import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:path/path.dart' as p;
import '../database/db_helper.dart';
import '../services/player_service.dart';
import '../services/musik_scanner.dart';
import '../services/favoriten_service.dart';
import '../services/download_service.dart';
import '../services/navidrome_service.dart';
import '../services/playlist_service.dart';
import '../services/cloud_service.dart';
import '../services/melo_logger.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';
import '../models/song.dart';
import '../models/tag.dart';

class MeloHomeViewModel extends ChangeNotifier {
  final PlayerService player = PlayerService();
  final DbHelper db = DbHelper();
  final FavoritenService favoriten = FavoritenService();
  final MusikScanner scanner = MusikScanner();
  final DownloadService downloader = DownloadService();
  final NavidromeService navidrome = NavidromeService();
  final PlaylistService playlists = PlaylistService();
  final CloudService cloud = CloudService();
  Timer? _autoSyncTimer;

  List<Song> songs = [];
  Set<String> aktiveTags = {};
  bool ladt = true;
  Set<int> favoritenIds = {};
  List<Map<String, String>> tags = [];
  List<Song> letzteSongs = [];
  Map<String, int> tagCounts = {};
  bool zeigeBotschaft = false;
  bool serverLadt = false;
  List<SubsonicAlbum> navidromeAlben = [];
  Map<String, Tag> _tagsMap = {}; // Name → Tag für Filter-Lookup
  Map<String, Tag> get tagsMap => _tagsMap;

  int _playCount = 0;
  static const int _botschaftSchwellwert = 10;
  String? _nutzerBotschaft;

  /// Per-User Easteregg-Botschaften
  static const _botschaften = {
    'Baka': '💌 Seit 2008 – Danke, dass du immer da bist ♥',
    'Tinker': '🎀 Für meine beste Freundin – Melo & Melo 💕',
  };

  String? get nutzerBotschaft => _nutzerBotschaft;

  void setzeNutzer(String name) {
    _nutzerBotschaft = _botschaften[name];
  }
  StreamSubscription<Duration>? _positionsSub;
  int _letzteGespeicherteSekunde = -1;

  void _startePositionTracking() {
    _positionsSub?.cancel();
    _letzteGespeicherteSekunde = -1;
    _positionsSub = player.positionStream.listen((pos) {
      final s = player.aktuellerSong;
      final sek = pos.inSeconds;
      if (s?.id != null && sek > 0 && sek % 10 == 0 && sek != _letzteGespeicherteSekunde) {
        _letzteGespeicherteSekunde = sek;
        db.positionAktualisieren(s!.id!, sek);
      }
    });
  }

  static const _defaultTags = [
    {'name': 'Alle', 'icon': ''},
    {'name': '❤️ Für uns', 'icon': '❤️'},
    {'name': 'Nightcore', 'icon': '⚡'},
    {'name': 'Traurig', 'icon': '😢'},
    {'name': 'Party', 'icon': '🎉'},
    {'name': 'Mitsingen', 'icon': '🎤'},
    {'name': '2000er', 'icon': '📀'},
  ];

  List<Song> get gefilterteSongs {
    if (aktiveTags.isEmpty) return songs;
    // Favoriten-Filter
    if (aktiveTags.contains('★ Favoriten')) {
      return songs.where((s) => s.id != null && favoritenIds.contains(s.id)).toList();
    }
    // Filter: Songs mit ALLEN aktiven Tags (AND-Logik)
    return songs.where((s) {
      if (s.tagIds == null) return false;
      return aktiveTags.every((tagName) {
        final tag = _tagsMap[tagName];
        return tag != null && s.tagIds!.contains(tag.id);
      });
    }).toList();
  }

  Future<void> ladeSongs() async {
    ladt = true;
    notifyListeners();

    try {
      // Auto-Restore der Navidrome-Session beim Start
      // Dummies bereinigen
      await db.alteDummiesLoeschen();

      await navidrome.ladeGespeicherteZugangsdaten();
      if (navidrome.istVerbunden) {
        ladeNavidromeAlben();
      }

      // Echte Songs aus SQLite laden (ohne unspielbare Fake-Dummies)
      songs = await db.alleSongs();

      favoritenIds = await favoriten.favoritenIds();
      letzteSongs = await db.letzteWiedergaben();
      await ladeTags();
      _starteCloudSyncScheduler();
    } catch (e, stack) {
      debugPrint('ladeSongs Fehler: $e\n$stack');
    }

    ladt = false;
    notifyListeners();
  }

  Map<String, int> _berechneTagCounts() {
    final counts = <String, int>{};
    for (final s in songs) {
      if (s.tagIds == null) continue;
      for (final tagId in s.tagIds!) {
        for (final entry in _tagsMap.entries) {
          if (entry.value.id == tagId) {
            counts[entry.key] = (counts[entry.key] ?? 0) + 1;
          }
        }
      }
    }
    return counts;
  }

  Future<void> ladeTags() async {
    var dbTags = await db.alleTags();
    if (dbTags.isEmpty) {
      for (final t in _defaultTags) {
        if (t['name'] != 'Alle') {
          await db.tagErstellen(t['name']!, icon: t['icon']);
        }
      }
      dbTags = await db.alleTags();
    }

    // Tags-Map füllen
    _tagsMap = {for (final t in dbTags) t.name: t};

    // Tag-IDs für jeden Song laden
    for (final song in songs) {
      if (song.id != null) {
        final songTags = await db.tagsFuerSong(song.id!);
        song.tagIds = songTags.map((t) => t.id!).toSet();
      }
    }

    tags = _defaultTags;
    tagCounts = _berechneTagCounts();
    notifyListeners();
  }

  void spieleSong(Song song, {List<Song>? warteschlange}) {
    player.setWarteschlange(warteschlange ?? songs,
      startIndex: (warteschlange ?? songs).indexWhere((s) => s.id == song.id));
    // Wiederaufnahme
    final pos = (song.zuletztPosition != null && song.zuletztPosition! > 5)
        ? song.zuletztPosition! : 0;
    player.spiele(song, position: pos);

    // Position-Tracking starten (alle 10s speichern)
    _startePositionTracking();

    // In Verlauf speichern
    if (song.id != null) {
      db.positionAktualisieren(song.id!, song.zuletztPosition ?? 0);
    }

    // Play-Counter für Hidden Message
    _playCount++;
    if (_playCount >= _botschaftSchwellwert && !zeigeBotschaft) {
      zeigeBotschaft = true;
      notifyListeners();
    }

    // Letzte Songs aktualisieren
    db.letzteWiedergaben().then((liste) {
      letzteSongs = liste;
      notifyListeners();
    });
  }

  /// Manuell die Botschaft "Seit 2008" anzeigen
  void botschaftAnzeigen() {
    zeigeBotschaft = true;
    notifyListeners();
  }

  /// Botschaft ausblenden
  void botschaftAusblenden() {
    zeigeBotschaft = false;
    notifyListeners();
  }

  void toggleTag(String tag) {
    if (tag == 'Alle') {
      aktiveTags.clear();
    } else if (aktiveTags.contains(tag)) {
      aktiveTags.remove(tag);
    } else {
      aktiveTags.add(tag);
    }
    notifyListeners();
  }

  Future<void> favoritenUmschalten(Song song) async {
    if (song.id == null) return;
    await favoriten.umschalten(song.id!);
    favoritenIds = await favoriten.favoritenIds();
    notifyListeners();
  }

  // ─── Navidrome Server-Sync ─────────────────────────

  /// Navidrome-Zugangsdaten setzen
  void verbindeNavidrome(String url, String user, String password) {
    navidrome.setCredentials(url, user, password);
  }

  /// Verbindung testen und Alben laden
  Future<bool> ladeNavidromeAlben() async {
    if (!navidrome.istVerbunden) return false;
    serverLadt = true;
    notifyListeners();
    final ok = await navidrome.ping();
    if (ok) {
      navidromeAlben = await navidrome.getAlben();
    }
    serverLadt = false;
    notifyListeners();
    return ok;
  }

  /// Songs eines Albums laden
  Future<List<SubsonicSong>> ladeAlbumSongs(String albumId) async {
    return navidrome.getSongs(albumId);
  }

  /// Song von Navidrome runterladen
  Future<bool> downloadNavidromeSong(SubsonicSong s) async {
    final song = await navidrome.downloadSong(s);
    if (song != null) {
      await ladeSongs();
      return true;
    }
    return false;
  }

  /// Song direkt vom Server streamen (ohne Download)
  void starteNavidromeStream(SubsonicSong s) {
    final uri = navidrome.streamUrl(s.id);
    final song = Song(
      titel: s.titel,
      kuenstler: s.kuenstler,
      album: s.album,
      dauerSekunden: s.dauerSekunden,
      dateiPfad: '',
      groesseBytes: s.groesseBytes,
      downloadQuelle: 'server',
      streamUrl: uri.toString(),
    );
    player.spiele(song);
  }

  @override
  void dispose() {
    _autoSyncTimer?.cancel();
    _positionsSub?.cancel();
    player.dispose();
    super.dispose();
  }

  Future<void> _starteCloudSyncScheduler() async {
    _autoSyncTimer?.cancel();
    final prefs = await SharedPreferences.getInstance();
    final autoSync = prefs.getBool('cloud_auto') ?? true;
    final intervalStunden = prefs.getInt('cloud_interval') ?? 6;

    if (!autoSync || intervalStunden <= 0) return;

    _autoSyncTimer = Timer.periodic(Duration(hours: intervalStunden), (_) async {
      try {
        await cloud.restoreLogin();
        if (!cloud.istAngemeldet) return;
        final serverSongs = await cloud.listSongs();
        if (serverSongs.isEmpty) return;

        // Nur neue Songs herunterladen
        final dir = Directory('${(await getApplicationDocumentsDirectory()).path}/music');
        if (!await dir.exists()) await dir.create(recursive: true);
        final localFiles = dir.listSync().whereType<File>()
            .map((f) => f.path.split('/').last).toSet();

        for (final s in serverSongs) {
          final title = p.basename(s['title'].toString());
          if (localFiles.contains(title)) continue; // schon lokal
          await cloud.download(s['id'].toString(), '${dir.path}/$title');
        }

        await ladeSongs(); // UI aktualisieren
      } catch (e) {
        MeloLogger().fehler('background_auto_sync', e);
      }
    });
  }
}