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

import '../player/audio_handler.dart';
import '../playlists/create_playlist_dialog.dart';
import '../settings/app_settings.dart';
import '../shared/cover.dart';
import '../shared/favorite_button.dart';
import 'category_service.dart';
import 'database.dart';
import 'playlist_service.dart';
import 'song_detail_sheet.dart';
import 'song_media.dart';

/// Scrollbare Songliste; Tippen spielt die ganze Liste ab dem Song ab.
class SongList extends StatelessWidget {
  const SongList(this.songs, {super.key});
  final List<Song> songs;

  /// Öffnet ein Bottom-Sheet mit allen Playlisten, um [song] hinzuzufügen.
  Future<void> _showAddToPlaylist(BuildContext context, Song song) async {
    final db = context.read<MeloDb>();
    final service = context.read<PlaylistService>();
    await showModalBottomSheet(
      context: context,
      builder: (sheetContext) => SafeArea(
        child: StreamBuilder<List<Playlist>>(
          stream: db.watchPlaylists(),
          builder: (context, snapshot) {
            final playlists = snapshot.data ?? const [];
            return Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                ListTile(
                  leading: const Icon(Icons.add),
                  title: const Text('Neue Playlist'),
                  onTap: () async {
                    final newId = await showDialog<String?>(
                      context: sheetContext,
                      builder: (_) => const CreatePlaylistDialog(),
                    );
                    if (newId == null) return;
                    final position = (await db.watchPlaylistSongs(newId).first).length;
                    await service.addSongToPlaylist(newId, song.id, position);
                    if (sheetContext.mounted) {
                      Navigator.pop(sheetContext);
                      ScaffoldMessenger.of(sheetContext).showSnackBar(
                        const SnackBar(content: Text('Zu Playlist hinzugefügt')),
                      );
                    }
                  },
                ),
                for (final playlist in playlists)
                  ListTile(
                    leading: const Icon(Icons.playlist_play),
                    title: Text(playlist.name),
                    onTap: () async {
                      final position =
                          (await db.watchPlaylistSongs(playlist.id).first).length;
                      await service.addSongToPlaylist(playlist.id, song.id, position);
                      if (sheetContext.mounted) {
                        Navigator.pop(sheetContext);
                        ScaffoldMessenger.of(sheetContext).showSnackBar(
                          SnackBar(content: Text('Zu ${playlist.name} hinzugefügt')),
                        );
                      }
                    },
                  ),
              ],
            );
          },
        ),
      ),
    );
  }

  /// "Künstler | Kategorie1 · Kategorie2" — wie im UI-Entwurf.
  static String _subtitle(Song song, List<String> categories) {
    final artist = song.artist ?? 'Unbekannt';
    if (categories.isEmpty) return artist;
    return '$artist | ${categories.join(' · ')}';
  }

  /// Menü hinter dem Drei-Punkte-Symbol einer Songzeile.
  ///
  /// Die Offline-Meldungen greifen hier heute nie: diese Liste zeigt nur
  /// Titel der Bibliothek, und die liegen als Datei vor. Sie stehen trotzdem
  /// da, weil die Alternative — den Rückgabewert wegwerfen und "hinzugefügt"
  /// melden — still lügen würde, sobald ein Server-Titel hier ankommt.
  Future<void> _showMenu(BuildContext context, Song song) async {
    final handler = context.read<MeloAudioHandler>();
    final categories = context.read<CategoryService>();
    final settings = context.read<AppSettings>();
    final messenger = ScaffoldMessenger.of(context);
    MediaItem item() => songToMediaItem(
          song,
          cover: categories.coverFor(song,
              groupByCategory: settings.groupCoversByCategory),
        );
    await showModalBottomSheet(
      context: context,
      builder: (sheetContext) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(
              leading: const Icon(Icons.info_outline),
              title: const Text('Metadaten'),
              onTap: () {
                Navigator.pop(sheetContext);
                SongDetailSheet.show(context, song);
              },
            ),
            ListTile(
              leading: const Icon(Icons.playlist_play),
              title: const Text('Als Nächstes spielen'),
              onTap: () async {
                Navigator.pop(sheetContext);
                final ok = await handler.playNext(item());
                messenger.showSnackBar(SnackBar(
                    content: Text(ok
                        ? 'Läuft als Nächstes'
                        : nichtOfflineHinweis)));
              },
            ),
            ListTile(
              leading: const Icon(Icons.queue),
              title: const Text('Zur Warteschlange hinzufügen'),
              subtitle: const Text(
                  'Nur für jetzt — nicht in Favoriten oder Wiedergabelisten'),
              onTap: () async {
                Navigator.pop(sheetContext);
                final ok = await handler.addToQueue(item());
                messenger.showSnackBar(SnackBar(
                    content: Text(ok
                        ? 'Zur Warteschlange hinzugefügt'
                        : nichtOfflineHinweis)));
              },
            ),
            ListTile(
              leading: const Icon(Icons.playlist_add),
              title: const Text('Zu Wiedergabeliste hinzufügen'),
              onTap: () {
                Navigator.pop(sheetContext);
                _showAddToPlaylist(context, song);
              },
            ),
          ],
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final handler = context.read<MeloAudioHandler>();
    final categories = context.watch<CategoryService>();
    final settings = context.watch<AppSettings>();
    return ListView.builder(
      itemCount: songs.length,
      itemBuilder: (context, i) {
        final s = songs[i];
        final cover = categories.coverFor(s,
            groupByCategory: settings.groupCoversByCategory);
        return ListTile(
          leading: CoverImage(
            artUri: cover != null ? Uri.file(cover) : null,
            size: 48,
            radius: 6,
          ),
          title: Text(s.title, maxLines: 1, overflow: TextOverflow.ellipsis),
          subtitle: Text(
            _subtitle(s, categories.of(s.id)),
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
          trailing: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              FavoriteButton(songId: s.id),
              IconButton(
                tooltip: 'Mehr',
                icon: const Icon(Icons.more_vert),
                onPressed: () => _showMenu(context, s),
              ),
            ],
          ),
          onTap: () async {
            final messenger = ScaffoldMessenger.of(context);
            try {
              final uebersprungen = await playSongs(
                handler,
                songs,
                i,
                coverOf: (song) => categories.coverFor(song,
                    groupByCategory: settings.groupCoversByCategory),
              );
              if (uebersprungen > 0) {
                messenger.showSnackBar(
                  SnackBar(content: Text(offlineHinweis(uebersprungen))),
                );
              }
            } catch (e) {
              messenger.showSnackBar(
                SnackBar(content: Text('Wiedergabe fehlgeschlagen: $e')),
              );
            }
          },
        );
      },
    );
  }
}