// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;

import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

import {BaseGuard} from "../guard/BaseGuard.sol";
import {IGuard} from "../interfaces/IGuard.sol";

/// @title Guardable - A contract that manages fallback calls made to this contract
contract Guardable is OwnableUpgradeable {
  address public guard;

  event ChangedGuard(address guard);

  /// `guard_` does not implement IERC165.
  error NotIERC165Compliant(address guard_);

  /// @dev Set a guard that checks transactions before execution.
  /// @param _guard The address of the guard to be used or the 0 address to disable the guard.
  function setGuard(address _guard) external onlyOwner {
    if (_guard != address(0)) {
      if (!BaseGuard(_guard).supportsInterface(type(IGuard).interfaceId))
        revert NotIERC165Compliant(_guard);
    }
    guard = _guard;
    emit ChangedGuard(guard);
  }

  function getGuard() external view returns (address _guard) {
    return guard;
  }
}