// Author: fruit.com.cn

import 'dart:async';

import 'package:flutter/foundation.dart';

import '../../core/data/models/watch_progress.dart';
import '../../core/data/repositories/watch_history_repository.dart';

/// 首页频道，只依赖目录中已有数据排序或过滤。
enum HomeChannel { hot, free, newReleases, ranking }

/// 浏览型首页的本地 UI 状态。
class HomeBrowseLogic extends ChangeNotifier {
  HomeBrowseLogic({required this.history}) {
    unawaited(refreshRecent());
  }

  static const int recentLimit = 20;

  final WatchHistoryRepository history;
  HomeChannel channel = HomeChannel.hot;
  List<WatchProgress> recent = const [];
  bool loadingRecent = false;
  bool _disposed = false;

  /// 第一条未完成且存在真实播放位置的记录。
  WatchProgress? get primaryRecord {
    for (final record in recent) {
      if (!record.finished && record.hasPosition) return record;
    }
    return null;
  }

  /// 切换频道，不触发额外网络请求。
  void selectChannel(HomeChannel value) {
    if (channel == value) return;
    channel = value;
    _notify();
  }

  /// 重新加载续看数据；未登录时返回空列表。
  Future<void> refreshRecent() async {
    loadingRecent = true;
    _notify();
    try {
      recent = await history.recent(limit: recentLimit);
    } catch (_) {
      recent = const [];
    } finally {
      loadingRecent = false;
      _notify();
    }
  }

  /// 首页重新可见时刷新续看数据。
  void syncPage({required bool active, required bool wasActive}) {
    if (active && !wasActive) unawaited(refreshRecent());
  }

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

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