// Author: fruit.com.cn

import 'package:flutter/material.dart';

import '../../core/data/models/drama.dart';
import '../../core/data/models/watch_progress.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;
  WatchProgress? resumeRecord;
  final TextEditingController search = TextEditingController();
  final FocusNode searchFocus = FocusNode();
  final ScrollController scroll = ScrollController();
  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);
    refreshResume();
  }

  Future<void> refreshResume() async {
    try {
      final recent = await history.recent(limit: 1);
      if (recent.isEmpty || recent.first.finished) {
        resumeRecord = null;
      } else {
        resumeRecord = recent.first;
      }
    } catch (_) {
      resumeRecord = null;
    }
    notify();
  }

  void onSearchChanged() => notify();

  List<Drama> filtered(List<Drama> dramas) {
    final query = search.text.trim().toLowerCase();
    if (query.isEmpty) return dramas;
    return dramas.where((drama) {
      final haystack = [
        drama.title,
        drama.genre,
        drama.category,
        drama.synopsis,
      ].join(' ').toLowerCase();
      return haystack.contains(query);
    }).toList();
  }

  Drama? resumeDrama(List<Drama> dramas) {
    final record = resumeRecord;
    if (record == null) return null;
    for (final drama in dramas) {
      if (drama.id == record.dramaId) return drama;
    }
    return null;
  }

  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)));
  }

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