// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

import {IAuthorizedReceiver} from "./interfaces/IAuthorizedReceiver.sol";

// solhint-disable gas-custom-errors
abstract contract AuthorizedReceiver is IAuthorizedReceiver {
  mapping(address sender => bool authorized) private s_authorizedSenders;
  address[] private s_authorizedSenderList;

  event AuthorizedSendersChanged(address[] senders, address changedBy);

  // @notice Sets the fulfillment permission for a given node. Use `true` to allow, `false` to disallow.
  // @param senders The addresses of the authorized Chainlink node
  function setAuthorizedSenders(
    address[] calldata senders
  ) external override validateAuthorizedSenderSetter {
    require(senders.length > 0, "Must have at least 1 sender");
    // Set previous authorized senders to false
    uint256 authorizedSendersLength = s_authorizedSenderList.length;
    for (uint256 i = 0; i < authorizedSendersLength; ++i) {
      s_authorizedSenders[s_authorizedSenderList[i]] = false;
    }
    // Set new to true
    for (uint256 i = 0; i < senders.length; ++i) {
      require(s_authorizedSenders[senders[i]] == false, "Must not have duplicate senders");
      s_authorizedSenders[senders[i]] = true;
    }
    // Replace list
    s_authorizedSenderList = senders;
    emit AuthorizedSendersChanged(senders, msg.sender);
  }

  // @notice Retrieve a list of authorized senders
  // @return array of addresses
  function getAuthorizedSenders() external view override returns (address[] memory) {
    return s_authorizedSenderList;
  }

  // @notice Use this to check if a node is authorized for fulfilling requests
  // @param sender The address of the Chainlink node
  // @return The authorization status of the node
  function isAuthorizedSender(
    address sender
  ) public view override returns (bool) {
    return s_authorizedSenders[sender];
  }

  // @notice customizable guard of who can update the authorized sender list
  // @return bool whether sender can update authorized sender list
  function _canSetAuthorizedSenders() internal virtual returns (bool);

  // @notice validates the sender is an authorized sender
  function _validateIsAuthorizedSender() internal view {
    require(isAuthorizedSender(msg.sender), "Not authorized sender");
  }

  // @notice prevents non-authorized addresses from calling this method
  modifier validateAuthorizedSender() {
    _validateIsAuthorizedSender();
    _;
  }

  // @notice prevents non-authorized addresses from calling this method
  modifier validateAuthorizedSenderSetter() {
    require(_canSetAuthorizedSenders(), "Cannot set authorized senders");
    _;
  }
}