part of 'queue_tab.dart';

extension _QueueTabNavigation on _QueueTabState {
  Future<void> _openFile(
    String filePath, {
    String title = '',
    String artist = '',
    String album = '',
    String coverUrl = '',
  }) async {
    final cleanPath = _cleanFilePath(filePath);
    try {
      final fallbackTitle = cleanPath.split('/').last.split('\\').last;
      await ref
          .read(playbackProvider.notifier)
          .playLocalPath(
            path: cleanPath,
            title: title.isNotEmpty ? title : fallbackTitle,
            artist: artist,
            album: album,
            coverUrl: coverUrl,
          );
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(context.l10n.snackbarCannotOpenFile(e.toString())),
          ),
        );
      }
    }
  }

  /// Plays [item] and queues the rest of the merged library (downloaded + local
  /// in display order) so playback continues to the next track. Honors player
  /// mode and shuffle.
  Future<void> _playLibraryItem(
    UnifiedLibraryItem item,
    List<UnifiedLibraryItem> libraryItems,
  ) async {
    final playableItems = libraryItems
        .where(
          (u) => u.filePath.trim().isNotEmpty && !isCueVirtualPath(u.filePath),
        )
        .toList();
    if (playableItems.isEmpty) return;

    var start = playableItems.indexWhere((u) => u.id == item.id);
    if (start < 0) start = 0;

    try {
      await ref
          .read(playbackProvider.notifier)
          .playMediaQueue(
            playableItems.map(_toPlayableMedia),
            startIndex: start,
            externalPath: item.filePath,
          );
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(context.l10n.snackbarCannotOpenFile(e.toString())),
          ),
        );
      }
    }
  }

  PlayableMedia _toPlayableMedia(UnifiedLibraryItem item) {
    final history = item.historyItem;
    if (history != null) return playableFromHistory(history);
    final local = item.localItem;
    if (local != null) return playableFromLocal(local);

    final cover = item.coverUrl ?? item.localCoverPath ?? '';
    String? art;
    if (cover.isNotEmpty) {
      art =
          (cover.startsWith('http') ||
              cover.startsWith('content://') ||
              cover.startsWith('file://'))
          ? cover
          : Uri.file(cover).toString();
    }
    return PlayableMedia(
      id: item.id,
      source: item.filePath,
      title: item.trackName,
      artist: item.artistName,
      album: item.albumName,
      artUri: art,
    );
  }

  void _precacheCover(String? url) {
    if (url == null || url.isEmpty) return;
    if (!url.startsWith('http://') && !url.startsWith('https://')) {
      return;
    }
    final dpr = MediaQuery.devicePixelRatioOf(
      context,
    ).clamp(1.0, 3.0).toDouble();
    final targetSize = (360 * dpr).round().clamp(512, 1024).toInt();
    precacheImage(
      ResizeImage(
        cachedCoverImageProvider(url),
        width: targetSize,
        height: targetSize,
      ),
      context,
    );
  }

  Future<void> _navigateToMetadataScreen(DownloadItem item) async {
    final historyItem = ref
        .read(downloadHistoryProvider)
        .items
        .firstWhere(
          (h) => h.filePath == item.filePath,
          orElse: () => DownloadHistoryItem(
            id: item.id,
            trackName: item.track.name,
            artistName: item.track.artistName,
            albumName: item.track.albumName,
            coverUrl: item.track.coverUrl,
            filePath: item.filePath ?? '',
            downloadedAt: DateTime.now(),
            service: item.service,
          ),
        );

    final navigator = Navigator.of(context);
    _precacheCover(historyItem.coverUrl);
    _searchFocusNode.unfocus();
    final beforeModTime = await _readFileModTimeMillis(historyItem.filePath);
    if (!mounted) return;
    final result = await navigator.push(
      slidePageRoute<bool>(page: TrackMetadataScreen(item: historyItem)),
    );
    _searchFocusNode.unfocus();
    if (result == true) {
      await _scheduleDownloadedEmbeddedCoverRefreshForPath(
        historyItem.filePath,
        beforeModTime: beforeModTime,
        force: true,
      );
      return;
    }
    await _scheduleDownloadedEmbeddedCoverRefreshForPath(
      historyItem.filePath,
      beforeModTime: beforeModTime,
    );
  }

  Future<void> _navigateToHistoryMetadataScreen(
    DownloadHistoryItem item, {
    List<DownloadHistoryItem>? navigationItems,
    int? navigationIndex,
  }) async {
    final navigator = Navigator.of(context);
    _precacheCover(item.coverUrl);
    _searchFocusNode.unfocus();
    final beforeModTime = await _readFileModTimeMillis(item.filePath);
    if (!mounted) return;
    final result = await navigator.push(
      slidePageRoute<bool>(
        page: TrackMetadataScreen(
          item: item,
          historyNavigationItems: navigationItems,
          navigationIndex: navigationIndex,
          coverHeroTag: 'cover_lib_dl_${item.id}',
        ),
      ),
    );
    _searchFocusNode.unfocus();
    if (result == true) {
      await _scheduleDownloadedEmbeddedCoverRefreshForPath(
        item.filePath,
        beforeModTime: beforeModTime,
        force: true,
      );
      return;
    }
    await _scheduleDownloadedEmbeddedCoverRefreshForPath(
      item.filePath,
      beforeModTime: beforeModTime,
    );
  }

  void _navigateToLocalMetadataScreen(
    LocalLibraryItem item, {
    List<LocalLibraryItem>? navigationItems,
    int? navigationIndex,
  }) {
    _searchFocusNode.unfocus();
    Navigator.push(
      context,
      slidePageRoute<void>(
        page: TrackMetadataScreen(
          localItem: item,
          localNavigationItems: navigationItems,
          navigationIndex: navigationIndex,
          coverHeroTag: 'cover_lib_local_${item.id}',
        ),
      ),
    ).then((_) => _searchFocusNode.unfocus());
  }

  List<DownloadHistoryItem> _filterHistoryItems(
    List<DownloadHistoryItem> items,
    String filterMode,
    Map<String, int> albumCounts, [
    String searchQuery = '',
  ]) {
    var filteredItems = items;
    if (searchQuery.isNotEmpty) {
      final query = searchQuery;
      filteredItems = items.where((item) {
        final searchKey = _historySearchKeyForItem(item);
        return searchKey.contains(query);
      }).toList();
    }

    if (filterMode == 'all') return filteredItems;

    switch (filterMode) {
      case 'albums':
        return filteredItems.where((item) {
          final key =
              '${item.albumName.toLowerCase()}|${(item.albumArtist ?? item.artistName).toLowerCase()}';
          return (albumCounts[key] ?? 0) > 1;
        }).toList();
      case 'singles':
        return filteredItems.where((item) {
          final key =
              '${item.albumName.toLowerCase()}|${(item.albumArtist ?? item.artistName).toLowerCase()}';
          return (albumCounts[key] ?? 0) == 1;
        }).toList();
      default:
        return filteredItems;
    }
  }

  void _navigateWithUnfocus(Route<dynamic> route) {
    _searchFocusNode.unfocus();
    Navigator.of(context).push(route).then((_) => _searchFocusNode.unfocus());
  }

  void _navigateToDownloadedAlbum(_GroupedAlbum album) {
    _navigateWithUnfocus(
      slidePageRoute(
        page: DownloadedAlbumScreen(
          albumName: album.albumName,
          artistName: album.artistName,
          coverUrl: album.coverUrl,
        ),
      ),
    );
  }

  Future<void> _navigateToLocalAlbum(_GroupedLocalAlbum album) async {
    var tracks = album.tracks;
    if (tracks.isEmpty && album.displayTrackCount > 0) {
      var rows = album.albumKey.isNotEmpty
          ? await LibraryDatabase.instance.getQueueLocalAlbumTracksByKey(
              album.albumKey,
            )
          : await LibraryDatabase.instance.getQueueLocalAlbumTracks(
              album.albumName,
              album.artistName,
            );
      if (rows.isEmpty && album.albumKey.isNotEmpty) {
        rows = await LibraryDatabase.instance.getQueueLocalAlbumTracks(
          album.albumName,
          album.artistName,
        );
      }
      tracks = rows.map(LocalLibraryItem.fromJson).toList(growable: false);
      if (!mounted) return;
    }
    _navigateWithUnfocus(
      slidePageRoute(
        page: LocalAlbumScreen(
          albumName: album.albumName,
          artistName: album.artistName,
          coverPath: album.coverPath,
          tracks: tracks,
        ),
      ),
    );
  }

  void _openWishlistFolder() {
    _navigateWithUnfocus(
      MaterialPageRoute(
        builder: (_) => const LibraryTracksFolderScreen(
          mode: LibraryTracksFolderMode.wishlist,
        ),
      ),
    );
  }

  void _openLovedFolder() {
    _navigateWithUnfocus(
      MaterialPageRoute(
        builder: (_) => const LibraryTracksFolderScreen(
          mode: LibraryTracksFolderMode.loved,
        ),
      ),
    );
  }

  void _openFavoriteArtistsFolder() {
    _navigateWithUnfocus(
      MaterialPageRoute(builder: (_) => const FavoriteArtistsScreen()),
    );
  }

  void _openPlaylistById(String playlistId) {
    _navigateWithUnfocus(
      MaterialPageRoute(
        builder: (_) => LibraryTracksFolderScreen(
          mode: LibraryTracksFolderMode.playlist,
          playlistId: playlistId,
        ),
      ),
    );
  }

  Future<void> _showCreatePlaylistDialog(BuildContext context) async {
    final controller = TextEditingController();
    final formKey = GlobalKey<FormState>();

    final playlistName = await showDialog<String>(
      context: context,
      builder: (dialogContext) {
        return AlertDialog(
          title: Text(dialogContext.l10n.collectionCreatePlaylist),
          content: Form(
            key: formKey,
            child: TextFormField(
              controller: controller,
              autofocus: true,
              decoration: InputDecoration(
                hintText: dialogContext.l10n.collectionPlaylistNameHint,
              ),
              validator: (value) {
                final trimmed = value?.trim() ?? '';
                if (trimmed.isEmpty) {
                  return dialogContext.l10n.collectionPlaylistNameRequired;
                }
                return null;
              },
              onFieldSubmitted: (_) {
                if (formKey.currentState?.validate() != true) return;
                Navigator.of(dialogContext).pop(controller.text.trim());
              },
            ),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(dialogContext).pop(),
              child: Text(dialogContext.l10n.dialogCancel),
            ),
            FilledButton(
              onPressed: () {
                if (formKey.currentState?.validate() != true) return;
                Navigator.of(dialogContext).pop(controller.text.trim());
              },
              child: Text(dialogContext.l10n.actionCreate),
            ),
          ],
        );
      },
    );

    if (playlistName == null || playlistName.isEmpty) return;
    await ref
        .read(libraryCollectionsProvider.notifier)
        .createPlaylist(playlistName);
  }

  /// Pass a finite [size] (e.g. 56) for list view, or `null` for grid view
  /// where the widget should expand to fill its parent.
  Widget _buildPlaylistCover(
    BuildContext context,
    UserPlaylistCollection playlist,
    ColorScheme colorScheme, [
    double? size,
  ]) {
    final borderRadius = BorderRadius.circular(8);
    final dpr = MediaQuery.devicePixelRatioOf(context);
    final cacheExtent = size != null
        ? (size * dpr).round().clamp(64, 1024)
        : 420;
    final placeholder = _playlistIconFallback(colorScheme, size);

    final customCoverPath = playlist.coverImagePath;
    if (customCoverPath != null && customCoverPath.isNotEmpty) {
      return ClipRRect(
        borderRadius: borderRadius,
        child: Image.file(
          File(customCoverPath),
          width: size,
          height: size,
          fit: BoxFit.cover,
          cacheWidth: cacheExtent,
          gaplessPlayback: true,
          filterQuality: FilterQuality.low,
          frameBuilder: (_, child, frame, wasSynchronouslyLoaded) {
            if (wasSynchronouslyLoaded || frame != null) return child;
            return placeholder;
          },
          errorBuilder: (_, _, _) => placeholder,
        ),
      );
    }

    final firstCoverUrl = playlist.tracks
        .where((e) => e.track.coverUrl != null && e.track.coverUrl!.isNotEmpty)
        .map((e) => e.track.coverUrl!)
        .firstOrNull;

    if (firstCoverUrl != null) {
      // Guard against local file paths that may have been stored as coverUrl
      final isLocalPath =
          !firstCoverUrl.startsWith('http://') &&
          !firstCoverUrl.startsWith('https://');
      if (isLocalPath) {
        return ClipRRect(
          borderRadius: borderRadius,
          child: Image.file(
            File(firstCoverUrl),
            width: size,
            height: size,
            fit: BoxFit.cover,
            cacheWidth: cacheExtent,
            gaplessPlayback: true,
            filterQuality: FilterQuality.low,
            frameBuilder: (_, child, frame, wasSynchronouslyLoaded) {
              if (wasSynchronouslyLoaded || frame != null) return child;
              return placeholder;
            },
            errorBuilder: (_, _, _) => placeholder,
          ),
        );
      }
      return CachedCoverImage(
        imageUrl: firstCoverUrl,
        width: size,
        height: size,
        memCacheWidth: cacheExtent,
        borderRadius: borderRadius,
        placeholder: (_, _) => placeholder,
        errorWidget: (_, _, _) => placeholder,
      );
    }

    return placeholder;
  }

  /// Icon fallback for playlists with no cover.
  /// When [size] is null the container expands to fill its parent (grid view)
  /// and uses a fixed icon size.
  Widget _playlistIconFallback(ColorScheme colorScheme, [double? size]) {
    return Container(
      width: size,
      height: size,
      decoration: BoxDecoration(
        color: const Color(0xFF5085A5),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Icon(
        Icons.queue_music,
        color: Colors.white,
        size: size != null ? size * 0.5 : 40,
      ),
    );
  }

  /// Handle a track being dropped onto a playlist.
  /// When selection mode is active and the dragged item is among the selected,
  /// all selected tracks are added to the playlist.
  Future<void> _onTrackDroppedOnPlaylist(
    BuildContext context,
    UnifiedLibraryItem item,
    String playlistId,
    String playlistName, {
    List<UnifiedLibraryItem> allItems = const [],
  }) async {
    final notifier = ref.read(libraryCollectionsProvider.notifier);

    if (_isSelectionMode &&
        _selectedIds.isNotEmpty &&
        _selectedIds.contains(item.id)) {
      final selectedItems = allItems
          .where((e) => _selectedIds.contains(e.id))
          .toList();
      if (selectedItems.isEmpty) {
        selectedItems.add(item);
      }

      final batchResult = await notifier.addTracksToPlaylist(
        playlistId,
        selectedItems.map((selected) => selected.toTrack()),
      );
      final addedCount = batchResult.addedCount;
      final alreadyCount = batchResult.alreadyInPlaylistCount;

      if (!context.mounted) return;
      final message = addedCount > 0
          ? alreadyCount > 0
                ? context.l10n.collectionAddedTracksToPlaylistWithExisting(
                    addedCount,
                    playlistName,
                    alreadyCount,
                  )
                : context.l10n.collectionAddedTracksToPlaylist(
                    addedCount,
                    playlistName,
                  )
          : context.l10n.collectionAlreadyInPlaylist(playlistName);
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(SnackBar(content: Text(message)));
      _exitSelectionMode();
      return;
    }

    final track = item.toTrack();
    final added = await notifier.addTrackToPlaylist(playlistId, track);

    if (!context.mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(
          added
              ? context.l10n.collectionAddedToPlaylist(playlistName)
              : context.l10n.collectionAlreadyInPlaylist(playlistName),
        ),
      ),
    );
  }

  Widget _buildDragFeedback(
    BuildContext context,
    UnifiedLibraryItem item,
    ColorScheme colorScheme,
  ) {
    final isDraggingMultiple =
        _isSelectionMode &&
        _selectedIds.contains(item.id) &&
        _selectedIds.length > 1;
    final count = isDraggingMultiple ? _selectedIds.length : 1;

    return Material(
      elevation: 6,
      borderRadius: BorderRadius.circular(12),
      color: colorScheme.surfaceContainerHighest,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.playlist_add, size: 18, color: colorScheme.primary),
            const SizedBox(width: 8),
            ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 180),
              child: Text(
                isDraggingMultiple ? '$count tracks' : item.trackName,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: Theme.of(
                  context,
                ).textTheme.bodySmall?.copyWith(fontWeight: FontWeight.w600),
              ),
            ),
          ],
        ),
      ),
    );
  }

}