import 'dart:async';
import 'dart:convert';
import 'dart:io';


enum HttpClientStatus {
  idle,
  connecting,
  connected,
  disconnected,
  error,
}

typedef HttpClientStatusHandler = void Function(HttpClientStatus status);

class HttpClientWrap {
  final Duration retryInterval;
  final Map<String, String>? defaultHeaders;

  HttpClient? _httpClient;
  bool _disposed = false;

  HttpClientStatus _status = HttpClientStatus.idle;
  HttpClientStatus get status => _status;

  final List<HttpClientStatusHandler> _statusHandlers = [];

  HttpClientWrap({
    this.retryInterval = const Duration(seconds: 5),
    this.defaultHeaders,
  });

  /// 发送 GET 请求
  Future<dynamic> get(String url, {Map<String, String>? headers, dynamic body}) async {
    return _sendRequest(url, 'GET', headers: headers, body: body);
  }

  /// 发送 POST 请求
  Future<dynamic> post(String url, {Map<String, String>? headers, dynamic body}) async {
    return _sendRequest(url, 'POST', headers: headers, body: body);
  }

  /// 发送 PUT 请求
  Future<dynamic> put(String url, {Map<String, String>? headers, dynamic body}) async {
    return _sendRequest(url, 'PUT', headers: headers, body: body);
  }

  /// 发送 DELETE 请求
  Future<dynamic> delete(String url, {Map<String, String>? headers}) async {
    return _sendRequest(url, 'DELETE', headers: headers);
  }

  Future<dynamic> _sendRequest(
      String url,
      String method, {
        Map<String, String>? headers,
        dynamic body,
      }) async {
    if (_disposed) {
      throw StateError('HTTP Client has been disposed');
    }

    _updateStatus(HttpClientStatus.connecting);
    _httpClient ??= HttpClient();

    try {

      late final Uri uri;
      if ((method == 'GET') && (body != null)) {
        uri = Uri.parse(url).replace(
          queryParameters: body,
        );
      } else {
        uri = Uri.parse(url);
      }

      final request = await _httpClient!.openUrl(method, uri);

      // 设置请求头
      final mergedHeaders = {...?defaultHeaders, ...?headers};
      mergedHeaders.forEach((key, value) {
        request.headers.set(key, value);
      });

      // 添加请求体（如果是POST/PUT）
      if (body != null && (method == 'POST' || method == 'PUT')) {
        if (body is Map || body is List) {
          request.write(jsonEncode(body));
        } else {
          request.write(body.toString());
        }
      }

      final response = await request.close();
      _updateStatus(HttpClientStatus.connected);

      // 处理响应
      final responseBody = await response.transform(utf8.decoder).join();
      dynamic decodedResponse;

      try {
        decodedResponse = jsonDecode(responseBody);
      } catch (e) {
        decodedResponse = responseBody;
      }

      // Log.d('get response: $decodedResponse');

      _updateStatus(HttpClientStatus.idle);
      return decodedResponse; // 直接返回响应数据

    } catch (e) {
      _handleError(e);
      _scheduleRetry();
      rethrow; // 抛出异常以便调用方捕获
    }
  }

  /// 添加状态监听器
  void addStatusListener(HttpClientStatusHandler handler) {
    _statusHandlers.add(handler);
  }

  /// 移除状态监听器
  void removeStatusListener(HttpClientStatusHandler handler) {
    _statusHandlers.remove(handler);
  }

  /// 释放资源
  Future<void> dispose() async {
    _disposed = true;
    _httpClient?.close();
    _httpClient = null;
    _statusHandlers.clear();
    _updateStatus(HttpClientStatus.disconnected);
  }

  void _handleError(dynamic error) {
    _updateStatus(HttpClientStatus.error);
  }

  void _scheduleRetry() {
    if (_disposed) return;

    Timer(retryInterval, () {
      _updateStatus(HttpClientStatus.idle);
    });
  }

  void _updateStatus(HttpClientStatus status) {
    _status = status;
    for (final handler in _statusHandlers) {
      handler(status);
    }
  }
}