// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;
import "@openzeppelin/contracts/access/Ownable.sol";

contract Approval is Ownable {
  mapping(address => bool) private approvalLists;

  /**
   * @dev Allow operation to reverse signature.
   */
  function addApprovalList(address user) external onlyOwner {
    require(!approvalLists[user], "MinterFactory: Invalid user address");
    approvalLists[user] = true;
  }

  /**
   * @dev Remove operation from approval list.
   */
  function removeApprovalList(address user) external onlyOwner {
    approvalLists[user] = false;
  }

  modifier approvaled() {
    require(
      _msgSender() == address(this) || approvalLists[_msgSender()],
      "Must be valid approval list"
    );
    _;
  }
}