// File: src/OneWayBondingCurve.sol



// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.15;

import {IERC20} from "@openzeppelin/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/token/ERC20/utils/SafeERC20.sol";
import {AggregatorV3Interface} from "./external/AggregatorV3Interface.sol";
import {AaveV2Ethereum} from "@aave-address-book/AaveV2Ethereum.sol";

/// @title OneWayBondingCurve
/// @author Llama
/// @notice One Way Bonding Curve to purchase discounted aUSDC for BAL upto a 100k BAL Ceiling
contract OneWayBondingCurve {
    using SafeERC20 for IERC20;

    /********************************
     *   CONSTANTS AND IMMUTABLES   *
     ********************************/

    uint256 public constant BAL_AMOUNT_CAP = 100_000e18;

    IERC20 public constant BAL = IERC20(0xba100000625a3754423978a60c9317c58a424e3D);
    IERC20 public constant USDC = IERC20(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
    IERC20 public constant AUSDC = IERC20(0xBcca60bB61934080951369a648Fb03DF4F96263C);

    AggregatorV3Interface public constant BAL_USD_FEED =
        AggregatorV3Interface(0xdF2917806E30300537aEB49A7663062F4d1F2b5F);

    /*************************
     *   STORAGE VARIABLES   *
     *************************/

    /// @notice Cumulative aUSDC Purchased
    uint256 public totalAusdcPurchased;

    /// @notice Cumulative BAL Received
    uint256 public totalBalReceived;

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

    event Purchase(address indexed tokenIn, address indexed tokenOut, uint256 amountIn, uint256 amountOut);

    /****************************
     *   ERRORS AND MODIFIERS   *
     ****************************/

    error OnlyNonZeroAmount();
    error ExcessBalAmountIn();
    error InvalidOracleAnswer();

    /*****************
     *   FUNCTIONS   *
     *****************/

    /// @notice Purchase USDC for BAL
    /// @param amountIn Amount of BAL input
    /// @param toUnderlying Whether to receive as USDC (true) or aUSDC (false)
    /// @return amountOut Amount of USDC received
    /// @dev Purchaser has to approve BAL transfer before calling this function
    function purchase(uint256 amountIn, bool toUnderlying) external returns (uint256) {
        if (amountIn == 0) revert OnlyNonZeroAmount();
        if (amountIn > availableBalToBeFilled()) revert ExcessBalAmountIn();

        uint256 amountOut = getAmountOut(amountIn);
        if (amountOut == 0) revert OnlyNonZeroAmount();

        totalBalReceived += amountIn;
        totalAusdcPurchased += amountOut;

        // Execute the purchase
        BAL.safeTransferFrom(msg.sender, AaveV2Ethereum.COLLECTOR, amountIn);
        if (toUnderlying) {
            AUSDC.safeTransferFrom(AaveV2Ethereum.COLLECTOR, address(this), amountOut);
            // Withdrawing entire aUSDC balance in this contract since we can't directly use 'amountOut' as
            // input due to +1/-1 precision issues caused by rounding on aTokens while it's being transferred.
            amountOut = AaveV2Ethereum.POOL.withdraw(address(USDC), type(uint256).max, msg.sender);
            emit Purchase(address(BAL), address(USDC), amountIn, amountOut);
        } else {
            AUSDC.safeTransferFrom(AaveV2Ethereum.COLLECTOR, msg.sender, amountOut);
            emit Purchase(address(BAL), address(AUSDC), amountIn, amountOut);
        }

        return amountOut;
    }

    /// @notice Returns how close to the 100k BAL amount cap we are
    /// @return availableBalToBeFilled the amount of BAL left to be filled
    /// @dev Purchaser check this function before calling purchase() to see if there is BAL left to be filled
    function availableBalToBeFilled() public view returns (uint256) {
        return BAL_AMOUNT_CAP - totalBalReceived;
    }

    /// @notice Returns amount of USDC that will be received after a bonding curve purchase of BAL
    /// @param amountIn the amount of BAL used to purchase
    /// @return amountOutWithBonus the amount of USDC received with 50 bps incentive included
    /// @dev Purchaser check this function before calling purchase() to see the amount of USDC you'll get for given BAL
    function getAmountOut(uint256 amountIn) public view returns (uint256) {
        /** 
            The actual calculation is a collapsed version of this to prevent precision loss:
            => amountOut = (amountBALWei / 10^balDecimals) * (chainlinkPrice / chainlinkPrecision) * 10^usdcDecimals
            => amountOut = (amountBalWei / 10^18) * (chainlinkPrice / 10^8) * 10^6
         */
        uint256 amountOut = (amountIn * getOraclePrice()) / 10**20;
        // 50 bps arbitrage incentive
        return (amountOut * 10050) / 10000;
    }

    /// @notice The peg price of the referenced oracle as USD per BAL
    function getOraclePrice() public view returns (uint256) {
        (, int256 price, , , ) = BAL_USD_FEED.latestRoundData();
        if (price <= 0) revert InvalidOracleAnswer();
        return uint256(price);
    }

    /// @notice Transfer any tokens accidentally sent to this contract to Aave V2 Collector
    /// @param tokens List of token addresses
    function rescueTokens(address[] calldata tokens) external {
        for (uint256 i = 0; i < tokens.length; ++i) {
            IERC20(tokens[i]).safeTransfer(AaveV2Ethereum.COLLECTOR, IERC20(tokens[i]).balanceOf(address(this)));
        }
    }
}

// File: lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

// File: src/external/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.15;

interface AggregatorV3Interface {
    function decimals() external view returns (uint8);

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

    function version() external view returns (uint256);

    // getRoundData and latestRoundData should both raise "No data present"
    // if they do not have data to report, instead of returning unset values
    // which could be misinterpreted as actual reported values.
    function getRoundData(uint80 _roundId)
        external
        view
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        );

    function latestRoundData()
        external
        view
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        );
}

// File: lib/aave-address-book/src/AaveV2Ethereum.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0;

import {ILendingPoolAddressesProvider, ILendingPool, ILendingPoolConfigurator, IAaveOracle, IAaveProtocolDataProvider} from "./AaveV2.sol";

library AaveV2Ethereum {
    ILendingPoolAddressesProvider internal constant POOL_ADDRESSES_PROVIDER =
        ILendingPoolAddressesProvider(
            0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5
        );

    ILendingPool internal constant POOL =
        ILendingPool(0x7d2768dE32b0b80b7a3454c06BdAc94A69DDc7A9);

    ILendingPoolConfigurator internal constant POOL_CONFIGURATOR =
        ILendingPoolConfigurator(0x311Bb771e4F8952E6Da169b425E7e92d6Ac45756);

    IAaveOracle internal constant ORACLE =
        IAaveOracle(0xA50ba011c48153De246E5192C8f9258A2ba79Ca9);

    IAaveProtocolDataProvider internal constant AAVE_PROTOCOL_DATA_PROVIDER =
        IAaveProtocolDataProvider(0x057835Ad21a177dbdd3090bB1CAE03EaCF78Fc6d);

    address internal constant POOL_ADMIN =
        0xEE56e2B3D491590B5b31738cC34d5232F378a8D5;

    address internal constant EMERGENCY_ADMIN =
        0xCA76Ebd8617a03126B6FB84F9b1c1A0fB71C2633;

    address internal constant COLLECTOR =
        0x464C71f6c2F760DdA6093dCB91C24c39e5d6e18c;

    address internal constant COLLECTOR_CONTROLLER =
        0x3d569673dAa0575c936c7c67c4E6AedA69CC630C;
}

// File: lib/openzeppelin-contracts/contracts/token/ERC20/extensions/draft-IERC20Permit.sol



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

pragma solidity ^0.8.0;

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

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

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

// File: lib/openzeppelin-contracts/contracts/utils/Address.sol



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: lib/aave-address-book/src/AaveV2.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0;

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

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

  struct UserConfigurationMap {
    uint256 data;
  }

  enum InterestRateMode {
    NONE,
    STABLE,
    VARIABLE
  }
}

library ConfiguratorInputTypes {
  struct InitReserveInput {
    address aTokenImpl;
    address stableDebtTokenImpl;
    address variableDebtTokenImpl;
    uint8 underlyingAssetDecimals;
    address interestRateStrategyAddress;
    address underlyingAsset;
    address treasury;
    address incentivesController;
    string underlyingAssetName;
    string aTokenName;
    string aTokenSymbol;
    string variableDebtTokenName;
    string variableDebtTokenSymbol;
    string stableDebtTokenName;
    string stableDebtTokenSymbol;
    bytes params;
  }

  struct UpdateATokenInput {
    address asset;
    address treasury;
    address incentivesController;
    string name;
    string symbol;
    address implementation;
    bytes params;
  }

  struct UpdateDebtTokenInput {
    address asset;
    address incentivesController;
    string name;
    string symbol;
    address implementation;
    bytes params;
  }
}

interface ILendingPoolAddressesProvider {
  event MarketIdSet(string newMarketId);
  event LendingPoolUpdated(address indexed newAddress);
  event ConfigurationAdminUpdated(address indexed newAddress);
  event EmergencyAdminUpdated(address indexed newAddress);
  event LendingPoolConfiguratorUpdated(address indexed newAddress);
  event LendingPoolCollateralManagerUpdated(address indexed newAddress);
  event PriceOracleUpdated(address indexed newAddress);
  event LendingRateOracleUpdated(address indexed newAddress);
  event ProxyCreated(bytes32 id, address indexed newAddress);
  event AddressSet(bytes32 id, address indexed newAddress, bool hasProxy);

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

  function setMarketId(string calldata marketId) external;

  function setAddress(bytes32 id, address newAddress) external;

  function setAddressAsProxy(bytes32 id, address impl) external;

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

  function getLendingPool() external view returns (address);

  function setLendingPoolImpl(address pool) external;

  function getLendingPoolConfigurator() external view returns (address);

  function setLendingPoolConfiguratorImpl(address configurator) external;

  function getLendingPoolCollateralManager() external view returns (address);

  function setLendingPoolCollateralManager(address manager) external;

  function getPoolAdmin() external view returns (address);

  function setPoolAdmin(address admin) external;

  function getEmergencyAdmin() external view returns (address);

  function setEmergencyAdmin(address admin) external;

  function getPriceOracle() external view returns (address);

  function setPriceOracle(address priceOracle) external;

  function getLendingRateOracle() external view returns (address);

  function setLendingRateOracle(address lendingRateOracle) external;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  function setReserveInterestRateStrategyAddress(
    address reserve,
    address rateStrategyAddress
  ) external;

  function setConfiguration(address reserve, uint256 configuration) external;

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

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

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

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

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

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

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

  function getAddressesProvider()
    external
    view
    returns (ILendingPoolAddressesProvider);

  function setPause(bool val) external;

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

interface ILendingPoolConfigurator {
  /**
   * @dev Emitted when a reserve is initialized.
   * @param asset The address of the underlying asset of the reserve
   * @param aToken The address of the associated aToken contract
   * @param stableDebtToken The address of the associated stable rate debt token
   * @param variableDebtToken The address of the associated variable rate debt token
   * @param interestRateStrategyAddress The address of the interest rate strategy for the reserve
   **/
  event ReserveInitialized(
    address indexed asset,
    address indexed aToken,
    address stableDebtToken,
    address variableDebtToken,
    address interestRateStrategyAddress
  );

  /**
   * @dev Emitted when borrowing is enabled on a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param stableRateEnabled True if stable rate borrowing is enabled, false otherwise
   **/
  event BorrowingEnabledOnReserve(
    address indexed asset,
    bool stableRateEnabled
  );

  /**
   * @dev Emitted when borrowing is disabled on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  event BorrowingDisabledOnReserve(address indexed asset);

  /**
   * @dev Emitted when the collateralization risk parameters for the specified asset are updated.
   * @param asset The address of the underlying asset of the reserve
   * @param ltv The loan to value of the asset when used as collateral
   * @param liquidationThreshold The threshold at which loans using this asset as collateral will be considered undercollateralized
   * @param liquidationBonus The bonus liquidators receive to liquidate this asset
   **/
  event CollateralConfigurationChanged(
    address indexed asset,
    uint256 ltv,
    uint256 liquidationThreshold,
    uint256 liquidationBonus
  );

  /**
   * @dev Emitted when stable rate borrowing is enabled on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  event StableRateEnabledOnReserve(address indexed asset);

  /**
   * @dev Emitted when stable rate borrowing is disabled on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  event StableRateDisabledOnReserve(address indexed asset);

  /**
   * @dev Emitted when a reserve is activated
   * @param asset The address of the underlying asset of the reserve
   **/
  event ReserveActivated(address indexed asset);

  /**
   * @dev Emitted when a reserve is deactivated
   * @param asset The address of the underlying asset of the reserve
   **/
  event ReserveDeactivated(address indexed asset);

  /**
   * @dev Emitted when a reserve is frozen
   * @param asset The address of the underlying asset of the reserve
   **/
  event ReserveFrozen(address indexed asset);

  /**
   * @dev Emitted when a reserve is unfrozen
   * @param asset The address of the underlying asset of the reserve
   **/
  event ReserveUnfrozen(address indexed asset);

  /**
   * @dev Emitted when a reserve factor is updated
   * @param asset The address of the underlying asset of the reserve
   * @param factor The new reserve factor
   **/
  event ReserveFactorChanged(address indexed asset, uint256 factor);

  /**
   * @dev Emitted when the reserve decimals are updated
   * @param asset The address of the underlying asset of the reserve
   * @param decimals The new decimals
   **/
  event ReserveDecimalsChanged(address indexed asset, uint256 decimals);

  /**
   * @dev Emitted when a reserve interest strategy contract is updated
   * @param asset The address of the underlying asset of the reserve
   * @param strategy The new address of the interest strategy contract
   **/
  event ReserveInterestRateStrategyChanged(
    address indexed asset,
    address strategy
  );

  /**
   * @dev Emitted when an aToken implementation is upgraded
   * @param asset The address of the underlying asset of the reserve
   * @param proxy The aToken proxy address
   * @param implementation The new aToken implementation
   **/
  event ATokenUpgraded(
    address indexed asset,
    address indexed proxy,
    address indexed implementation
  );

  /**
   * @dev Emitted when the implementation of a stable debt token is upgraded
   * @param asset The address of the underlying asset of the reserve
   * @param proxy The stable debt token proxy address
   * @param implementation The new aToken implementation
   **/
  event StableDebtTokenUpgraded(
    address indexed asset,
    address indexed proxy,
    address indexed implementation
  );

  /**
   * @dev Emitted when the implementation of a variable debt token is upgraded
   * @param asset The address of the underlying asset of the reserve
   * @param proxy The variable debt token proxy address
   * @param implementation The new aToken implementation
   **/
  event VariableDebtTokenUpgraded(
    address indexed asset,
    address indexed proxy,
    address indexed implementation
  );

  /**
   * @dev Initializes a reserve
   * @param aTokenImpl  The address of the aToken contract implementation
   * @param stableDebtTokenImpl The address of the stable debt token contract
   * @param variableDebtTokenImpl The address of the variable debt token contract
   * @param underlyingAssetDecimals The decimals of the reserve underlying asset
   * @param interestRateStrategyAddress The address of the interest rate strategy contract for this reserve
   **/
  function initReserve(
    address aTokenImpl,
    address stableDebtTokenImpl,
    address variableDebtTokenImpl,
    uint8 underlyingAssetDecimals,
    address interestRateStrategyAddress
  ) external;

  function batchInitReserve(
    ConfiguratorInputTypes.InitReserveInput[] calldata input
  ) external;

  /**
   * @dev Updates the aToken implementation for the reserve
   * @param asset The address of the underlying asset of the reserve to be updated
   * @param implementation The address of the new aToken implementation
   **/
  function updateAToken(address asset, address implementation) external;

  /**
   * @dev Updates the stable debt token implementation for the reserve
   * @param asset The address of the underlying asset of the reserve to be updated
   * @param implementation The address of the new aToken implementation
   **/
  function updateStableDebtToken(address asset, address implementation)
    external;

  /**
   * @dev Updates the variable debt token implementation for the asset
   * @param asset The address of the underlying asset of the reserve to be updated
   * @param implementation The address of the new aToken implementation
   **/
  function updateVariableDebtToken(address asset, address implementation)
    external;

  /**
   * @dev Enables borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param stableBorrowRateEnabled True if stable borrow rate needs to be enabled by default on this reserve
   **/
  function enableBorrowingOnReserve(address asset, bool stableBorrowRateEnabled)
    external;

  /**
   * @dev Disables borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function disableBorrowingOnReserve(address asset) external;

  /**
   * @dev Configures the reserve collateralization parameters
   * all the values are expressed in percentages with two decimals of precision. A valid value is 10000, which means 100.00%
   * @param asset The address of the underlying asset of the reserve
   * @param ltv The loan to value of the asset when used as collateral
   * @param liquidationThreshold The threshold at which loans using this asset as collateral will be considered undercollateralized
   * @param liquidationBonus The bonus liquidators receive to liquidate this asset. The values is always above 100%. A value of 105%
   * means the liquidator will receive a 5% bonus
   **/
  function configureReserveAsCollateral(
    address asset,
    uint256 ltv,
    uint256 liquidationThreshold,
    uint256 liquidationBonus
  ) external;

  /**
   * @dev Enable stable rate borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function enableReserveStableRate(address asset) external;

  /**
   * @dev Disable stable rate borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function disableReserveStableRate(address asset) external;

  /**
   * @dev Activates a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function activateReserve(address asset) external;

  /**
   * @dev Deactivates a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function deactivateReserve(address asset) external;

  /**
   * @dev Freezes a reserve. A frozen reserve doesn't allow any new deposit, borrow or rate swap
   *  but allows repayments, liquidations, rate rebalances and withdrawals
   * @param asset The address of the underlying asset of the reserve
   **/
  function freezeReserve(address asset) external;

  /**
   * @dev Unfreezes a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function unfreezeReserve(address asset) external;

  /**
   * @dev Updates the reserve factor of a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param reserveFactor The new reserve factor of the reserve
   **/
  function setReserveFactor(address asset, uint256 reserveFactor) external;

  /**
   * @dev Sets the interest rate strategy of a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param rateStrategyAddress The new address of the interest strategy contract
   **/
  function setReserveInterestRateStrategyAddress(
    address asset,
    address rateStrategyAddress
  ) external;

  /**
   * @dev pauses or unpauses all the actions of the protocol, including aToken transfers
   * @param val true if protocol needs to be paused, false otherwise
   **/
  function setPoolPause(bool val) external;
}

interface IAaveOracle {
  event WethSet(address indexed weth);
  event AssetSourceUpdated(address indexed asset, address indexed source);
  event FallbackOracleUpdated(address indexed fallbackOracle);

  /// @notice Returns the WETH address (reference asset of the oracle)
  function WETH() external returns (address);

  /// @notice External function called by the Aave governance to set or replace sources of assets
  /// @param assets The addresses of the assets
  /// @param sources The address of the source of each asset
  function setAssetSources(
    address[] calldata assets,
    address[] calldata sources
  ) external;

  /// @notice Sets the fallbackOracle
  /// - Callable only by the Aave governance
  /// @param fallbackOracle The address of the fallbackOracle
  function setFallbackOracle(address fallbackOracle) external;

  /// @notice Gets an asset price by address
  /// @param asset The asset address
  function getAssetPrice(address asset) external view returns (uint256);

  /// @notice Gets a list of prices from a list of assets addresses
  /// @param assets The list of assets addresses
  function getAssetsPrices(address[] calldata assets)
    external
    view
    returns (uint256[] memory);

  /// @notice Gets the address of the source for an asset address
  /// @param asset The address of the asset
  /// @return address The address of the source
  function getSourceOfAsset(address asset) external view returns (address);

  /// @notice Gets the address of the fallback oracle
  /// @return address The addres of the fallback oracle
  function getFallbackOracle() external view returns (address);
}

struct TokenData {
  string symbol;
  address tokenAddress;
}

// TODO: incomplete interface
interface IAaveProtocolDataProvider {
  function getReserveConfigurationData(address asset)
    external
    view
    returns (
      uint256 decimals,
      uint256 ltv,
      uint256 liquidationThreshold,
      uint256 liquidationBonus,
      uint256 reserveFactor,
      bool usageAsCollateralEnabled,
      bool borrowingEnabled,
      bool stableBorrowRateEnabled,
      bool isActive,
      bool isFrozen
    );

  function getAllReservesTokens() external view returns (TokenData[] memory);

  function getReserveTokensAddresses(address asset)
    external
    view
    returns (
      address aTokenAddress,
      address stableDebtTokenAddress,
      address variableDebtTokenAddress
    );

  function getUserReserveData(address asset, address user)
    external
    view
    returns (
      uint256 currentATokenBalance,
      uint256 currentStableDebt,
      uint256 currentVariableDebt,
      uint256 principalStableDebt,
      uint256 scaledVariableDebt,
      uint256 stableBorrowRate,
      uint256 liquidityRate,
      uint40 stableRateLastUpdated,
      bool usageAsCollateralEnabled
    );
}