// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

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

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

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

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

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

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

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

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

// File: @openzeppelin/contracts/interfaces/IERC4626.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC4626.sol)

pragma solidity ^0.8.0;

import "../token/ERC20/IERC20.sol";
import "../token/ERC20/extensions/IERC20Metadata.sol";

/**
 * @dev Interface of the ERC4626 "Tokenized Vault Standard", as defined in
 * https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
 *
 * _Available since v4.7._
 */
interface IERC4626 is IERC20, IERC20Metadata {
    event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);

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

    /**
     * @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
     *
     * - MUST be an ERC-20 token contract.
     * - MUST NOT revert.
     */
    function asset() external view returns (address assetTokenAddress);

    /**
     * @dev Returns the total amount of the underlying asset that is “managed” by Vault.
     *
     * - SHOULD include any compounding that occurs from yield.
     * - MUST be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT revert.
     */
    function totalAssets() external view returns (uint256 totalManagedAssets);

    /**
     * @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToShares(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToAssets(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
     * through a deposit call.
     *
     * - MUST return a limited value if receiver is subject to some deposit limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
     * - MUST NOT revert.
     */
    function maxDeposit(address receiver) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
     *   call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
     *   in the same transaction.
     * - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
     *   deposit would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewDeposit(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   deposit execution, and are accounted for during deposit.
     * - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function deposit(uint256 assets, address receiver) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
     * - MUST return a limited value if receiver is subject to some mint limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
     * - MUST NOT revert.
     */
    function maxMint(address receiver) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
     *   in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
     *   same transaction.
     * - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
     *   would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by minting.
     */
    function previewMint(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
     *   execution, and are accounted for during mint.
     * - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function mint(uint256 shares, address receiver) external returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
     * Vault, through a withdraw call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxWithdraw(address owner) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
     *   call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
     *   called
     *   in the same transaction.
     * - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
     *   the withdrawal would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewWithdraw(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   withdraw execution, and are accounted for during withdraw.
     * - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
     * through a redeem call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxRedeem(address owner) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
     *   in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
     *   same transaction.
     * - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
     *   redemption would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by redeeming.
     */
    function previewRedeem(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   redeem execution, and are accounted for during redeem.
     * - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

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

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

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

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/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;

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    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));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    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");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    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");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation 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).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // 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 cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
}

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



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

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

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

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

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

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

// File: contracts/aave-v3/flashloan/base/FlashLoanSimpleReceiverBase.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.8.10;

import { IFlashLoanSimpleReceiver } from "../interfaces/IFlashLoanSimpleReceiver.sol";
import { IPoolAddressesProvider } from "../../interfaces/IPoolAddressesProvider.sol";
import { IPool } from "../../interfaces/IPool.sol";

/**
 * @title FlashLoanSimpleReceiverBase
 * @author Aave
 * @notice Base contract to develop a flashloan-receiver contract.
 */
abstract contract FlashLoanSimpleReceiverBase is IFlashLoanSimpleReceiver {
  IPoolAddressesProvider public immutable override ADDRESSES_PROVIDER;
  IPool public immutable override POOL;

  constructor(IPoolAddressesProvider provider) {
    ADDRESSES_PROVIDER = provider;
    POOL = IPool(provider.getPool());
  }
}

// File: contracts/aave-v3/flashloan/interfaces/IFlashLoanSimpleReceiver.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;

import { IPoolAddressesProvider } from "../../interfaces/IPoolAddressesProvider.sol";
import { IPool } from "../../interfaces/IPool.sol";

/**
 * @title IFlashLoanSimpleReceiver
 * @author Aave
 * @notice Defines the basic interface of a flashloan-receiver contract.
 * @dev Implement this interface to develop a flashloan-compatible flashLoanReceiver contract
 */
interface IFlashLoanSimpleReceiver {
  /**
   * @notice Executes an operation after receiving the flash-borrowed asset
   * @dev Ensure that the contract can return the debt + premium, e.g., has
   *      enough funds to repay and has approved the Pool to pull the total amount
   * @param asset The address of the flash-borrowed asset
   * @param amount The amount of the flash-borrowed asset
   * @param premium The fee of the flash-borrowed asset
   * @param initiator The address of the flashloan initiator
   * @param params The byte-encoded params passed when initiating the flashloan
   * @return True if the execution of the operation succeeds, false otherwise
   */
  function executeOperation(
    address asset,
    uint256 amount,
    uint256 premium,
    address initiator,
    bytes calldata params
  ) external returns (bool);

  function ADDRESSES_PROVIDER() external view returns (IPoolAddressesProvider);

  function POOL() external view returns (IPool);
}

// File: contracts/aave-v3/interfaces/IPool.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;

import { IPoolAddressesProvider } from "./IPoolAddressesProvider.sol";
import { DataTypes } from "../protocol/libraries/types/DataTypes.sol";

/**
 * @title IPool
 * @author Aave
 * @notice Defines the basic interface for an Aave Pool.
 */
interface IPool {
  /**
   * @dev Emitted on mintUnbacked()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The address initiating the supply
   * @param onBehalfOf The beneficiary of the supplied assets, receiving the aTokens
   * @param amount The amount of supplied assets
   * @param referralCode The referral code used
   */
  event MintUnbacked(
    address indexed reserve,
    address user,
    address indexed onBehalfOf,
    uint256 amount,
    uint16 indexed referralCode
  );

  /**
   * @dev Emitted on backUnbacked()
   * @param reserve The address of the underlying asset of the reserve
   * @param backer The address paying for the backing
   * @param amount The amount added as backing
   * @param fee The amount paid in fees
   */
  event BackUnbacked(address indexed reserve, address indexed backer, uint256 amount, uint256 fee);

  /**
   * @dev Emitted on supply()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The address initiating the supply
   * @param onBehalfOf The beneficiary of the supply, receiving the aTokens
   * @param amount The amount supplied
   * @param referralCode The referral code used
   */
  event Supply(
    address indexed reserve,
    address user,
    address indexed onBehalfOf,
    uint256 amount,
    uint16 indexed referralCode
  );

  /**
   * @dev Emitted on withdraw()
   * @param reserve The address of the underlying asset being withdrawn
   * @param user The address initiating the withdrawal, owner of aTokens
   * @param to The 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 interestRateMode The rate mode: 1 for Stable, 2 for Variable
   * @param borrowRate The numeric rate at which the user has borrowed, expressed in ray
   * @param referralCode The referral code used
   */
  event Borrow(
    address indexed reserve,
    address user,
    address indexed onBehalfOf,
    uint256 amount,
    DataTypes.InterestRateMode interestRateMode,
    uint256 borrowRate,
    uint16 indexed referralCode
  );

  /**
   * @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
   * @param useATokens True if the repayment is done using aTokens, `false` if done with underlying asset directly
   */
  event Repay(
    address indexed reserve,
    address indexed user,
    address indexed repayer,
    uint256 amount,
    bool useATokens
  );

  /**
   * @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 interestRateMode The current interest rate mode of the position being swapped: 1 for Stable, 2 for Variable
   */
  event SwapBorrowRateMode(
    address indexed reserve,
    address indexed user,
    DataTypes.InterestRateMode interestRateMode
  );

  /**
   * @dev Emitted on borrow(), repay() and liquidationCall() when using isolated assets
   * @param asset The address of the underlying asset of the reserve
   * @param totalDebt The total isolation mode debt for the reserve
   */
  event IsolationModeTotalDebtUpdated(address indexed asset, uint256 totalDebt);

  /**
   * @dev Emitted when the user selects a certain asset category for eMode
   * @param user The address of the user
   * @param categoryId The category id
   */
  event UserEModeSet(address indexed user, uint8 categoryId);

  /**
   * @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 interestRateMode The flashloan mode: 0 for regular flashloan, 1 for Stable debt, 2 for Variable debt
   * @param premium The fee flash borrowed
   * @param referralCode The referral code used
   */
  event FlashLoan(
    address indexed target,
    address initiator,
    address indexed asset,
    uint256 amount,
    DataTypes.InterestRateMode interestRateMode,
    uint256 premium,
    uint16 indexed referralCode
  );

  /**
   * @dev Emitted when a borrower is liquidated.
   * @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 liquidator
   * @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.
   * @param reserve The address of the underlying asset of the reserve
   * @param liquidityRate The next liquidity rate
   * @param stableBorrowRate The next stable borrow rate
   * @param variableBorrowRate The next variable borrow rate
   * @param liquidityIndex The next liquidity index
   * @param variableBorrowIndex The next variable borrow index
   */
  event ReserveDataUpdated(
    address indexed reserve,
    uint256 liquidityRate,
    uint256 stableBorrowRate,
    uint256 variableBorrowRate,
    uint256 liquidityIndex,
    uint256 variableBorrowIndex
  );

  /**
   * @dev Emitted when the protocol treasury receives minted aTokens from the accrued interest.
   * @param reserve The address of the reserve
   * @param amountMinted The amount minted to the treasury
   */
  event MintedToTreasury(address indexed reserve, uint256 amountMinted);

  /**
   * @notice Mints an `amount` of aTokens to the `onBehalfOf`
   * @param asset The address of the underlying asset to mint
   * @param amount The amount to mint
   * @param onBehalfOf The address that will receive the aTokens
   * @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 mintUnbacked(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode
  ) external;

  /**
   * @notice Back the current unbacked underlying with `amount` and pay `fee`.
   * @param asset The address of the underlying asset to back
   * @param amount The amount to back
   * @param fee The amount paid in fees
   * @return The backed amount
   */
  function backUnbacked(address asset, uint256 amount, uint256 fee) external returns (uint256);

  /**
   * @notice Supplies an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
   * - E.g. User supplies 100 USDC and gets in return 100 aUSDC
   * @param asset The address of the underlying asset to supply
   * @param amount The amount to be supplied
   * @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 supply(address asset, uint256 amount, address onBehalfOf, uint16 referralCode) external;

  /**
   * @notice Supply with transfer approval of asset to be supplied done via permit function
   * see: https://eips.ethereum.org/EIPS/eip-2612 and https://eips.ethereum.org/EIPS/eip-713
   * @param asset The address of the underlying asset to supply
   * @param amount The amount to be supplied
   * @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 deadline The deadline timestamp that the permit is valid
   * @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 permitV The V parameter of ERC712 permit sig
   * @param permitR The R parameter of ERC712 permit sig
   * @param permitS The S parameter of ERC712 permit sig
   */
  function supplyWithPermit(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode,
    uint256 deadline,
    uint8 permitV,
    bytes32 permitR,
    bytes32 permitS
  ) external;

  /**
   * @notice 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 The 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);

  /**
   * @notice Allows users to borrow a specific `amount` of the reserve underlying asset, provided that the borrower
   * already supplied 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 The 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 The 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 interestRateMode The interest rate mode at of the debt the user wants to repay: 1 for Stable, 2 for Variable
   * @param onBehalfOf The 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 interestRateMode,
    address onBehalfOf
  ) external returns (uint256);

  /**
   * @notice Repay with transfer approval of asset to be repaid done via permit function
   * see: https://eips.ethereum.org/EIPS/eip-2612 and https://eips.ethereum.org/EIPS/eip-713
   * @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 interestRateMode 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
   * @param deadline The deadline timestamp that the permit is valid
   * @param permitV The V parameter of ERC712 permit sig
   * @param permitR The R parameter of ERC712 permit sig
   * @param permitS The S parameter of ERC712 permit sig
   * @return The final amount repaid
   */
  function repayWithPermit(
    address asset,
    uint256 amount,
    uint256 interestRateMode,
    address onBehalfOf,
    uint256 deadline,
    uint8 permitV,
    bytes32 permitR,
    bytes32 permitS
  ) external returns (uint256);

  /**
   * @notice Repays a borrowed `amount` on a specific reserve using the reserve aTokens, burning the
   * equivalent debt tokens
   * - E.g. User repays 100 USDC using 100 aUSDC, burning 100 variable/stable debt tokens
   * @dev  Passing uint256.max as amount will clean up any residual aToken dust balance, if the user aToken
   * balance is not enough to cover the whole debt
   * @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 interestRateMode The interest rate mode at of the debt the user wants to repay: 1 for Stable, 2 for Variable
   * @return The final amount repaid
   */
  function repayWithATokens(
    address asset,
    uint256 amount,
    uint256 interestRateMode
  ) external returns (uint256);

  /**
   * @notice Allows a borrower to swap his debt between stable and variable mode, or vice versa
   * @param asset The address of the underlying asset borrowed
   * @param interestRateMode The current interest rate mode of the position being swapped: 1 for Stable, 2 for Variable
   */
  function swapBorrowRateMode(address asset, uint256 interestRateMode) external;

  /**
   * @notice 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 supply APY is below REBALANCE_UP_THRESHOLD * maxVariableBorrowRate, which means that too
   *        much has been borrowed at a stable rate and suppliers 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;

  /**
   * @notice Allows suppliers to enable/disable a specific supplied asset as collateral
   * @param asset The address of the underlying asset supplied
   * @param useAsCollateral True if the user wants to use the supply as collateral, false otherwise
   */
  function setUserUseReserveAsCollateral(address asset, bool useAsCollateral) external;

  /**
   * @notice 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;

  /**
   * @notice Allows smartcontracts to access the liquidity of the pool within one transaction,
   * as long as the amount taken plus a fee is returned.
   * @dev IMPORTANT There are security concerns for developers of flashloan receiver contracts that must be kept
   * into consideration. For further details please visit https://docs.aave.com/developers/
   * @param receiverAddress The address of the contract receiving the funds, implementing IFlashLoanReceiver interface
   * @param assets The addresses of the assets being flash-borrowed
   * @param amounts The amounts of the assets being flash-borrowed
   * @param interestRateModes 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 The 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 interestRateModes,
    address onBehalfOf,
    bytes calldata params,
    uint16 referralCode
  ) external;

  /**
   * @notice Allows smartcontracts to access the liquidity of the pool within one transaction,
   * as long as the amount taken plus a fee is returned.
   * @dev IMPORTANT There are security concerns for developers of flashloan receiver contracts that must be kept
   * into consideration. For further details please visit https://docs.aave.com/developers/
   * @param receiverAddress The address of the contract receiving the funds, implementing IFlashLoanSimpleReceiver interface
   * @param asset The address of the asset being flash-borrowed
   * @param amount The amount of the asset being flash-borrowed
   * @param params Variadic packed params to pass to the receiver as extra information
   * @param referralCode The 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 flashLoanSimple(
    address receiverAddress,
    address asset,
    uint256 amount,
    bytes calldata params,
    uint16 referralCode
  ) external;

  /**
   * @notice Returns the user account data across all the reserves
   * @param user The address of the user
   * @return totalCollateralBase The total collateral of the user in the base currency used by the price feed
   * @return totalDebtBase The total debt of the user in the base currency used by the price feed
   * @return availableBorrowsBase The borrowing power left of the user in the base currency used by the price feed
   * @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 totalCollateralBase,
      uint256 totalDebtBase,
      uint256 availableBorrowsBase,
      uint256 currentLiquidationThreshold,
      uint256 ltv,
      uint256 healthFactor
    );

  /**
   * @notice Initializes a reserve, activating it, assigning an aToken and debt tokens and an
   * interest rate strategy
   * @dev Only callable by the PoolConfigurator contract
   * @param asset The address of the underlying asset of the reserve
   * @param aTokenAddress The address of the aToken that will be assigned to the reserve
   * @param stableDebtAddress The address of the StableDebtToken that will be assigned to the reserve
   * @param variableDebtAddress The address of the VariableDebtToken that will be assigned to the reserve
   * @param interestRateStrategyAddress The address of the interest rate strategy contract
   */
  function initReserve(
    address asset,
    address aTokenAddress,
    address stableDebtAddress,
    address variableDebtAddress,
    address interestRateStrategyAddress
  ) external;

  /**
   * @notice Drop a reserve
   * @dev Only callable by the PoolConfigurator contract
   * @param asset The address of the underlying asset of the reserve
   */
  function dropReserve(address asset) external;

  /**
   * @notice Updates the address of the interest rate strategy contract
   * @dev Only callable by the PoolConfigurator contract
   * @param asset The address of the underlying asset of the reserve
   * @param rateStrategyAddress The address of the interest rate strategy contract
   */
  function setReserveInterestRateStrategyAddress(
    address asset,
    address rateStrategyAddress
  ) external;

  /**
   * @notice Sets the configuration bitmap of the reserve as a whole
   * @dev Only callable by the PoolConfigurator contract
   * @param asset The address of the underlying asset of the reserve
   * @param configuration The new configuration bitmap
   */
  function setConfiguration(
    address asset,
    DataTypes.ReserveConfigurationMap calldata configuration
  ) external;

  /**
   * @notice 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);

  /**
   * @notice 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);

  /**
   * @notice Returns the 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);

  /**
   * @notice Returns the normalized variable debt per unit of asset
   * @dev WARNING: This function is intended to be used primarily by the protocol itself to get a
   * "dynamic" variable index based on time, current stored index and virtual rate at the current
   * moment (approx. a borrower would get if opening a position). This means that is always used in
   * combination with variable debt supply/balances.
   * If using this function externally, consider that is possible to have an increasing normalized
   * variable debt that is not equivalent to how the variable debt index would be updated in storage
   * (e.g. only updates with non-zero variable debt supply)
   * @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);

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

  /**
   * @notice Validates and finalizes an aToken transfer
   * @dev Only callable by the overlying aToken of the `asset`
   * @param asset The address of the underlying asset of the aToken
   * @param from The user from which the aTokens are transferred
   * @param to The user receiving the aTokens
   * @param amount The amount being transferred/withdrawn
   * @param balanceFromBefore The aToken balance of the `from` user before the transfer
   * @param balanceToBefore The aToken balance of the `to` user before the transfer
   */
  function finalizeTransfer(
    address asset,
    address from,
    address to,
    uint256 amount,
    uint256 balanceFromBefore,
    uint256 balanceToBefore
  ) external;

  /**
   * @notice Returns the list of the underlying assets of all the initialized reserves
   * @dev It does not include dropped reserves
   * @return The addresses of the underlying assets of the initialized reserves
   */
  function getReservesList() external view returns (address[] memory);

  /**
   * @notice Returns the address of the underlying asset of a reserve by the reserve id as stored in the DataTypes.ReserveData struct
   * @param id The id of the reserve as stored in the DataTypes.ReserveData struct
   * @return The address of the reserve associated with id
   */
  function getReserveAddressById(uint16 id) external view returns (address);

  /**
   * @notice Returns the PoolAddressesProvider connected to this contract
   * @return The address of the PoolAddressesProvider
   */
  function ADDRESSES_PROVIDER() external view returns (IPoolAddressesProvider);

  /**
   * @notice Updates the protocol fee on the bridging
   * @param bridgeProtocolFee The part of the premium sent to the protocol treasury
   */
  function updateBridgeProtocolFee(uint256 bridgeProtocolFee) external;

  /**
   * @notice Updates flash loan premiums. Flash loan premium consists of two parts:
   * - A part is sent to aToken holders as extra, one time accumulated interest
   * - A part is collected by the protocol treasury
   * @dev The total premium is calculated on the total borrowed amount
   * @dev The premium to protocol is calculated on the total premium, being a percentage of `flashLoanPremiumTotal`
   * @dev Only callable by the PoolConfigurator contract
   * @param flashLoanPremiumTotal The total premium, expressed in bps
   * @param flashLoanPremiumToProtocol The part of the premium sent to the protocol treasury, expressed in bps
   */
  function updateFlashloanPremiums(
    uint128 flashLoanPremiumTotal,
    uint128 flashLoanPremiumToProtocol
  ) external;

  /**
   * @notice Configures a new category for the eMode.
   * @dev In eMode, the protocol allows very high borrowing power to borrow assets of the same category.
   * The category 0 is reserved as it's the default for volatile assets
   * @param id The id of the category
   * @param config The configuration of the category
   */
  function configureEModeCategory(uint8 id, DataTypes.EModeCategory memory config) external;

  /**
   * @notice Returns the data of an eMode category
   * @param id The id of the category
   * @return The configuration data of the category
   */
  function getEModeCategoryData(uint8 id) external view returns (DataTypes.EModeCategory memory);

  /**
   * @notice Allows a user to use the protocol in eMode
   * @param categoryId The id of the category
   */
  function setUserEMode(uint8 categoryId) external;

  /**
   * @notice Returns the eMode the user is using
   * @param user The address of the user
   * @return The eMode id
   */
  function getUserEMode(address user) external view returns (uint256);

  /**
   * @notice Resets the isolation mode total debt of the given asset to zero
   * @dev It requires the given asset has zero debt ceiling
   * @param asset The address of the underlying asset to reset the isolationModeTotalDebt
   */
  function resetIsolationModeTotalDebt(address asset) external;

  /**
   * @notice Returns the percentage of available liquidity that can be borrowed at once at stable rate
   * @return The percentage of available liquidity to borrow, expressed in bps
   */
  function MAX_STABLE_RATE_BORROW_SIZE_PERCENT() external view returns (uint256);

  /**
   * @notice Returns the total fee on flash loans
   * @return The total fee on flashloans
   */
  function FLASHLOAN_PREMIUM_TOTAL() external view returns (uint128);

  /**
   * @notice Returns the part of the bridge fees sent to protocol
   * @return The bridge fee sent to the protocol treasury
   */
  function BRIDGE_PROTOCOL_FEE() external view returns (uint256);

  /**
   * @notice Returns the part of the flashloan fees sent to protocol
   * @return The flashloan fee sent to the protocol treasury
   */
  function FLASHLOAN_PREMIUM_TO_PROTOCOL() external view returns (uint128);

  /**
   * @notice Returns the maximum number of reserves supported to be listed in this Pool
   * @return The maximum number of reserves supported
   */
  function MAX_NUMBER_RESERVES() external view returns (uint16);

  /**
   * @notice Mints the assets accrued through the reserve factor to the treasury in the form of aTokens
   * @param assets The list of reserves for which the minting needs to be executed
   */
  function mintToTreasury(address[] calldata assets) external;

  /**
   * @notice Rescue and transfer tokens locked in this contract
   * @param token The address of the token
   * @param to The address of the recipient
   * @param amount The amount of token to transfer
   */
  function rescueTokens(address token, address to, uint256 amount) external;

  /**
   * @notice Supplies an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
   * - E.g. User supplies 100 USDC and gets in return 100 aUSDC
   * @dev Deprecated: Use the `supply` function instead
   * @param asset The address of the underlying asset to supply
   * @param amount The amount to be supplied
   * @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;
}

// File: contracts/aave-v3/interfaces/IPoolAddressesProvider.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;

/**
 * @title IPoolAddressesProvider
 * @author Aave
 * @notice Defines the basic interface for a Pool Addresses Provider.
 */
interface IPoolAddressesProvider {
  /**
   * @dev Emitted when the market identifier is updated.
   * @param oldMarketId The old id of the market
   * @param newMarketId The new id of the market
   */
  event MarketIdSet(string indexed oldMarketId, string indexed newMarketId);

  /**
   * @dev Emitted when the pool is updated.
   * @param oldAddress The old address of the Pool
   * @param newAddress The new address of the Pool
   */
  event PoolUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the pool configurator is updated.
   * @param oldAddress The old address of the PoolConfigurator
   * @param newAddress The new address of the PoolConfigurator
   */
  event PoolConfiguratorUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the price oracle is updated.
   * @param oldAddress The old address of the PriceOracle
   * @param newAddress The new address of the PriceOracle
   */
  event PriceOracleUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the ACL manager is updated.
   * @param oldAddress The old address of the ACLManager
   * @param newAddress The new address of the ACLManager
   */
  event ACLManagerUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the ACL admin is updated.
   * @param oldAddress The old address of the ACLAdmin
   * @param newAddress The new address of the ACLAdmin
   */
  event ACLAdminUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the price oracle sentinel is updated.
   * @param oldAddress The old address of the PriceOracleSentinel
   * @param newAddress The new address of the PriceOracleSentinel
   */
  event PriceOracleSentinelUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the pool data provider is updated.
   * @param oldAddress The old address of the PoolDataProvider
   * @param newAddress The new address of the PoolDataProvider
   */
  event PoolDataProviderUpdated(address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when a new proxy is created.
   * @param id The identifier of the proxy
   * @param proxyAddress The address of the created proxy contract
   * @param implementationAddress The address of the implementation contract
   */
  event ProxyCreated(
    bytes32 indexed id,
    address indexed proxyAddress,
    address indexed implementationAddress
  );

  /**
   * @dev Emitted when a new non-proxied contract address is registered.
   * @param id The identifier of the contract
   * @param oldAddress The address of the old contract
   * @param newAddress The address of the new contract
   */
  event AddressSet(bytes32 indexed id, address indexed oldAddress, address indexed newAddress);

  /**
   * @dev Emitted when the implementation of the proxy registered with id is updated
   * @param id The identifier of the contract
   * @param proxyAddress The address of the proxy contract
   * @param oldImplementationAddress The address of the old implementation contract
   * @param newImplementationAddress The address of the new implementation contract
   */
  event AddressSetAsProxy(
    bytes32 indexed id,
    address indexed proxyAddress,
    address oldImplementationAddress,
    address indexed newImplementationAddress
  );

  /**
   * @notice Returns the id of the Aave market to which this contract points to.
   * @return The market id
   */
  function getMarketId() external view returns (string memory);

  /**
   * @notice Associates an id with a specific PoolAddressesProvider.
   * @dev This can be used to create an onchain registry of PoolAddressesProviders to
   * identify and validate multiple Aave markets.
   * @param newMarketId The market id
   */
  function setMarketId(string calldata newMarketId) external;

  /**
   * @notice Returns an address by its identifier.
   * @dev The returned address might be an EOA or a contract, potentially proxied
   * @dev It returns ZERO if there is no registered address with the given id
   * @param id The id
   * @return The address of the registered for the specified id
   */
  function getAddress(bytes32 id) external view returns (address);

  /**
   * @notice General function to update the implementation of a proxy registered with
   * certain `id`. If there is no proxy registered, it will instantiate one and
   * set as implementation the `newImplementationAddress`.
   * @dev IMPORTANT Use this function carefully, only for ids that don't have an explicit
   * setter function, in order to avoid unexpected consequences
   * @param id The id
   * @param newImplementationAddress The address of the new implementation
   */
  function setAddressAsProxy(bytes32 id, address newImplementationAddress) external;

  /**
   * @notice Sets an address for an id replacing the address saved in the addresses map.
   * @dev IMPORTANT Use this function carefully, as it will do a hard replacement
   * @param id The id
   * @param newAddress The address to set
   */
  function setAddress(bytes32 id, address newAddress) external;

  /**
   * @notice Returns the address of the Pool proxy.
   * @return The Pool proxy address
   */
  function getPool() external view returns (address);

  /**
   * @notice Updates the implementation of the Pool, or creates a proxy
   * setting the new `pool` implementation when the function is called for the first time.
   * @param newPoolImpl The new Pool implementation
   */
  function setPoolImpl(address newPoolImpl) external;

  /**
   * @notice Returns the address of the PoolConfigurator proxy.
   * @return The PoolConfigurator proxy address
   */
  function getPoolConfigurator() external view returns (address);

  /**
   * @notice Updates the implementation of the PoolConfigurator, or creates a proxy
   * setting the new `PoolConfigurator` implementation when the function is called for the first time.
   * @param newPoolConfiguratorImpl The new PoolConfigurator implementation
   */
  function setPoolConfiguratorImpl(address newPoolConfiguratorImpl) external;

  /**
   * @notice Returns the address of the price oracle.
   * @return The address of the PriceOracle
   */
  function getPriceOracle() external view returns (address);

  /**
   * @notice Updates the address of the price oracle.
   * @param newPriceOracle The address of the new PriceOracle
   */
  function setPriceOracle(address newPriceOracle) external;

  /**
   * @notice Returns the address of the ACL manager.
   * @return The address of the ACLManager
   */
  function getACLManager() external view returns (address);

  /**
   * @notice Updates the address of the ACL manager.
   * @param newAclManager The address of the new ACLManager
   */
  function setACLManager(address newAclManager) external;

  /**
   * @notice Returns the address of the ACL admin.
   * @return The address of the ACL admin
   */
  function getACLAdmin() external view returns (address);

  /**
   * @notice Updates the address of the ACL admin.
   * @param newAclAdmin The address of the new ACL admin
   */
  function setACLAdmin(address newAclAdmin) external;

  /**
   * @notice Returns the address of the price oracle sentinel.
   * @return The address of the PriceOracleSentinel
   */
  function getPriceOracleSentinel() external view returns (address);

  /**
   * @notice Updates the address of the price oracle sentinel.
   * @param newPriceOracleSentinel The address of the new PriceOracleSentinel
   */
  function setPriceOracleSentinel(address newPriceOracleSentinel) external;

  /**
   * @notice Returns the address of the data provider.
   * @return The address of the DataProvider
   */
  function getPoolDataProvider() external view returns (address);

  /**
   * @notice Updates the address of the data provider.
   * @param newDataProvider The address of the new DataProvider
   */
  function setPoolDataProvider(address newDataProvider) external;
}

// File: contracts/aave-v3/interfaces/IPoolDataProvider.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;

import { IPoolAddressesProvider } from "./IPoolAddressesProvider.sol";

/**
 * @title IPoolDataProvider
 * @author Aave
 * @notice Defines the basic interface of a PoolDataProvider
 */
interface IPoolDataProvider {
  struct TokenData {
    string symbol;
    address tokenAddress;
  }

  /**
   * @notice Returns the address for the PoolAddressesProvider contract.
   * @return The address for the PoolAddressesProvider contract
   */
  function ADDRESSES_PROVIDER() external view returns (IPoolAddressesProvider);

  /**
   * @notice Returns the list of the existing reserves in the pool.
   * @dev Handling MKR and ETH in a different way since they do not have standard `symbol` functions.
   * @return The list of reserves, pairs of symbols and addresses
   */
  function getAllReservesTokens() external view returns (TokenData[] memory);

  /**
   * @notice Returns the list of the existing ATokens in the pool.
   * @return The list of ATokens, pairs of symbols and addresses
   */
  function getAllATokens() external view returns (TokenData[] memory);

  /**
   * @notice Returns the configuration data of the reserve
   * @dev Not returning borrow and supply caps for compatibility, nor pause flag
   * @param asset The address of the underlying asset of the reserve
   * @return decimals The number of decimals of the reserve
   * @return ltv The ltv of the reserve
   * @return liquidationThreshold The liquidationThreshold of the reserve
   * @return liquidationBonus The liquidationBonus of the reserve
   * @return reserveFactor The reserveFactor of the reserve
   * @return usageAsCollateralEnabled True if the usage as collateral is enabled, false otherwise
   * @return borrowingEnabled True if borrowing is enabled, false otherwise
   * @return stableBorrowRateEnabled True if stable rate borrowing is enabled, false otherwise
   * @return isActive True if it is active, false otherwise
   * @return isFrozen True if it is frozen, false otherwise
   */
  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
    );

  /**
   * @notice Returns the efficiency mode category of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The eMode id of the reserve
   */
  function getReserveEModeCategory(address asset) external view returns (uint256);

  /**
   * @notice Returns the caps parameters of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return borrowCap The borrow cap of the reserve
   * @return supplyCap The supply cap of the reserve
   */
  function getReserveCaps(
    address asset
  ) external view returns (uint256 borrowCap, uint256 supplyCap);

  /**
   * @notice Returns if the pool is paused
   * @param asset The address of the underlying asset of the reserve
   * @return isPaused True if the pool is paused, false otherwise
   */
  function getPaused(address asset) external view returns (bool isPaused);

  /**
   * @notice Returns the siloed borrowing flag
   * @param asset The address of the underlying asset of the reserve
   * @return True if the asset is siloed for borrowing
   */
  function getSiloedBorrowing(address asset) external view returns (bool);

  /**
   * @notice Returns the protocol fee on the liquidation bonus
   * @param asset The address of the underlying asset of the reserve
   * @return The protocol fee on liquidation
   */
  function getLiquidationProtocolFee(address asset) external view returns (uint256);

  /**
   * @notice Returns the unbacked mint cap of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The unbacked mint cap of the reserve
   */
  function getUnbackedMintCap(address asset) external view returns (uint256);

  /**
   * @notice Returns the debt ceiling of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The debt ceiling of the reserve
   */
  function getDebtCeiling(address asset) external view returns (uint256);

  /**
   * @notice Returns the debt ceiling decimals
   * @return The debt ceiling decimals
   */
  function getDebtCeilingDecimals() external pure returns (uint256);

  /**
   * @notice Returns the reserve data
   * @param asset The address of the underlying asset of the reserve
   * @return unbacked The amount of unbacked tokens
   * @return accruedToTreasuryScaled The scaled amount of tokens accrued to treasury that is to be minted
   * @return totalAToken The total supply of the aToken
   * @return totalStableDebt The total stable debt of the reserve
   * @return totalVariableDebt The total variable debt of the reserve
   * @return liquidityRate The liquidity rate of the reserve
   * @return variableBorrowRate The variable borrow rate of the reserve
   * @return stableBorrowRate The stable borrow rate of the reserve
   * @return averageStableBorrowRate The average stable borrow rate of the reserve
   * @return liquidityIndex The liquidity index of the reserve
   * @return variableBorrowIndex The variable borrow index of the reserve
   * @return lastUpdateTimestamp The timestamp of the last update of the reserve
   */
  function getReserveData(
    address asset
  )
    external
    view
    returns (
      uint256 unbacked,
      uint256 accruedToTreasuryScaled,
      uint256 totalAToken,
      uint256 totalStableDebt,
      uint256 totalVariableDebt,
      uint256 liquidityRate,
      uint256 variableBorrowRate,
      uint256 stableBorrowRate,
      uint256 averageStableBorrowRate,
      uint256 liquidityIndex,
      uint256 variableBorrowIndex,
      uint40 lastUpdateTimestamp
    );

  /**
   * @notice Returns the total supply of aTokens for a given asset
   * @param asset The address of the underlying asset of the reserve
   * @return The total supply of the aToken
   */
  function getATokenTotalSupply(address asset) external view returns (uint256);

  /**
   * @notice Returns the total debt for a given asset
   * @param asset The address of the underlying asset of the reserve
   * @return The total debt for asset
   */
  function getTotalDebt(address asset) external view returns (uint256);

  /**
   * @notice Returns the user data in a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param user The address of the user
   * @return currentATokenBalance The current AToken balance of the user
   * @return currentStableDebt The current stable debt of the user
   * @return currentVariableDebt The current variable debt of the user
   * @return principalStableDebt The principal stable debt of the user
   * @return scaledVariableDebt The scaled variable debt of the user
   * @return stableBorrowRate The stable borrow rate of the user
   * @return liquidityRate The liquidity rate of the reserve
   * @return stableRateLastUpdated The timestamp of the last update of the user stable rate
   * @return usageAsCollateralEnabled True if the user is using the asset as collateral, false
   *         otherwise
   */
  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
    );

  /**
   * @notice Returns the token addresses of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return aTokenAddress The AToken address of the reserve
   * @return stableDebtTokenAddress The StableDebtToken address of the reserve
   * @return variableDebtTokenAddress The VariableDebtToken address of the reserve
   */
  function getReserveTokensAddresses(
    address asset
  )
    external
    view
    returns (
      address aTokenAddress,
      address stableDebtTokenAddress,
      address variableDebtTokenAddress
    );

  /**
   * @notice Returns the address of the Interest Rate strategy
   * @param asset The address of the underlying asset of the reserve
   * @return irStrategyAddress The address of the Interest Rate strategy
   */
  function getInterestRateStrategyAddress(
    address asset
  ) external view returns (address irStrategyAddress);

  /**
   * @notice Returns whether the reserve has FlashLoans enabled or disabled
   * @param asset The address of the underlying asset of the reserve
   * @return True if FlashLoans are enabled, false otherwise
   */
  function getFlashLoanEnabled(address asset) external view returns (bool);
}

// File: contracts/aave-v3/interfaces/IPriceOracle.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;

interface IPriceOracle {
  function getAssetPrice(address _asset) external view returns (uint256);
}

// File: contracts/aave-v3/protocol/libraries/math/PercentageMath.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.0;

/**
 * @title PercentageMath library
 * @author Aave
 * @notice Provides functions to perform percentage calculations
 * @dev Percentages are defined by default with 2 decimals of precision (100.00). The precision is indicated by PERCENTAGE_FACTOR
 * @dev Operations are rounded. If a value is >=.5, will be rounded up, otherwise rounded down.
 */
library PercentageMath {
  // Maximum percentage factor (100.00%)
  uint256 internal constant PERCENTAGE_FACTOR = 1e4;

  // Half percentage factor (50.00%)
  uint256 internal constant HALF_PERCENTAGE_FACTOR = 0.5e4;

  /**
   * @notice Executes a percentage multiplication
   * @dev assembly optimized for improved gas savings, see https://twitter.com/transmissions11/status/1451131036377571328
   * @param value The value of which the percentage needs to be calculated
   * @param percentage The percentage of the value to be calculated
   * @return result value percentmul percentage
   */
  function percentMul(uint256 value, uint256 percentage) internal pure returns (uint256 result) {
    // to avoid overflow, value <= (type(uint256).max - HALF_PERCENTAGE_FACTOR) / percentage
    assembly {
      if iszero(
        or(
          iszero(percentage),
          iszero(gt(value, div(sub(not(0), HALF_PERCENTAGE_FACTOR), percentage)))
        )
      ) {
        revert(0, 0)
      }

      result := div(add(mul(value, percentage), HALF_PERCENTAGE_FACTOR), PERCENTAGE_FACTOR)
    }
  }

  /**
   * @notice Executes a percentage division
   * @dev assembly optimized for improved gas savings, see https://twitter.com/transmissions11/status/1451131036377571328
   * @param value The value of which the percentage needs to be calculated
   * @param percentage The percentage of the value to be calculated
   * @return result value percentdiv percentage
   */
  function percentDiv(uint256 value, uint256 percentage) internal pure returns (uint256 result) {
    // to avoid overflow, value <= (type(uint256).max - halfPercentage) / PERCENTAGE_FACTOR
    assembly {
      if or(
        iszero(percentage),
        iszero(iszero(gt(value, div(sub(not(0), div(percentage, 2)), PERCENTAGE_FACTOR))))
      ) {
        revert(0, 0)
      }

      result := div(add(mul(value, PERCENTAGE_FACTOR), div(percentage, 2)), percentage)
    }
  }
}

// File: contracts/aave-v3/protocol/libraries/types/DataTypes.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.0;

library DataTypes {
  struct ReserveData {
    //stores the reserve configuration
    ReserveConfigurationMap configuration;
    //the liquidity index. Expressed in ray
    uint128 liquidityIndex;
    //the current supply rate. Expressed in ray
    uint128 currentLiquidityRate;
    //variable borrow index. Expressed in ray
    uint128 variableBorrowIndex;
    //the current variable borrow rate. Expressed in ray
    uint128 currentVariableBorrowRate;
    //the current stable borrow rate. Expressed in ray
    uint128 currentStableBorrowRate;
    //timestamp of last update
    uint40 lastUpdateTimestamp;
    //the id of the reserve. Represents the position in the list of the active reserves
    uint16 id;
    //aToken address
    address aTokenAddress;
    //stableDebtToken address
    address stableDebtTokenAddress;
    //variableDebtToken address
    address variableDebtTokenAddress;
    //address of the interest rate strategy
    address interestRateStrategyAddress;
    //the current treasury balance, scaled
    uint128 accruedToTreasury;
    //the outstanding unbacked aTokens minted through the bridging feature
    uint128 unbacked;
    //the outstanding debt borrowed against this asset in isolation mode
    uint128 isolationModeTotalDebt;
  }

  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: asset is paused
    //bit 61: borrowing in isolation mode is enabled
    //bit 62-63: reserved
    //bit 64-79: reserve factor
    //bit 80-115 borrow cap in whole tokens, borrowCap == 0 => no cap
    //bit 116-151 supply cap in whole tokens, supplyCap == 0 => no cap
    //bit 152-167 liquidation protocol fee
    //bit 168-175 eMode category
    //bit 176-211 unbacked mint cap in whole tokens, unbackedMintCap == 0 => minting disabled
    //bit 212-251 debt ceiling for isolation mode with (ReserveConfiguration::DEBT_CEILING_DECIMALS) decimals
    //bit 252-255 unused

    uint256 data;
  }

  struct UserConfigurationMap {
    /**
     * @dev Bitmap of the users collaterals and borrows. It is divided in pairs of bits, one pair per asset.
     * The first bit indicates if an asset is used as collateral by the user, the second whether an
     * asset is borrowed by the user.
     */
    uint256 data;
  }

  struct EModeCategory {
    // each eMode category has a custom ltv and liquidation threshold
    uint16 ltv;
    uint16 liquidationThreshold;
    uint16 liquidationBonus;
    // each eMode category may or may not have a custom oracle to override the individual assets price oracles
    address priceSource;
    string label;
  }

  enum InterestRateMode {
    NONE,
    STABLE,
    VARIABLE
  }

  struct ReserveCache {
    uint256 currScaledVariableDebt;
    uint256 nextScaledVariableDebt;
    uint256 currPrincipalStableDebt;
    uint256 currAvgStableBorrowRate;
    uint256 currTotalStableDebt;
    uint256 nextAvgStableBorrowRate;
    uint256 nextTotalStableDebt;
    uint256 currLiquidityIndex;
    uint256 nextLiquidityIndex;
    uint256 currVariableBorrowIndex;
    uint256 nextVariableBorrowIndex;
    uint256 currLiquidityRate;
    uint256 currVariableBorrowRate;
    uint256 reserveFactor;
    ReserveConfigurationMap reserveConfiguration;
    address aTokenAddress;
    address stableDebtTokenAddress;
    address variableDebtTokenAddress;
    uint40 reserveLastUpdateTimestamp;
    uint40 stableDebtLastUpdateTimestamp;
  }

  struct ExecuteLiquidationCallParams {
    uint256 reservesCount;
    uint256 debtToCover;
    address collateralAsset;
    address debtAsset;
    address user;
    bool receiveAToken;
    address priceOracle;
    uint8 userEModeCategory;
    address priceOracleSentinel;
  }

  struct ExecuteSupplyParams {
    address asset;
    uint256 amount;
    address onBehalfOf;
    uint16 referralCode;
  }

  struct ExecuteBorrowParams {
    address asset;
    address user;
    address onBehalfOf;
    uint256 amount;
    InterestRateMode interestRateMode;
    uint16 referralCode;
    bool releaseUnderlying;
    uint256 maxStableRateBorrowSizePercent;
    uint256 reservesCount;
    address oracle;
    uint8 userEModeCategory;
    address priceOracleSentinel;
  }

  struct ExecuteRepayParams {
    address asset;
    uint256 amount;
    InterestRateMode interestRateMode;
    address onBehalfOf;
    bool useATokens;
  }

  struct ExecuteWithdrawParams {
    address asset;
    uint256 amount;
    address to;
    uint256 reservesCount;
    address oracle;
    uint8 userEModeCategory;
  }

  struct ExecuteSetUserEModeParams {
    uint256 reservesCount;
    address oracle;
    uint8 categoryId;
  }

  struct FinalizeTransferParams {
    address asset;
    address from;
    address to;
    uint256 amount;
    uint256 balanceFromBefore;
    uint256 balanceToBefore;
    uint256 reservesCount;
    address oracle;
    uint8 fromEModeCategory;
  }

  struct FlashloanParams {
    address receiverAddress;
    address[] assets;
    uint256[] amounts;
    uint256[] interestRateModes;
    address onBehalfOf;
    bytes params;
    uint16 referralCode;
    uint256 flashLoanPremiumToProtocol;
    uint256 flashLoanPremiumTotal;
    uint256 maxStableRateBorrowSizePercent;
    uint256 reservesCount;
    address addressesProvider;
    uint8 userEModeCategory;
    bool isAuthorizedFlashBorrower;
  }

  struct FlashloanSimpleParams {
    address receiverAddress;
    address asset;
    uint256 amount;
    bytes params;
    uint16 referralCode;
    uint256 flashLoanPremiumToProtocol;
    uint256 flashLoanPremiumTotal;
  }

  struct FlashLoanRepaymentParams {
    uint256 amount;
    uint256 totalPremium;
    uint256 flashLoanPremiumToProtocol;
    address asset;
    address receiverAddress;
    uint16 referralCode;
  }

  struct CalculateUserAccountDataParams {
    UserConfigurationMap userConfig;
    uint256 reservesCount;
    address user;
    address oracle;
    uint8 userEModeCategory;
  }

  struct ValidateBorrowParams {
    ReserveCache reserveCache;
    UserConfigurationMap userConfig;
    address asset;
    address userAddress;
    uint256 amount;
    InterestRateMode interestRateMode;
    uint256 maxStableLoanPercent;
    uint256 reservesCount;
    address oracle;
    uint8 userEModeCategory;
    address priceOracleSentinel;
    bool isolationModeActive;
    address isolationModeCollateralAddress;
    uint256 isolationModeDebtCeiling;
  }

  struct ValidateLiquidationCallParams {
    ReserveCache debtReserveCache;
    uint256 totalDebt;
    uint256 healthFactor;
    address priceOracleSentinel;
  }

  struct CalculateInterestRatesParams {
    uint256 unbacked;
    uint256 liquidityAdded;
    uint256 liquidityTaken;
    uint256 totalStableDebt;
    uint256 totalVariableDebt;
    uint256 averageStableBorrowRate;
    uint256 reserveFactor;
    address reserve;
    address aToken;
  }

  struct InitReserveParams {
    address asset;
    address aTokenAddress;
    address stableDebtAddress;
    address variableDebtAddress;
    address interestRateStrategyAddress;
    uint16 reservesCount;
    uint16 maxNumberReserves;
  }
}

// File: contracts/backloop/interfaces/ILeverager.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.8.10;

import { IFlashLoanSimpleReceiver } from "../../aave-v3/flashloan/interfaces/IFlashLoanSimpleReceiver.sol";

interface ILeverager is IFlashLoanSimpleReceiver {
  /**
   * @dev Emitted when the sender swap tokens.
   * @param account Address who create operation.
   * @param toToken The address of the token to buy.
   * @param fromToken The address of the token to sell.
   * @param amount The amount of the token to sell.
   * @param buyAmount The amount of tokens received.
   */
  event Exchange(
    address indexed account,
    address toToken,
    address fromToken,
    uint256 amount,
    uint256 buyAmount
  );

  /**
   * @dev Emitted when a user opens a new position.
   * @param account Address of the user who opened the position.
   * @param supplyAmount The amount of the asset supplied to the protocol.
   * @param collateralAmount The amount of collateral provided.
   * @param debtAmount The amount of debt taken on by the user.
   * @param flashLoanFee The fee associated with using the flash loan.
   * @param protocolFee The fee taken by the protocol for the operation.
   */
  event OpenPosition(
    address indexed account,
    uint256 supplyAmount,
    uint256 collateralAmount,
    uint256 debtAmount,
    uint256 flashLoanFee,
    uint256 protocolFee
  );

  /**
   * @dev Emitted when a user closes an existing position.
   * @param account Address of the user who closed the position.
   * @param withdrawnAmount The amount withdrawn from the position.
   * @param repaidAmount The amount repaid to cover the debt.
   * @param flashLoanFee The fee associated with using the flash loan for closing.
   * @param protocolFee The fee taken by the protocol for the operation.
   */
  event ClosePosition(
    address indexed account,
    uint256 withdrawnAmount,
    uint256 repaidAmount,
    uint256 flashLoanFee,
    uint256 protocolFee
  );

  /**
   * @dev Initiates a flashloan leveraging mechanism.
   * @notice Users must approve this contract for COLLATERAL_ASSET and DEBT_ASSET prior to call.
   *         Users must approveDelegation to this contract prior to call.
   *         Users must use reserve as collateral.
   * @param amount Amount to be used as basis for the flashloan.
   * @param multiplier Multiplier for flashloan amount. Determines how much will be borrowed in relation to the user's input.
   * @param data Data from router(1Inch or Uniswap) API.
   */
  function openPosition(uint256 amount, uint256 multiplier, bytes calldata data) external;

  /**
   * @dev Initiates a flashloan leveraging mechanism to close a position.
   * @notice Users must approve this contract for asDAI prior to call.
   *         User inputs the amount of the debt asset to be repaid
   * -> send api call to 1inch or uniswap to get the amount of DAI to be flashloaned - debt asset -> DAI
   * -> pass the DAI amount to this amount parameter
   * -> send api call again to 1inch or uniswap to get the calldata for the swap - DAI -> debt asset
   * @param amount Amount to be used as basis for the flashloan.
   * @param data Data from router(1Inch or Uniswap) API.
   */
  function closePosition(uint256 amount, bytes calldata data) external;

  /**
   * @dev Approves the DAI to 1Inch or Uniswap router.
   * @param router Address of the router.
   */
  function approveRouter(address router) external;

  /**
   * @dev Calculates the amount to be borrowed from Aave v3.
   * @param asset The asset to be borrowed.
   * @param amount The origin amount of DAI supplied by the user.
   * @param multiplier Multiplier for flashloan amount. Determines how much will be borrowed in relation to the user's input.
   */
  function getBorrowAmount(
    address asset,
    uint256 amount,
    uint256 multiplier
  ) external view returns (uint256);

  /**
   * @dev Fetches the debt asset's address.
   * @return Address of the debt asset.
   */
  function DEBT_ASSET() external view returns (address);

  /**
   * @dev Fetches the current protocol fee.
   * @return Current protocol fee.
   */
  function PROTOCOL_FEE() external view returns (uint256);

  /**
   * @dev Fetches the DEX router's address.
   * @return Address of the DEX router.
   */
  function ROUTER() external view returns (address);

  /**
   * @dev Fetches the treasury's address.
   * @return Address of the treasury.
   */
  function TREASURY_ADDRESS() external view returns (address);

  /**
   * @dev Fetches the withdrawal ratio.
   * @return withdrawal ratio.
   */
  function WITHDRAWAL_RATIO() external view returns (uint256);

  /**
   * @dev Allows owner to update address of the debt asset.
   * @param debtAsset Address of the new debt asset.
   */
  function setDebtAsset(address debtAsset) external;

  /**
   * @dev Allows owner to set a new protocol fee.
   * @param protocolFee New fee for the protocol.
   */
  function setProtocolFee(uint256 protocolFee) external;

  /**
   * @dev Allows owner to set a new DEX router address.
   * @param router Address of the new DEX router.
   */
  function setRouter(address router) external;

  /**
   * @dev Allows owner to set a new treasury address.
   * @param treasuryAddress Address of the new treasury.
   */
  function setTreasuryAddress(address treasuryAddress) external;

  /**
   * @dev Allows owner to set a new withdrawal ratio.
   * @param withdrawalRatio New ratio for withdrawal.
   */
  function setWithdrawalRatio(uint256 withdrawalRatio) external;
}

// File: contracts/backloop/Leverager.sol



// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.8.10;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/interfaces/IERC4626.sol";
import { ILeverager } from "./interfaces/ILeverager.sol";
import { IPool } from "../aave-v3/interfaces/IPool.sol";
import { IPoolAddressesProvider } from "../aave-v3/interfaces/IPoolAddressesProvider.sol";
import { IPoolDataProvider } from "../aave-v3/interfaces/IPoolDataProvider.sol";
import { IPriceOracle } from "../aave-v3/interfaces/IPriceOracle.sol";
import { FlashLoanSimpleReceiverBase } from "../aave-v3/flashloan/base/FlashLoanSimpleReceiverBase.sol";
import { PercentageMath } from "../aave-v3/protocol/libraries/math/PercentageMath.sol";

enum Action {
  Open,
  Close
}

// use Aave v3 flashloan
contract Leverager is ILeverager, FlashLoanSimpleReceiverBase, Ownable {
  using SafeERC20 for IERC20;
  using PercentageMath for uint256;

  /* ============ Constants ============ */
  uint16 internal constant REFERRAL_CODE = 0;
  uint256 internal constant INTEREST_RATE_MODE = 2;
  address internal constant DAI = 0x6B175474E89094C44Da98b954EedeAC495271d0F; // Address of the asset to be supplied to yield protocol
  address internal constant SDAI = 0x83F20F44975D03b1b09e64809B757c47f942BEeA; // Address of the asset to be deposited

  /* ============ State Variables ============ */
  address internal _debtAsset; // Address of the asset to be borrowed
  // Address of a dex router (e.g., Uniswap, 1Inch).
  address internal _router;
  address internal _treasuryAddress; // 20
  // Fee of the protocol, expressed in basis points (bps).
  uint256 internal _protocolFee;
  // Ratio of the amount to be withdrawn from Aave v3 to not touch liquidation threshold.
  uint256 internal _withdrawalRatio;

  struct FlashLoanVars {
    address router;
    address debtAsset;
    uint256 supplyAmount;
    uint256 depositAmount;
    uint256 borrowAmount;
    uint256 repayAmount;
    uint256 withdrawnAmount;
    uint256 protocolFee;
    IPool aave;
  }

  constructor(
    IPoolAddressesProvider provider,
    address debtAsset,
    address router,
    address treasuryAddress,
    uint256 protocolFee,
    uint256 withdrawalRatio
  ) FlashLoanSimpleReceiverBase(provider) {
    _debtAsset = debtAsset;
    _router = router;
    _treasuryAddress = treasuryAddress;
    _protocolFee = protocolFee;
    _withdrawalRatio = withdrawalRatio;
  }

  /* ============ External Functions ============ */

  /**
   * @dev Initiates a flashloan leveraging mechanism to open a position.
   * @notice Users must approve this contract for DAI prior to call.
   *         Users must approveDelegation debt asset to this contract prior to call.
   *         Users must use reserve as collateral.
   * @param amount Amount to be used as basis for the flashloan.
   * @param multiplier Multiplier for flashloan amount. Determines how much will be borrowed in relation to the user's input.
   * @param data Data from router(1Inch or Uniswap) API.
   */
  function openPosition(uint256 amount, uint256 multiplier, bytes calldata data) external {
    bytes memory params = abi.encode(msg.sender, amount, data, Action.Open);

    POOL.flashLoanSimple(
      address(this), // receiver
      DAI, // flashloan asset
      amount.percentMul(multiplier), // flashloan amount
      params,
      REFERRAL_CODE
    );
  }

  /**
   * @dev Initiates a flashloan leveraging mechanism to close a position.
   * @notice Users must approve this contract for asDAI prior to call.
   * -> send api call to 1inch or uniswap to get the amount of DAI to be flashloaned - debt asset -> DAI
   * -> pass the DAI amount to this amount parameter
   * -> send api call again to 1inch or uniswap to get the calldata for the swap - DAI -> debt asset
   * @param amount Amount to be used as basis for the flashloan.
   * @param data Data from router(1Inch or Uniswap) API.
   */
  function closePosition(uint256 amount, bytes calldata data) external {
    bytes memory params = abi.encode(msg.sender, amount, data, Action.Close);

    POOL.flashLoanSimple(
      address(this), // receiver
      DAI, // flashloan asset
      amount, // flashloan amount
      params,
      REFERRAL_CODE
    );
  }

  /**
   * @dev Handles the logic post receiving the flashloan.
   * @param asset Address of the flashloan asset.
   * @param amount Amount of the flashloan.
   * @param premium Amount to be paid as premium for the flashloan.
   * @param initiator Address initiating the flashloan.
   * @param params Additional data required for processing.
   * @return A boolean indicating if the operation was successful.
   */
  function executeOperation(
    address asset,
    uint256 amount,
    uint256 premium,
    address initiator,
    bytes calldata params
  ) external returns (bool) {
    // _amount = amount of user input
    (address sender, uint256 _amount, bytes memory data, Action action) = abi.decode(
      params,
      (address, uint256, bytes, Action)
    );
    FlashLoanVars memory vars;

    vars.debtAsset = _debtAsset;
    vars.router = _router; // 1Inch or Uniswap
    vars.aave = POOL; // aave v3
    vars.protocolFee = _protocolFee;

    if (action == Action.Open) {
      // Read storage variables once and keep them in memory
      vars.supplyAmount = _amount + amount; // flashloan amount + amount from sender

      // Step 1: Transfer assets from sender
      IERC20(asset).safeTransferFrom(sender, address(this), _amount);

      // Step 2: Supply dai to sDai vault
      vars.depositAmount = _supplyToSDai(asset, vars.supplyAmount);

      // Step 3: Supply to Aave v3
      _depositToAave(vars.depositAmount, sender, vars.aave);

      // Step 4: Borrow from Aave v3
      vars.borrowAmount = _borrowFromAave(vars.debtAsset, vars.depositAmount, sender, vars.aave);

      // Step 5: Perform Swap debt asset to DAI
      _swap(vars.router, DAI, vars.debtAsset, vars.borrowAmount, sender, data);

      // Step 6: Repay flashloan, charge fees and transfer leftover to sender
      _repayLoanAndFees(amount, premium, sender, vars.protocolFee, address(vars.aave));

      emit OpenPosition(
        sender,
        _amount,
        vars.depositAmount,
        vars.borrowAmount,
        premium,
        vars.protocolFee
      );
    } else {
      // Step 1: Swap DAI to debt asset
      vars.repayAmount = _swap(vars.router, vars.debtAsset, DAI, amount, sender, data);

      // Step 2: Repay debt asset to Aave v3
      _repayToAave(vars.debtAsset, vars.repayAmount, sender, vars.aave);

      // Step 3: Withdraw sDAI from Aave v3
      vars.withdrawnAmount = _withdrawFromAave(sender, vars.aave);

      // Step 4: Withdraw DAI from sDAI vault
      _redeemFromSDai(vars.withdrawnAmount);

      // Step 5: Repay flashloan, charge fees and transfer principal + profit to the sender
      _repayLoanAndFees(amount, premium, sender, vars.protocolFee, address(vars.aave));

      // Step 6: Transfer leftover amount of debt asset to the sender
      IERC20(vars.debtAsset).safeTransfer(sender, IERC20(vars.debtAsset).balanceOf(address(this)));

      emit ClosePosition(sender, vars.withdrawnAmount, vars.repayAmount, premium, vars.protocolFee);
    }

    return true;
  }

  /**
   * @dev Approves the DAI to 1Inch or Uniswap router.
   * @param router Address of the router.
   */
  function approveRouter(address router) external onlyOwner {
    IERC20(_debtAsset).approve(router, type(uint256).max);
  }

  /**
   * @dev Calculates the amount to be borrowed from Aave v3.
   * @param asset The asset to be borrowed.
   * @param amount The origin amount of DAI supplied by the user.
   * @param multiplier Multiplier for flashloan amount. Determines how much will be borrowed in relation to the user's input.
   */
  function getBorrowAmount(
    address asset,
    uint256 amount,
    uint256 multiplier
  ) external view returns (uint256) {
    uint256 flashLoanAmount = amount.percentMul(multiplier);
    // sDAI share that deposited to Aave v3
    uint256 depositAmount = IERC4626(SDAI).previewDeposit(amount + flashLoanAmount);

    return _calcBorrowAmount(asset, depositAmount);
  }

  /**
   * @dev Fetches the debt asset's address.
   * @return Address of the debt asset.
   */
  function DEBT_ASSET() external view returns (address) {
    return _debtAsset;
  }

  /**
   * @dev Fetches the current protocol fee.
   * @return Current protocol fee.
   */
  function PROTOCOL_FEE() external view returns (uint256) {
    return _protocolFee;
  }

  /**
   * @dev Fetches the DEX router's address.
   * @return Address of the DEX router.
   */
  function ROUTER() external view returns (address) {
    return _router;
  }

  /**
   * @dev Fetches the treasury's address.
   * @return Address of the treasury.
   */
  function TREASURY_ADDRESS() external view returns (address) {
    return _treasuryAddress;
  }

  /**
   * @dev Fetches the withdrawal ratio.
   * @return withdrawal ratio.
   */
  function WITHDRAWAL_RATIO() external view returns (uint256) {
    return _withdrawalRatio;
  }

  /**
   * @dev Allows owner to update address of the debt asset.
   * @param debtAsset Address of the new debt asset.
   */
  function setDebtAsset(address debtAsset) external onlyOwner {
    _debtAsset = debtAsset;
  }

  /**
   * @dev Allows owner to set a new protocol fee.
   * @param protocolFee New fee for the protocol.
   */
  function setProtocolFee(uint256 protocolFee) external onlyOwner {
    _protocolFee = protocolFee;
  }

  /**
   * @dev Allows owner to set a new DEX router address.
   * @param router Address of the new DEX router.
   */
  function setRouter(address router) external onlyOwner {
    _router = router;
  }

  /**
   * @dev Allows owner to set a new treasury address.
   * @param treasuryAddress Address of the new treasury.
   */
  function setTreasuryAddress(address treasuryAddress) external onlyOwner {
    _treasuryAddress = treasuryAddress;
  }

  /**
   * @dev Allows owner to set a new withdrawal ratio.
   * @param withdrawalRatio New ratio for withdrawal.
   */
  function setWithdrawalRatio(uint256 withdrawalRatio) external onlyOwner {
    _withdrawalRatio = withdrawalRatio;
  }

  /* ============ Internal Functions ============ */

  /**
   * @dev Supplies assets to a yield-generating protocol. e.g. supply DAI to DSR(sDAI).
   * @notice This function takes the sum of the flash loan amount and the deposit amount to supply to a yield protocol.
   * @param asset The asset that will be supplied to the yield protocol.
   * @param amount The leveraged amount deposited of sDAI by the user.
   * @return The sDAI balance(shares of sDAI vault) to supply to the aave v3
   */
  function _supplyToSDai(address asset, uint256 amount) internal returns (uint256) {
    // approve DAI to sDAI
    if (IERC20(asset).allowance(address(this), SDAI) < amount) {
      IERC20(asset).safeApprove(SDAI, type(uint256).max);
    }

    return IERC4626(SDAI).deposit(amount, address(this));
  }

  /**
   * @dev Redeems sDAI shares for DAI tokens.
   * @notice This function takes the amount of sDAI shares to redeem and returns the amount of DAI tokens withdrawn from the sDAI vault.
   * @param shares The number of sDAI shares to redeem.
   * @return amount The amount of DAI tokens withdrawn from the sDAI vault.
   */
  function _redeemFromSDai(uint256 shares) internal returns (uint256) {
    return IERC4626(SDAI).redeem(shares, address(this), address(this));
  }

  /**
   * @dev Deposit yield-bearing assets to Aave v3. e.g. supply sDAI to Aave v3.
   * @notice This function takes yield-bearing assets and deposits them into Aave v3.
   * @param amount The amount of the yield-bearing asset.
   * @param onBehalfOf The address that will receive the aTokens.
   * @param aave The Aave v3 lending pool.
   */
  function _depositToAave(uint256 amount, address onBehalfOf, IPool aave) internal {
    // approve sDAI to aave v3
    if (IERC20(SDAI).allowance(address(this), address(aave)) < amount) {
      IERC20(SDAI).safeApprove(address(aave), type(uint256).max);
    }

    // deposit sDAI to aave v3 on behalf of sender
    aave.supply(SDAI, amount, onBehalfOf, REFERRAL_CODE);
  }

  /**
   * @dev Borrows an asset from Aave. e.g. borrow debt asset from Aave v3.
   * @notice This function borrows an amount based on the supplied collateral's LTV ratio.
   * @param asset The asset that will be borrowed from Aave v3.
   * @param depositAmount The amount of sDAI deposited to Aave pool.
   * @param onBehalfOf The address that will receive the borrowed amount.
   * @param pool The Aave v3 lending pool.
   * @return The amount borrowed.
   */
  function _borrowFromAave(
    address asset,
    uint256 depositAmount,
    address onBehalfOf,
    IPool pool
  ) internal returns (uint256) {
    uint256 amount = _calcBorrowAmount(asset, depositAmount);

    // borrow debt asset from aave v3 on behalf of sender
    pool.borrow(asset, amount, INTEREST_RATE_MODE, REFERRAL_CODE, onBehalfOf);

    return amount;
  }

  /**
   * @dev Repays a debt to the Aave lending pool.
   * @param asset The asset to repay (e.g., DAI, USDC).
   * @param amount The amount to repay.
   * @param onBehalfOf Address of the account for which the debt will be repaid.
   * @param pool The Aave lending pool.
   */
  function _repayToAave(address asset, uint256 amount, address onBehalfOf, IPool pool) internal {
    // approve debt asset to aave v3
    if (IERC20(asset).allowance(address(this), address(pool)) < amount) {
      IERC20(asset).safeApprove(address(pool), type(uint256).max);
    }
    // calc maximum withdrawable amount
    pool.repay(asset, amount, INTEREST_RATE_MODE, onBehalfOf);
  }

  /**
   * @dev Withdraws aToken (interest-bearing token) from Aave.
   * @notice This function transfers asDAI from the sender to this contract and withdraws the amount of sDAI from Aave v3.
   * @param sender The address that initiated the operation.
   * @param pool The Aave lending pool.
   * @return The amount of sDAI withdrawn.
   */
  function _withdrawFromAave(address sender, IPool pool) internal returns (uint256) {
    address aTokenAddress = pool.getReserveData(SDAI).aTokenAddress;
    uint256 balance = IERC20(aTokenAddress).balanceOf(sender);

    if (_userHasMultipleCollaterals(sender, pool)) {
      balance = balance.percentMul(_withdrawalRatio);
    }
    // Transfer asDAI to address(this)
    IERC20(aTokenAddress).transferFrom(sender, address(this), balance);

    return pool.withdraw(SDAI, balance, address(this));
  }

  /**
   * @dev Swap ERC20_Token using dex or dex aggregator.
   * @notice Swap tokens from exchanges like kyber, 0x etc, with calculation done off-chain.
   * @param toToken The address of the token to buy.
   * @param fromToken The address of the token to sell.
   * @param amount The amount of the token to sell.
   * @param sender The address that initiated the operation.
   * @param callData Data from router(1Inch or Uniswap) API.
   */
  function _swap(
    address router,
    address toToken,
    address fromToken,
    uint256 amount,
    address sender,
    bytes memory callData
  ) internal returns (uint256) {
    if (IERC20(fromToken).allowance(address(this), address(router)) < amount) {
      IERC20(fromToken).safeApprove(address(router), type(uint256).max);
    }

    uint256 initalBalalance = IERC20(toToken).balanceOf(address(this));

    (bool success, bytes memory results) = router.call(callData);

    if (!success) {
      revert(string(results));
    }

    uint256 finalBalalance = IERC20(toToken).balanceOf(address(this));
    uint256 buyAmount = finalBalalance - initalBalalance;

    emit Exchange(sender, toToken, fromToken, amount, buyAmount);

    return buyAmount;
  }

  /**
   * @dev Repays the flash loan and handles protocol fees.
   * @notice This function repays the flash loan amount, handles protocol fees, and transfers value(leftover | amount) amount back to the sender.
   * @param amount The amount of the flash loan.
   * @param premium The premium for the flash loan.
   * @param sender The address that initiated the operation.
   * @param protocolFee The protocol fee in basis point.
   * @param aave The Aave v3 lending pool.
   */
  function _repayLoanAndFees(
    uint256 amount,
    uint256 premium,
    address sender,
    uint256 protocolFee,
    address aave
  ) internal {
    uint256 balance = IERC20(DAI).balanceOf(address(this));
    uint256 amountOwing = amount + premium; // flash loan repay amount
    uint256 fee = amount.percentMul(protocolFee);

    require(balance >= amountOwing + fee, "Not enough funds to repay flashloan");

    /**
     * on position open, below remain represents the leftover amount of DAI
     * on position close, below remain + leftover amount of debt asset represents the principal + profit amount after charging fees
     */
    uint256 remain = balance - (amountOwing + fee);

    // transfer protocol fee to treasury
    if (protocolFee > 0) {
      IERC20(DAI).safeTransfer(_treasuryAddress, fee);
    }
    // transfer the remaining amount to sender
    IERC20(DAI).safeTransfer(sender, remain);

    // approve the LendingPool contract allowance to *pull* the owed amount
    IERC20(DAI).safeApprove(aave, amountOwing);
  }

  /**
   * @dev Calculates the amount to be borrowed from Aave v3.
   * @param asset The asset to be borrowed.
   * @param amount The amount of sDAI deposited to Aave pool.
   */
  function _calcBorrowAmount(address asset, uint256 amount) internal view returns (uint256) {
    uint8 decimals = IERC20Metadata(asset).decimals();
    IPoolAddressesProvider addressProvider = ADDRESSES_PROVIDER;
    IPriceOracle oracle = IPriceOracle(addressProvider.getPriceOracle());

    (, uint256 ltv, , , , , , , , ) = IPoolDataProvider(addressProvider.getPoolDataProvider())
      .getReserveConfigurationData(SDAI);

    // prices in eth
    uint256 sDaiPrice = oracle.getAssetPrice(SDAI);
    uint256 assetPrice = oracle.getAssetPrice(asset);
    // borrow amount in eth
    uint256 amountInEth = (amount * sDaiPrice).percentMul(ltv) / assetPrice;

    // round down to avoid aritheic overflow
    return (((amountInEth * (10 ** decimals)) / 1e18 / (10 ** decimals)) * (10 ** decimals));
  }

  /**
   * @dev Checks if the user has multiple collaterals.
   * @param user The address of the user.
   * @param pool The Aave v3 lending pool.
   * @return A boolean indicating if the user has multiple collaterals.
   */
  function _userHasMultipleCollaterals(address user, IPool pool) internal view returns (bool) {
    IPriceOracle oracle = IPriceOracle(ADDRESSES_PROVIDER.getPriceOracle());
    uint256 balance = IERC20(pool.getReserveData(SDAI).aTokenAddress).balanceOf(user);
    uint256 price = oracle.getAssetPrice(SDAI);
    uint256 sDaiAmountInEth = (balance * price) / 1e18;
    (uint256 totalCollateralBase, , , , , ) = pool.getUserAccountData(user);

    return totalCollateralBase > sDaiAmountInEth;
  }
}