianPaused;
}

contract ComptrollerV3Storage is ComptrollerV2Storage {
  struct CompMarketState {
    // The market's last updated compBorrowIndex or compSupplyIndex
    uint224 index;
    // The block number the index was last updated at
    uint32 block;
  }

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

  /// @notice The rate at which the flywheel distributes COMP, per block
  uint256 public compRate;

  /// @notice The portion of compRate that each market currently receives
  mapping(address => uint256) public compSpeeds;

  /// @notice The COMP market supply state for each market
  mapping(address => CompMarketState) public compSupplyState;

  /// @notice The COMP market borrow state for each market
  mapping(address => CompMarketState) public compBorrowState;

  /// @notice The COMP borrow index for each market for each supplier as of the last time they accrued COMP
  mapping(address => mapping(address => uint256)) public compSupplierIndex;

  /// @notice The COMP borrow index for each market for each borrower as of the last time they accrued COMP
  mapping(address => mapping(address => uint256)) public compBorrowerIndex;

  /// @notice The COMP accrued but not yet transferred to each user
  mapping(address => uint256) public compAccrued;
}

contract ComptrollerV4Storage is ComptrollerV3Storage {
  // @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 cToken address. Defaults to zero which corresponds to unlimited borrowing.
  mapping(address => uint256) public borrowCaps;
}

contract ComptrollerV5Storage is ComptrollerV4Storage {
  /// @notice The portion of COMP that each contributor receives per block
  mapping(address => uint256) public compContributorSpeeds;

  /// @notice Last block at which a contributor's COMP rewards have been allocated
  mapping(address => uint256) public lastContributorBlock;
}

contract ComptrollerV6Storage is ComptrollerV5Storage {
  /// @notice The rate at which comp is distributed to the corresponding borrow market (per block)
  mapping(address => uint256) public compBorrowSpeeds;

  /// @notice The rate at which comp is distributed to the corresponding supply market (per block)
  mapping(address => uint256) public compSupplySpeeds;
}

contract ComptrollerV7Storage is ComptrollerV6Storage {
  /// @notice Flag indicating whether the function to fix COMP accruals has been executed (RE: proposal 62 bug)
  bool public proposal65FixExecuted;

  /// @notice Accounting storage mapping account addresses to how much COMP they owe the protocol.
  mapping(address => uint256) public compReceivable;
}

// File: contracts/CToken.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./ComptrollerInterface.sol";
import "./CTokenInterfaces.sol";
import "./ErrorReporter.sol";
import "./EIP20Interface.sol";
import "./InterestRateModel.sol";
import "./ExponentialNoError.sol";

/**
 * @title Compound's CToken Contract
 * @notice Abstract base for CTokens
 * @author Compound
 */
abstract contract CToken is CTokenInterface, ExponentialNoError, 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_,
    uint256 initialExchangeRateMantissa_,
    string memory name_,
    string memory symbol_,
    uint8 decimals_
  ) public {
    require(msg.sender == admin, "only admin may initialize the market");
    require(accrualBlockNumber == 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
    uint256 err = _setComptroller(comptroller_);
    require(err == NO_ERROR, "setting comptroller failed");

    // Initialize block number and borrow index (block number mocks depend on comptroller being set)
    accrualBlockNumber = getBlockNumber();
    borrowIndex = mantissaOne;

    // Set the interest rate model (depends on block number / borrow index)
    err = _setInterestRateModelFresh(interestRateModel_);
    require(err == 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 0 if the transfer succeeded, else revert
   */
  function transferTokens(
    address spender,
    address src,
    address dst,
    uint256 tokens
  ) internal returns (uint256) {
    /* Fail if transfer not allowed */
    uint256 allowed = comptroller.transferAllowed(address(this), src, dst, tokens);
    if (allowed != 0 && spender != admin) {
      revert TransferComptrollerRejection(allowed);
    }

    /* Do not allow self-transfers */
    if (src == dst) {
      revert TransferNotAllowed();
    }

    /* Get the allowance, infinite for the account owner */
    uint256 startingAllowance = 0;
    if (spender == src || spender == admin) {
      startingAllowance = type(uint256).max;
    } else {
      startingAllowance = transferAllowances[src][spender];
    }

    /* Do the calculations, checking for {under,over}flow */
    uint256 allowanceNew = startingAllowance - tokens;
    uint256 srcTokensNew = accountTokens[src] - tokens;
    uint256 dstTokensNew = accountTokens[dst] + tokens;

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

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

    /* Eat some of the allowance (if necessary) */
    if (startingAllowance != type(uint256).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 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) == 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) == 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 (uint256.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 (-1 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 (uint256) {
    Exp memory exchangeRate = Exp({ mantissa: exchangeRateCurrent() });
    return mul_ScalarTruncate(exchangeRate, accountTokens[owner]);
  }

  /**
   * @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 (
      uint256,
      uint256,
      uint256,
      uint256
    )
  {
    return (NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal());
  }

  /**
   * @dev Function to simply retrieve block number
   *  This exists mainly for inheriting test contracts to stub this result.
   */
  function getBlockNumber() internal view virtual returns (uint256) {
    return block.number;
  }

  /**
   * @notice Returns the current per-block borrow interest rate for this cToken
   * @return The borrow interest rate per block, scaled by 1e18
   */
  function borrowRatePerBlock() external view override returns (uint256) {
    return interestRateModel.getBorrowRate(getCashPrior(), totalBorrows, totalReserves);
  }

  /**
   * @notice Returns the current per-block supply interest rate for this cToken
   * @return The supply interest rate per block, scaled by 1e18
   */
  function supplyRatePerBlock() external view override returns (uint256) {
    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 (uint256) {
    accrueInterest();
    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 (uint256) {
    accrueInterest();
    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 (uint256) {
    return borrowBalanceStoredInternal(account);
  }

  /**
   * @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 (uint256) {
    /* 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 0;
    }

    /* Calculate new borrow balance using the interest index:
     *  recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex
     */
    uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex;
    return principalTimesIndex / borrowSnapshot.interestIndex;
  }

  /**
   * @notice Accrue interest then return the up-to-date exchange rate
   * @return Calculated exchange rate scaled by 1e18
   */
  function exchangeRateCurrent() public override nonReentrant returns (uint256) {
    accrueInterest();
    return exchangeRateStored();
  }

  /**
   * @notice Calculates the exchange rate from the underlying to the CToken
   * @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 (uint256) {
    return exchangeRateStoredInternal();
  }

  /**
   * @notice Calculates the exchange rate from the underlying to the CToken
   * @dev This function does not accrue interest before calculating the exchange rate
   * @return calculated exchange rate scaled by 1e18
   */
  function exchangeRateStoredInternal() internal view virtual returns (uint256) {
    uint256 _totalSupply = totalSupply;
    if (_totalSupply == 0) {
      /*
       * If there are no tokens minted:
       *  exchangeRate = initialExchangeRate
       */
      return initialExchangeRateMantissa;
    } else {
      /*
       * Otherwise:
       *  exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply
       */
      uint256 totalCash = getCashPrior();
      uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves;
      uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply;

      return exchangeRate;
    }
  }

  /**
   * @notice Get cash balance of this cToken in the underlying asset
   * @return The quantity of underlying asset owned by this contract
   */
  function getCash() external view override returns (uint256) {
    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 (uint256) {
    /* Remember the initial block number */
    uint256 currentBlockNumber = getBlockNumber();
    uint256 accrualBlockNumberPrior = accrualBlockNumber;

    /* Short-circuit accumulating 0 interest */
    if (accrualBlockNumberPrior == currentBlockNumber) {
      return NO_ERROR;
    }

    /* Read the previous values out of storage */
    uint256 cashPrior = getCashPrior();
    uint256 borrowsPrior = totalBorrows;
    uint256 reservesPrior = totalReserves;
    uint256 borrowIndexPrior = borrowIndex;

    /* Calculate the current borrow interest rate */
    uint256 borrowRateMantissa = interestRateModel.getBorrowRate(cashPrior, borrowsPrior, reservesPrior);
    require(borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high");

    /* Calculate the number of blocks elapsed since the last accrual */
    uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior;

    /*
     * 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 = mul_(Exp({ mantissa: borrowRateMantissa }), blockDelta);
    uint256 interestAccumulated = mul_ScalarTruncate(simpleInterestFactor, borrowsPrior);
    uint256 totalBorrowsNew = interestAccumulated + borrowsPrior;
    uint256 totalReservesNew = mul_ScalarTruncateAddUInt(Exp({ mantissa: reserveFactorMantissa }), interestAccumulated, reservesPrior);
    uint256 borrowIndexNew = mul_ScalarTruncateAddUInt(simpleInterestFactor, borrowIndexPrior, borrowIndexPrior);

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

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

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

    return NO_ERROR;
  }

  /**
   * @notice Sender supplies assets into the market and receives cTokens in exchange
   * @dev Accrues interest whether or not the operation succeeds, unless reverted
   * @param mintAmount The amount of the underlying asset to supply
   */
  function mintInternal(uint256 mintAmount) internal nonReentrant {
    accrueInterest();
    // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to
    mintFresh(msg.sender, mintAmount);
  }

  /**
   * @notice User supplies assets into the market and receives cTokens 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
   */
  function mintFresh(address minter, uint256 mintAmount) internal {
    /* Fail if mint not allowed */
    uint256 allowed = comptroller.mintAllowed(address(this), minter, mintAmount);
    if (allowed != 0) {
      revert MintComptrollerRejection(allowed);
    }

    /* Verify market's block number equals current block number */
    if (accrualBlockNumber != getBlockNumber()) {
      revert MintFreshnessCheck();
    }

    Exp memory exchangeRate = Exp({ mantissa: exchangeRateStoredInternal() });

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

    /*
     *  We call `doTransferIn` for the minter and the mintAmount.
     *  Note: The cToken must handle variations between ERC-20 and ETH 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 cToken holds an additional `actualMintAmount`
     *  of cash.
     */
    uint256 actualMintAmount = doTransferIn(minter, mintAmount);

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

    uint256 mintTokens = div_(actualMintAmount, exchangeRate);

    /*
     * We calculate the new total supply of cTokens and minter token balance, checking for overflow:
     *  totalSupplyNew = totalSupply + mintTokens
     *  accountTokensNew = accountTokens[minter] + mintTokens
     * And write them into storage
     */
    totalSupply = totalSupply + mintTokens;
    accountTokens[minter] = accountTokens[minter] + mintTokens;

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

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

  /**
   * @notice Sender redeems cTokens in exchange for the underlying asset
   * @dev Accrues interest whether or not the operation succeeds, unless reverted
   * @param redeemTokens The number of cTokens to redeem into underlying
   */
  function redeemInternal(uint256 redeemTokens) internal nonReentrant {
    accrueInterest();
    // redeemFresh emits redeem-specific logs on errors, so we don't need to
    redeemFresh(payable(msg.sender), redeemTokens, 0);
  }

  /**
   * @notice Sender redeems cTokens 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 cTokens
   */
  function redeemUnderlyingInternal(uint256 redeemAmount) internal nonReentrant {
    accrueInterest();
    // redeemFresh emits redeem-specific logs on errors, so we don't need to
    redeemFresh(payable(msg.sender), 0, redeemAmount);
  }

  /**
   * @notice User redeems cTokens 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 cTokens 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 cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero)
   */
  function redeemFresh(
    address payable redeemer,
    uint256 redeemTokensIn,
    uint256 redeemAmountIn
  ) internal {
    require(redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero");

    /* exchangeRate = invoke Exchange Rate Stored() */
    Exp memory exchangeRate = Exp({ mantissa: exchangeRateStoredInternal() });

    uint256 redeemTokens;
    uint256 redeemAmount;
    /* 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
       */
      redeemTokens = redeemTokensIn;
      redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn);
    } else {
      /*
       * We get the current exchange rate and calculate the amount to be redeemed:
       *  redeemTokens = redeemAmountIn / exchangeRate
       *  redeemAmount = redeemAmountIn
       */
      redeemTokens = div_(redeemAmountIn, exchangeRate);
      redeemAmount = redeemAmountIn;
    }

    /* Fail if redeem not allowed */
    uint256 allowed = comptroller.redeemAllowed(address(this), redeemer, redeemTokens);
    if (allowed != 0) {
      revert RedeemComptrollerRejection(allowed);
    }

    /* Verify market's block number equals current block number */
    if (accrualBlockNumber != getBlockNumber()) {
      revert RedeemFreshnessCheck();
    }

    /* Fail gracefully if protocol has insufficient cash */
    if (getCashPrior() < redeemAmount) {
      revert RedeemTransferOutNotPossible();
    }

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

    /*
     * We write the previously calculated values into storage.
     *  Note: Avoid token reentrancy attacks by writing reduced supply before external transfer.
     */
    totalSupply = totalSupply - redeemTokens;
    accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens;

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

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

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

  /**
   * @notice Sender borrows assets from the protocol to their own address
   * @param borrowAmount The amount of the underlying asset to borrow
   */
  function borrowInternal(uint256 borrowAmount) internal nonReentrant {
    accrueInterest();
    // borrowFresh emits borrow-specific logs on errors, so we don't need to
    borrowFresh(payable(msg.sender), borrowAmount);
  }

  /**
   * @notice Users borrow assets from the protocol to their own address
   * @param borrowAmount The amount of the underlying asset to borrow
   */
  function borrowFresh(address payable borrower, uint256 borrowAmount) internal {
    /* Fail if borrow not allowed */
    uint256 allowed = comptroller.borrowAllowed(address(this), borrower, borrowAmount);
    if (allowed != 0) {
      revert BorrowComptrollerRejection(allowed);
    }

    /* Verify market's block number equals current block number */
    if (accrualBlockNumber != getBlockNumber()) {
      revert BorrowFreshnessCheck();
    }

    /* Fail gracefully if protocol has insufficient underlying cash */
    if (getCashPrior() < borrowAmount) {
      revert BorrowCashNotAvailable();
    }

    /*
     * We calculate the new borrower and total borrow balances, failing on overflow:
     *  accountBorrowNew = accountBorrow + borrowAmount
     *  totalBorrowsNew = totalBorrows + borrowAmount
     */
    uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower);
    uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount;
    uint256 totalBorrowsNew = totalBorrows + borrowAmount;

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

    /*
         * We write the previously calculated values into storage.
         *  Note: Avoid token reentrancy attacks by writing increased borrow before external transfer.
        `*/
    accountBorrows[borrower].principal = accountBorrowsNew;
    accountBorrows[borrower].interestIndex = borrowIndex;
    totalBorrows = totalBorrowsNew;

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

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

  /**
   * @notice Sender repays their own borrow
   * @param repayAmount The amount to repay, or -1 for the full outstanding amount
   */
  function repayBorrowInternal(uint256 repayAmount) internal nonReentrant {
    accrueInterest();
    // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
    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, or -1 for the full outstanding amount
   */
  function repayBorrowBehalfInternal(address borrower, uint256 repayAmount) internal nonReentrant {
    accrueInterest();
    // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
    repayBorrowFresh(msg.sender, borrower, repayAmount);
  }

  /**
   * @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, or -1 for the full outstanding amount
   * @return (uint) the actual repayment amount.
   */
  function repayBorrowFresh(
    address payer,
    address borrower,
    uint256 repayAmount
  ) internal returns (uint256) {
    /* Fail if repayBorrow not allowed */
    uint256 allowed = comptroller.repayBorrowAllowed(address(this), payer, borrower, repayAmount);
    if (allowed != 0) {
      revert RepayBorrowComptrollerRejection(allowed);
    }

    /* Verify market's block number equals current block number */
    if (accrualBlockNumber != getBlockNumber()) {
      revert RepayBorrowFreshnessCheck();
    }

    /* We fetch the amount the borrower owes, with accumulated interest */
    uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower);

    /* If repayAmount == -1, repayAmount = accountBorrows */
    uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount;

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

    /*
     * We call doTransferIn for the payer and the repayAmount
     *  Note: The cToken must handle variations between ERC-20 and ETH underlying.
     *  On success, the cToken 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.
     */
    uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal);

    /*
     * We calculate the new borrower and total borrow balances, failing on underflow:
     *  accountBorrowsNew = accountBorrows - actualRepayAmount
     *  totalBorrowsNew = totalBorrows - actualRepayAmount
     */
    uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount;
    uint256 totalBorrowsNew = totalBorrows - actualRepayAmount;

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

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

    return actualRepayAmount;
  }

  /**
   * @notice The sender liquidates the borrowers collateral.
   *  The collateral seized is transferred to the liquidator.
   * @param borrower The borrower of this cToken to be liquidated
   * @param cTokenCollateral The market in which to seize collateral from the borrower
   * @param repayAmount The amount of the underlying borrowed asset to repay
   */
  function liquidateBorrowInternal(
    address borrower,
    uint256 repayAmount,
    CTokenInterface cTokenCollateral
  ) internal nonReentrant {
    require(msg.sender == admin, "only dAMM Foundation can liquidate borrowers");
    accrueInterest();
    uint256 error = cTokenCollateral.accrueInterest();
    if (error != NO_ERROR) {
      // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
      revert LiquidateAccrueCollateralInterestFailed(error);
    }

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

  /**
   * @notice The liquidator liquidates the borrowers collateral.
   *  The collateral seized is transferred to the liquidator.
   * @param borrower The lender of this cToken to be liquidated, in the case of dAMM
   * @param liquidator The address repaying the borrow and seizing collateral
   * @param cTokenCollateral The market in which to seize collateral from the borrower
   * @param repayAmount The amount of the underlying borrowed asset to repay
   */
  function liquidateBorrowFresh(
    address liquidator,
    address borrower,
    uint256 repayAmount,
    CTokenInterface cTokenCollateral
  ) internal {
    /* Fail if liquidate not allowed */
    uint256 allowed = comptroller.liquidateBorrowAllowed(address(this), address(cTokenCollateral), liquidator, borrower, repayAmount);
    if (allowed != 0) {
      revert LiquidateComptrollerRejection(allowed);
    }

    /* Verify market's block number equals current block number */
    if (accrualBlockNumber != getBlockNumber()) {
      revert LiquidateFreshnessCheck();
    }

    /* Verify cTokenCollateral market's block number equals current block number */
    if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) {
      revert LiquidateCollateralFreshnessCheck();
    }

    /* Fail if borrower = liquidator */
    if (borrower == liquidator) {
      revert LiquidateLiquidatorIsBorrower();
    }

    /* Fail if repayAmount = 0 */
    if (repayAmount == 0) {
      revert LiquidateCloseAmountIsZero();
    }

    /* Fail if repayAmount = -1 */
    if (repayAmount == type(uint256).max) {
      revert LiquidateCloseAmountIsUintMax();
    }

    /* Fail if repayBorrow fails */
    uint256 actualRepayAmount = repayBorrowFresh(liquidator, borrower, repayAmount);

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

    /* We calculate the number of collateral tokens that will be seized */
    (uint256 amountSeizeError, uint256 seizeTokens) = comptroller.liquidateCalculateSeizeTokens(address(this), address(cTokenCollateral), actualRepayAmount);
    require(amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED");

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

    // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call
    if (address(cTokenCollateral) == address(this)) {
      seizeInternal(address(this), liquidator, borrower, seizeTokens);
    } else {
      require(cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed");
    }

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

  /**
   * @notice Transfers collateral tokens (this market) to the liquidator.
   * @dev Will fail unless called by another cToken during the process of liquidation.
   *  Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter.
   * @param liquidator The account receiving seized collateral
   * @param borrower The account having collateral seized
   * @param seizeTokens The number of cTokens to seize
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function seize(
    address liquidator,
    address borrower,
    uint256 seizeTokens
  ) external override nonReentrant returns (uint256) {
    seizeInternal(msg.sender, liquidator, borrower, seizeTokens);

    return NO_ERROR;
  }

  /**
   * @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 CToken.
   *  Its absolutely critical to use msg.sender as the seizer cToken and not a parameter.
   * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken)
   * @param liquidator The account receiving seized collateral
   * @param borrower The account having collateral seized
   * @param seizeTokens The number of cTokens to seize
   */
  function seizeInternal(
    address seizerToken,
    address liquidator,
    address borrower,
    uint256 seizeTokens
  ) internal {
    /* Fail if seize not allowed */
    uint256 allowed = comptroller.seizeAllowed(address(this), seizerToken, liquidator, borrower, seizeTokens);
    if (allowed != 0) {
      revert LiquidateSeizeComptrollerRejection(allowed);
    }

    /* Fail if borrower = liquidator */
    if (borrower == liquidator) {
      revert LiquidateSeizeLiquidatorIsBorrower();
    }

    /*
     * We calculate the new borrower and liquidator token balances, failing on underflow/overflow:
     *  borrowerTokensNew = accountTokens[borrower] - seizeTokens
     *  liquidatorTokensNew = accountTokens[liquidator] + seizeTokens
     */
    uint256 protocolSeizeTokens = mul_(seizeTokens, Exp({ mantissa: protocolSeizeShareMantissa }));
    uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens;
    Exp memory exchangeRate = Exp({ mantissa: exchangeRateStoredInternal() });
    uint256 protocolSeizeAmount = mul_ScalarTruncate(exchangeRate, protocolSeizeTokens);
    uint256 totalReservesNew = totalReserves + protocolSeizeAmount;

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

    /* We write the calculated values into storage */
    totalReserves = totalReservesNew;
    totalSupply = totalSupply - protocolSeizeTokens;
    accountTokens[borrower] = accountTokens[borrower] - seizeTokens;
    accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens;

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

  /*** 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 (uint256) {
    // Check caller = admin
    if (msg.sender != admin) {
      revert SetPendingAdminOwnerCheck();
    }

    // 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 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 (uint256) {
    // Check caller is pendingAdmin and pendingAdmin ≠ address(0)
    if (msg.sender != pendingAdmin || msg.sender == address(0)) {
      revert AcceptAdminPendingAdminCheck();
    }

    // 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 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 (uint256) {
    // Check caller is admin
    if (msg.sender != admin) {
      revert SetComptrollerOwnerCheck();
    }

    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 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(uint256 newReserveFactorMantissa) external override nonReentrant returns (uint256) {
    accrueInterest();
    // _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(uint256 newReserveFactorMantissa) internal returns (uint256) {
    // Check caller is admin
    if (msg.sender != admin) {
      revert SetReserveFactorAdminCheck();
    }

    // Verify market's block number equals current block number
    if (accrualBlockNumber != getBlockNumber()) {
      revert SetReserveFactorFreshCheck();
    }

    // Check newReserveFactor ≤ maxReserveFactor
    if (newReserveFactorMantissa > reserveFactorMaxMantissa) {
      revert SetReserveFactorBoundsCheck();
    }

    uint256 oldReserveFactorMantissa = reserveFactorMantissa;
    reserveFactorMantissa = newReserveFactorMantissa;

    emit NewReserveFactor(oldReserveFactorMantissa, newReserveFactorMantissa);

    return 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(uint256 addAmount) internal nonReentrant returns (uint256) {
    accrueInterest();

    // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to.
    _addReservesFresh(addAmount);
    return NO_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(uint256 addAmount) internal returns (uint256, uint256) {
    // totalReserves + actualAddAmount
    uint256 totalReservesNew;
    uint256 actualAddAmount;

    // We fail gracefully unless market's block number equals current block number
    if (accrualBlockNumber != getBlockNumber()) {
      revert AddReservesFactorFreshCheck(actualAddAmount);
    }

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

    /*
     * We call doTransferIn for the caller and the addAmount
     *  Note: The cToken must handle variations between ERC-20 and ETH underlying.
     *  On success, the cToken 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;

    // 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 (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(uint256 reduceAmount) external override nonReentrant returns (uint256) {
    accrueInterest();
    // _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(uint256 reduceAmount) internal returns (uint256) {
    // totalReserves - reduceAmount
    uint256 totalReservesNew;

    // Check caller is admin
    if (msg.sender != admin) {
      revert ReduceReservesAdminCheck();
    }

    // We fail gracefully unless market's block number equals current block number
    if (accrualBlockNumber != getBlockNumber()) {
      revert ReduceReservesFreshCheck();
    }

    // Fail gracefully if protocol has insufficient underlying cash
    if (getCashPrior() < reduceAmount) {
      revert ReduceReservesCashNotAvailable();
    }

    // Check reduceAmount ≤ reserves[n] (totalReserves)
    if (reduceAmount > totalReserves) {
      revert ReduceReservesCashValidation();
    }

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

    totalReservesNew = totalReserves - reduceAmount;

    // 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 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 (uint256) {
    accrueInterest();
    // _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 (uint256) {
    // 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) {
      revert SetInterestRateModelOwnerCheck();
    }

    // We fail gracefully unless market's block number equals current block number
    if (accrualBlockNumber != getBlockNumber()) {
      revert SetInterestRateModelFreshCheck();
    }

    // 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 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 (uint256);

  /**
   * @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, uint256 amount) internal virtual returns (uint256);

  /**
   * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather 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, uint256 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
  }
}

// File: contracts/PriceOracle.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./CToken.sol";

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

  /**
   * @notice Get the underlying price of a cToken asset
   * @param cToken The cToken to get the underlying price of
   * @return The underlying asset price mantissa (scaled by 1e18).
   *  Zero means the price is unavailable.
   */
  function getUnderlyingPrice(CToken cToken) external view virtual returns (uint256);
}

// File: contracts/ComptrollerInterface.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

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 cTokens) virtual external returns (uint[] memory);
    function exitMarket(address cToken) virtual external returns (uint);

    /*** Policy Hooks ***/

    function mintAllowed(address cToken, address minter, uint mintAmount) virtual external returns (uint);
    function mintVerify(address cToken, address minter, uint mintAmount, uint mintTokens) virtual external;

    function redeemAllowed(address cToken, address redeemer, uint redeemTokens) virtual external returns (uint);
    function redeemVerify(address cToken, address redeemer, uint redeemAmount, uint redeemTokens) virtual external;

    function whitelistBorrowerAdd(address borrower) virtual external returns (uint);
    function setBorrowerLimits(address borrower, uint256 _borrowLimit) virtual external returns (uint);
    function getBorrowerLimits(address borrower) virtual external returns (uint);


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

    function repayBorrowAllowed(
        address cToken,
        address payer,
        address borrower,
        uint repayAmount) virtual external returns (uint);
    function repayBorrowVerify(
        address cToken,
        address payer,
        address borrower,
        uint repayAmount,
        uint borrowerIndex) virtual external;

    function liquidateBorrowAllowed(
        address cTokenBorrowed,
        address cTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount) virtual external returns (uint);
    function liquidateBorrowVerify(
        address cTokenBorrowed,
        address cTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount,
        uint seizeTokens) virtual external;

    function seizeAllowed(
        address cTokenCollateral,
        address cTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens) virtual external returns (uint);
    function seizeVerify(
        address cTokenCollateral,
        address cTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens) virtual external;

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

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

    function liquidateCalculateSeizeTokens(
        address cTokenBorrowed,
        address cTokenCollateral,
        uint repayAmount) virtual external view returns (uint, uint);
}

// File: contracts/CTokenInterfaces.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./ComptrollerInterface.sol";
import "./InterestRateModel.sol";
import "./EIP20NonStandardInterface.sol";
import "./ErrorReporter.sol";

contract CTokenStorage {
  /**
   * @dev Guard variable for re-entrancy checks
   */
  bool internal _notEntered;

  /**
   * @notice EIP-20 token name for this token
   */
  string public name;

  /**
   * @notice EIP-20 token symbol for this token
   */
  string public symbol;

  /**
   * @notice EIP-20 token decimals for this token
   */
  uint8 public decimals;

  // Maximum borrow rate that can ever be applied (.0005% / block)
  uint256 internal constant borrowRateMaxMantissa = 0.0005e16;

  // Maximum fraction of interest that can be set aside for reserves
  uint256 internal constant reserveFactorMaxMantissa = 1e18;

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

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

  /**
   * @notice Contract which oversees inter-cToken operations
   */
  ComptrollerInterface public comptroller;

  /**
   * @notice Model which tells what the current interest rate should be
   */
  InterestRateModel public interestRateModel;

  // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0)
  uint256 internal initialExchangeRateMantissa;

  /**
   * @notice Fraction of interest currently set aside for reserves
   */
  uint256 public reserveFactorMantissa;

  /**
   * @notice Block number that interest was last accrued at
   */
  uint256 public accrualBlockNumber;

  /**
   * @notice Accumulator of the total earned interest rate since the opening of the market
   */
  uint256 public borrowIndex;

  /**
   * @notice Total amount of outstanding borrows of the underlying in this market
   */
  uint256 public totalBorrows;

  /**
   * @notice Total amount of reserves of the underlying held in this market
   */
  uint256 public totalReserves;

  /**
   * @notice Total number of tokens in circulation
   */
  uint256 public totalSupply;

  // Official record of token balances for each account
  mapping(address => uint256) internal accountTokens;

  // Approved token transfer amounts on behalf of others
  mapping(address => mapping(address => uint256)) internal transferAllowances;

  /**
   * @notice Container for borrow balance information
   * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action
   * @member interestIndex Global borrowIndex as of the most recent balance-changing action
   */
  struct BorrowSnapshot {
    uint256 principal;
    uint256 interestIndex;
  }

  // Mapping of account addresses to outstanding borrow balances
  mapping(address => BorrowSnapshot) internal accountBorrows;

  /**
   * @notice Share of seized collateral that is added to reserves
   */
  uint256 public constant protocolSeizeShareMantissa = 2.8e16; //2.8%
}

abstract contract CTokenInterface is CTokenStorage {
  /**
   * @notice Indicator that this is a CToken contract (for inspection)
   */
  bool public constant isCToken = true;

  /*** Market Events ***/

  /**
   * @notice Event emitted when interest is accrued
   */
  event AccrueInterest(uint256 cashPrior, uint256 interestAccumulated, uint256 borrowIndex, uint256 totalBorrows);

  /**
   * @notice Event emitted when tokens are minted
   */
  event Mint(address minter, uint256 mintAmount, uint256 mintTokens);

  /**
   * @notice Event emitted when tokens are redeemed
   */
  event Redeem(address redeemer, uint256 redeemAmount, uint256 redeemTokens);

  /**
   * @notice Event emitted when underlying is borrowed
   */
  event Borrow(address borrower, uint256 borrowAmount, uint256 accountBorrows, uint256 totalBorrows);

  /**
   * @notice Event emitted when a borrow is repaid
   */
  event RepayBorrow(address payer, address borrower, uint256 repayAmount, uint256 accountBorrows, uint256 totalBorrows);

  /**
   * @notice Event emitted when a borrow is liquidated
   */
  event LiquidateBorrow(address liquidator, address borrower, uint256 repayAmount, address cTokenCollateral, uint256 seizeTokens);

  /*** Admin Events ***/

  /**
   * @notice Event emitted when pendingAdmin is changed
   */
  event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);

  /**
   * @notice Event emitted when pendingAdmin is accepted, which means admin is updated
   */
  event NewAdmin(address oldAdmin, address newAdmin);

  /**
   * @notice Event emitted when comptroller is changed
   */
  event NewComptroller(ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller);

  /**
   * @notice Event emitted when interestRateModel is changed
   */
  event NewMarketInterestRateModel(InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel);

  /**
   * @notice Event emitted when the reserve factor is changed
   */
  event NewReserveFactor(uint256 oldReserveFactorMantissa, uint256 newReserveFactorMantissa);

  /**
   * @notice Event emitted when the reserves are added
   */
  event ReservesAdded(address benefactor, uint256 addAmount, uint256 newTotalReserves);

  /**
   * @notice Event emitted when the reserves are reduced
   */
  event ReservesReduced(address admin, uint256 reduceAmount, uint256 newTotalReserves);

  /**
   * @notice EIP20 Transfer event
   */
  event Transfer(address indexed from, address indexed to, uint256 amount);

  /**
   * @notice EIP20 Approval event
   */
  event Approval(address indexed owner, address indexed spender, uint256 amount);

  /*** User Interface ***/

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

  function transferFrom(
    address src,
    address dst,
    uint256 amount
  ) external virtual returns (bool);

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

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

  function balanceOf(address owner) external view virtual returns (uint256);

  function balanceOfUnderlying(address owner) external virtual returns (uint256);

  function getAccountSnapshot(address account)
    external
    view
    virtual
    returns (
      uint256,
      uint256,
      uint256,
      uint256
    );

  function borrowRatePerBlock() external view virtual returns (uint256);

  function supplyRatePerBlock() external view virtual returns (uint256);

  function totalBorrowsCurrent() external virtual returns (uint256);

  function borrowBalanceCurrent(address account) external virtual returns (uint256);

  function borrowBalanceStored(address account) external view virtual returns (uint256);

  function exchangeRateCurrent() external virtual returns (uint256);

  function exchangeRateStored() external view virtual returns (uint256);

  function getCash() external view virtual returns (uint256);

  function accrueInterest() external virtual returns (uint256);

  function seize(
    address liquidator,
    address borrower,
    uint256 seizeTokens
  ) external virtual returns (uint256);

  /*** Admin Functions ***/

  function _setPendingAdmin(address payable newPendingAdmin) external virtual returns (uint256);

  function _acceptAdmin() external virtual returns (uint256);

  function _setComptroller(ComptrollerInterface newComptroller) external virtual returns (uint256);

  function _setReserveFactor(uint256 newReserveFactorMantissa) external virtual returns (uint256);

  function _reduceReserves(uint256 reduceAmount) external virtual returns (uint256);

  function _setInterestRateModel(InterestRateModel newInterestRateModel) external virtual returns (uint256);
}

contract CErc20Storage {
  /**
   * @notice Underlying asset for this CToken
   */
  address public underlying;
}

abstract contract CErc20Interface is CErc20Storage {
  /*** User Interface ***/

  function mint(uint256 mintAmount) external virtual returns (uint256);

  function redeem(uint256 redeemTokens) external virtual returns (uint256);

  function redeemUnderlying(uint256 redeemAmount) external virtual returns (uint256);

  function borrow(uint256 borrowAmount) external virtual returns (uint256);

  function repayBorrow(uint256 repayAmount) external virtual returns (uint256);

  function repayBorrowBehalf(address borrower, uint256 repayAmount) external virtual returns (uint256);

  function liquidateBorrow(
    address borrower,
    uint256 repayAmount,
    CTokenInterface cTokenCollateral
  ) external virtual returns (uint256);

  function sweepToken(EIP20NonStandardInterface token) external virtual;

  /*** Admin Functions ***/

  function _addReserves(uint256 addAmount) external virtual returns (uint256);
}

contract CDelegationStorage {
  /**
   * @notice Implementation address for this contract
   */
  address public implementation;
}

abstract contract CDelegatorInterface is CDelegationStorage {
  /**
   * @notice Emitted when implementation is changed
   */
  event NewImplementation(address oldImplementation, address newImplementation);

  /**
   * @notice Called by the admin to update the implementation of the delegator
   * @param implementation_ The address of the new implementation for delegation
   * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation
   * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation
   */
  function _setImplementation(
    address implementation_,
    bool allowResign,
    bytes memory becomeImplementationData
  ) external virtual;
}

abstract contract CDelegateInterface is CDelegationStorage {
  /**
   * @notice Called by the delegator on a delegate to initialize it for duty
   * @dev Should revert if any issues arise which make it unfit for delegation
   * @param data The encoded bytes data for any initialization
   */
  function _becomeImplementation(bytes memory data) external virtual;

  /**
   * @notice Called by the delegator on a delegate to forfeit its responsibility
   */
  function _resignImplementation() external virtual;
}

// File: contracts/EIP20Interface.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @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);
}

// File: contracts/InterestRateModel.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @title Compound's InterestRateModel Interface
 * @author Compound
 */
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 block
   * @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 block (as a percentage, and scaled by 1e18)
   */
  function getBorrowRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves
  ) external view virtual returns (uint256);

  /**
   * @notice Calculates the current supply interest rate per block
   * @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 block (as a percentage, and scaled by 1e18)
   */
  function getSupplyRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves,
    uint256 reserveFactorMantissa
  ) external view virtual returns (uint256);
}

// File: contracts/ExponentialNoError.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @title Exponential module for storing fixed-precision decimals
 * @author Compound
 * @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 {
  uint256 constant expScale = 1e18;
  uint256 constant doubleScale = 1e36;
  uint256 constant halfExpScale = expScale / 2;
  uint256 constant mantissaOne = expScale;

  struct Exp {
    uint256 mantissa;
  }

  struct Double {
    uint256 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 (uint256) {
    // 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, uint256 scalar) internal pure returns (uint256) {
    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,
    uint256 scalar,
    uint256 addend
  ) internal pure returns (uint256) {
    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(uint256 n, string memory errorMessage) internal pure returns (uint224) {
    require(n < 2**224, errorMessage);
    return uint224(n);
  }

  function safe32(uint256 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_(uint256 a, uint256 b) internal pure returns (uint256) {
    return a + b;
  }

  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_(uint256 a, uint256 b) internal pure returns (uint256) {
    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, uint256 b) internal pure returns (Exp memory) {
    return Exp({ mantissa: mul_(a.mantissa, b) });
  }

  function mul_(uint256 a, Exp memory b) internal pure returns (uint256) {
    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, uint256 b) internal pure returns (Double memory) {
    return Double({ mantissa: mul_(a.mantissa, b) });
  }

  function mul_(uint256 a, Double memory b) internal pure returns (uint256) {
    return mul_(a, b.mantissa) / doubleScale;
  }

  function mul_(uint256 a, uint256 b) internal pure returns (uint256) {
    return a * b;
  }

  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, uint256 b) internal pure returns (Exp memory) {
    return Exp({ mantissa: div_(a.mantissa, b) });
  }

  function div_(uint256 a, Exp memory b) internal pure returns (uint256) {
    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, uint256 b) internal pure returns (Double memory) {
    return Double({ mantissa: div_(a.mantissa, b) });
  }

  function div_(uint256 a, Double memory b) internal pure returns (uint256) {
    return div_(mul_(a, doubleScale), b.mantissa);
  }

  function div_(uint256 a, uint256 b) internal pure returns (uint256) {
    return a / b;
  }

  function fraction(uint256 a, uint256 b) internal pure returns (Double memory) {
    return Double({ mantissa: div_(mul_(a, doubleScale), b) });
  }
}

// File: contracts/EIP20NonStandardInterface.sol



// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @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);
}