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

import '../library/category_service.dart';
import '../library/database.dart';
import '../library/playlist_service.dart';
import '../library/song_media.dart';
import '../player/audio_handler.dart';
import '../settings/app_settings.dart';
import '../shared/cover.dart';
import '../shared/theme.dart';

/// Playlist-Detailansicht: Songs anzeigen, per Drag & Drop umsortieren, entfernen.
class PlaylistDetailScreen extends StatelessWidget {
  const PlaylistDetailScreen({super.key, required this.playlist});
  final Playlist playlist;

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    final handler = context.read<MeloAudioHandler>();
    final service = context.read<PlaylistService>();
    final categories = context.watch<CategoryService>();
    final settings = context.watch<AppSettings>();
    return Scaffold(
      appBar: AppBar(title: Text(playlist.name)),
      body: StreamBuilder<List<Song>>(
        stream: db.watchPlaylistSongs(playlist.id),
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Center(
              child: Text('Fehler: ${snapshot.error}',
                  style: const TextStyle(color: MeloTheme.text2)),
            );
          }
          final songs = snapshot.data ?? const [];
          if (songs.isEmpty) {
            return const Center(
              child: Text('Playlist ist leer — füge Songs aus der Bibliothek hinzu',
                  style: TextStyle(color: MeloTheme.text2)),
            );
          }
          return ReorderableListView.builder(
            itemCount: songs.length,
            onReorderItem: (oldIndex, newIndex) {
              final reordered = List<Song>.from(songs);
              final moved = reordered.removeAt(oldIndex);
              reordered.insert(newIndex, moved);
              service.reorderAll(playlist.id, reordered.map((s) => s.id).toList());
            },
            itemBuilder: (context, i) {
              final s = songs[i];
              return ListTile(
                key: ValueKey(s.id),
                leading: Builder(builder: (context) {
                  final cover = categories.coverFor(s,
                      groupByCategory: settings.groupCoversByCategory);
                  return CoverImage(
                    artUri: cover != null ? Uri.file(cover) : null,
                    size: 48,
                    radius: 6,
                  );
                }),
                title: Text(s.title, maxLines: 1, overflow: TextOverflow.ellipsis),
                subtitle: Text(s.artist ?? 'Unbekannt',
                    maxLines: 1, overflow: TextOverflow.ellipsis),
                trailing: IconButton(
                  tooltip: 'Aus Playlist entfernen',
                  icon: const Icon(Icons.remove_circle_outline),
                  onPressed: () => service.removeSongFromPlaylist(playlist.id, s.id),
                ),
                onTap: () async {
                  try {
                    await playSongs(
                      handler,
                      songs,
                      i,
                      coverOf: (song) => categories.coverFor(song,
                          groupByCategory: settings.groupCoversByCategory),
                    );
                  } catch (e) {
                    if (context.mounted) {
                      ScaffoldMessenger.of(context).showSnackBar(
                        SnackBar(content: Text('Wiedergabe fehlgeschlagen: $e')),
                      );
                    }
                  }
                },
              );
            },
          );
        },
      ),
    );
  }
}