import 'dart:async';
import 'dart:convert';
import 'package:flutter_foreground_task/flutter_foreground_task.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:geolocator/geolocator.dart';
import 'package:http/http.dart' as http;
import '../config/api.dart';

class BackgroundGeoService {
  static final BackgroundGeoService _instance = BackgroundGeoService._init();

  factory BackgroundGeoService() => _instance;

  BackgroundGeoService._init();

  final http.Client _client = http.Client();
  final FlutterLocalNotificationsPlugin _notifications =
      FlutterLocalNotificationsPlugin();
  String? _token;
  String? _geoId;
  bool _isReady = false;
  bool _notificationsInitialized = false;

  bool get isReady => _isReady;
  Future<bool> get isStarted async => await FlutterForegroundTask.isRunningService;
  String? get token => _token;
  String? get geoId => _geoId;

  Future<void> initNotifications() async {
    if (_notificationsInitialized) return;

    const androidSettings = AndroidInitializationSettings(
      '@mipmap/ic_launcher',
    );
    const iosSettings = DarwinInitializationSettings();
    const initSettings = InitializationSettings(
      android: androidSettings,
      iOS: iosSettings,
    );

    await _notifications.initialize(
      initSettings,
      onDidReceiveNotificationResponse: _onNotificationResponse,
    );

    _notificationsInitialized = true;
  }

  void configure({required String token, required String geoId}) {
    _token = token;
    _geoId = geoId;
  }

  Future<void> init() async {
    if (_isReady) return;

    await initNotifications();

    FlutterForegroundTask.initCommunicationPort();

    FlutterForegroundTask.addTaskDataCallback(_onTaskData);

    _isReady = true;
  }

  Future<void> start() async {
    if (!_isReady) return;
    if (_token == null || _geoId == null || _geoId!.isEmpty) return;

    final androidOptions = AndroidNotificationOptions(
      channelId: 'background_geo_channel',
      channelName: 'Background Geolocation',
      channelDescription: 'Отслеживание позиции в фоновом режиме',
      channelImportance: NotificationChannelImportance.HIGH,
      priority: NotificationPriority.HIGH,
    );

    final iosOptions = IOSNotificationOptions(
      showNotification: true,
      playSound: true,
    );

    final taskOptions = ForegroundTaskOptions(
      eventAction: ForegroundTaskEventAction.repeat(15000),
      autoRunOnBoot: true,
      allowWakeLock: true,
    );

    FlutterForegroundTask.init(
      androidNotificationOptions: androidOptions,
      iosNotificationOptions: iosOptions,
      foregroundTaskOptions: taskOptions,
    );

    await FlutterForegroundTask.startService(
      notificationTitle: 'Family Safety',
      notificationText: 'Отслеживание позиции активно',
    );
  }

  Future<void> stop() async {
    await FlutterForegroundTask.stopService();
  }

  void dispose() {
    _isReady = false;
    _token = null;
    _geoId = null;
  }

  static void _onTaskData(Object data) {}

  Future<void> _sendPosition(double latitude, double longitude) async {
    if (_token == null || _geoId == null || _geoId!.isEmpty) return;

    try {
      final response = await _client.put(
        Uri.parse('${ApiConfig.geoUrl}?id=$_geoId'),
        headers: {
          'Content-Type': 'application/json',
          'Authorization': 'Bearer $_token',
        },
        body: jsonEncode({
          'x': longitude,
          'y': latitude,
        }),
      );

      if (response.statusCode != 200) {
        _showErrorNotification(
          'Не удалось отправить позицию. Код ответа: ${response.statusCode}',
        );
      }
    } catch (e) {
      _showErrorNotification('Ошибка отправки позиции: $e');
    }
  }

  Future<void> _showErrorNotification(String message) async {
    if (!_notificationsInitialized) return;

    const androidDetails = AndroidNotificationDetails(
      'background_geo_errors',
      'Background Geo Errors',
      channelDescription: 'Уведомления об ошибках геолокации в фоне',
      importance: Importance.high,
      priority: Priority.high,
      ticker: 'geo_error',
    );
    const iosDetails = DarwinNotificationDetails();
    const details = NotificationDetails(
      android: androidDetails,
      iOS: iosDetails,
    );

    await _notifications.show(
      0,
      'Ошибка геолокации',
      message,
      details,
      payload: 'geo_error',
    );
  }

  void _onNotificationResponse(NotificationResponse response) {
    print('[Notification] ${response.payload}');
  }
}

class BackgroundTaskHandler extends TaskHandler {
  int _locationCount = 0;

  @override
  Future<void> onStart(DateTime timestamp, TaskStarter starter) async {}

  @override
  void onRepeatEvent(DateTime timestamp) {
    _locationCount++;

    if (_locationCount % 2 != 0) return;

    _getLocationAndSend();
  }

  @override
  void onReceiveData(Object data) {}

  @override
  void onNotificationButtonPressed(String id) {}

  @override
  void onNotificationPressed() {}

  @override
  void onNotificationDismissed() {}

  @override
  Future<void> onDestroy(DateTime timestamp) async {}

  Future<void> _getLocationAndSend() async {
    try {
      final position = await Geolocator.getCurrentPosition();

      final bgGeo = BackgroundGeoService();
      await bgGeo._sendPosition(position.latitude, position.longitude);
    } catch (e) {
      print('[BackgroundGeo] Error getting location: $e');
    }
  }
}