// 心情 BLoC — 通过 API 加载心情统计数据

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:nuanji_app/data/models/journal_entry.dart';
import 'package:nuanji_app/data/remote/api_client.dart';

// ===== 模型 =====

/// 心情统计数据
class MoodStats {
  final List<MoodCount> moodCounts;
  final int streakDays;
  final int totalJournals;
  final Mood? dominantMood;

  const MoodStats({
    this.moodCounts = const [],
    this.streakDays = 0,
    this.totalJournals = 0,
    this.dominantMood,
  });
}

/// 单种心情的统计
class MoodCount {
  final Mood mood;
  final int count;
  final double percentage;

  const MoodCount({
    required this.mood,
    required this.count,
    required this.percentage,
  });
}

/// 统计周期
enum StatsPeriod { week, month, quarter }

// ===== State =====

/// 心情页面状态
class MoodState {
  final MoodStats stats;
  final StatsPeriod selectedPeriod;
  final bool isLoading;
  final String? errorMessage;

  const MoodState({
    this.stats = const MoodStats(),
    this.selectedPeriod = StatsPeriod.week,
    this.isLoading = false,
    this.errorMessage,
  });

  MoodState copyWith({
    MoodStats? stats,
    StatsPeriod? selectedPeriod,
    bool? isLoading,
    String? errorMessage,
  }) =>
      MoodState(
        stats: stats ?? this.stats,
        selectedPeriod: selectedPeriod ?? this.selectedPeriod,
        isLoading: isLoading ?? this.isLoading,
        errorMessage: errorMessage,
      );
}

// ===== BLoC =====

/// 心情统计 BLoC — ChangeNotifier 模式
class MoodBloc extends ChangeNotifier {
  final ApiClient _api;
  MoodState _state = const MoodState();
  MoodState get state => _state;

  MoodBloc({required ApiClient api}) : _api = api;

  /// 初始加载
  void load() {
    _state = _state.copyWith(isLoading: true);
    notifyListeners();
    _loadStats();
  }

  /// 切换统计周期
  void changePeriod(StatsPeriod period) {
    if (period == _state.selectedPeriod) return;
    _state = _state.copyWith(selectedPeriod: period, isLoading: true);
    notifyListeners();
    _loadStats();
  }

  Future<void> _loadStats() async {
    try {
      final periodStr = switch (_state.selectedPeriod) {
        StatsPeriod.week => 'week',
        StatsPeriod.month => 'month',
        StatsPeriod.quarter => 'quarter',
      };

      final response = await _api.get(
        '/diary/stats/mood',
        queryParams: {'period': periodStr},
      );
      final body = response.data as Map<String, dynamic>;
      final data = body['data'] as Map<String, dynamic>;

      final counts = (data['mood_counts'] as List? ?? [])
          .map((item) {
            final m = item as Map<String, dynamic>;
            return MoodCount(
              mood: Mood.values.firstWhere(
                (v) => v.value == m['mood'],
                orElse: () => Mood.happy,
              ),
              count: (m['count'] as num).toInt(),
              percentage: (m['percentage'] as num).toDouble(),
            );
          })
          .toList();

      final dominant = data['dominant_mood'] != null
          ? Mood.values.firstWhere(
              (v) => v.value == data['dominant_mood'],
              orElse: () => Mood.happy,
            )
          : null;

      _state = _state.copyWith(
        isLoading: false,
        stats: MoodStats(
          moodCounts: counts,
          streakDays: (data['streak_days'] as num?)?.toInt() ?? 0,
          totalJournals: (data['total_journals'] as num?)?.toInt() ?? 0,
          dominantMood: dominant,
        ),
      );
    } catch (e) {
      debugPrint('MoodBloc._loadStats 失败: $e');
      _state = _state.copyWith(
        isLoading: false,
        errorMessage: '加载统计数据失败',
      );
    }
    notifyListeners();
  }
}