import 'dart:async';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter_background_service/flutter_background_service.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: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 یافتن تخفیف های اطراف شما...",
    );

    service.on('setAsForeground').listen((event) {
      service.setAsForegroundService();
    });

    service.on('setAsBackground').listen((event) {
      service.setAsBackgroundService();
    });
  }

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

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

    try {
      // Check location service status
      bool serviceEnabled = await Geolocator.isLocationServiceEnabled();
      if (!serviceEnabled) {
        debugPrint("Background Service: Location service is disabled.");
        return;
      }

      // Check location permission using Geolocator
      LocationPermission permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.denied || 
          permission == LocationPermission.deniedForever) {
        debugPrint("Background Service: Location permission not granted. Status: $permission");
        return;
      }

      final position = await Geolocator.getCurrentPosition(
          locationSettings: const LocationSettings(
            accuracy: LocationAccuracy.high,
          ));
      final token = await storage.read(key: 'accessToken');
      final userID = await storage.read(key: 'userID');

      if (token != null && token.isNotEmpty && userID != null) {
        if (!mqttService.isConnected) {
          await mqttService.connect(token);
        }
        
        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,
    ),
  );
}