import 'package:flutter/material.dart';
import 'dart:io' show Platform;
import 'package:audio_service/audio_service.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:permission_handler/permission_handler.dart';
import 'database/db_helper.dart';
import 'services/favoriten_service.dart';
import 'services/auth_service.dart';
import 'services/cloud_service.dart';
import 'services/melo_logger.dart';
import 'services/audio_handler.dart';
import 'services/musik_scanner.dart';
import 'utils/farb_theme.dart';
import 'screens/home_screen.dart';
import 'screens/login_screen.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Logger startet sofort – zeichnet ALLES auf
  MeloLogger().init('2.35');

  try {
    await DbHelper().db;
    await FavoritenService().init();
    // Hintergrund-Audio-Service starten
    await AudioService.init(
      builder: () => MeloAudioHandler(),
      config: const AudioServiceConfig(
        androidNotificationChannelId: 'de.baka.melo.audio',
        androidNotificationChannelName: 'Melo Wiedergabe',
        androidNotificationOngoing: true,
      ),
    );
    MeloLogger().zustand('start_ok', {'db': 'ok', 'audio': 'ok'});
  } catch (e, stack) {
    MeloLogger().fehler('App-Start', e, stack);
  }

  // Auth initialisieren (Token aus SharedPreferences laden + online validieren)
  await AuthService().initialisieren();

  // Android-Berechtigungen beim Start abfragen (Issue #4)
  // Speicherzugriff für Musik-Scan (READ_MEDIA_AUDIO / Storage)
  await MusikScanner().frageSpeicherZugriff();

  // POST_NOTIFICATIONS für Android 13+ (Notifications für Downloads, Player)
  if (Platform.isAndroid) {
    await Permission.notification.request();
  }

  // Auto-Sync beim Start (wenn eingeloggt und Auto-Sync aktiv)
  _starteAutoSyncFallsNoetig();

  runApp(const MeloApp());
}

/// Führt Cloud-Auto-Sync beim App-Start aus, falls konfiguriert
Future<void> _starteAutoSyncFallsNoetig() async {
  try {
    final auth = AuthService();
    if (!auth.istEingeloggt) return;

    // Prüfen, ob Auto-Sync aktiviert ist
    final SharedPreferences prefs =
        await SharedPreferences.getInstance();
    final autoSync = prefs.getBool('cloud_auto') ?? true;
    if (!autoSync) return;

    final cloud = CloudService();
    final ok = await cloud.login(auth.benutzer);
    if (!ok) return;

    // Letzten Sync prüfen — nur syncen wenn nötig
    final lastSync = prefs.getString('cloud_last_sync_ts');
    final now = DateTime.now();

    if (lastSync != null) {
      final last = DateTime.tryParse(lastSync);
      if (last != null) {
        final interval = prefs.getInt('cloud_interval') ?? 6;
        if (now.difference(last).inHours < interval) {
          return; // Noch nicht fällig
        }
      }
    }

    // Sync ausführen
    MeloLogger().aktion('auto_sync_start', {});
    final st = await cloud.status();
    if (st != null) {
      final serverSongs = await cloud.listSongs();
      MeloLogger().aktion('auto_sync_done',
          {'songs': serverSongs.length});
    }
    await prefs.setString('cloud_last_sync_ts', now.toIso8601String());
  } catch (e) {
    MeloLogger().fehler('auto_sync_init', e);
  }
}

class MeloApp extends StatelessWidget {
  const MeloApp({super.key});

  @override
  Widget build(BuildContext context) {
    final auth = AuthService();

    return MaterialApp(
      title: 'Melo',
      debugShowCheckedModeBanner: false,
      theme: MeloTheme.theme,
      home: auth.istEingeloggt
          ? const Scaffold(body: MeloHome())
          : const LoginScreen(),
    );
  }
}