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

import {ConfirmedOwner} from "../../shared/access/ConfirmedOwner.sol";
import {CrossDomainOwnableInterface} from "./interfaces/CrossDomainOwnableInterface.sol";

/**
 * @title The CrossDomainOwnable contract
 * @notice A contract with helpers for cross-domain contract ownership.
 */
contract CrossDomainOwnable is CrossDomainOwnableInterface, ConfirmedOwner {
  address internal s_l1Owner;
  address internal s_l1PendingOwner;

  constructor(address newl1Owner) ConfirmedOwner(msg.sender) {
    _setL1Owner(newl1Owner);
  }

  /**
   * @notice transfer ownership of this account to a new L1 owner
   * @param to new L1 owner that will be allowed to call the forward fn
   */
  function transferL1Ownership(address to) public virtual override onlyL1Owner {
    _transferL1Ownership(to);
  }

  /**
   * @notice accept ownership of this account to a new L1 owner
   */
  function acceptL1Ownership() public virtual override onlyProposedL1Owner {
    _setL1Owner(s_l1PendingOwner);
  }

  /**
   * @notice Get the current owner
   */
  function l1Owner() public view override returns (address) {
    return s_l1Owner;
  }

  /**
   * @notice validate, transfer ownership, and emit relevant events
   */
  function _transferL1Ownership(address to) internal {
    // solhint-disable-next-line gas-custom-errors
    require(to != msg.sender, "Cannot transfer to self");

    s_l1PendingOwner = to;

    emit L1OwnershipTransferRequested(s_l1Owner, to);
  }

  /**
   * @notice set ownership, emit relevant events. Used in acceptOwnership()
   */
  function _setL1Owner(address to) internal {
    address oldOwner = s_l1Owner;
    s_l1Owner = to;
    s_l1PendingOwner = address(0);

    emit L1OwnershipTransferred(oldOwner, to);
  }

  /**
   * @notice Reverts if called by anyone other than the L1 owner.
   */
  modifier onlyL1Owner() virtual {
    // solhint-disable-next-line gas-custom-errors
    require(msg.sender == s_l1Owner, "Only callable by L1 owner");
    _;
  }

  /**
   * @notice Reverts if called by anyone other than the L1 owner.
   */
  modifier onlyProposedL1Owner() virtual {
    // solhint-disable-next-line gas-custom-errors
    require(msg.sender == s_l1PendingOwner, "Only callable by proposed L1 owner");
    _;
  }
}