import 'dart:async';
// lib/pages/webdav_file_list_page.dart
import 'package:flutter/material.dart';
import '../services/webdav_service.dart';
import '../constants/ui_constants.dart';
import '../base/base_state.dart';
import '../controllers/playback_controller.dart';
import '../database/song_database.dart';
import '../services/audio_service.dart';
import '../services/metadata_events.dart';
import '../widgets/song_artwork.dart';
import '../widgets/add_to_playlist_sheet.dart';

class WebDAVFileListPage extends StatefulWidget {
  final String currentPath;

  const WebDAVFileListPage({super.key, this.currentPath = '/'});

  @override
  State<WebDAVFileListPage> createState() => _WebDAVFileListPageState();
}

class _WebDAVFileListPageState extends BaseState<WebDAVFileListPage> {
  List<WebDAVItem> _items = [];
  bool _isLoading = true;
  String _errorMessage = '';
  String _currentPath = '/';

  /// path -> 元数据行（songs 表），用于把文件名替换成标签里的标题/艺术家
  Map<String, Map<String, dynamic>> _metaByPath = {};
  String? _lastSyncedSongPath;
  StreamSubscription<MetadataUpdate>? _metaSub;

  /// 已收藏的歌曲路径
  Set<String> _favoritePaths = {};

  // 安全解码
  String _safeDecode(String input) {
    try {
      return Uri.decodeComponent(input);
    } catch (_) {
      return input;
    }
  }

  @override
  void initState() {
    super.initState();
    _currentPath = widget.currentPath;
    AudioService().addListener(_onPlaybackChanged);
    _loadDirectory();
  }

  @override
  void dispose() {
    AudioService().removeListener(_onPlaybackChanged);
    super.dispose();
  }

  /// 元数据补全后，按 path 更新列表行的标题/艺术家/封面
  void _onMetadataUpdate(MetadataUpdate update) {
    if (!_items.any((item) => item.path == update.path)) return;
    if (!mounted) return;
    safeSetState(() {
      _metaByPath = {..._metaByPath, update.path: update.row};
    });
  }
  /// 播放中的歌一旦补全了元数据，立刻刷新列表里对应的那一行
  void _onPlaybackChanged() {
    final path = AudioService().currentSong?.id;
    if (path == null || path == _lastSyncedSongPath) return;
    _lastSyncedSongPath = path;
    _syncMetadataFor(path);
  }

  Future<void> _syncMetadataFor(String path) async {
    if (!_items.any((item) => item.path == path)) return;
    final row = await SongDatabase().getSongByPath(path);
    if (row == null || !mounted) return;
    final title = (row['title'] as String?)?.trim() ?? '';
    if (title.isEmpty) return;
    safeSetState(() {
      _metaByPath = {..._metaByPath, path: row};
    });
  }

  /// 收藏 / 取消收藏：整行点击是播放，右侧红心专门做收藏
  Future<void> _toggleFavorite(String path) async {
    final wasFavorite = _favoritePaths.contains(path);
    try {
      await SongDatabase().toggleFavorite(path);
      if (!mounted) return;
      safeSetState(() {
        final next = {..._favoritePaths};
        if (wasFavorite) {
          next.remove(path);
        } else {
          next.add(path);
        }
        _favoritePaths = next;
      });
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('收藏失败: $e')),
        );
      }
    }
  }

  // ============================================================
  // 加载目录
  // ============================================================
  Future<void> _loadDirectory() async {
    safeSetState(() {
      _isLoading = true;
      _errorMessage = '';
    });

    try {
      final items =
          await WebDAVService.instance.listDirectory(path: _currentPath);

      // 一次性把本目录下所有文件的元数据查出来，列表直接用标签显示
      final paths = items
          .where((item) => !item.isDirectory)
          .map((item) => item.path)
          .toList();
      var meta = <String, Map<String, dynamic>>{};
      try {
        meta = await SongDatabase().getSongsByPaths(paths);
      } catch (e) {
        debugPrint('⚠️ [WebDAVList] 批量读取元数据失败: $e');
      }

      var favorites = <String>{};
      try {
        final favRows = await SongDatabase().getFavorites();
        favorites = favRows
            .map((row) => row['song_id'] as String?)
            .whereType<String>()
            .toSet();
      } catch (e) {
        debugPrint('⚠️ [WebDAVList] 读取收藏失败: $e');
      }

      if (mounted) {
        safeSetState(() {
          _items = items;
          _metaByPath = meta;
          _favoritePaths = favorites;
          _isLoading = false;
        });
        // 如果当前正在播的歌就在这个目录里，补一次同步
        _lastSyncedSongPath = null;
        _onPlaybackChanged();
      }
    } catch (e) {
      if (mounted) {
        safeSetState(() {
          _errorMessage = '加载失败: $e';
          _isLoading = false;
        });
      }
    }
  }

  // ============================================================
  // 进入子目录
  // ============================================================
  void _enterDirectory(WebDAVItem dir) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => WebDAVFileListPage(currentPath: dir.path),
      ),
    );
  }

  // ============================================================
  // ⭐ 播放单首（使用 PlaybackController）
  // ============================================================
  void _playSong(WebDAVItem file) async {
    try {
      await PlaybackController().playFromWebDAV(
        directoryPath: _currentPath,
        clickedSongPath: file.path,
        allItems: _items,
      );

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('正在播放: ${_safeDecode(file.name)}'),
            backgroundColor: const Color(0xFF4CAF50),
            duration: const Duration(seconds: 1),
          ),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('播放失败: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  // ============================================================
  // ⭐ 全部播放（使用 PlaybackController）
  // ============================================================
  void _playAll() async {
    try {
      await PlaybackController().playAllFromWebDAV(
        directoryPath: _currentPath,
        allItems: _items,
      );

      if (mounted) {
        final musicCount = _items.where((item) => !item.isDirectory).length;
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('开始播放全部 ($musicCount 首)'),
            backgroundColor: const Color(0xFF4CAF50),
            duration: const Duration(seconds: 1),
          ),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('播放失败: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  // ============================================================
  // 显示路径
  // ============================================================
  String _getDisplayPath() {
    if (_currentPath == '/' || _currentPath.isEmpty) return '根目录';

    final decoded = _safeDecode(_currentPath);
    final parts = decoded.split('/').where((s) => s.isNotEmpty).toList();

    if (parts.isEmpty) return '根目录';
    if (parts.length <= 2) return parts.join(' / ');
    return '... / ${parts.sublist(parts.length - 2).join(' / ')}';
  }

  // ============================================================
  // Build
  // ============================================================
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF0E1211),
      appBar: AppBar(
        title: Text(
          _getDisplayPath(),
          style: const TextStyle(fontSize: 16),
        ),
        backgroundColor: Colors.transparent,
        elevation: 0,
        foregroundColor: Colors.white,
        leading: IconButton(
          icon: const Icon(Icons.arrow_back_ios_new),
          onPressed: () => Navigator.pop(context),
        ),
        actions: [
          IconButton(
            icon: const Icon(Icons.playlist_play),
            onPressed: _playAll,
            tooltip: '全部播放',
          ),
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _loadDirectory,
            tooltip: '刷新',
          ),
        ],
      ),
      body: _isLoading
          ? const Center(
              child: CircularProgressIndicator(
                color: Color(0xFFB8D4D0),
              ),
            )
          : _errorMessage.isNotEmpty
              ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Icon(Icons.error_outline,
                          size: 48, color: Colors.grey[600]),
                      const SizedBox(height: 16),
                      Text(
                        _errorMessage,
                        style: TextStyle(color: Colors.grey[400]),
                        textAlign: TextAlign.center,
                      ),
                      const SizedBox(height: 16),
                      ElevatedButton(
                        onPressed: _loadDirectory,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: const Color(0xFFB8D4D0),
                          foregroundColor: Colors.black87,
                        ),
                        child: const Text('重试'),
                      ),
                    ],
                  ),
                )
              : _items.isEmpty
                  ? Center(
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          Icon(Icons.folder_open,
                              size: 48, color: Colors.grey[600]),
                          const SizedBox(height: 16),
                          Text(
                            '此目录为空',
                            style: TextStyle(color: Colors.grey[400]),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            '支持格式: MP3, FLAC, M4A, APE, WAV, OPUS',
                            style: TextStyle(
                                color: Colors.grey[600], fontSize: 12),
                          ),
                        ],
                      ),
                    )
                  : ListView.builder(
                      padding: const EdgeInsets.only(
                        left: 16,
                        right: 16,
                        top: 8,
                        bottom: UIConstants.miniPlayerBottomSpace,
                      ),
                      itemCount: _items.length,
                      itemBuilder: (context, index) {
                        final item = _items[index];
                        return _buildListItem(item);
                      },
                    ),
    );
  }

  // ============================================================
  // 构建列表项
  // ============================================================
  Widget _buildListItem(WebDAVItem item) {
    final displayName = _safeDecode(item.name);

    if (item.isDirectory) {
      return ListTile(
        contentPadding: const EdgeInsets.symmetric(horizontal: 4),
        visualDensity: VisualDensity.compact,
        leading: const Icon(
          Icons.folder_outlined,
          color: Color(0xFFB8D4D0),
          size: 32,
        ),
        title: Text(
          displayName,
          style: const TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.w500,
            color: Colors.white,
          ),
          maxLines: 1,
          overflow: TextOverflow.ellipsis,
        ),
        subtitle: Text(
          '文件夹',
          style: TextStyle(
            fontSize: 12,
            color: Colors.grey[500],
          ),
        ),
        trailing: const Icon(
          Icons.chevron_right,
          color: Colors.grey,
        ),
        onTap: () => _enterDirectory(item),
      );
    } else {
      final sizeStr = item.size != null
          ? '${(item.size! / 1024 / 1024).toStringAsFixed(1)} MB'
          : '';
      // 有标签就用标签，没有才退回文件名（例如新歌尚未抓取元数据）
      final meta = _metaByPath[item.path];
      final metaTitle = (meta?['title'] as String?)?.trim() ?? '';
      final metaArtist = (meta?['artist'] as String?)?.trim() ?? '';
      final hasMeta = metaTitle.isNotEmpty;
      final titleText = hasMeta ? metaTitle : displayName;
      final subtitleText = [
        if (hasMeta && metaArtist.isNotEmpty && metaArtist != '未知艺术家')
          metaArtist,
        if (sizeStr.isNotEmpty) sizeStr,
      ].join(' · ');

      return ListTile(
        contentPadding: const EdgeInsets.symmetric(horizontal: 4),
        visualDensity: VisualDensity.compact,
        leading: SongArtwork(
          filePath: meta?['artwork_path'] as String?,
          size: 44,
          fallbackIcon: Icons.audiotrack,
        ),
        title: Text(
          titleText,
          style: const TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.w400,
            color: Colors.white,
          ),
          maxLines: 1,
          overflow: TextOverflow.ellipsis,
        ),
        subtitle: Text(
          subtitleText,
          style: TextStyle(
            fontSize: 12,
            color: Colors.grey[500],
          ),
        ),
        trailing: IconButton(
          tooltip: '收藏',
          icon: Icon(
            _favoritePaths.contains(item.path)
                ? Icons.favorite
                : Icons.favorite_border,
            color: _favoritePaths.contains(item.path)
                ? const Color(0xFFE05C5C)
                : Colors.grey,
          ),
          onPressed: () => _toggleFavorite(item.path),
        ),
        onTap: () => _playSong(item),
        onLongPress: () => showAddToPlaylistSheet(context, songPath: item.path),
      );
    }
  }
}