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

import 'package:flutter/services.dart';
import 'package:path/path.dart' as path;
import 'package:path_provider/path_provider.dart';

import '../../utils/log/logger.dart';
import '../constants/enums.dart';
import 'base_core_api.dart';
import 'windows/vpn_windows_service.dart';

/// Windows 实现
class WindowsCoreApi implements BaseCoreApi {
  static const _tag = 'WindowsCoreApi';

  WindowsCoreApi._() {
    _initEventChannel();
    // 初始化vpn服务
    _initVpnService();
  }

  // 创建vpn服务
  static final _vpn = VpnWindowsService();

  StreamSubscription? _ssStatus;

  bool _isVpnInited = false;

  /// 内部构造方法，供 BaseCoreApi 工厂使用
  factory WindowsCoreApi.create() => WindowsCoreApi._();

  // Windows Method Channel
  static const MethodChannel _channel = MethodChannel('app.xixi.nomo/core_api');

  // Windows 事件流控制器
  static final StreamController<String> _eventController =
      StreamController<String>.broadcast();

  // Windows 事件流
  static Stream<String> get eventStream => _eventController.stream;

  // 初始化事件监听
  void _initEventChannel() {
    // 监听来自 Windows 原生端的方法调用
    _channel.setMethodCallHandler(_handleMethodCall);
  }

  // 处理来自 Windows 原生端的方法调用
  Future<dynamic> _handleMethodCall(MethodCall call) async {
    switch (call.method) {
      case 'onEventChange':
        // 原生端发送事件，转发到事件流
        final String event = call.arguments as String;
        _eventController.add(event);
        return null;
      default:
        throw PlatformException(
          code: 'Unimplemented',
          message: 'Method ${call.method} not implemented',
        );
    }
  }

  void _initVpnService() {
    if (_isVpnInited) {
      return;
    }
    _isVpnInited = true;

    // 初始化vpn服务 10秒超时
    _vpn.initialize(10, false);

    // 监听VPN服务状态
    _ssStatus = _vpn.onStatusChanged.listen((event) async {
      switch (event) {
        case ConnectionState.connecting:
          // 正在连接
          _eventController.add(
            '{"type":"vpn_status","status":1,"code":0,"message":""}',
          );
          break;

        // 已经连接
        case ConnectionState.connected:
          _eventController.add(
            '{"type":"vpn_status","status":2,"code":0,"message":""}',
          );
          break;

        // 连接错误
        case ConnectionState.error:
          _eventController.add(
            '{"type":"vpn_status","status":3,"code":0,"message":""}',
          );
          _vpn.stop();
          break;

        // 已经断开
        case ConnectionState.disconnected:
          _eventController.add(
            '{"type":"vpn_status","status":0,"code":0,"message":""}',
          );
          break;
      }

      // TODO: 通知状态变更
    });
  }

  @override
  Future<String?> getApps() async {
    // Windows 不需要获取应用列表
    return null;
  }

  @override
  Future<String?> getSystemLocale() async {
    return Platform.localeName;
  }

  @override
  Future<bool?> connect(
    String sessionId,
    int socksPort,
    String tunnelConfig,
    String configJson,
    int remainTime,
    bool isCountdown,
    List<String> allowVpnApps,
    List<String> disallowVpnApps,
    String accessToken,
    String aesKey,
    String aesIv,
    int locationId,
    String locationCode,
    List<String> baseUrls,
    String params,
    int peekTimeInterval,
  ) async {
    try {
      String geoPath = await _getGeoDirectory();
      log(_tag, 'geoPath: $geoPath');

      final selfExecutable = Platform.resolvedExecutable;
      //List<String> apps = isSplitTunnelEnabled ? splitTunnelApps : [];

      List<String> allowExes = [];
      List<String> disallowExes = [selfExecutable];

      // 连接vpn
      Map<String, dynamic> params = {
        'sessionId': sessionId,
        'connectOptions': jsonEncode({
          'geoPath': geoPath,
          'nodesConfig': configJson,
        }),
        'allowExes': allowExes,
        'disallowExes': disallowExes,
      };

      log(_tag, jsonEncode(params));

      // 连接vpn
      _vpn.start(params);
      return true;
    } catch (e) {
      // 通知连接出错
      _eventController.add(
        '{"type":"vpn_status","status":3,"code":0,"message":""}',
      );
      //logger.e('get nodes error: $e');

      return false;
    }
  }

  @override
  Future<bool?> disconnect() async {
    // 实现 Windows 断开连接逻辑
    await _vpn.stop();
    return true;
  }

  @override
  Future<String?> getRemoteIp() async {
    // 实现 Windows 获取远程 IP
    return await _vpn.getRemoteAddress();
  }

  @override
  Future<String?> getAdvertisingId() async {
    // Windows 不支持广告 ID
    return null;
  }

  @override
  Future<bool?> moveTaskToBack() async {
    // Windows 不需要此功能
    return true;
  }

  @override
  Future<bool?> isConnected() async {
    return _vpn.isOnline && _vpn.status == ConnectionState.connected;
  }

  @override
  Future<String?> getSimInfo() async {
    // Windows 不支持 SIM 卡信息
    return null;
  }

  @override
  Future<String?> getChannel() async {
    // TODO: 实现 Windows 渠道获取
    return 'windows';
  }

  /// 发送事件（供 Windows 实现内部使用）
  ///
  /// Windows 原生端可以通过 MethodChannel 发送事件：
  /// ```cpp
  /// // C++ 示例
  /// flutter::MethodChannel<flutter::EncodableValue> channel(
  ///     messenger, "app.xixi.nomo/core_api",
  ///     &flutter::StandardMethodCodec::GetInstance());
  ///
  /// // 发送 VPN 状态变化
  /// channel.InvokeMethod("onEventChange",
  ///     flutter::EncodableValue("{\"type\":\"vpn_status\",\"status\":2}"));
  /// ```
  ///
  /// 事件 JSON 格式：
  /// - vpn_status: {"type":"vpn_status","status":0|1|2|3,"code":0,"message":""}
  ///   - status: 0=idle, 1=connecting, 2=connected, 3=error
  /// - timer_update: {"type":"timer_update","currentTime":123,"mode":"countdown"}
  /// - boost_result: {"type":"boost_result","locationCode":"US","nodeId":"xxx","success":true}
  static void sendEvent(String event) {
    _eventController.add(event);
  }

  /// 释放资源
  static void dispose() {
    _eventController.close();
  }

  /// 获取 geo 文件目录
  Future<String> _getGeoDirectory() async {
    try {
      final appDir = await getApplicationSupportDirectory();
      final geoDir = Directory(path.join(appDir.path, 'geo'));
      return geoDir.path;
    } catch (_) {
      return '';
    }
  }
}