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

import '../library/database.dart';
import '../library/playlist_service.dart';
import '../library/song_list.dart';
import '../shared/theme.dart';
import 'create_playlist_dialog.dart';
import 'playlist_detail_screen.dart';

/// Playlisten-Tab: Favoriten-Kurzeinstieg oben, darunter alle eigenen Playlisten.
class PlaylistsScreen extends StatelessWidget {
  const PlaylistsScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    return Scaffold(
      appBar: AppBar(title: const Text('Playlisten')),
      body: Column(
        children: [
          StreamBuilder<List<Song>>(
            stream: db.watchFavorites(),
            builder: (context, snapshot) {
              final count = snapshot.data?.length ?? 0;
              return ListTile(
                leading: const Icon(Icons.favorite, color: MeloTheme.red),
                title: const Text('Favoriten'),
                subtitle: Text('$count Songs'),
                onTap: () => Navigator.push(
                  context,
                  MaterialPageRoute(builder: (_) => const FavoritesListScreen()),
                ),
              );
            },
          ),
          const Divider(height: 1),
          Expanded(
            child: StreamBuilder<List<Playlist>>(
              stream: db.watchPlaylists(),
              builder: (context, snapshot) {
                if (snapshot.hasError) {
                  return Center(
                    child: Text('Fehler: ${snapshot.error}',
                        style: const TextStyle(color: Colors.white54)),
                  );
                }
                final playlists = snapshot.data ?? const [];
                if (playlists.isEmpty) {
                  return const _Empty();
                }
                return ListView.builder(
                  itemCount: playlists.length,
                  itemBuilder: (context, i) => _PlaylistTile(playlist: playlists[i]),
                );
              },
            ),
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        tooltip: 'Neue Playlist',
        onPressed: () => showDialog<String?>(
          context: context,
          builder: (_) => const CreatePlaylistDialog(),
        ),
        child: const Icon(Icons.add),
      ),
    );
  }
}

class _PlaylistTile extends StatelessWidget {
  const _PlaylistTile({required this.playlist});
  final Playlist playlist;

  Future<void> _confirmDelete(BuildContext context) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Playlist löschen?'),
        content: Text('„${playlist.name}“ wird dauerhaft gelöscht.'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('Abbrechen'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(ctx, true),
            child: const Text('Löschen'),
          ),
        ],
      ),
    );
    if (confirmed == true && context.mounted) {
      await context.read<PlaylistService>().deletePlaylist(playlist.id);
    }
  }

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    return StreamBuilder<List<Song>>(
      stream: db.watchPlaylistSongs(playlist.id),
      builder: (context, snapshot) {
        final count = snapshot.data?.length ?? 0;
        return ListTile(
          leading: const Icon(Icons.playlist_play),
          title: Text(playlist.name),
          subtitle: Text('$count Songs'),
          trailing: IconButton(
            tooltip: 'Playlist löschen',
            icon: const Icon(Icons.delete_outline),
            onPressed: () => _confirmDelete(context),
          ),
          onLongPress: () => _confirmDelete(context),
          onTap: () => Navigator.push(
            context,
            MaterialPageRoute(builder: (_) => PlaylistDetailScreen(playlist: playlist)),
          ),
        );
      },
    );
  }
}

class _Empty extends StatelessWidget {
  const _Empty();

  @override
  Widget build(BuildContext context) {
    return const Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(Icons.playlist_play, size: 64, color: Colors.white24),
          SizedBox(height: 12),
          Text('Noch keine Playlisten', style: TextStyle(color: Colors.white54)),
          SizedBox(height: 8),
          Text('Tippe auf + um eine Playlist zu erstellen',
              style: TextStyle(color: Colors.white38, fontSize: 12)),
        ],
      ),
    );
  }
}

/// Gepushte Ansicht der favorisierten Songs.
class FavoritesListScreen extends StatelessWidget {
  const FavoritesListScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    return Scaffold(
      appBar: AppBar(title: const Text('Favoriten')),
      body: StreamBuilder<List<Song>>(
        stream: db.watchFavorites(),
        builder: (context, snapshot) {
          final songs = snapshot.data ?? const [];
          if (songs.isEmpty) {
            return const Center(
              child: Text('Noch keine Favoriten', style: TextStyle(color: Colors.white54)),
            );
          }
          return SongList(songs);
        },
      ),
    );
  }
}