Melo/lib/library/artist_list.dart

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

import 'database.dart';
import 'song_grouping.dart';
import 'song_list.dart';

/// Bibliotheks-Tab: Künstler-Übersicht, gruppiert aus [MeloDb.watchSongs].
class ArtistListScreen extends StatelessWidget {
  const ArtistListScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    return StreamBuilder<List<Song>>(
      stream: db.watchSongs(),
      builder: (context, snapshot) {
        final songs = snapshot.data ?? const [];
        if (songs.isEmpty) {
          return const Center(
            child: Text('Keine Künstler', style: TextStyle(color: Colors.white54)),
          );
        }
        final grouped = groupByArtist(songs);
        final artists = grouped.keys.toList();
        return ListView.builder(
          itemCount: artists.length,
          itemBuilder: (context, i) {
            final artist = artists[i];
            final artistSongs = grouped[artist]!;
            return ListTile(
              title: Text(artist, maxLines: 1, overflow: TextOverflow.ellipsis),
              subtitle: Text('${artistSongs.length} Songs'),
              onTap: () => Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (_) => _ArtistSongsScreen(artist: artist, songs: artistSongs),
                ),
              ),
            );
          },
        );
      },
    );
  }
}

/// Zeigt alle Songs eines Künstlers.
class _ArtistSongsScreen extends StatelessWidget {
  const _ArtistSongsScreen({required this.artist, required this.songs});
  final String artist;
  final List<Song> songs;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(artist)),
      body: SongList(songs),
    );
  }
}

/// Künstler-Übersicht als eigener Bildschirm (Schnellzugriff "Künstler").
class ArtistsScreen extends StatelessWidget {
  const ArtistsScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Künstler')),
      body: const ArtistListScreen(),
    );
  }
}