import 'dart:async';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter_background_service/flutter_background_service.dart';
import 'package:flutter_background_service_android/flutter_background_service_android.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:geolocator/geolocator.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:proxibuy/services/mqtt_service.dart';

const notificationChannelId = 'proxibuy_foreground_service';
const notificationId = 888;

@pragma('vm:entry-point')
void onStart(ServiceInstance service) async {
  DartPluginRegistrant.ensureInitialized();

  final MqttService mqttService = MqttService();
  const storage = FlutterSecureStorage();

  if (service is AndroidServiceInstance) {
    service.setForegroundNotificationInfo(
      title: "ProxiBuy فعال است",
      content: "در حال جستجو برای تخفیف های اطراف شما...",
    );

    service.on('stopService').listen((event) {
      service.stopSelf();
    });
  }

  mqttService.messages.listen((data) {
    service.invoke('update', {'offers': data});
  });

  Timer.periodic(const Duration(seconds: 30), (timer) async {
    debugPrint("✅ Background Service: Sending location...");

    var locationStatus = await Permission.location.status;
    if (!locationStatus.isGranted) {
      debugPrint("Background Service: Location permission not granted.");
      return;
    }

    try {
      final position = await Geolocator.getCurrentPosition(
          desiredAccuracy: LocationAccuracy.high);
      final token = await storage.read(key: 'accessToken');
      final userID = await storage.read(key: 'userID');

      if (token != null && userID != null) {
        if (!mqttService.isConnected) {
          await mqttService.connect(token);
          final topic = 'user-proxybuy/$userID';
          mqttService.subscribe(topic);
        }

        if (mqttService.isConnected) {
          final payload = {
            "userID": userID,
            "lat": position.latitude,
            "lng": position.longitude
          };
          mqttService.publish("proxybuy/sendGps", payload);
          debugPrint("Background Service: GPS sent successfully.");
        }
      }
    } catch (e) {
      debugPrint("❌ Background Service Error: $e");
    }
  });
}

Future<void> initializeService() async {
  final service = FlutterBackgroundService();

  const AndroidNotificationChannel channel = AndroidNotificationChannel(
    notificationChannelId,
    'ProxiBuy Background Service',
    description: 'This channel is used for location service notifications.',
    importance: Importance.low,
  );

  final flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
          AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);

  await service.configure(
    androidConfiguration: AndroidConfiguration(
      onStart: onStart,
      isForegroundMode: true,
      autoStart: true,
      notificationChannelId: notificationChannelId,
      initialNotificationTitle: 'ProxiBuy فعال است',
      initialNotificationContent: 'در حال جستجو برای تخفیف‌های اطراف شما...',
      foregroundServiceNotificationId: notificationId,
    ),
    iosConfiguration: IosConfiguration(
      autoStart: true,
      onForeground: onStart,
    ),
  );
}