/// 时间: 2026-03-31
/// 功能: 统计数据管理
/// 介绍: 管理应用的各种统计数据，包括浏览次数、答题次数、点赞数等
/// 最新变化: 新建文件

import 'package:shared_preferences/shared_preferences.dart';

class StatisticsManager {
  static const String _todayViewsKey = 'today_views';
  static const String _weekViewsKey = 'week_views';
  static const String _firstUseTimeKey = 'first_use_time';
  static const String _todayLikesKey = 'today_likes';
  static const String _todayQuestionsKey = 'today_questions';
  static const String _lastViewDateKey = 'last_view_date';
  static const String _lastWeekKey = 'last_week_start';
  static const String _lastQuestionDateKey = 'last_question_date';

  static StatisticsManager? _instance;

  StatisticsManager._internal();

  factory StatisticsManager() {
    _instance ??= StatisticsManager._internal();
    return _instance!;
  }

  /// 记录一次浏览
  Future<void> recordView() async {
    final prefs = await SharedPreferences.getInstance();
    final now = DateTime.now();
    final today = _formatDate(now);
    final weekStart = _getWeekStart(now);

    final lastViewDate = prefs.getString(_lastViewDateKey);
    final lastWeekStart = prefs.getString(_lastWeekKey);

    if (lastViewDate != today) {
      await prefs.setInt(_todayViewsKey, 0);
      await prefs.setString(_lastViewDateKey, today);
    }

    if (lastWeekStart != weekStart) {
      await prefs.setInt(_weekViewsKey, 0);
      await prefs.setString(_lastWeekKey, weekStart);
    }

    final todayViews = prefs.getInt(_todayViewsKey) ?? 0;
    final weekViews = prefs.getInt(_weekViewsKey) ?? 0;

    await prefs.setInt(_todayViewsKey, todayViews + 1);
    await prefs.setInt(_weekViewsKey, weekViews + 1);
  }

  /// 获取今日浏览次数
  Future<int> getTodayViews() async {
    final prefs = await SharedPreferences.getInstance();
    final today = _formatDate(DateTime.now());
    final lastViewDate = prefs.getString(_lastViewDateKey);

    if (lastViewDate != today) {
      return 0;
    }

    return prefs.getInt(_todayViewsKey) ?? 0;
  }

  /// 获取本周浏览次数
  Future<int> getWeekViews() async {
    final prefs = await SharedPreferences.getInstance();
    final now = DateTime.now();
    final weekStart = _getWeekStart(now);
    final lastWeekStart = prefs.getString(_lastWeekKey);

    if (lastWeekStart != weekStart) {
      return 0;
    }

    return prefs.getInt(_weekViewsKey) ?? 0;
  }

  /// 记录首次使用时间
  Future<void> recordFirstUse() async {
    final prefs = await SharedPreferences.getInstance();
    if (!prefs.containsKey(_firstUseTimeKey)) {
      await prefs.setString(_firstUseTimeKey, DateTime.now().toIso8601String());
    }
  }

  /// 获取首次使用时间
  Future<String> getFirstUseTime() async {
    final prefs = await SharedPreferences.getInstance();
    final timeStr = prefs.getString(_firstUseTimeKey);
    if (timeStr == null) {
      return '未记录';
    }
    final date = DateTime.parse(timeStr);
    return '${date.year}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
  }

  /// 记录今日点赞
  Future<void> recordTodayLike() async {
    final prefs = await SharedPreferences.getInstance();
    final now = DateTime.now();
    final today = _formatDate(now);
    final lastLikeDate = prefs.getString('last_like_date');

    if (lastLikeDate != today) {
      await prefs.setInt(_todayLikesKey, 0);
      await prefs.setString('last_like_date', today);
    }

    final todayLikes = prefs.getInt(_todayLikesKey) ?? 0;
    await prefs.setInt(_todayLikesKey, todayLikes + 1);
  }

  /// 获取今日点赞数
  Future<int> getTodayLikes() async {
    final prefs = await SharedPreferences.getInstance();
    final today = _formatDate(DateTime.now());
    final lastLikeDate = prefs.getString('last_like_date');

    if (lastLikeDate != today) {
      return 0;
    }

    return prefs.getInt(_todayLikesKey) ?? 0;
  }

  /// 获取数据占用空间
  Future<String> getDataSize() async {
    try {
      final prefs = await SharedPreferences.getInstance();
      final keys = prefs.getKeys();
      int totalBytes = 0;

      for (final key in keys) {
        final value = prefs.get(key);
        if (value != null) {
          totalBytes += value.toString().length * 2;
        }
      }

      if (totalBytes < 1024) {
        return '$totalBytes B';
      } else if (totalBytes < 1024 * 1024) {
        return '${(totalBytes / 1024).toStringAsFixed(1)} KB';
      } else {
        return '${(totalBytes / (1024 * 1024)).toStringAsFixed(1)} MB';
      }
    } catch (e) {
      return '计算失败';
    }
  }

  /// 获取累计浏览数
  Future<int> getTotalViews() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getInt('total_views') ?? 0;
  }

  /// 记录累计浏览
  Future<void> recordTotalView() async {
    final prefs = await SharedPreferences.getInstance();
    final totalViews = prefs.getInt('total_views') ?? 0;
    await prefs.setInt('total_views', totalViews + 1);
  }

  /// 获取累计点赞数
  Future<int> getTotalLikes() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getInt('total_likes') ?? 0;
  }

  /// 记录累计点赞
  Future<void> recordTotalLike() async {
    final prefs = await SharedPreferences.getInstance();
    final totalLikes = prefs.getInt('total_likes') ?? 0;
    await prefs.setInt('total_likes', totalLikes + 1);
  }

  /// 获取累计答题数
  Future<int> getTotalQuestions() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getInt('totalQuestions') ?? 0;
  }

  /// 记录今日答题
  Future<void> recordTodayQuestion() async {
    final prefs = await SharedPreferences.getInstance();
    final now = DateTime.now();
    final today = _formatDate(now);
    final lastQuestionDate = prefs.getString(_lastQuestionDateKey);

    if (lastQuestionDate != today) {
      await prefs.setInt(_todayQuestionsKey, 0);
      await prefs.setString(_lastQuestionDateKey, today);
    }

    final todayQuestions = prefs.getInt(_todayQuestionsKey) ?? 0;
    await prefs.setInt(_todayQuestionsKey, todayQuestions + 1);
  }

  /// 获取今日答题数
  Future<int> getTodayQuestions() async {
    final prefs = await SharedPreferences.getInstance();
    final today = _formatDate(DateTime.now());
    final lastQuestionDate = prefs.getString(_lastQuestionDateKey);

    if (lastQuestionDate != today) {
      return 0;
    }

    return prefs.getInt(_todayQuestionsKey) ?? 0;
  }

  /// 获取使用天数
  Future<int> getUseDays() async {
    final prefs = await SharedPreferences.getInstance();
    final timeStr = prefs.getString(_firstUseTimeKey);
    if (timeStr == null) {
      return 1;
    }
    try {
      final firstUseDate = DateTime.parse(timeStr);
      final today = DateTime.now();
      final difference = today.difference(firstUseDate);
      return difference.inDays + 1;
    } catch (e) {
      return 1;
    }
  }

  /// 格式化日期为 YYYY-MM-DD
  String _formatDate(DateTime date) {
    return '${date.year}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
  }

  /// 获取本周开始日期（周一）
  String _getWeekStart(DateTime date) {
    final monday = date.subtract(Duration(days: date.weekday - 1));
    return _formatDate(monday);
  }
}