// File: contracts/AutomationExecutor.sol



// SPDX-License-Identifier: AGPL-3.0-or-later

/// AutomationExecutor.sol

// Copyright (C) 2021-2021 Oazo Apps Limited

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
pragma solidity ^0.8.0;

import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IWETH } from "./interfaces/IWETH.sol";
import { BotLike } from "./interfaces/BotLike.sol";
import { IExchange } from "./interfaces/IExchange.sol";
import { ICommand } from "./interfaces/ICommand.sol";

contract AutomationExecutor {
    using SafeERC20 for IERC20;

    event CallerAdded(address indexed caller);
    event CallerRemoved(address indexed caller);

    BotLike public immutable bot;
    IERC20 public immutable dai;
    IWETH public immutable weth;

    address public exchange;
    address public owner;

    mapping(address => bool) public callers;

    constructor(
        BotLike _bot,
        IERC20 _dai,
        IWETH _weth,
        address _exchange
    ) {
        bot = _bot;
        weth = _weth;
        dai = _dai;
        exchange = _exchange;
        owner = msg.sender;
        callers[owner] = true;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "executor/only-owner");
        _;
    }

    modifier auth(address caller) {
        require(callers[caller], "executor/not-authorized");
        _;
    }

    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "executor/invalid-new-owner");
        owner = newOwner;
    }

    function setExchange(address newExchange) external onlyOwner {
        require(newExchange != address(0), "executor/invalid-new-exchange");
        exchange = newExchange;
    }

    function addCallers(address[] calldata _callers) external onlyOwner {
        uint256 length = _callers.length;
        for (uint256 i = 0; i < length; ++i) {
            address caller = _callers[i];
            require(!callers[caller], "executor/duplicate-whitelist");
            callers[caller] = true;
            emit CallerAdded(caller);
        }
    }

    function removeCallers(address[] calldata _callers) external onlyOwner {
        uint256 length = _callers.length;
        for (uint256 i = 0; i < length; ++i) {
            address caller = _callers[i];
            callers[caller] = false;
            emit CallerRemoved(caller);
        }
    }

    function execute(
        bytes calldata executionData,
        uint256 cdpId,
        bytes calldata triggerData,
        address commandAddress,
        uint256 triggerId,
        uint256 daiCoverage,
        uint256 minerBribe,
        int256 gasRefund
    ) external auth(msg.sender) {
        uint256 initialGasAvailable = gasleft();
        bot.execute(executionData, cdpId, triggerData, commandAddress, triggerId, daiCoverage);

        if (minerBribe > 0) {
            block.coinbase.transfer(minerBribe);
        }
        uint256 finalGasAvailable = gasleft();
        uint256 etherUsed = tx.gasprice *
            uint256(int256(initialGasAvailable - finalGasAvailable) - gasRefund);

        payable(msg.sender).transfer(
            address(this).balance > etherUsed ? etherUsed : address(this).balance
        );
    }

    function swap(
        address otherAsset,
        bool toDai,
        uint256 amount,
        uint256 receiveAtLeast,
        address callee,
        bytes calldata withData
    ) external auth(msg.sender) {
        IERC20 fromToken = toDai ? IERC20(otherAsset) : dai;
        require(
            amount > 0 && amount <= fromToken.balanceOf(address(this)),
            "executor/invalid-amount"
        );

        fromToken.safeApprove(exchange, amount);
        if (toDai) {
            IExchange(exchange).swapTokenForDai(
                otherAsset,
                amount,
                receiveAtLeast,
                callee,
                withData
            );
        } else {
            IExchange(exchange).swapDaiForToken(
                otherAsset,
                amount,
                receiveAtLeast,
                callee,
                withData
            );
        }
    }

    function withdraw(address asset, uint256 amount) external onlyOwner {
        if (asset == address(0)) {
            require(amount <= address(this).balance, "executor/invalid-amount");
            (bool sent, ) = payable(owner).call{ value: amount }("");
            require(sent, "executor/withdrawal-failed");
        } else {
            IERC20(asset).safeTransfer(owner, amount);
        }
    }

    function unwrapWETH(uint256 amount) external onlyOwner {
        weth.withdraw(amount);
    }

    function revokeAllowance(IERC20 token, address target) external onlyOwner {
        token.safeApprove(target, 0);
    }

    receive() external payable {}
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

    /**
     * @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);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

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

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

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

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

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

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

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

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

// File: contracts/interfaces/IWETH.sol



//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

interface IWETH {
    function withdraw(uint256 wad) external;
}

// File: contracts/interfaces/BotLike.sol



//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

interface BotLike {
    function addRecord(
        uint256 cdpId,
        uint256 triggerType,
        uint256 replacedTriggerId,
        bytes memory triggerData
    ) external;

    function removeRecord(
        // This function should be executed allways in a context of AutomationBot address not DsProxy,
        //msg.sender should be dsProxy
        uint256 cdpId,
        uint256 triggerId
    ) external;

    function execute(
        bytes calldata executionData,
        uint256 cdpId,
        bytes calldata triggerData,
        address commandAddress,
        uint256 triggerId,
        uint256 daiCoverage
    ) external;
}

// File: contracts/interfaces/IExchange.sol



//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

interface IExchange {
    function swapTokenForDai(
        address asset,
        uint256 amount,
        uint256 receiveAtLeast,
        address callee,
        bytes calldata withData
    ) external;

    function swapDaiForToken(
        address asset,
        uint256 amount,
        uint256 receiveAtLeast,
        address callee,
        bytes calldata withData
    ) external;
}

// File: contracts/interfaces/ICommand.sol



//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

interface ICommand {
    function isTriggerDataValid(uint256 _cdpId, bytes memory triggerData)
        external
        view
        returns (bool);

    function isExecutionCorrect(uint256 cdpId, bytes memory triggerData)
        external
        view
        returns (bool);

    function isExecutionLegal(uint256 cdpId, bytes memory triggerData) external view returns (bool);

    function execute(
        bytes calldata executionData,
        uint256 cdpId,
        bytes memory triggerData
    ) external;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(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) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(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) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}