nj/app/lib/features/mood/bloc/mood_bloc.dart

// 心情 BLoC — 管理心情统计和趋势数据

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

// ===== 心情统计模型 =====

/// 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,
  });
}

/// 心情趋势数据点
class MoodTrendPoint {
  final DateTime date;
  final Mood mood;
  final int journalCount;

  const MoodTrendPoint({
    required this.date,
    required this.mood,
    required this.journalCount,
  });
}

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

// ===== 心情页面状态 =====

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

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

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

// ===== 心情 BLoC =====

class MoodBloc extends ChangeNotifier {
  MoodState _state = const MoodState();
  MoodState get state => _state;

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

  /// 加载统计数据
  Future<void> _loadStats() async {
    // Phase 1: 占位数据，待 API 集成后替换
    await Future.delayed(const Duration(milliseconds: 300));

    _state = _state.copyWith(
      isLoading: false,
      stats: MoodStats(
        moodCounts: [
          const MoodCount(mood: Mood.happy, count: 12, percentage: 40.0),
          const MoodCount(mood: Mood.calm, count: 8, percentage: 26.7),
          const MoodCount(mood: Mood.thinking, count: 5, percentage: 16.7),
          const MoodCount(mood: Mood.sad, count: 3, percentage: 10.0),
          const MoodCount(mood: Mood.angry, count: 2, percentage: 6.6),
        ],
        streakDays: 7,
        totalJournals: 30,
        dominantMood: Mood.happy,
      ),
    );
    notifyListeners();
  }

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