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

import {ConfirmedOwner} from "../../../../shared/access/ConfirmedOwner.sol";
import {FunctionsClient} from "../FunctionsClient.sol";
import {FunctionsRequest} from "../libraries/FunctionsRequest.sol";

/// @title Chainlink Functions example Client contract implementation
contract FunctionsClientExample is FunctionsClient, ConfirmedOwner {
  using FunctionsRequest for FunctionsRequest.Request;

  uint32 public constant MAX_CALLBACK_GAS = 70_000;

  bytes32 public s_lastRequestId;
  bytes32 public s_lastResponse;
  bytes32 public s_lastError;
  uint32 public s_lastResponseLength;
  uint32 public s_lastErrorLength;

  error UnexpectedRequestID(bytes32 requestId);

  constructor(
    address router
  ) FunctionsClient(router) ConfirmedOwner(msg.sender) {}

  /// @notice Send a simple request
  /// @param source JavaScript source code
  /// @param encryptedSecretsReferences Encrypted secrets payload
  /// @param args List of arguments accessible from within the source code
  /// @param subscriptionId Billing ID
  function sendRequest(
    string calldata source,
    bytes calldata encryptedSecretsReferences,
    string[] calldata args,
    uint64 subscriptionId,
    bytes32 jobId
  ) external onlyOwner {
    FunctionsRequest.Request memory req;
    req._initializeRequestForInlineJavaScript(source);
    if (encryptedSecretsReferences.length > 0) req._addSecretsReference(encryptedSecretsReferences);
    if (args.length > 0) req._setArgs(args);
    s_lastRequestId = _sendRequest(req._encodeCBOR(), subscriptionId, MAX_CALLBACK_GAS, jobId);
  }

  /// @notice Store latest result/error
  /// @param requestId The request ID, returned by sendRequest()
  /// @param response Aggregated response from the user code
  /// @param err Aggregated error from the user code or from the execution pipeline
  /// @dev Either response or error parameter will be set, but never both
  function _fulfillRequest(bytes32 requestId, bytes memory response, bytes memory err) internal override {
    if (s_lastRequestId != requestId) {
      revert UnexpectedRequestID(requestId);
    }
    // Save only the first 32 bytes of response/error to always fit within MAX_CALLBACK_GAS
    s_lastResponse = _bytesToBytes32(response);
    s_lastResponseLength = uint32(response.length);
    s_lastError = _bytesToBytes32(err);
    s_lastErrorLength = uint32(err.length);
  }

  function _bytesToBytes32(
    bytes memory b
  ) private pure returns (bytes32 out) {
    uint256 maxLen = 32;
    if (b.length < 32) {
      maxLen = b.length;
    }
    for (uint256 i = 0; i < maxLen; ++i) {
      out |= bytes32(b[i]) >> (i * 8);
    }
    return out;
  }
}