venera/lib/components/comic.dart

part of 'components.dart';

class ComicTile extends StatelessWidget {
  const ComicTile({
    super.key,
    required this.comic,
    this.enableLongPressed = true,
    this.badge,
    this.menuOptions,
    this.onTap,
  });

  final Comic comic;

  final bool enableLongPressed;

  final String? badge;

  final List<MenuEntry>? menuOptions;

  final VoidCallback? onTap;

  void _onTap() {
    if (onTap != null) {
      onTap!();
      return;
    }
    App.mainNavigatorKey?.currentContext
        ?.to(() => ComicPage(id: comic.id, sourceKey: comic.sourceKey));
  }

  void onLongPress(BuildContext context) {
    var renderBox = context.findRenderObject() as RenderBox;
    var size = renderBox.size;
    var location = renderBox.localToGlobal(
      Offset(size.width / 2, size.height / 2),
    );
    showMenu(location, context);
  }

  void onSecondaryTap(TapDownDetails details, BuildContext context) {
    showMenu(details.globalPosition, context);
  }

  void showMenu(Offset location, BuildContext context) {
    showMenuX(
      App.rootContext,
      location,
      [
        MenuEntry(
          icon: Icons.chrome_reader_mode_outlined,
          text: 'Details'.tl,
          onClick: () {
            App.mainNavigatorKey?.currentContext
                ?.to(() => ComicPage(id: comic.id, sourceKey: comic.sourceKey));
          },
        ),
        MenuEntry(
          icon: Icons.copy,
          text: 'Copy Title'.tl,
          onClick: () {
            Clipboard.setData(ClipboardData(text: comic.title));
            App.rootContext.showMessage(message: 'Title copied'.tl);
          },
        ),
        MenuEntry(
          icon: Icons.stars_outlined,
          text: 'Add to favorites'.tl,
          onClick: () {
            addFavorite(comic);
          },
        ),
        MenuEntry(
          icon: Icons.block,
          text: 'Block'.tl,
          onClick: () => block(context),
        ),
        ...?menuOptions,
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    var type = appdata.settings['comicDisplayMode'];

    Widget child = type == 'detailed'
        ? _buildDetailedMode(context)
        : _buildBriefMode(context);

    var isFavorite = appdata.settings['showFavoriteStatusOnTile']
        ? LocalFavoritesManager()
            .isExist(comic.id, ComicType(comic.sourceKey.hashCode))
        : false;
    var history = appdata.settings['showHistoryStatusOnTile']
        ? HistoryManager()
            .findSync(comic.id, ComicType(comic.sourceKey.hashCode))
        : null;
    if (history?.page == 0) {
      history!.page = 1;
    }

    if (!isFavorite && history == null) {
      return child;
    }

    return Stack(
      children: [
        Positioned.fill(
          child: child,
        ),
        Positioned(
          left: type == 'detailed' ? 16 : 6,
          top: 8,
          child: Container(
            height: 24,
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(4),
            ),
            clipBehavior: Clip.antiAlias,
            child: Row(
              children: [
                if (isFavorite)
                  Container(
                    height: 24,
                    width: 24,
                    color: Colors.green,
                    child: const Icon(
                      Icons.bookmark_rounded,
                      size: 16,
                      color: Colors.white,
                    ),
                  ),
                if (history != null)
                  Container(
                    height: 24,
                    color: Colors.blue.withOpacity(0.9),
                    constraints: const BoxConstraints(minWidth: 24),
                    padding: const EdgeInsets.symmetric(horizontal: 4),
                    child: CustomPaint(
                      painter:
                          _ReadingHistoryPainter(history.page, history.maxPage),
                    ),
                  )
              ],
            ),
          ),
        )
      ],
    );
  }

  Widget buildImage(BuildContext context) {
    ImageProvider image;
    if (comic is LocalComic) {
      image = FileImage((comic as LocalComic).coverFile);
    } else if (comic.cover.startsWith('file://')) {
      image = FileImage(File(comic.cover.substring(7)));
    } else if (comic.sourceKey == 'local') {
      var localComic = LocalManager().find(comic.id, ComicType.local);
      if (localComic == null) {
        return const SizedBox();
      }
      image = FileImage(localComic.coverFile);
    } else {
      image = CachedImageProvider(
        comic.cover,
        sourceKey: comic.sourceKey,
        cid: comic.id,
      );
    }
    return AnimatedImage(
      image: image,
      fit: BoxFit.cover,
      width: double.infinity,
      height: double.infinity,
    );
  }

  Widget _buildDetailedMode(BuildContext context) {
    return LayoutBuilder(builder: (context, constrains) {
      final height = constrains.maxHeight - 16;
      return InkWell(
          borderRadius: BorderRadius.circular(12),
          onTap: _onTap,
          onLongPress: enableLongPressed ? () => onLongPress(context) : null,
          onSecondaryTapDown: (detail) => onSecondaryTap(detail, context),
          child: Padding(
            padding: const EdgeInsets.fromLTRB(16, 8, 24, 8),
            child: Row(
              children: [
                Container(
                  width: height * 0.68,
                  height: double.infinity,
                  decoration: BoxDecoration(
                    color: Theme.of(context).colorScheme.secondaryContainer,
                    borderRadius: BorderRadius.circular(8),
                  ),
                  clipBehavior: Clip.antiAlias,
                  child: buildImage(context),
                ),
                SizedBox.fromSize(
                  size: const Size(16, 5),
                ),
                Expanded(
                  child: _ComicDescription(
                    title: comic.maxPage == null
                        ? comic.title.replaceAll("\n", "")
                        : "[${comic.maxPage}P]${comic.title.replaceAll("\n", "")}",
                    subtitle: comic.subtitle ?? '',
                    description: comic.description,
                    badge: badge ?? comic.language,
                    tags: comic.tags,
                    maxLines: 2,
                    enableTranslate: ComicSource.find(comic.sourceKey)
                            ?.enableTagsTranslate ??
                        false,
                    rating: comic.stars,
                  ),
                ),
              ],
            ),
          ));
    });
  }

  Widget _buildBriefMode(BuildContext context) {
    return Padding(
        padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 8),
        child: LayoutBuilder(
          builder: (context, constraints) {
            return InkWell(
              borderRadius: BorderRadius.circular(8),
              onTap: _onTap,
              onLongPress:
                  enableLongPressed ? () => onLongPress(context) : null,
              onSecondaryTapDown: (detail) => onSecondaryTap(detail, context),
              child: Column(
                children: [
                  Expanded(
                    child: SizedBox(
                      child: Stack(
                        children: [
                          Positioned.fill(
                            child: Container(
                              decoration: BoxDecoration(
                                color: Theme.of(context)
                                    .colorScheme
                                    .secondaryContainer,
                                borderRadius: BorderRadius.circular(8),
                              ),
                              clipBehavior: Clip.antiAlias,
                              child: buildImage(context),
                            ),
                          ),
                          Positioned(
                              bottom: 0,
                              right: 0,
                              child: Padding(
                                padding: const EdgeInsets.symmetric(
                                    horizontal: 4, vertical: 4),
                                child: ClipRRect(
                                  borderRadius: const BorderRadius.only(
                                    topLeft: Radius.circular(10.0),
                                    topRight: Radius.circular(10.0),
                                    bottomRight: Radius.circular(10.0),
                                    bottomLeft: Radius.circular(10.0),
                                  ),
                                  child: Container(
                                    color: Colors.black.withOpacity(0.5),
                                    child: Padding(
                                      padding:
                                          const EdgeInsets.fromLTRB(8, 6, 8, 6),
                                      child: ConstrainedBox(
                                        constraints: BoxConstraints(
                                          maxWidth: constraints.maxWidth * 0.88,
                                        ),
                                        child: Text(
                                          comic.description.isEmpty
                                              ? comic.subtitle
                                                      ?.replaceAll('\n', '') ??
                                                  ''
                                              : comic.description
                                                  .split('|')
                                                  .join('\n'),
                                          style: const TextStyle(
                                            fontWeight: FontWeight.w500,
                                            fontSize: 12,
                                            color: Colors.white,
                                          ),
                                          textAlign: TextAlign.right,
                                          maxLines: 2,
                                          overflow: TextOverflow.ellipsis,
                                        ),
                                      ),
                                    ),
                                  ),
                                ),
                              )),
                        ],
                      ),
                    ),
                  ),
                  Padding(
                    padding: const EdgeInsets.fromLTRB(8, 4, 8, 0),
                    child: Text(
                      comic.title.replaceAll('\n', ''),
                      style: const TextStyle(
                        fontWeight: FontWeight.w500,
                        fontSize: 14.0,
                      ),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                ],
              ),
            );
          },
        ));
  }

  void block(BuildContext comicTileContext) {
    showDialog(
      context: App.rootContext,
      builder: (context) {
        var words = <String>[];
        var all = <String>[];
        all.addAll(comic.title.split(' ').where((element) => element != ''));
        if (comic.subtitle != null && comic.subtitle != "") {
          all.add(comic.subtitle!);
        }
        all.addAll(comic.tags ?? []);
        return StatefulBuilder(builder: (context, setState) {
          return ContentDialog(
            title: 'Block'.tl,
            content: Wrap(
              runSpacing: 8,
              spacing: 8,
              children: [
                for (var word in all)
                  OptionChip(
                    text: word,
                    isSelected: words.contains(word),
                    onTap: () {
                      setState(() {
                        if (!words.contains(word)) {
                          words.add(word);
                        } else {
                          words.remove(word);
                        }
                      });
                    },
                  ),
              ],
            ).paddingHorizontal(16),
            actions: [
              Button.filled(
                onPressed: () {
                  context.pop();
                  for (var word in words) {
                    appdata.settings['blockedWords'].add(word);
                  }
                  appdata.saveData();
                  context.showMessage(message: 'Blocked'.tl);
                  comicTileContext
                      .findAncestorStateOfType<_SliverGridComicsState>()!
                      .update();
                },
                child: Text('Block'.tl),
              ),
            ],
          );
        });
      },
    );
  }
}

class _ComicDescription extends StatelessWidget {
  const _ComicDescription({
    required this.title,
    required this.subtitle,
    required this.description,
    required this.enableTranslate,
    this.badge,
    this.maxLines = 2,
    this.tags,
    this.rating,
  });

  final String title;
  final String subtitle;
  final String description;
  final String? badge;
  final List<String>? tags;
  final int maxLines;
  final bool enableTranslate;
  final double? rating;

  @override
  Widget build(BuildContext context) {
    if (tags != null) {
      tags!.removeWhere((element) => element.removeAllBlank == "");
      for (var s in tags!) {
        s = s.replaceAll("\n", " ");
      }
    }
    var enableTranslate =
        App.locale.languageCode == 'zh' && this.enableTranslate;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        Text(
          title.trim(),
          style: const TextStyle(
            fontWeight: FontWeight.w500,
            fontSize: 14.0,
          ),
          maxLines: maxLines,
          overflow: TextOverflow.ellipsis,
          softWrap: true,
        ),
        if (subtitle != "")
          Text(
            subtitle,
            style: TextStyle(
                fontSize: 10.0,
                color: context.colorScheme.onSurface.withOpacity(0.7)),
            maxLines: 1,
            softWrap: true,
            overflow: TextOverflow.ellipsis,
          ),
        const SizedBox(
          height: 4,
        ),
        if (tags != null)
          Expanded(
            child: LayoutBuilder(builder: (context, constraints) {
              if (constraints.maxHeight < 22) {
                return Container();
              }
              int cnt = (constraints.maxHeight - 22).toInt() ~/ 25;
              return Container(
                clipBehavior: Clip.antiAlias,
                height: 22 + cnt * 25,
                width: double.infinity,
                decoration: const BoxDecoration(),
                child: Wrap(
                  runAlignment: WrapAlignment.start,
                  clipBehavior: Clip.antiAlias,
                  crossAxisAlignment: WrapCrossAlignment.end,
                  spacing: 4,
                  runSpacing: 3,
                  children: [
                    for (var s in tags!)
                      Container(
                          height: 22,
                          padding: const EdgeInsets.fromLTRB(3, 2, 3, 2),
                          constraints: BoxConstraints(
                            maxWidth: constraints.maxWidth * 0.45,
                          ),
                          decoration: BoxDecoration(
                            color: s == "Unavailable"
                                ? Theme.of(context).colorScheme.errorContainer
                                : Theme.of(context)
                                    .colorScheme
                                    .secondaryContainer,
                            borderRadius:
                                const BorderRadius.all(Radius.circular(8)),
                          ),
                          child: Center(
                              widthFactor: 1,
                              child: Text(
                                enableTranslate
                                    ? TagsTranslation.translateTag(s)
                                    : s.split(':').last,
                                style: const TextStyle(fontSize: 12),
                                softWrap: true,
                                overflow: TextOverflow.ellipsis,
                                maxLines: 1,
                              ))),
                  ],
                ),
              ).toAlign(Alignment.topCenter);
            }),
          )
        else
          const Spacer(),
        Row(
          crossAxisAlignment: CrossAxisAlignment.end,
          children: [
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  if (rating != null) StarRating(value: rating!, size: 18),
                  Text(
                    description,
                    style: const TextStyle(
                      fontSize: 12.0,
                    ),
                  ),
                ],
              ),
            ),
            if (badge != null)
              Container(
                  padding: const EdgeInsets.fromLTRB(6, 4, 6, 4),
                  decoration: BoxDecoration(
                    color: Theme.of(context).colorScheme.tertiaryContainer,
                    borderRadius: const BorderRadius.all(Radius.circular(8)),
                  ),
                  child: Center(
                    child: Text(
                      "${badge![0].toUpperCase()}${badge!.substring(1).toLowerCase()}",
                      style: const TextStyle(fontSize: 12),
                    ),
                  )),
          ],
        )
      ],
    );
  }
}

class _ReadingHistoryPainter extends CustomPainter {
  final int page;
  final int? maxPage;

  const _ReadingHistoryPainter(this.page, this.maxPage);

  @override
  void paint(Canvas canvas, Size size) {
    if (maxPage == null) {
      // 在中央绘制page
      final textPainter = TextPainter(
        text: TextSpan(
          text: "$page",
          style: TextStyle(
            fontSize: size.width * 0.8,
            color: Colors.white,
          ),
        ),
        textDirection: TextDirection.ltr,
      );
      textPainter.layout();
      textPainter.paint(
          canvas,
          Offset((size.width - textPainter.width) / 2,
              (size.height - textPainter.height) / 2));
    } else if (page == maxPage) {
      // 在中央绘制勾
      final paint = Paint()
        ..color = Colors.white
        ..strokeWidth = 2
        ..style = PaintingStyle.stroke;
      canvas.drawLine(Offset(size.width * 0.2, size.height * 0.5),
          Offset(size.width * 0.45, size.height * 0.75), paint);
      canvas.drawLine(Offset(size.width * 0.45, size.height * 0.75),
          Offset(size.width * 0.85, size.height * 0.3), paint);
    } else {
      // 在左上角绘制page, 在右下角绘制maxPage
      final textPainter = TextPainter(
        text: TextSpan(
          text: "$page",
          style: TextStyle(
            fontSize: size.width * 0.8,
            color: Colors.white,
          ),
        ),
        textDirection: TextDirection.ltr,
      );
      textPainter.layout();
      textPainter.paint(canvas, const Offset(0, 0));
      final textPainter2 = TextPainter(
        text: TextSpan(
          text: "/$maxPage",
          style: TextStyle(
            fontSize: size.width * 0.5,
            color: Colors.white,
          ),
        ),
        textDirection: TextDirection.ltr,
      );
      textPainter2.layout();
      textPainter2.paint(
          canvas,
          Offset(size.width - textPainter2.width,
              size.height - textPainter2.height));
    }
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) {
    return oldDelegate is! _ReadingHistoryPainter ||
        oldDelegate.page != page ||
        oldDelegate.maxPage != maxPage;
  }
}

class SliverGridComics extends StatefulWidget {
  const SliverGridComics(
      {super.key,
      required this.comics,
      this.onLastItemBuild,
      this.badgeBuilder,
      this.menuBuilder,
      this.onTap,
      this.selections});

  final List<Comic> comics;

  final Map<Comic, bool>? selections;

  final void Function()? onLastItemBuild;

  final String? Function(Comic)? badgeBuilder;

  final List<MenuEntry> Function(Comic)? menuBuilder;

  final void Function(Comic)? onTap;

  @override
  State<SliverGridComics> createState() => _SliverGridComicsState();
}

class _SliverGridComicsState extends State<SliverGridComics> {
  List<Comic> comics = [];

  @override
  void didUpdateWidget(covariant SliverGridComics oldWidget) {
    if (oldWidget.comics != widget.comics) {
      comics.clear();
      for (var comic in widget.comics) {
        if (isBlocked(comic) == null) {
          comics.add(comic);
        }
      }
    }
    super.didUpdateWidget(oldWidget);
  }

  @override
  void initState() {
    for (var comic in widget.comics) {
      if (isBlocked(comic) == null) {
        comics.add(comic);
      }
    }
    super.initState();
  }

  void update() {
    setState(() {
      comics.clear();
      for (var comic in widget.comics) {
        if (isBlocked(comic) == null) {
          comics.add(comic);
        }
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return _SliverGridComics(
      comics: comics,
      selection: widget.selections,
      onLastItemBuild: widget.onLastItemBuild,
      badgeBuilder: widget.badgeBuilder,
      menuBuilder: widget.menuBuilder,
      onTap: widget.onTap,
    );
  }
}

class _SliverGridComics extends StatelessWidget {
  const _SliverGridComics({
    required this.comics,
    this.onLastItemBuild,
    this.badgeBuilder,
    this.menuBuilder,
    this.onTap,
    this.selection,
  });

  final List<Comic> comics;

  final Map<Comic, bool>? selection;

  final void Function()? onLastItemBuild;

  final String? Function(Comic)? badgeBuilder;

  final List<MenuEntry> Function(Comic)? menuBuilder;

  final void Function(Comic)? onTap;

  @override
  Widget build(BuildContext context) {
    return SliverGrid(
      delegate: SliverChildBuilderDelegate(
        (context, index) {
          if (index == comics.length - 1) {
            onLastItemBuild?.call();
          }
          var badge = badgeBuilder?.call(comics[index]);
          var isSelected =
              selection == null ? false : selection![comics[index]] ?? false;
          var comic = ComicTile(
            comic: comics[index],
            badge: badge,
            menuOptions: menuBuilder?.call(comics[index]),
            onTap: onTap != null ? () => onTap!(comics[index]) : null,
          );
          if(selection == null) {
            return comic;
          }
          return Container(
            decoration: BoxDecoration(
              color: isSelected
                  ? Theme.of(context).colorScheme.surfaceContainer
                  : null,
              borderRadius: BorderRadius.circular(12),
            ),
            margin: const EdgeInsets.all(4),
            child: comic,
          );
        },
        childCount: comics.length,
      ),
      gridDelegate: SliverGridDelegateWithComics(),
    );
  }
}

/// return the first blocked keyword, or null if not blocked
String? isBlocked(Comic item) {
  for (var word in appdata.settings['blockedWords']) {
    if (item.title.contains(word)) {
      return word;
    }
    if (item.subtitle?.contains(word) ?? false) {
      return word;
    }
    if (item.description.contains(word)) {
      return word;
    }
    for (var tag in item.tags ?? <String>[]) {
      if (tag == word) {
        return word;
      }
      if (tag.contains(':')) {
        tag = tag.split(':')[1];
        if (tag == word) {
          return word;
        }
      }
    }
  }
  return null;
}

class ComicList extends StatefulWidget {
  const ComicList({
    super.key,
    this.loadPage,
    this.loadNext,
    this.leadingSliver,
    this.trailingSliver,
    this.errorLeading,
    this.menuBuilder,
  });

  final Future<Res<List<Comic>>> Function(int page)? loadPage;

  final Future<Res<List<Comic>>> Function(String? next)? loadNext;

  final Widget? leadingSliver;

  final Widget? trailingSliver;

  final Widget? errorLeading;

  final List<MenuEntry> Function(Comic)? menuBuilder;

  @override
  State<ComicList> createState() => ComicListState();
}

class ComicListState extends State<ComicList> {
  int? _maxPage;

  final Map<int, List<Comic>> _data = {};

  int _page = 1;

  String? _error;

  final Map<int, bool> _loading = {};

  String? _nextUrl;

  void remove(Comic c) {
    if (_data[_page] == null || !_data[_page]!.remove(c)) {
      for (var page in _data.values) {
        if (page.remove(c)) {
          break;
        }
      }
    }
    setState(() {});
  }

  Widget _buildPageSelector() {
    return Row(
      children: [
        FilledButton(
          onPressed: _page > 1
              ? () {
                  setState(() {
                    _error = null;
                    _page--;
                  });
                }
              : null,
          child: Text("Back".tl),
        ).fixWidth(84),
        Expanded(
          child: Center(
            child: Material(
              color: Theme.of(context).colorScheme.surfaceContainer,
              borderRadius: BorderRadius.circular(8),
              child: InkWell(
                borderRadius: BorderRadius.circular(8),
                onTap: () {
                  String value = '';
                  showDialog(
                    context: App.rootContext,
                    builder: (context) {
                      return ContentDialog(
                        title: "Jump to page".tl,
                        content: TextField(
                          keyboardType: TextInputType.number,
                          decoration: InputDecoration(
                            labelText: "Page".tl,
                          ),
                          inputFormatters: <TextInputFormatter>[
                            FilteringTextInputFormatter.digitsOnly
                          ],
                          onChanged: (v) {
                            value = v;
                          },
                        ).paddingHorizontal(16),
                        actions: [
                          Button.filled(
                            onPressed: () {
                              Navigator.of(context).pop();
                              var page = int.tryParse(value);
                              if (page == null) {
                                context.showMessage(message: "Invalid page".tl);
                              } else {
                                if (page > 0 &&
                                    (_maxPage == null || page <= _maxPage!)) {
                                  setState(() {
                                    _error = null;
                                    _page = page;
                                  });
                                } else {
                                  context.showMessage(
                                      message: "Invalid page".tl);
                                }
                              }
                            },
                            child: Text("Jump".tl),
                          ),
                        ],
                      );
                    },
                  );
                },
                child: Padding(
                  padding:
                      const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
                  child: Text("Page $_page / ${_maxPage ?? '?'}"),
                ),
              ),
            ),
          ),
        ),
        FilledButton(
          onPressed: _page < (_maxPage ?? (_page + 1))
              ? () {
                  setState(() {
                    _error = null;
                    _page++;
                  });
                }
              : null,
          child: Text("Next".tl),
        ).fixWidth(84),
      ],
    ).paddingVertical(8).paddingHorizontal(16);
  }

  Widget _buildSliverPageSelector() {
    return SliverToBoxAdapter(
      child: _buildPageSelector(),
    );
  }

  Future<void> _loadPage(int page) async {
    if (widget.loadPage == null && widget.loadNext == null) {
      _error = "loadPage and loadNext can't be null at the same time";
      Future.microtask(() {
        setState(() {});
      });
    }
    if (_loading[page] == true) {
      return;
    }
    _loading[page] = true;
    try {
      if (widget.loadPage != null) {
        var res = await widget.loadPage!(page);
        if (!mounted) return;
        if (res.success) {
          if (res.data.isEmpty) {
            _data[page] = const [];
            setState(() {
              _maxPage = page;
            });
          } else {
            setState(() {
              _data[page] = res.data;
              if (res.subData != null && res.subData is int) {
                _maxPage = res.subData;
              }
            });
          }
        } else {
          setState(() {
            _error = res.errorMessage ?? "Unknown error".tl;
          });
        }
      } else {
        try {
          while (_data[page] == null) {
            await _fetchNext();
          }
          setState(() {});
        } catch (e) {
          setState(() {
            _error = e.toString();
          });
        }
      }
    } finally {
      _loading[page] = false;
    }
  }

  Future<void> _fetchNext() async {
    var res = await widget.loadNext!(_nextUrl);
    _data[_data.length + 1] = res.data;
    if (res.subData == null) {
      _maxPage = _data.length;
    } else {
      _nextUrl = res.subData;
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_error != null) {
      return Column(
        children: [
          if (widget.errorLeading != null) widget.errorLeading!,
          _buildPageSelector(),
          Expanded(
            child: NetworkError(
              withAppbar: false,
              message: _error!,
              retry: () {
                setState(() {
                  _error = null;
                });
              },
            ),
          ),
        ],
      );
    }
    if (_data[_page] == null) {
      _loadPage(_page);
      return Column(
        children: [
          if (widget.errorLeading != null) widget.errorLeading!,
          const Expanded(
            child: Center(
              child: CircularProgressIndicator(),
            ),
          ),
        ],
      );
    }
    return SmoothCustomScrollView(
      slivers: [
        if (widget.leadingSliver != null) widget.leadingSliver!,
        if (_maxPage != 1) _buildSliverPageSelector(),
        SliverGridComics(
          comics: _data[_page] ?? const [],
          menuBuilder: widget.menuBuilder,
        ),
        if (_data[_page]!.length > 6 && _maxPage != 1)
          _buildSliverPageSelector(),
        if (widget.trailingSliver != null) widget.trailingSliver!,
      ],
    );
  }
}

class StarRating extends StatelessWidget {
  const StarRating({
    super.key,
    required this.value,
    this.onTap,
    this.size = 20,
  });

  final double value; // 0-5

  final VoidCallback? onTap;

  final double size;

  @override
  Widget build(BuildContext context) {
    var interval = size * 0.1;
    var value = this.value;
    if (value.isNaN) {
      value = 0;
    }
    var child = SizedBox(
      height: size,
      width: size * 5 + interval * 4,
      child: Row(
        children: [
          for (var i = 0; i < 5; i++)
            _Star(
              value: (value - i).clamp(0.0, 1.0),
              size: size,
            ).paddingRight(i == 4 ? 0 : interval),
        ],
      ),
    );
    return onTap == null
        ? child
        : GestureDetector(
            onTap: onTap,
            child: child,
          );
  }
}

class _Star extends StatelessWidget {
  const _Star({required this.value, required this.size});

  final double value; // 0-1

  final double size;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: size,
      height: size,
      child: Stack(
        children: [
          Icon(
            Icons.star_outline,
            size: size,
            color: context.colorScheme.secondary,
          ),
          ClipRect(
            clipper: _StarClipper(value),
            child: Icon(
              Icons.star,
              size: size,
              color: context.colorScheme.secondary,
            ),
          ),
        ],
      ),
    );
  }
}

class _StarClipper extends CustomClipper<Rect> {
  final double value;

  _StarClipper(this.value);

  @override
  Rect getClip(Size size) {
    return Rect.fromLTWH(0, 0, size.width * value, size.height);
  }

  @override
  bool shouldReclip(covariant CustomClipper<Rect> oldClipper) {
    return oldClipper is! _StarClipper || oldClipper.value != value;
  }
}

class RatingWidget extends StatefulWidget {
  /// star number
  final int count;

  /// Max score
  final double maxRating;

  /// Current score value
  final double value;

  /// Star size
  final double size;

  /// Space between the stars
  final double padding;

  /// Whether the score can be modified by sliding
  final bool selectable;

  /// Callbacks when ratings change
  final ValueChanged<double> onRatingUpdate;

  const RatingWidget(
      {super.key,
      this.maxRating = 10.0,
      this.count = 5,
      this.value = 10.0,
      this.size = 20,
      required this.padding,
      this.selectable = false,
      required this.onRatingUpdate});

  @override
  State<RatingWidget> createState() => _RatingWidgetState();
}

class _RatingWidgetState extends State<RatingWidget> {
  double value = 10;

  @override
  Widget build(BuildContext context) {
    return Listener(
      onPointerDown: (PointerDownEvent event) {
        double x = event.localPosition.dx;
        if (x < 0) x = 0;
        pointValue(x);
      },
      onPointerMove: (PointerMoveEvent event) {
        double x = event.localPosition.dx;
        if (x < 0) x = 0;
        pointValue(x);
      },
      onPointerUp: (_) {},
      behavior: HitTestBehavior.deferToChild,
      child: buildRowRating(),
    );
  }

  pointValue(double dx) {
    if (!widget.selectable) {
      return;
    }
    if (dx >=
        widget.size * widget.count + widget.padding * (widget.count - 1)) {
      value = widget.maxRating;
    } else {
      for (double i = 1; i < widget.count + 1; i++) {
        if (dx > widget.size * i + widget.padding * (i - 1) &&
            dx < widget.size * i + widget.padding * i) {
          value = i * (widget.maxRating / widget.count);
          break;
        } else if (dx > widget.size * (i - 1) + widget.padding * (i - 1) &&
            dx < widget.size * i + widget.padding * i) {
          value = (dx - widget.padding * (i - 1)) /
              (widget.size * widget.count) *
              widget.maxRating;
          break;
        }
      }
    }
    if (value % 1 >= 0.5) {
      value = value ~/ 1 + 1;
    } else {
      value = (value ~/ 1).toDouble();
    }
    if (value < 0) {
      value = 0;
    } else if (value > 10) {
      value = 10;
    }
    setState(() {
      widget.onRatingUpdate(value);
    });
  }

  int fullStars() {
    return (value / (widget.maxRating / widget.count)).floor();
  }

  double star() {
    if (widget.count / fullStars() == widget.maxRating / value) {
      return 0;
    }
    return (value % (widget.maxRating / widget.count)) /
        (widget.maxRating / widget.count);
  }

  List<Widget> buildRow() {
    int full = fullStars();
    List<Widget> children = [];
    for (int i = 0; i < full; i++) {
      children.add(Icon(
        Icons.star,
        size: widget.size,
        color: context.colorScheme.secondary,
      ));
      if (i < widget.count - 1) {
        children.add(
          SizedBox(
            width: widget.padding,
          ),
        );
      }
    }
    if (full < widget.count) {
      children.add(ClipRect(
        clipper: SMClipper(rating: star() * widget.size),
        child: Icon(
          Icons.star,
          size: widget.size,
          color: context.colorScheme.secondary,
        ),
      ));
    }

    return children;
  }

  List<Widget> buildNormalRow() {
    List<Widget> children = [];
    for (int i = 0; i < widget.count; i++) {
      children.add(Icon(
        Icons.star_border,
        size: widget.size,
        color: context.colorScheme.secondary,
      ));
      if (i < widget.count - 1) {
        children.add(SizedBox(
          width: widget.padding,
        ));
      }
    }
    return children;
  }

  Widget buildRowRating() {
    return Stack(
      children: <Widget>[
        Row(
          children: buildNormalRow(),
        ),
        Row(
          children: buildRow(),
        )
      ],
    );
  }

  @override
  void initState() {
    super.initState();
    value = widget.value;
  }
}

class SMClipper extends CustomClipper<Rect> {
  final double rating;

  SMClipper({required this.rating});

  @override
  Rect getClip(Size size) {
    return Rect.fromLTRB(0.0, 0.0, rating, size.height);
  }

  @override
  bool shouldReclip(SMClipper oldClipper) {
    return rating != oldClipper.rating;
  }
}