Contract Source Code:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/security/ReentrancyGuard.sol";
import "openzeppelin-contracts/contracts/token/ERC20/IERC20.sol";
import "openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
import "openzeppelin-contracts-upgradeable/contracts/access/Ownable2StepUpgradeable.sol";
import "openzeppelin-contracts-upgradeable/contracts/proxy/utils/Initializable.sol";
import "openzeppelin-contracts-upgradeable/contracts/proxy/utils/UUPSUpgradeable.sol";
import "./ApeFinanceStorage.sol";
import "../../interfaces/IApeFinance.sol";
import "../../interfaces/IAToken.sol";
import "../../interfaces/IDeferLiquidityCheck.sol";
import "../../interfaces/IInterestRateModel.sol";
import "../../interfaces/IPriceOracle.sol";
import "../../interfaces/IPToken.sol";
import "../../libraries/Arrays.sol";
import "../../libraries/DataTypes.sol";
import "../../libraries/PauseFlags.sol";
import "../../libraries/SubAccounts.sol";

contract ApeFinance is
    Initializable,
    UUPSUpgradeable,
    Ownable2StepUpgradeable,
    ReentrancyGuard,
    ApeFinanceStorage,
    IApeFinance
{
    using SafeERC20 for IERC20;
    using Arrays for address[];
    using PauseFlags for DataTypes.MarketConfig;
    using SubAccounts for address;

    /**
     * @notice Initialize the contract.
     * @param _admin The address of the admin
     */
    function initialize(address _admin) public initializer {
        __Ownable_init();
        __UUPSUpgradeable_init();

        transferOwnership(_admin);
    }

    /**
     * @notice Check if the caller is the market configurator.
     */
    modifier onlyMarketConfigurator() {
        _checkMarketConfigurator();
        _;
    }

    /**
     * @notice Check if the caller is the reserve manager.
     */
    modifier onlyReserveManager() {
        _checkReserveManager();
        _;
    }

    /**
     * @notice Check if the caller is the credit limit manager.
     */
    modifier onlyCreditLimitManager() {
        require(msg.sender == creditLimitManager, "!manager");
        _;
    }

    /**
     * @notice Check if the user has authorized the caller.
     */
    modifier isAuthorized(address from) {
        _checkAuthorized(from, msg.sender);
        _;
    }

    /* ========== VIEW FUNCTIONS ========== */

    /**
     * @notice Get all markets.
     * @return The list of all markets
     */
    function getAllMarkets() public view returns (address[] memory) {
        return allMarkets;
    }

    /**
     * @notice Whether or not a market is listed.
     * @param market The address of the market to check
     * @return true if the market is listed, false otherwise
     */
    function isMarketListed(address market) public view returns (bool) {
        DataTypes.Market storage m = markets[market];
        return m.config.isListed;
    }

    /**
     * @notice Get the exchange rate of a market.
     * @param market The address of the market
     * @return The exchange rate
     */
    function getExchangeRate(address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return _getExchangeRate(m);
    }

    /**
     * @notice Get the total supply of a market.
     * @param market The address of the market
     * @return The total supply
     */
    function getTotalSupply(address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return m.totalSupply;
    }

    /**
     * @notice Get the total borrow of a market.
     * @param market The address of the market
     * @return The total borrow
     */
    function getTotalBorrow(address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return m.totalBorrow;
    }

    /**
     * @notice Get the total cash of a market.
     * @param market The address of the market
     * @return The total cash
     */
    function getTotalCash(address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return m.totalCash;
    }

    /**
     * @notice Get the total reserves of a market.
     * @param market The address of the market
     * @return The total reserves
     */
    function getTotalReserves(address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return m.totalReserves;
    }

    /**
     * @notice Get the borrow balance of a user in a market.
     * @param user The address of the user
     * @param market The address of the market
     * @return The borrow balance
     */
    function getBorrowBalance(address user, address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return _getBorrowBalance(m, user);
    }

    /**
     * @notice Get the AToken balance of a user in a market.
     * @param user The address of the user
     * @param market The address of the market
     * @return The AToken balance
     */
    function getATokenBalance(address user, address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return m.userSupplies[user];
    }

    /**
     * @notice Get the supply balance of a user in a market.
     * @param user The address of the user
     * @param market The address of the market
     * @return The supply balance
     */
    function getSupplyBalance(address user, address market) public view returns (uint256) {
        DataTypes.Market storage m = markets[market];
        return (m.userSupplies[user] * _getExchangeRate(m)) / 1e18;
    }

    /**
     * @notice Get the account liquidity of a user.
     * @param user The address of the user
     * @return The total collateral value, liquidation collateral value, and total debt value of the user
     */
    function getAccountLiquidity(address user) public view returns (uint256, uint256, uint256) {
        return _getAccountLiquidity(user);
    }

    /**
     * @notice Get the user's allowed extensions.
     * @param user The address of the user
     * @return The list of allowed extensions
     */
    function getUserAllowedExtensions(address user) public view returns (address[] memory) {
        return allAllowedExtensions[user];
    }

    /**
     * @notice Whether or not a user has allowed an extension.
     * @param user The address of the user
     * @param extension The address of the extension
     * @return true if the user has allowed the extension, false otherwise
     */
    function isAllowedExtension(address user, address extension) public view returns (bool) {
        return allowedExtensions[user][extension];
    }

    /**
     * @notice Get the credit limit of a user in a market.
     * @param user The address of the user
     * @param market The address of the market
     * @return The credit limit
     */
    function getCreditLimit(address user, address market) public view returns (uint256) {
        return creditLimits[user][market];
    }

    /**
     * @notice Get the list of all credit markets for a user.
     * @param user The address of the user
     * @return The list of all credit markets
     */
    function getUserCreditMarkets(address user) public view returns (address[] memory) {
        return allCreditMarkets[user];
    }

    /**
     * @notice Whether or not an account is a credit account.
     * @param user The address of the user
     * @return true if the account is a credit account, false otherwise
     */
    function isCreditAccount(address user) public view returns (bool) {
        return allCreditMarkets[user].length > 0;
    }

    /**
     * @notice Get the configuration of a market.
     * @param market The address of the market
     * @return The market configuration
     */
    function getMarketConfiguration(address market) public view returns (DataTypes.MarketConfig memory) {
        return markets[market].config;
    }

    /**
     * @notice Check if an account is liquidatable.
     * @param user The address of the account to check
     * @return true if the account is liquidatable, false otherwise
     */
    function isUserLiquidatable(address user) public view returns (bool) {
        return _isLiquidatable(user);
    }

    /**
     * @notice Calculate the amount of aToken that can be seized in a liquidation.
     * @param marketBorrow The address of the market being borrowed from
     * @param marketCollateral The address of the market being used as collateral
     * @param repayAmount The amount of the borrowed asset being repaid
     * @return The amount of aToken that can be seized
     */
    function calculateLiquidationOpportunity(address marketBorrow, address marketCollateral, uint256 repayAmount)
        public
        view
        returns (uint256)
    {
        DataTypes.Market storage mCollateral = markets[marketCollateral];
        DataTypes.Market storage mBorrow = markets[marketCollateral];

        return _getLiquidationSeizeAmount(marketBorrow, marketCollateral, mBorrow, mCollateral, repayAmount);
    }

    /* ========== MUTATIVE FUNCTIONS ========== */

    /**
     * @notice Accrue the interest of a market.
     * @param market The address of the market
     */
    function accrueInterest(address market) external {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");

        _accrueInterest(market, m);
    }

    /**
     * @notice Check the account liquidity of a user.
     * @param user The address of the user
     */
    function checkAccountLiquidity(address user) public {
        _checkAccountLiquidity(user);
    }

    /**
     * @notice Supply an amount of asset to ApeFinance.
     * @param from The address which will supply the asset
     * @param to The address which will hold the balance
     * @param market The address of the market
     * @param amount The amount of asset to supply
     */
    function supply(address from, address to, address market, uint256 amount)
        external
        nonReentrant
        isAuthorized(from)
    {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");
        require(!m.config.isSupplyPaused(), "supply paused");
        require(!isCreditAccount(to), "cannot supply to credit account");

        _accrueInterest(market, m);

        if (m.config.supplyCap != 0) {
            uint256 totalSupplyUnderlying = m.totalSupply * _getExchangeRate(m) / 1e18;
            require(totalSupplyUnderlying + amount <= m.config.supplyCap, "supply cap reached");
        }

        uint256 aTokenAmount = (amount * 1e18) / _getExchangeRate(m);
        require(aTokenAmount > 0, "zero aToken amount");

        // Update storage.
        m.totalCash += amount;
        m.totalSupply += aTokenAmount;
        m.userSupplies[to] += aTokenAmount;

        // Enter the market.
        if (amount > 0) {
            _enterMarket(market, to);
        }

        IAToken(m.config.aTokenAddress).mint(to, aTokenAmount); // Only emits Transfer event.
        IERC20(market).safeTransferFrom(from, address(this), amount);

        emit Supply(market, from, to, amount, aTokenAmount);
    }

    /**
     * @notice Borrow an amount of asset from ApeFinance.
     * @param from The address which will borrow the asset
     * @param to The address which will receive the token
     * @param market The address of the market
     * @param amount The amount of asset to borrow
     */
    function borrow(address from, address to, address market, uint256 amount)
        external
        nonReentrant
        isAuthorized(from)
    {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");
        require(!m.config.isBorrowPaused(), "borrow paused");
        require(m.totalCash >= amount, "insufficient cash");

        _accrueInterest(market, m);

        uint256 newTotalBorrow = m.totalBorrow + amount;
        uint256 newUserBorrowBalance = _getBorrowBalance(m, from) + amount;

        if (m.config.borrowCap != 0) {
            require(newTotalBorrow <= m.config.borrowCap, "borrow cap reached");
        }

        // Update storage.
        m.totalCash -= amount;
        m.totalBorrow = newTotalBorrow;
        m.userBorrows[from].borrowBalance = newUserBorrowBalance;
        m.userBorrows[from].borrowIndex = m.borrowIndex;

        // Enter the market.
        if (amount > 0) {
            _enterMarket(market, from);
        }

        IERC20(market).safeTransfer(to, amount);

        if (isCreditAccount(from)) {
            require(from == to, "credit account can only borrow to itself");
            require(creditLimits[from][market] >= newUserBorrowBalance, "insufficient credit limit");
        } else {
            _checkAccountLiquidity(from);
        }

        emit Borrow(market, from, to, amount, newUserBorrowBalance, newTotalBorrow);
    }

    /**
     * @notice Redeem an amount of asset from ApeFinance.
     * @param from The address which will redeem the asset
     * @param to The address which will receive the token
     * @param market The address of the market
     * @param amount The amount of asset to redeem, or type(uint256).max for max
     * @return The actual amount of asset redeemed
     */
    function redeem(address from, address to, address market, uint256 amount)
        external
        nonReentrant
        isAuthorized(from)
        returns (uint256)
    {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");

        _accrueInterest(market, m);

        uint256 userSupply = m.userSupplies[from];
        uint256 totalCash = m.totalCash;

        uint256 aTokenAmount;
        if (amount == type(uint256).max) {
            aTokenAmount = userSupply;
            amount = (aTokenAmount * _getExchangeRate(m)) / 1e18;
        } else {
            aTokenAmount = (amount * 1e18) / _getExchangeRate(m);
        }

        require(aTokenAmount > 0, "zero aToken amount");
        require(userSupply >= aTokenAmount, "insufficient balance");
        require(totalCash >= amount, "insufficient cash");

        uint256 newUserSupply = userSupply - aTokenAmount;

        // Update storage.
        m.userSupplies[from] = newUserSupply;
        m.totalCash = totalCash - amount;
        m.totalSupply -= aTokenAmount;

        // Check if need to exit the market.
        if (newUserSupply == 0 && _getBorrowBalance(m, from) == 0) {
            _exitMarket(market, from);
        }

        IAToken(m.config.aTokenAddress).burn(from, aTokenAmount); // Only emits Transfer event.
        IERC20(market).safeTransfer(to, amount);

        _checkAccountLiquidity(from);

        emit Redeem(market, from, to, amount, aTokenAmount);

        return amount;
    }

    /**
     * @notice Repay an amount of asset to ApeFinance.
     * @param from The address which will repay the asset
     * @param to The address which will hold the balance
     * @param market The address of the market
     * @param amount The amount of asset to repay, or type(uint256).max for max
     * @return The actual amount of asset repaid
     */
    function repay(address from, address to, address market, uint256 amount)
        external
        nonReentrant
        isAuthorized(from)
        returns (uint256)
    {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");
        if (isCreditAccount(to)) {
            require(from == to, "credit account can only repay for itself");
        }

        _accrueInterest(market, m);

        return _repay(m, from, to, market, amount);
    }

    /**
     * @notice Liquidate an undercollateralized borrower.
     * @param liquidator The address which will liquidate the borrower
     * @param borrower The address of the borrower
     * @param marketBorrow The address of the borrow market
     * @param marketCollateral The address of the collateral market
     * @param repayAmount The amount of asset to repay, or type(uint256).max for max
     * @return The actual amount of asset repaid and the amount of collateral seized
     */
    function liquidate(
        address liquidator,
        address borrower,
        address marketBorrow,
        address marketCollateral,
        uint256 repayAmount
    ) external nonReentrant isAuthorized(liquidator) returns (uint256, uint256) {
        DataTypes.Market storage mBorrow = markets[marketBorrow];
        DataTypes.Market storage mCollateral = markets[marketCollateral];
        require(mBorrow.config.isListed, "borrow market not listed");
        require(mCollateral.config.isListed, "collateral market not listed");
        require(_isMarketSeizable(mCollateral), "collateral market cannot be seized");
        require(!isCreditAccount(liquidator) && !isCreditAccount(borrower), "cannot liquidate credit account");
        require(liquidator != borrower, "cannot self liquidate");

        _accrueInterest(marketBorrow, mBorrow);
        _accrueInterest(marketCollateral, mCollateral);

        // Check if the borrower is actually liquidatable.
        require(_isLiquidatable(borrower), "borrower not liquidatable");

        // Repay the debt.
        repayAmount = _repay(mBorrow, liquidator, borrower, marketBorrow, repayAmount);

        // Seize the collateral.
        uint256 aTokenAmount =
            _getLiquidationSeizeAmount(marketBorrow, marketCollateral, mBorrow, mCollateral, repayAmount);
        _transferAToken(marketCollateral, mCollateral, borrower, liquidator, aTokenAmount);
        IAToken(mCollateral.config.aTokenAddress).seize(borrower, liquidator, aTokenAmount); // Only emits Transfer event.

        emit Liquidate(liquidator, borrower, marketBorrow, marketCollateral, repayAmount, aTokenAmount);

        return (repayAmount, aTokenAmount);
    }

    /**
     * @notice Defer the liquidity check to a user.
     * @dev The message sender must implement the IDeferLiquidityCheck.
     * @param user The address of the user
     * @param data The data to pass to the callback
     */
    function deferLiquidityCheck(address user, bytes memory data) external isAuthorized(user) {
        require(!isCreditAccount(user), "credit account cannot defer liquidity check");
        require(liquidityCheckStatus[user] == LIQUIDITY_CHECK_NORMAL, "reentry defer liquidity check");
        liquidityCheckStatus[user] = LIQUIDITY_CHECK_DEFERRED;

        IDeferLiquidityCheck(msg.sender).onDeferredLiquidityCheck(data);

        uint8 status = liquidityCheckStatus[user];
        liquidityCheckStatus[user] = LIQUIDITY_CHECK_NORMAL;

        if (status == LIQUIDITY_CHECK_DIRTY) {
            _checkAccountLiquidity(user);
        }
    }

    /**
     * @notice User enables or disables an extension.
     * @param extension The address of the extension
     * @param allowed Whether to allow or disallow the extension
     */
    function setUserExtension(address extension, bool allowed) external {
        _setAccountExtension(msg.sender, extension, allowed);
    }

    /**
     * @notice Set the extension for a sub account.
     * @param primary The address of the primary account
     * @param subAccountId The ID of the sub account
     * @param allowed Whether to allow or disallow the extension
     */
    function setSubAccountExtension(address primary, uint256 subAccountId, bool allowed)
        external
        isAuthorized(primary)
    {
        address account = primary.getSubAccount(subAccountId);

        _setAccountExtension(account, msg.sender, allowed);
    }

    /**
     * @notice Transfer AToken from one account to another.
     * @dev This function is callable by the AToken contract only.
     * @param market The address of the market
     * @param from The address to transfer from
     * @param to The address to transfer to
     * @param amount The amount to transfer
     */
    function transferAToken(address market, address from, address to, uint256 amount) external {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");
        require(msg.sender == m.config.aTokenAddress, "!authorized");
        require(!m.config.isTransferPaused(), "transfer paused");
        require(from != to, "cannot self transfer");
        require(!isCreditAccount(to), "cannot transfer to credit account");

        _accrueInterest(market, m);
        _transferAToken(market, m, from, to, amount);

        _checkAccountLiquidity(from);
    }

    /* ========== RESTRICTED FUNCTIONS ========== */

    /**
     * @notice List a market.
     * @dev This function is callable by the market configurator only.
     * @param market The address of the market
     * @param config The market configuration
     */
    function listMarket(address market, DataTypes.MarketConfig calldata config) external onlyMarketConfigurator {
        DataTypes.Market storage m = markets[market];
        m.lastUpdateTimestamp = _getNow();
        m.borrowIndex = INITIAL_BORROW_INDEX;
        m.config = config;
        allMarkets.push(market);

        emit MarketListed(market, m.lastUpdateTimestamp, m.config);
    }

    /**
     * @notice Delist a market.
     * @dev This function is callable by the market configurator only.
     * @param market The address of the market
     */
    function delistMarket(address market) external onlyMarketConfigurator {
        DataTypes.Market storage m = markets[market];
        // The nested mapping like userBorrows can't be deleted completely, so we just set `isListed` to false.
        m.config.isListed = false;
        // `isDelisted` is needed to distinguish delisted markets from markets that have never been listed before.
        m.config.isDelisted = true;
        allMarkets.deleteElement(market);

        emit MarketDelisted(market);
    }

    /**
     * @notice Set the market configuration.
     * @dev This function is callable by the market configurator only.
     * @param market The address of the market
     * @param config The market configuration
     */
    function setMarketConfiguration(address market, DataTypes.MarketConfig calldata config)
        external
        onlyMarketConfigurator
    {
        DataTypes.Market storage m = markets[market];
        m.config = config;

        emit MarketConfigurationChanged(market, config);
    }

    /**
     * @notice Set the credit limit for a user in a market.
     * @dev This function is callable by the credit limit manager only.
     * @param user The address of the user
     * @param market The address of the market
     * @param credit The credit limit
     */
    function setCreditLimit(address user, address market, uint256 credit) external onlyCreditLimitManager {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");

        if (credit == 0 && creditLimits[user][market] != 0) {
            allCreditMarkets[user].deleteElement(market);
        } else if (credit != 0 && creditLimits[user][market] == 0) {
            allCreditMarkets[user].push(market);
        }

        creditLimits[user][market] = credit;
        emit CreditLimitChanged(user, market, credit);
    }

    /**
     * @notice Increase reserves by absorbing the surplus cash.
     * @dev This function is callable by the reserve manager only.
     * @param market The address of the market
     */
    function absorbToReserves(address market) external onlyReserveManager {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");

        _accrueInterest(market, m);

        uint256 amount = IERC20(market).balanceOf(address(this)) - m.totalCash;

        if (amount > 0) {
            uint256 aTokenAmount = (amount * 1e18) / _getExchangeRate(m);

            // Update internal cash, and total reserves.
            m.totalCash += amount;
            m.totalReserves += aTokenAmount;

            emit ReservesIncreased(market, aTokenAmount, amount);
        }
    }

    /**
     * @notice Reduce reserves by withdrawing the requested amount.
     * @dev This function is callable by the reserve manager only.
     * @param market The address of the market
     * @param aTokenAmount The amount of aToken to withdraw
     * @param recipient The address which will receive the underlying asset
     */
    function reduceReserves(address market, uint256 aTokenAmount, address recipient) external onlyReserveManager {
        DataTypes.Market storage m = markets[market];
        require(m.config.isListed, "not listed");

        _accrueInterest(market, m);

        uint256 amount = (aTokenAmount * _getExchangeRate(m)) / 1e18;

        require(m.totalCash >= amount, "insufficient cash");
        require(m.totalReserves >= aTokenAmount, "insufficient reserves");

        // Update internal cash, and total reserves.
        unchecked {
            m.totalCash -= amount;
            m.totalReserves -= aTokenAmount;
        }

        IERC20(market).safeTransfer(recipient, amount);

        emit ReservesDecreased(market, recipient, aTokenAmount, amount);
    }

    /**
     * @notice Set the price oracle.
     * @param oracle The address of the price oracle
     */
    function setPriceOracle(address oracle) external onlyOwner {
        priceOracle = oracle;

        emit PriceOracleSet(oracle);
    }

    /**
     * @notice Set the market configurator.
     * @param configurator The address of the market configurator
     */
    function setMarketConfigurator(address configurator) external onlyOwner {
        marketConfigurator = configurator;

        emit MarketConfiguratorSet(configurator);
    }

    /**
     * @notice Set the credit limit manager.
     * @param manager The address of the credit limit manager
     */
    function setCreditLimitManager(address manager) external onlyOwner {
        creditLimitManager = manager;

        emit CreditLimitManagerSet(manager);
    }

    /**
     * @notice Set the reserve manager.
     * @param manager The address of the reserve manager
     */
    function setReserveManager(address manager) external onlyOwner {
        reserveManager = manager;

        emit ReserveManagerSet(manager);
    }

    /**
     * @notice Seize the unlisted token.
     * @param token The address of the token
     * @param recipient The address which will receive the token
     */
    function seize(address token, address recipient) external onlyOwner {
        DataTypes.Market storage m = markets[token];
        require(!m.config.isListed, "cannot seize listed market");

        uint256 balance = IERC20(token).balanceOf(address(this));
        if (balance > 0) {
            IERC20(token).safeTransfer(recipient, balance);

            emit TokenSeized(token, recipient, balance);
        }
    }

    /* ========== INTERNAL FUNCTIONS ========== */

    /**
     * @dev _authorizeUpgrade is used by UUPSUpgradeable to determine if it's allowed to upgrade a proxy implementation.
     * @param newImplementation The new implementation
     *
     * Ref: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/proxy/utils/UUPSUpgradeable.sol
     */
    function _authorizeUpgrade(address newImplementation) internal override onlyOwner {}

    /**
     * @dev Get the current timestamp.
     * @return The current timestamp, casted to uint40
     */
    function _getNow() internal view virtual returns (uint40) {
        require(block.timestamp < 2 ** 40, "timestamp too large");
        return uint40(block.timestamp);
    }

    /**
     * @dev Check if the operator is authorized.
     * @param from The address of the user
     * @param operator The address of the operator
     */
    function _checkAuthorized(address from, address operator) internal view {
        require(from == operator || (!isCreditAccount(from) && isAllowedExtension(from, operator)), "!authorized");
    }

    /**
     * @dev Check if the message sender is the market configurator.
     */
    function _checkMarketConfigurator() internal view {
        require(msg.sender == marketConfigurator, "!configurator");
    }

    /**
     * @dev Check if the message sender is the credit limit manager.
     */
    function _checkReserveManager() internal view {
        require(msg.sender == reserveManager, "!reserveManager");
    }

    /**
     * @dev Get the exchange rate.
     * @param m The storage of the market
     * @return The exchange rate
     */
    function _getExchangeRate(DataTypes.Market storage m) internal view returns (uint256) {
        uint256 totalSupplyPlusReserves = m.totalSupply + m.totalReserves;
        if (totalSupplyPlusReserves == 0) {
            return m.config.initialExchangeRate;
        }
        return ((m.totalCash + m.totalBorrow) * 1e18) / totalSupplyPlusReserves;
    }

    /**
     * @dev Get the amount of aToken that can be seized in a liquidation.
     * @param marketBorrow The address of the market being borrowed from
     * @param marketCollateral The address of the market being used as collateral
     * @param mBorrow The storage of the borrow market
     * @param mCollateral The storage of the collateral market
     * @param repayAmount The amount of the borrowed asset being repaid
     * @return The amount of aToken that can be seized
     */
    function _getLiquidationSeizeAmount(
        address marketBorrow,
        address marketCollateral,
        DataTypes.Market storage mBorrow,
        DataTypes.Market storage mCollateral,
        uint256 repayAmount
    ) internal view returns (uint256) {
        uint256 borrowMarketPrice = _getMarketPrice(mBorrow, marketBorrow);
        uint256 collateralMarketPrice = _getMarketPrice(mCollateral, marketCollateral);

        // collateral amount = repayAmount * liquidationBonus * borrowMarketPrice / collateralMarketPrice
        // AToken amount = collateral amount / exchangeRate
        //   = repayAmount * (liquidationBonus * borrowMarketPrice) / (collateralMarketPrice * exchangeRate)
        uint256 numerator = (mCollateral.config.liquidationBonus * borrowMarketPrice) / FACTOR_SCALE;
        uint256 denominator = (_getExchangeRate(mCollateral) * collateralMarketPrice) / 1e18;

        return (repayAmount * numerator) / denominator;
    }

    /**
     * @dev Get the borrow balance of a user.
     * @param m The storage of the market
     * @param user The address of the user
     * @return The borrow balance
     */
    function _getBorrowBalance(DataTypes.Market storage m, address user) internal view returns (uint256) {
        DataTypes.UserBorrow memory b = m.userBorrows[user];

        if (b.borrowBalance == 0) {
            return 0;
        }

        // borrowBalanceWithInterests = borrowBalance * marketBorrowIndex / userBorrowIndex
        return (b.borrowBalance * m.borrowIndex) / b.borrowIndex;
    }

    /**
     * @dev Transfer AToken from one account to another.
     * @param market The address of the market
     * @param m The storage of the market
     * @param from The address to transfer from
     * @param to The address to transfer to
     * @param amount The amount to transfer
     */
    function _transferAToken(address market, DataTypes.Market storage m, address from, address to, uint256 amount)
        internal
    {
        require(from != address(0), "transfer from the zero address");
        require(to != address(0), "transfer to the zero address");

        uint256 fromBalance = m.userSupplies[from];
        require(amount > 0, "transfer zero amount");
        require(fromBalance >= amount, "transfer amount exceeds balance");

        _enterMarket(market, to);

        unchecked {
            m.userSupplies[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            m.userSupplies[to] += amount;
        }

        if (m.userSupplies[from] == 0 && _getBorrowBalance(m, from) == 0) {
            _exitMarket(market, from);
        }

        emit TransferAToken(market, from, to, amount);
    }

    /**
     * @dev Accrue interest to the current timestamp.
     * @param market The address of the market
     * @param m The storage of the market
     */
    function _accrueInterest(address market, DataTypes.Market storage m) internal {
        uint40 timestamp = _getNow();
        uint256 timeElapsed = uint256(timestamp - m.lastUpdateTimestamp);
        if (timeElapsed > 0) {
            uint256 totalCash = m.totalCash;
            uint256 borrowIndex = m.borrowIndex;
            uint256 totalBorrow = m.totalBorrow;
            uint256 totalSupply = m.totalSupply;
            uint256 totalReserves = m.totalReserves;

            uint256 borrowRatePerSecond =
                IInterestRateModel(m.config.interestRateModelAddress).getBorrowRate(totalCash, totalBorrow);
            uint256 interestFactor = borrowRatePerSecond * timeElapsed;
            uint256 interestIncreased = (interestFactor * totalBorrow) / 1e18;
            uint256 feeIncreased = (interestIncreased * m.config.reserveFactor) / FACTOR_SCALE;

            // Compute reservesIncreased.
            uint256 reservesIncreased = 0;
            if (feeIncreased > 0) {
                reservesIncreased = (feeIncreased * (totalSupply + totalReserves))
                    / (totalCash + totalBorrow + (interestIncreased - feeIncreased));
            }

            // Compute new states.
            borrowIndex += (interestFactor * borrowIndex) / 1e18;
            totalBorrow += interestIncreased;
            totalReserves += reservesIncreased;

            // Update state variables.
            m.lastUpdateTimestamp = timestamp;
            m.borrowIndex = borrowIndex;
            m.totalBorrow = totalBorrow;
            m.totalReserves = totalReserves;

            emit InterestAccrued(market, timestamp, borrowRatePerSecond, borrowIndex, totalBorrow, totalReserves);
        }
    }

    /**
     * @dev Enter a market.
     * @param market The address of the market
     * @param user The address of the user
     */
    function _enterMarket(address market, address user) internal {
        if (enteredMarkets[user][market]) {
            // Skip if user has entered the market.
            return;
        }

        enteredMarkets[user][market] = true;
        allEnteredMarkets[user].push(market);

        emit MarketEntered(market, user);
    }

    /**
     * @dev Exit a market.
     * @param market The address of the market
     * @param user The address of the user
     */
    function _exitMarket(address market, address user) internal {
        if (!enteredMarkets[user][market]) {
            // Skip if user has not entered the market.
            return;
        }

        enteredMarkets[user][market] = false;
        allEnteredMarkets[user].deleteElement(market);

        emit MarketExited(market, user);
    }

    /**
     * @dev Repay an amount of asset to ApeFinance.
     * @param m The market object
     * @param from The address which will repay the asset
     * @param to The address which will hold the balance
     * @param market The address of the market
     * @param amount The amount of asset to repay, or type(uint256).max for max
     * @return The actual amount repaid
     */
    function _repay(DataTypes.Market storage m, address from, address to, address market, uint256 amount)
        internal
        returns (uint256)
    {
        uint256 borrowBalance = _getBorrowBalance(m, to);
        if (amount == type(uint256).max) {
            amount = borrowBalance;
        }

        require(amount <= borrowBalance, "repay too much");

        uint256 newUserBorrowBalance = borrowBalance - amount;
        uint256 newTotalBorrow = m.totalBorrow - amount;

        // Update storage.
        m.userBorrows[to].borrowBalance = newUserBorrowBalance;
        m.userBorrows[to].borrowIndex = m.borrowIndex;
        m.totalCash += amount;
        m.totalBorrow = newTotalBorrow;

        // Check if need to exit the market.
        if (m.userSupplies[to] == 0 && newUserBorrowBalance == 0) {
            _exitMarket(market, to);
        }

        IERC20(market).safeTransferFrom(from, address(this), amount);

        emit Repay(market, from, to, amount, newUserBorrowBalance, newTotalBorrow);

        return amount;
    }

    /**
     * @dev Check the account liquidity of a user. If the account liquidity check is deferred, mark the status to dirty. It must be checked later.
     * @param user The address of the user
     */
    function _checkAccountLiquidity(address user) internal {
        uint8 status = liquidityCheckStatus[user];

        if (status == LIQUIDITY_CHECK_NORMAL) {
            (uint256 collateralValue,, uint256 debtValue) = _getAccountLiquidity(user);
            require(collateralValue >= debtValue, "insufficient collateral");
        } else if (status == LIQUIDITY_CHECK_DEFERRED) {
            liquidityCheckStatus[user] = LIQUIDITY_CHECK_DIRTY;
        }
    }

    /**
     * @dev Get the account liquidity of a user.
     * @param user The address of the user
     * @return The total collateral value, liquidation collateral value, and total debt value of the user
     */
    function _getAccountLiquidity(address user) internal view returns (uint256, uint256, uint256) {
        uint256 collateralValue;
        uint256 liquidationCollateralValue;
        uint256 debtValue;

        address[] memory userEnteredMarkets = allEnteredMarkets[user];
        for (uint256 i = 0; i < userEnteredMarkets.length; i++) {
            DataTypes.Market storage m = markets[userEnteredMarkets[i]];
            if (!m.config.isListed) {
                continue;
            }

            uint256 supplyBalance = m.userSupplies[user];
            uint256 borrowBalance = _getBorrowBalance(m, user);

            uint256 assetPrice = _getMarketPrice(m, userEnteredMarkets[i]);
            uint256 collateralFactor = m.config.collateralFactor;
            uint256 liquidationThreshold = m.config.liquidationThreshold;
            if (supplyBalance > 0 && collateralFactor > 0) {
                uint256 exchangeRate = _getExchangeRate(m);
                collateralValue += (supplyBalance * exchangeRate * assetPrice * collateralFactor) / 1e36 / FACTOR_SCALE;
                liquidationCollateralValue +=
                    (supplyBalance * exchangeRate * assetPrice * liquidationThreshold) / 1e36 / FACTOR_SCALE;
            }
            if (borrowBalance > 0) {
                debtValue += (borrowBalance * assetPrice) / 1e18;
            }
        }
        return (collateralValue, liquidationCollateralValue, debtValue);
    }

    /**
     * @dev Check if an account is liquidatable.
     * @param user The address of the account to check
     * @return true if the account is liquidatable, false otherwise
     */
    function _isLiquidatable(address user) internal view returns (bool) {
        (, uint256 liquidationCollateralValue, uint256 debtValue) = _getAccountLiquidity(user);
        return debtValue > liquidationCollateralValue;
    }

    /**
     * @dev Check if a market is seizable when a liquidation happens.
     * @param m The market object
     * @return true if the market is seizable, false otherwise
     */
    function _isMarketSeizable(DataTypes.Market storage m) internal view returns (bool) {
        return !m.config.isTransferPaused() && m.config.liquidationThreshold > 0;
    }

    /**
     * @dev Get the market price from the price oracle. If the market is a pToken, use its underlying to get the price.
     * @param m The market object
     * @param market The address of the market
     * @return The market price
     */
    function _getMarketPrice(DataTypes.Market storage m, address market) internal view returns (uint256) {
        address asset = m.config.isPToken ? IPToken(market).getUnderlying() : market;
        uint256 assetPrice = IPriceOracle(priceOracle).getPrice(asset);
        require(assetPrice > 0, "invalid price");
        return assetPrice;
    }

    /**
     * @dev Set the extension for an account.
     * @param account The address of the account
     * @param extension The address of the extension
     * @param allowed Whether to allow or disallow the extension
     */
    function _setAccountExtension(address account, address extension, bool allowed) internal {
        if (allowed && !allowedExtensions[account][extension]) {
            allowedExtensions[account][extension] = true;
            allAllowedExtensions[account].push(extension);

            emit ExtensionAdded(account, extension);
        } else if (!allowed && allowedExtensions[account][extension]) {
            allowedExtensions[account][extension] = false;
            allAllowedExtensions[account].deleteElement(extension);

            emit ExtensionRemoved(account, extension);
        }
    }
}

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

pragma solidity ^0.8.0;

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

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

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

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

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (access/Ownable2Step.sol)

pragma solidity ^0.8.0;

import "./OwnableUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which provides access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2StepUpgradeable is Initializable, OwnableUpgradeable {
    function __Ownable2Step_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable2Step_init_unchained() internal onlyInitializing {
    }
    address private _pendingOwner;

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

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

    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual override onlyOwner {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }

    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() external {
        address sender = _msgSender();
        require(pendingOwner() == sender, "Ownable2Step: caller is not the new owner");
        _transferOwnership(sender);
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

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

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

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

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * 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) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * 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: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (proxy/utils/UUPSUpgradeable.sol)

pragma solidity ^0.8.0;

import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
import "./Initializable.sol";

/**
 * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
 * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
 *
 * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
 * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
 * `UUPSUpgradeable` with a custom implementation of upgrades.
 *
 * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is Initializable, IERC1822ProxiableUpgradeable, ERC1967UpgradeUpgradeable {
    function __UUPSUpgradeable_init() internal onlyInitializing {
    }

    function __UUPSUpgradeable_init_unchained() internal onlyInitializing {
    }
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
    address private immutable __self = address(this);

    /**
     * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
     * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
     * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
     * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        require(address(this) != __self, "Function must be called through delegatecall");
        require(_getImplementation() == __self, "Function must be called through active proxy");
        _;
    }

    /**
     * @dev Check that the execution is not being performed through a delegate call. This allows a function to be
     * callable on the implementing contract but not through proxies.
     */
    modifier notDelegated() {
        require(address(this) == __self, "UUPSUpgradeable: must not be called through delegatecall");
        _;
    }

    /**
     * @dev Implementation of the ERC1822 {proxiableUUID} function. This returns the storage slot used by the
     * implementation. It is used to validate the implementation's compatibility when performing an upgrade.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
     */
    function proxiableUUID() external view virtual override notDelegated returns (bytes32) {
        return _IMPLEMENTATION_SLOT;
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeTo(address newImplementation) external virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(newImplementation, new bytes(0), false);
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(newImplementation, data, true);
    }

    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeTo} and {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal override onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./Constants.sol";
import "./Events.sol";
import "../../libraries/DataTypes.sol";

contract ApeFinanceStorage is Constants, Events {
    /// @notice The mapping of the supported markets
    mapping(address => DataTypes.Market) public markets;

    /// @notice The list of all supported markets
    address[] public allMarkets;

    /// @notice The mapping of a user's entered markets
    mapping(address => mapping(address => bool)) public enteredMarkets;

    /// @notice The list of all markets a user has entered
    mapping(address => address[]) public allEnteredMarkets;

    /// @notice The mapping of a user's allowed extensions
    mapping(address => mapping(address => bool)) public allowedExtensions;

    /// @notice The list of all allowed extensions for a user
    mapping(address => address[]) public allAllowedExtensions;

    /// @notice The mapping of the credit limits
    mapping(address => mapping(address => uint256)) public creditLimits;

    /// @notice The list of a user's credit markets
    mapping(address => address[]) public allCreditMarkets;

    /// @notice The mapping of the liquidity check status
    mapping(address => uint8) public liquidityCheckStatus;

    /// @notice The price oracle address
    address public priceOracle;

    /// @notice The market configurator address
    address public marketConfigurator;

    /// @notice The credit limit manager address
    address public creditLimitManager;

    /// @notice The reserve manager address
    address public reserveManager;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../libraries/DataTypes.sol";

interface IApeFinance {
    /* ========== USER INTERFACES ========== */

    function accrueInterest(address market) external;

    function supply(address from, address to, address market, uint256 amount) external;

    function borrow(address from, address to, address asset, uint256 amount) external;

    function redeem(address from, address to, address asset, uint256 amount) external returns (uint256);

    function repay(address from, address to, address asset, uint256 amount) external returns (uint256);

    function liquidate(
        address liquidator,
        address borrower,
        address marketBorrow,
        address marketCollateral,
        uint256 repayAmount
    ) external returns (uint256, uint256);

    function deferLiquidityCheck(address user, bytes memory data) external;

    function getBorrowBalance(address user, address market) external view returns (uint256);

    function getATokenBalance(address user, address market) external view returns (uint256);

    function getSupplyBalance(address user, address market) external view returns (uint256);

    function isMarketListed(address market) external view returns (bool);

    function getExchangeRate(address market) external view returns (uint256);

    function getTotalSupply(address market) external view returns (uint256);

    function getTotalBorrow(address market) external view returns (uint256);

    function getTotalCash(address market) external view returns (uint256);

    function getTotalReserves(address market) external view returns (uint256);

    function getAccountLiquidity(address user) external view returns (uint256, uint256, uint256);

    function isAllowedExtension(address user, address extension) external view returns (bool);

    function transferAToken(address market, address from, address to, uint256 amount) external;

    function setSubAccountExtension(address primary, uint256 subAccountId, bool allowed) external;

    /* ========== MARKET CONFIGURATOR INTERFACES ========== */

    function getMarketConfiguration(address market) external view returns (DataTypes.MarketConfig memory);

    function listMarket(address market, DataTypes.MarketConfig calldata config) external;

    function delistMarket(address market) external;

    function setMarketConfiguration(address market, DataTypes.MarketConfig calldata config) external;

    /* ========== CREDIT LIMIT MANAGER INTERFACES ========== */

    function getCreditLimit(address user, address market) external view returns (uint256);

    function getUserCreditMarkets(address user) external view returns (address[] memory);

    function isCreditAccount(address user) external view returns (bool);

    function setCreditLimit(address user, address market, uint256 credit) external;

    /* ========== RESERVE MANAGER INTERFACES ========== */

    function absorbToReserves(address market) external;

    function reduceReserves(address market, uint256 aTokenAmount, address recipient) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

    function burn(address account, uint256 amount) external;

    function seize(address from, address to, uint256 amount) external;

    function asset() external view returns (address);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IDeferLiquidityCheck {
    /**
     * @dev The callback function that deferLiquidityCheck will invoke.
     * @param data The arbitrary data that was passed in by the caller
     */
    function onDeferredLiquidityCheck(bytes memory data) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IInterestRateModel {
    function getUtilization(uint256 cash, uint256 borrow) external pure returns (uint256);

    function getBorrowRate(uint256 cash, uint256 borrow) external view returns (uint256);

    function getSupplyRate(uint256 cash, uint256 borrow) external view returns (uint256);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IPriceOracle {
    function getPrice(address asset) external view returns (uint256);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/token/ERC20/IERC20.sol";

interface IPToken is IERC20 {
    function getUnderlying() external view returns (address);

    function wrap(uint256 amount) external;

    function unwrap(uint256 amount) external;

    function absorb(address user) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library Arrays {
    /**
     * @dev Delete an element from an array.
     * @param self The array to delete from
     * @param element The element to delete
     */
    function deleteElement(address[] storage self, address element) internal {
        uint256 count = self.length;
        for (uint256 i = 0; i < count;) {
            if (self[i] == element) {
                if (i != count - 1) {
                    self[i] = self[count - 1];
                }
                self.pop();
                break;
            }

            unchecked {
                i++;
            }
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library DataTypes {
    struct UserBorrow {
        uint256 borrowBalance;
        uint256 borrowIndex;
    }

    struct MarketConfig {
        // 1 + 1 + 2 + 2 + 2 + 2 + 1 + 1 = 12
        bool isListed;
        uint8 pauseFlags;
        uint16 collateralFactor;
        uint16 liquidationThreshold;
        uint16 liquidationBonus;
        uint16 reserveFactor;
        bool isPToken;
        bool isDelisted;
        // 20 + 20 + 20 + 32 + 32 + 32
        address aTokenAddress;
        address debtTokenAddress;
        address interestRateModelAddress;
        uint256 supplyCap;
        uint256 borrowCap;
        uint256 initialExchangeRate;
    }

    struct Market {
        MarketConfig config;
        uint40 lastUpdateTimestamp;
        uint256 totalCash;
        uint256 totalBorrow;
        uint256 totalSupply;
        uint256 totalReserves;
        uint256 borrowIndex;
        mapping(address => UserBorrow) userBorrows;
        mapping(address => uint256) userSupplies;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./DataTypes.sol";

library PauseFlags {
    /// @dev Mask for specific actions in the pause flag bit array
    uint8 internal constant PAUSE_SUPPLY_MASK = 0xFE;
    uint8 internal constant PAUSE_BORROW_MASK = 0xFD;
    uint8 internal constant PAUSE_TRANSFER_MASK = 0xFB;

    /// @dev Offsets for specific actions in the pause flag bit array
    uint8 internal constant PAUSE_SUPPLY_OFFSET = 0;
    uint8 internal constant PAUSE_BORROW_OFFSET = 1;
    uint8 internal constant PAUSE_TRANSFER_OFFSET = 2;

    /// @dev Sets the market supply paused.
    function setSupplyPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
        self.pauseFlags = (self.pauseFlags & PAUSE_SUPPLY_MASK) | (toUInt8(paused) << PAUSE_SUPPLY_OFFSET);
    }

    /// @dev Returns true if the market supply is paused, and false otherwise.
    function isSupplyPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
        return toBool(self.pauseFlags & ~PAUSE_SUPPLY_MASK);
    }

    /// @dev Sets the market borrow paused.
    function setBorrowPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
        self.pauseFlags = (self.pauseFlags & PAUSE_BORROW_MASK) | (toUInt8(paused) << PAUSE_BORROW_OFFSET);
    }

    /// @dev Returns true if the market borrow is paused, and false otherwise.
    function isBorrowPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
        return toBool(self.pauseFlags & ~PAUSE_BORROW_MASK);
    }

    /// @dev Sets the market transfer paused.
    function setTransferPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
        self.pauseFlags = (self.pauseFlags & PAUSE_TRANSFER_MASK) | (toUInt8(paused) << PAUSE_TRANSFER_OFFSET);
    }

    /// @dev Returns true if the market transfer is paused, and false otherwise.
    function isTransferPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
        return toBool(self.pauseFlags & ~PAUSE_TRANSFER_MASK);
    }

    /// @dev Casts a boolean to uint8.
    function toUInt8(bool x) internal pure returns (uint8) {
        return x ? 1 : 0;
    }

    /// @dev Casts a uint8 to boolean.
    function toBool(uint8 x) internal pure returns (bool) {
        return x != 0;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library SubAccounts {
    function getSubAccount(address primary, uint256 subAccountId) internal pure returns (address) {
        require(subAccountId < 256, "invalid sub account id");
        return address(uint160(primary) ^ uint160(subAccountId));
    }

    function isSubAccountOf(address subAccount, address primary) internal pure returns (bool) {
        return (uint160(primary) | 0xFF) == (uint160(subAccount) | 0xFF);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

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

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

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

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

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

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

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

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

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

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

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

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

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

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

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

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return 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 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: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)

pragma solidity ^0.8.0;

/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822ProxiableUpgradeable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)

pragma solidity ^0.8.2;

import "../beacon/IBeaconUpgradeable.sol";
import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/StorageSlotUpgradeable.sol";
import "../utils/Initializable.sol";

/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967UpgradeUpgradeable is Initializable {
    function __ERC1967Upgrade_init() internal onlyInitializing {
    }

    function __ERC1967Upgrade_init_unchained() internal onlyInitializing {
    }
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822ProxiableUpgradeable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);

    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }

    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), data);
        }
    }

    /**
     * @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) private returns (bytes memory) {
        require(AddressUpgradeable.isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return AddressUpgradeable.verifyCallResult(success, returndata, "Address: low-level delegate call failed");
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

abstract contract Constants {
    uint256 internal constant INITIAL_BORROW_INDEX = 1e18;
    uint256 internal constant INITIAL_EXCHANGE_RATE = 1e18;
    uint256 internal constant FACTOR_SCALE = 10000;

    uint16 internal constant MAX_COLLATERAL_FACTOR = 9000; // 90%
    uint16 internal constant MAX_LIQUIDATION_THRESHOLD = 10000; // 100%
    uint16 internal constant MIN_LIQUIDATION_BONUS = 10000; // 100%
    uint16 internal constant MAX_LIQUIDATION_BONUS = 12500; // 125%
    uint16 internal constant MAX_LIQUIDATION_THRESHOLD_X_BONUS = 10000; // 100%
    uint16 internal constant MAX_RESERVE_FACTOR = 10000; // 100%

    uint8 internal constant LIQUIDITY_CHECK_NORMAL = 0;
    uint8 internal constant LIQUIDITY_CHECK_DEFERRED = 1;
    uint8 internal constant LIQUIDITY_CHECK_DIRTY = 2;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../../libraries/DataTypes.sol";

abstract contract Events {
    event MarketConfiguratorSet(address configurator);

    event CreditLimitManagerSet(address manager);

    event ReserveManagerSet(address manager);

    event CreditLimitChanged(address indexed user, address indexed market, uint256 credit);

    event PriceOracleSet(address priceOracle);

    event MarketListed(address indexed market, uint40 timestamp, DataTypes.MarketConfig config);

    event MarketDelisted(address indexed market);

    event MarketConfigurationChanged(address indexed market, DataTypes.MarketConfig config);

    event MarketEntered(address indexed market, address indexed user);

    event MarketExited(address indexed market, address indexed user);

    event InterestAccrued(
        address indexed market,
        uint40 timestamp,
        uint256 borrowRatePerSecond,
        uint256 borrowIndex,
        uint256 totalBorrow,
        uint256 totalReserves
    );

    event Supply(
        address indexed market, address indexed from, address indexed to, uint256 amount, uint256 aTokenAmount
    );

    event Borrow(
        address indexed market,
        address indexed from,
        address indexed to,
        uint256 amount,
        uint256 accountBorrow,
        uint256 totalBorrow
    );

    event Redeem(
        address indexed market, address indexed from, address indexed to, uint256 amount, uint256 aTokenAmount
    );

    event Repay(
        address indexed market,
        address indexed from,
        address indexed to,
        uint256 amount,
        uint256 accountBorrow,
        uint256 totalBorrow
    );

    event Liquidate(
        address indexed liquidator,
        address indexed borrower,
        address indexed marketBorrow,
        address marketCollateral,
        uint256 repayAmount,
        uint256 seizedAmount
    );

    event TransferAToken(address indexed market, address indexed from, address indexed to, uint256 aTokenAmount);

    event TokenSeized(address indexed token, address indexed recipient, uint256 amount);

    event ReservesIncreased(address indexed market, uint256 aTokenAmount, uint256 amount);

    event ReservesDecreased(address indexed market, address indexed recipient, uint256 aTokenAmount, uint256 amount);

    event ExtensionAdded(address indexed account, address indexed extension);

    event ExtensionRemoved(address indexed account, address indexed extension);
}

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

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)

pragma solidity ^0.8.0;

/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeaconUpgradeable {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}

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

pragma solidity ^0.8.0;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlotUpgradeable {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }
}