// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;

import "../core/HasSignature712.sol";
import "../utils/TimeChecker.sol";

interface IToken {
  function transferFrom(
    address from,
    address to,
    uint256 amount
  ) external returns (bool);

  function signApprove(
    address spender,
    uint256 amount,
    uint256 startTime,
    uint256 saltNonce,
    bytes calldata signature
  ) external;
}

contract ExecuteRelay is HasSignature712, TimeChecker {
  constructor() HasSignature712("ExecuteRelay", "1") {}

  address public tokenAddress;

  event MethodExecuted(
    address indexed sender,
    address indexed target,
    bytes data,
    uint256 gasUsed,
    uint256 tokenAmount
  );

  // function execute(
  //   address sender,
  //   address target,
  //   uint256 value,
  //   bytes calldata data,
  //   uint256 startTime,
  //   uint256 saltNonce,
  //   bytes calldata signature
  // ) external payable signatureValid(signature) timeValid(startTime) {
  //   bytes32 messageHash = getMessageHash(
  //     target,
  //     value,
  //     data,
  //     startTime,
  //     saltNonce
  //   );
  //   uint256 gasStart = gasleft();
  //   checkSigner712(sender, messageHash, signature);
  //   uint256 gasPrice = tx.gasprice;
  //   _call(target, value, data);
  //   uint256 gasUsed = gasStart - gasleft();
  //   uint256 tokenAmount = gasPrice * gasUsed; // TODO:: calc real token amount
  //   IToken(tokenAddress).signApprove(
  //     sender,
  //     tokenAmount,
  //     startTime,
  //     saltNonce,
  //     signature
  //   );
  //   IToken(tokenAddress).transferFrom(sender, address(this), tokenAmount);
  //   _useSignature(signature);
  //   emit MethodExecuted(sender, target, data, gasUsed, tokenAmount);
  // }

  /**
   * @dev Execute an operation's call.
   *
   * Emits a {CallExecuted} event.
   */
  function _call(address target, uint256 value, bytes calldata data) private {
    (bool success, ) = target.call{value: value}(data);
    require(success, "ExecuteRelay: underlying transaction reverted");
  }

  function getMessageHash(
    address _target,
    uint256 _value,
    bytes calldata _data,
    uint256 _startTime,
    uint256 _saltNonce
  ) public pure returns (bytes32) {
    bytes memory encoded = abi.encodePacked(
      _target,
      _value,
      _data,
      _startTime,
      _saltNonce
    );
    return keccak256(encoded);
  }
}