import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../library/database.dart';
import '../library/library_service.dart';
import '../library/permissions.dart';
import '../library/playlist_service.dart';
import '../services/cache_manager.dart';
import '../services/logger_service.dart';
import '../services/navidrome_service.dart';
import '../services/offline_mode.dart';
import '../player/audio_effects.dart';
import 'app_settings.dart';
import 'equalizer_screen.dart';
import 'library_stats.dart';

/// Settings-Tab: Bibliotheks-Statistik, Berechtigungen, Navidrome, Über Melo.
class SettingsScreen extends StatefulWidget {
  const SettingsScreen({super.key});

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  late final NavidromeService _navidrome = NavidromeService();
  late final CacheManager _cache = CacheManager();
  int _cacheSize = 0;

  @override
  void initState() {
    super.initState();
    _navidrome.ladeGespeicherteZugangsdaten();
    _cache.init().then((_) => _updateCacheSize());
  }

  Future<void> _updateCacheSize() async {
    final size = await _cache.getCacheSize();
    if (mounted) setState(() => _cacheSize = size);
  }

  /// Öffnet die Klangeffekt-Oberfläche des Systems (auf POCO/Xiaomi ist das
  /// Dolby Atmos). Nicht jedes Gerät bietet sie an.
  Future<void> _oeffneSystemKlangeffekte(BuildContext context) async {
    final effects = context.read<AudioEffects>();
    final messenger = ScaffoldMessenger.of(context);
    final geoeffnet = await effects.openSystemPanel();
    if (!geoeffnet) {
      messenger.showSnackBar(
        const SnackBar(
          content: Text('Dieses Gerät bietet keine System-Klangeffekte an'),
        ),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    return Scaffold(
      appBar: AppBar(title: const Text('Settings')),
      body: ListView(
        children: [
          const _SectionLabel('Bibliothek'),
          StreamBuilder<List<Song>>(
            stream: db.watchSongs(),
            builder: (context, snapshot) {
              final songs = snapshot.data ?? const [];
              return Column(
                children: [
                  ListTile(
                    leading: const Icon(Icons.library_music),
                    title: Text('${songs.length} Songs in der Bibliothek'),
                  ),
                  ListTile(
                    leading: const Icon(Icons.schedule),
                    title:
                        Text('${formatTotalDuration(songs)} Gesamtspieldauer'),
                  ),
                  Consumer<LibraryService>(
                    builder: (context, lib, _) => Column(
                      children: [
                        ListTile(
                          leading: const Icon(Icons.create_new_folder_outlined),
                          title: Text(addMusicLabel),
                          subtitle: const Text(
                              'Musikordner auswählen und einlesen'),
                          enabled: !lib.scanning,
                          onTap: lib.pickFolderAndScan,
                        ),
                        ListTile(
                          leading: const Icon(Icons.refresh),
                          title: const Text('Erneut scannen'),
                          subtitle: lib.scanning
                              ? Text('Scanne … ${lib.scanDone}'
                                  '${lib.scanTotal > 0 ? ' / ${lib.scanTotal}' : ''}')
                              : const Text('Bekannte Ordner neu einlesen'),
                          enabled: !lib.scanning,
                          onTap: lib.rescan,
                        ),
                      ],
                    ),
                  ),
                ],
              );
            },
          ),
          const Divider(height: 1),
          const _SectionLabel('Ton'),
          ListTile(
            leading: const Icon(Icons.graphic_eq),
            title: const Text('Equalizer'),
            subtitle: const Text('Klangprofile, Bass und Immersives Audio'),
            trailing: const Icon(Icons.chevron_right),
            onTap: () => Navigator.of(context).push(
              MaterialPageRoute(builder: (_) => const EqualizerScreen()),
            ),
          ),
          ListTile(
            leading: const Icon(Icons.surround_sound),
            title: const Text('Dolby Atmos'),
            subtitle: const Text('Klangeffekte des Systems öffnen'),
            trailing: const Icon(Icons.open_in_new),
            onTap: () => _oeffneSystemKlangeffekte(context),
          ),
          Consumer<AppSettings>(
            builder: (context, settings, _) => SwitchListTile(
              secondary: const Icon(Icons.equalizer),
              title: const Text('Gleiche Lautstärke'),
              subtitle: const Text(
                  'Senkt laute Titel ab (nur bei Dateien mit ReplayGain-Tag)'),
              value: settings.normalizeVolume,
              onChanged: settings.setNormalizeVolume,
            ),
          ),
          Consumer<AppSettings>(
            builder: (context, settings, _) => SwitchListTile(
              secondary: const Icon(Icons.headset),
              title: const Text('Automatische Wiedergabe'),
              subtitle: const Text(
                  'Startet, sobald Kopfhörer verbunden werden (auch Bluetooth)'),
              value: settings.autoPlayOnHeadphones,
              onChanged: settings.setAutoPlayOnHeadphones,
            ),
          ),
          const Divider(height: 1),
          const _SectionLabel('Darstellung'),
          Consumer<AppSettings>(
            builder: (context, settings, _) => SwitchListTile(
              secondary: const Icon(Icons.photo_library_outlined),
              title: const Text('Gleiche Kategorie = gleiches Coverbild'),
              subtitle: const Text(
                  'Songs einer Kategorie zeigen das Bild der ersten Kategorie'),
              value: settings.groupCoversByCategory,
              onChanged: settings.setGroupCoversByCategory,
            ),
          ),
          const Divider(height: 1),
          const _SectionLabel('Musikserver'),
          ListTile(
            leading: const Icon(Icons.cloud_circle),
            title: const Text('🌐 Navidrome'),
            subtitle: _navidrome.istVerbunden
                ? const Text('✅ Verbunden')
                : const Text('Nicht verbunden'),
            trailing: _navidrome.istVerbunden
                ? IconButton(
                    icon: const Icon(Icons.logout),
                    onPressed: () => _trennNavidrome(),
                  )
                : IconButton(
                    icon: const Icon(Icons.login),
                    onPressed: () => _zeigeNavidromeDialog(),
                  ),
          ),
          if (!_navidrome.istVerbunden)
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              child: Text(
                '💡 Tipp: Oder nutze Melo lokal ohne Server-Konto (nur deine Musik auf dem Gerät)',
                style: TextStyle(fontSize: 12, color: Colors.white54),
              ),
            ),
          ListTile(
            leading: const Icon(Icons.wifi_off),
            title: const Text('📴 Offline-Modus'),
            subtitle: const Text('Nur gecachte Lieder abspielen'),
            trailing: Consumer<OfflineMode>(
              builder: (context, offlineMode, _) {
                return Switch(
                  value: offlineMode.enabled,
                  onChanged: (value) => offlineMode.setEnabled(value),
                );
              },
            ),
          ),
          ListTile(
            leading: const Icon(Icons.storage),
            title: const Text('🗄️ Cache-Speicher'),
            subtitle: Text(_formatBytes(_cacheSize)),
            trailing: _cacheSize > 0
                ? IconButton(
                    tooltip: 'Cache löschen',
                    icon: const Icon(Icons.delete),
                    onPressed: () => _clearCache(),
                  )
                : null,
          ),
          ListTile(
            leading: const Icon(Icons.favorite),
            title: const Text('🌟 Favoriten-Sync'),
            subtitle: const Text('Favoriten vom Server importieren'),
            trailing: IconButton(
              tooltip: 'Vom Server laden',
              icon: const Icon(Icons.cloud_download),
              onPressed: () => _syncServerFavorites(),
            ),
          ),
          ListTile(
            leading: const Icon(Icons.playlist_play),
            title: const Text('📋 Playlisten-Sync'),
            subtitle: const Text('Server-Playlisten importieren'),
            trailing: IconButton(
              tooltip: 'Vom Server laden',
              icon: const Icon(Icons.cloud_download),
              onPressed: () => _syncServerPlaylists(),
            ),
          ),
          const Divider(height: 1),
          const _SectionLabel('Berechtigungen'),
          ListTile(
            leading: const Icon(Icons.mic_none),
            title: const Text('Musik-Berechtigung'),
            trailing: TextButton(
              onPressed: openMusicPermissionSettings,
              child: const Text('Einstellungen öffnen'),
            ),
          ),
          const Divider(height: 1),
          const _SectionLabel('Über Melo'),
          const ListTile(
            leading: Icon(Icons.info_outline),
            title: Text('Melo'),
            subtitle: Text('Deine Musik. Offline. Kein Abo.'),
          ),
        ],
      ),
    );
  }

  void _zeigeNavidromeDialog() {
    final urlCtrl = TextEditingController(text: 'https://musik.baka-net.de');
    final passCtrl = TextEditingController();
    String selectedUser = 'Baka';
    bool verbindet = false;
    bool obscure = true;
    String? fehler;

    showDialog(
      context: context,
      builder: (ctx) => StatefulBuilder(
        builder: (ctx, setDialogState) => AlertDialog(
          backgroundColor: Colors.grey.shade900,
          title: const Text('🌐 Navidrome Login',
              style: TextStyle(color: Colors.white, fontSize: 16)),
          content: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                TextField(
                  controller: urlCtrl,
                  style: const TextStyle(color: Colors.white),
                  decoration: const InputDecoration(
                    labelText: 'Server-URL',
                    labelStyle: TextStyle(color: Colors.grey),
                    border: OutlineInputBorder(),
                  ),
                ),
                const SizedBox(height: 12),
                const Text('Benutzer:', style: TextStyle(fontSize: 12, color: Colors.white70)),
                const SizedBox(height: 8),
                Row(
                  children: [
                    Expanded(
                      child: FilledButton(
                        onPressed: () => setDialogState(() => selectedUser = 'Baka'),
                        style: FilledButton.styleFrom(
                          backgroundColor: selectedUser == 'Baka'
                              ? Colors.redAccent
                              : Colors.grey.shade700,
                        ),
                        child: const Text('Baka'),
                      ),
                    ),
                    const SizedBox(width: 8),
                    Expanded(
                      child: FilledButton(
                        onPressed: () => setDialogState(() => selectedUser = 'Tinker'),
                        style: FilledButton.styleFrom(
                          backgroundColor: selectedUser == 'Tinker'
                              ? Colors.redAccent
                              : Colors.grey.shade700,
                        ),
                        child: const Text('Tinker'),
                      ),
                    ),
                    const SizedBox(width: 8),
                    Expanded(
                      child: FilledButton(
                        onPressed: () => setDialogState(() => selectedUser = 'Dustin'),
                        style: FilledButton.styleFrom(
                          backgroundColor: selectedUser == 'Dustin'
                              ? Colors.redAccent
                              : Colors.grey.shade700,
                        ),
                        child: const Text('Dustin'),
                      ),
                    ),
                  ],
                ),
                const SizedBox(height: 12),
                TextField(
                  controller: passCtrl,
                  style: const TextStyle(color: Colors.white),
                  obscureText: obscure,
                  decoration: InputDecoration(
                    labelText: 'Passwort',
                    labelStyle: const TextStyle(color: Colors.grey),
                    border: const OutlineInputBorder(),
                    // Anzeigen-Umschalter: verdeckte Tippfehler im Passwort
                    // sichtbar machen (häufigste Login-Fehlerquelle).
                    suffixIcon: IconButton(
                      icon: Icon(
                        obscure ? Icons.visibility_off : Icons.visibility,
                        color: Colors.grey,
                      ),
                      onPressed: () => setDialogState(() => obscure = !obscure),
                    ),
                  ),
                ),
                if (fehler != null) ...[
                  const SizedBox(height: 8),
                  Text(fehler!,
                      style: const TextStyle(color: Colors.red, fontSize: 12)),
                ],
                if (verbindet)
                  const Padding(
                    padding: EdgeInsets.only(top: 12),
                    child: SizedBox(
                      width: 20,
                      height: 20,
                      child: CircularProgressIndicator(
                          strokeWidth: 2, color: Colors.redAccent),
                    ),
                  ),
              ],
            ),
          ),
          actions: [
            TextButton(
                onPressed: () => Navigator.pop(ctx),
                child: const Text('Abbrechen')),
            TextButton(
              onPressed: verbindet
                  ? null
                  : () async {
                      setDialogState(() => verbindet = true);
                      // Randständige Leerzeichen entfernen (verdeckte
                      // Fehlerquelle im obscureText-Feld / bei Autofill).
                      final url = urlCtrl.text.trim();
                      final pass = passCtrl.text.trim();
                      logger.info(
                          'Navidrome Login-Versuch (pwLeer=${pass.isEmpty})');
                      _navidrome.setCredentials(url, selectedUser, pass);
                      final ok = await _navidrome.ping();
                      setDialogState(() => verbindet = false);
                      if (ok && ctx.mounted) {
                        logger.info('Navidrome Login erfolgreich');
                        await _navidrome.speichereZugangsdaten(
                            url, selectedUser, pass);
                        if (ctx.mounted) Navigator.pop(ctx);
                        if (mounted) setState(() {});
                      } else if (ctx.mounted) {
                        // Server-Meldung + Passwortlänge festhalten: „Wrong
                        // username or password" bei pwLen=10 zeigt sofort
                        // einen Tippfehler statt eines Netzwerkproblems.
                        final grund = _navidrome.letzterLoginFehler;
                        await logger.error(
                            'Navidrome Login fehlgeschlagen '
                            '(pwLen=${pass.length}, grund=${grund ?? 'unbekannt'})');
                        setDialogState(() =>
                            fehler = '❌ ${grund ?? 'Login fehlgeschlagen'}');
                      }
                    },
              child: const Text('Login',
                  style: TextStyle(color: Colors.redAccent)),
            ),
          ],
        ),
      ),
    ).then((_) {
      urlCtrl.dispose();
      passCtrl.dispose();
    });
  }

  Future<void> _trennNavidrome() async {
    await _navidrome.loescheZugangsdaten();
    if (mounted) setState(() {});
  }

  Future<void> _clearCache() async {
    await _cache.clearCache();
    if (mounted) {
      setState(() => _cacheSize = 0);
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Cache gelöscht')),
      );
    }
  }

  Future<void> _syncServerFavorites() async {
    final playlistService = context.read<PlaylistService>();
    if (!mounted) return;

    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Lade Favoriten vom Server...')),
    );

    final count = await playlistService.syncFavoritesFromServer();
    if (mounted) {
      if (count == 0) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('❌ Server nicht verbunden oder keine Favoriten')),
        );
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('✅ $count Favoriten importiert')),
        );
      }
    }
  }

  Future<void> _syncServerPlaylists() async {
    final playlistService = context.read<PlaylistService>();
    if (!mounted) return;

    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Lade Playlisten vom Server...')),
    );

    final count = await playlistService.syncPlaylistsFromServer();
    if (mounted) {
      if (count == 0) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('❌ Server nicht verbunden oder keine Playlisten')),
        );
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('✅ $count Playlisten importiert')),
        );
      }
    }
  }

  String _formatBytes(int bytes) {
    if (bytes < 1024) return '$bytes B';
    if (bytes < 1024 * 1024) return '${(bytes / 1024).toStringAsFixed(1)} KB';
    return '${(bytes / (1024 * 1024)).toStringAsFixed(1)} MB';
  }
}

/// Kleine graue Überschrift über einer Einstellungs-Gruppe.
class _SectionLabel extends StatelessWidget {
  const _SectionLabel(this.label);
  final String label;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 16, 16, 4),
      child: Text(
        label,
        style: const TextStyle(
          color: Colors.white54,
          fontSize: 12,
          fontWeight: FontWeight.bold,
        ),
      ),
    );
  }
}