ReelShort/lib/pages/discover/discover_logic.dart

// Author: fruit.com.cn

import 'package:flutter/material.dart';

import '../../core/data/models/drama.dart';
import '../../core/data/repositories/watch_history_repository.dart';
import '../../l10n/app_localizations.dart';

enum DiscoverPageAction { home, my, watchlist, detail, resume }

class DiscoverLogic extends ChangeNotifier {
  DiscoverLogic({required this.history, required this.drama}) {
    refreshPosition();
  }

  final WatchHistoryRepository history;
  Drama drama;
  late Future<Duration?> position;
  final TextEditingController search = TextEditingController();
  final FocusNode searchFocus = FocusNode();
  final ScrollController scroll = ScrollController();
  int category = 0;
  bool searchOpen = false;
  bool _disposed = false;

  void notify() {
    if (!_disposed) notifyListeners();
  }

  void refreshPosition() {
    // 续看位置来自服务端（每剧一条记录）；未登录或没有记录时给 null，UI 显示"从头看"
    position = history
        .resumePointFor(drama.id)
        .then((point) => point?.position)
        .catchError((Object _) => null);
  }

  void selectCategory(int index) {
    category = index;
    notify();
  }

  void onSearchChanged() => notify();

  bool get showSearch => searchOpen || search.text.isNotEmpty;

  void openSearch() {
    searchOpen = true;
    notify();
    searchFocus.requestFocus();
  }

  void syncDrama({
    required bool active,
    required bool wasActive,
    required Drama nextDrama,
    required bool dramaChanged,
    required int searchRequest,
    required int previousSearchRequest,
    required bool Function() isActive,
  }) {
    if (active && (!wasActive || dramaChanged)) {
      drama = nextDrama;
      refreshPosition();
      notify();
    }
    if (active && searchRequest != previousSearchRequest) {
      searchOpen = true;
      notify();
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (isActive()) searchFocus.requestFocus();
      });
    }
  }

  void act(
    BuildContext context,
    DiscoverPageAction action, {
    required bool embedded,
    ValueChanged<DiscoverPageAction>? onAction,
  }) {
    if (embedded) {
      onAction?.call(action);
    } else {
      Navigator.pop(context, action);
    }
  }

  Drama? dramaFor(String? dramaId, List<Drama> dramas) {
    for (final item in dramas) {
      if (item.id == dramaId) return item;
    }
    return null;
  }

  void openCard(
    BuildContext context,
    Drama? selected, {
    required bool embedded,
    ValueChanged<Drama>? onDramaSelected,
    ValueChanged<DiscoverPageAction>? onAction,
  }) {
    if (selected == null) {
      unavailable(context);
    } else if (embedded && onDramaSelected != null) {
      onDramaSelected(selected);
    } else {
      act(context, DiscoverPageAction.detail, embedded: embedded, onAction: onAction);
    }
  }

  void unavailable(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(l10n.artworkOnlyNotice)));
  }

  void catalogInfo(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(l10n.demoCatalogNotice)));
  }

  void showFilters(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final labels = [
      l10n.forYou,
      l10n.hot,
      l10n.newest,
      l10n.romance,
      l10n.actionGenre,
    ];
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: const Color(0xFF202126),
      showDragHandle: true,
      builder: (sheetContext) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(title: Text(l10n.filter)),
            for (var index = 0; index < labels.length; index++)
              ListTile(
                title: Text(labels[index]),
                trailing: index == category
                    ? const Icon(Icons.check_rounded, color: Color(0xFF2F7BFF))
                    : null,
                onTap: () {
                  selectCategory(index);
                  Navigator.pop(sheetContext);
                },
              ),
            const SizedBox(height: 8),
          ],
        ),
      ),
    );
  }

  @override
  void dispose() {
    _disposed = true;
    search.dispose();
    searchFocus.dispose();
    scroll.dispose();
    super.dispose();
  }
}