QingTing-Player/lib/widgets/add_to_playlist_sheet.dart

// lib/widgets/add_to_playlist_sheet.dart
import 'package:flutter/material.dart';

import '../models/playlist_summary.dart';
import '../repositories/playlist_repository.dart';

/// 把一首歌加入歌单的底部弹层。
///
/// 视觉先保持系统样式，等设计定稿后只换这个文件即可，
/// 调用方（文件列表长按）不用改。
Future<void> showAddToPlaylistSheet(
  BuildContext context, {
  required String songPath,
}) async {
  final repo = PlaylistRepository();
  List<PlaylistSummary> playlists;
  try {
    playlists = await repo.getSummaries();
  } catch (e) {
    if (context.mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('读取歌单失败: $e')),
      );
    }
    return;
  }
  if (!context.mounted) return;

  await showModalBottomSheet<void>(
    context: context,
    backgroundColor: const Color(0xFF1A1F1E),
    builder: (sheetContext) {
      return SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Padding(
              padding: EdgeInsets.fromLTRB(20, 18, 20, 8),
              child: Align(
                alignment: Alignment.centerLeft,
                child: Text(
                  '加入歌单',
                  style: TextStyle(
                    color: Colors.white,
                    fontSize: 16,
                    fontWeight: FontWeight.w500,
                  ),
                ),
              ),
            ),
            ListTile(
              leading: const Icon(Icons.add, color: Color(0xFFB8D4D0)),
              title: const Text(
                '新建歌单',
                style: TextStyle(color: Color(0xFFB8D4D0)),
              ),
              onTap: () async {
                Navigator.pop(sheetContext);
                await _createPlaylistAndAdd(context, repo, songPath);
              },
            ),
            const Divider(height: 1, color: Colors.white12),
            if (playlists.isEmpty)
              const Padding(
                padding: EdgeInsets.symmetric(vertical: 24),
                child: Text(
                  '还没有歌单，先新建一个',
                  style: TextStyle(color: Colors.grey, fontSize: 13),
                ),
              )
            else
              ConstrainedBox(
                constraints: const BoxConstraints(maxHeight: 320),
                child: ListView.builder(
                  shrinkWrap: true,
                  itemCount: playlists.length,
                  itemBuilder: (context, index) {
                    final playlist = playlists[index];
                    return ListTile(
                      leading: const Icon(
                        Icons.queue_music,
                        color: Color(0xFFB8D4D0),
                      ),
                      title: Text(
                        playlist.name,
                        style: const TextStyle(color: Colors.white),
                      ),
                      subtitle: Text(
                        '${playlist.songCount} 首',
                        style: const TextStyle(
                            color: Colors.grey, fontSize: 12),
                      ),
                      onTap: () async {
                        final added = await repo.addSongs(
                          playlist.id,
                          [songPath],
                        );
                        if (!sheetContext.mounted) return;
                        Navigator.pop(sheetContext);
                        ScaffoldMessenger.of(context).showSnackBar(
                          SnackBar(
                            content: Text(added > 0
                                ? '已加入「${playlist.name}」'
                                : '这首歌已经在「${playlist.name}」里了'),
                          ),
                        );
                      },
                    );
                  },
                ),
              ),
            const SizedBox(height: 8),
          ],
        ),
      );
    },
  );
}

Future<void> _createPlaylistAndAdd(
  BuildContext context,
  PlaylistRepository repo,
  String songPath,
) async {
  final controller = TextEditingController();
  final name = await showDialog<String>(
    context: context,
    builder: (dialogContext) => AlertDialog(
      backgroundColor: const Color(0xFF1A1F1E),
      title: const Text('新建歌单', style: TextStyle(color: Colors.white)),
      content: TextField(
        controller: controller,
        autofocus: true,
        style: const TextStyle(color: Colors.white),
        decoration: const InputDecoration(hintText: '歌单名称'),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(dialogContext),
          child: const Text('取消'),
        ),
        TextButton(
          onPressed: () =>
              Navigator.pop(dialogContext, controller.text.trim()),
          child: const Text('创建'),
        ),
      ],
    ),
  );

  if (name == null || name.isEmpty) return;

  try {
    final playlist = await repo.createPlaylist(name);
    await repo.addSongs(playlist.id, [songPath]);
    if (!context.mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text('已新建「$name」并加入这首歌')),
    );
  } catch (e) {
    if (!context.mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text('新建歌单失败: $e')),
    );
  }
}