// 心情页面 — 心情统计 + 趋势图 + 连续天数

import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:nuanji_app/core/theme/app_colors.dart';
import 'package:nuanji_app/data/models/journal_entry.dart';
import 'package:nuanji_app/data/remote/api_client.dart';
import '../bloc/mood_bloc.dart';

/// 心情页面 — 统计卡片 + 心情分布饼图 + 详情列表
class MoodPage extends StatefulWidget {
  const MoodPage({super.key});

  @override
  State<MoodPage> createState() => _MoodPageState();
}

class _MoodPageState extends State<MoodPage> {
  late final MoodBloc _bloc;

  @override
  void initState() {
    super.initState();
    _bloc = MoodBloc(api: context.read<ApiClient>());
    _bloc.load();
  }

  @override
  void dispose() {
    _bloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return ListenableBuilder(
      listenable: _bloc,
      builder: (context, _) {
        final state = _bloc.state;

        if (state.isLoading) {
          return const Center(child: CircularProgressIndicator());
        }

        if (state.errorMessage != null) {
          return Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(Icons.error_outline, size: 48, color: colorScheme.error),
                const SizedBox(height: 12),
                Text(state.errorMessage!, style: theme.textTheme.bodyMedium),
                const SizedBox(height: 16),
                FilledButton.tonal(
                  onPressed: _bloc.load,
                  child: const Text('重试'),
                ),
              ],
            ),
          );
        }

        return SingleChildScrollView(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              // 统计概览卡片
              _StatsOverviewCard(stats: state.stats, colorScheme: colorScheme),
              const SizedBox(height: 16),

              // 周期选择器
              _PeriodSelector(
                selectedPeriod: state.selectedPeriod,
                onPeriodChanged: _bloc.changePeriod,
              ),
              const SizedBox(height: 16),

              // 心情分布饼图
              _MoodDistributionChart(
                moodCounts: state.stats.moodCounts,
                colorScheme: colorScheme,
              ),
              const SizedBox(height: 24),

              // 心情详情列表
              Text(
                '心情详情',
                style: theme.textTheme.titleMedium?.copyWith(
                  fontWeight: FontWeight.bold,
                ),
              ),
              const SizedBox(height: 8),
              ...state.stats.moodCounts.map((mc) => _MoodCountTile(mc: mc)),

              const SizedBox(height: 24),

              // 连续天数鼓励卡片
              _StreakCard(streakDays: state.stats.streakDays),
            ],
          ),
        );
      },
    );
  }
}

/// 统计概览卡片
class _StatsOverviewCard extends StatelessWidget {
  const _StatsOverviewCard({
    required this.stats,
    required this.colorScheme,
  });

  final MoodStats stats;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final dominantEmoji = stats.dominantMood != null
        ? _moodEmoji(stats.dominantMood!)
        : '📝';

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(22),
      ),
      color: colorScheme.primaryContainer,
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Row(
          children: [
            // 主导心情图标
            Container(
              width: 56,
              height: 56,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                color: colorScheme.primary.withValues(alpha: 0.15),
              ),
              alignment: Alignment.center,
              child: Text(dominantEmoji, style: const TextStyle(fontSize: 28)),
            ),
            const SizedBox(width: 16),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    '心情概览',
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                  const SizedBox(height: 4),
                  Text(
                    '共 ${stats.totalJournals} 篇日记 · 连续 ${stats.streakDays} 天',
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.7),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/// 周期选择器
class _PeriodSelector extends StatelessWidget {
  const _PeriodSelector({
    required this.selectedPeriod,
    required this.onPeriodChanged,
  });

  final StatsPeriod selectedPeriod;
  final ValueChanged<StatsPeriod> onPeriodChanged;

  @override
  Widget build(BuildContext context) {
    return SegmentedButton<StatsPeriod>(
      segments: const [
        ButtonSegment(value: StatsPeriod.week, label: Text('周')),
        ButtonSegment(value: StatsPeriod.month, label: Text('月')),
        ButtonSegment(value: StatsPeriod.quarter, label: Text('季')),
      ],
      selected: {selectedPeriod},
      onSelectionChanged: (set) => onPeriodChanged(set.first),
    );
  }
}

/// 心情分布饼图
class _MoodDistributionChart extends StatelessWidget {
  const _MoodDistributionChart({
    required this.moodCounts,
    required this.colorScheme,
  });

  final List<MoodCount> moodCounts;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    if (moodCounts.isEmpty) {
      return const SizedBox.shrink();
    }

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(22),
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: SizedBox(
          height: 200,
          child: PieChart(
            PieChartData(
              sections: moodCounts.map((mc) {
                final color =
                    AppColors.moodColors[mc.mood.value] ?? colorScheme.primary;
                return PieChartSectionData(
                  value: mc.count.toDouble(),
                  color: color,
                  radius: 50,
                  title: '${mc.percentage.toStringAsFixed(0)}%',
                  titleStyle: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.bold,
                    color: colorScheme.onPrimary,
                  ),
                );
              }).toList(),
              sectionsSpace: 2,
              centerSpaceRadius: 40,
            ),
          ),
        ),
      ),
    );
  }
}

/// 心情计数列表项
class _MoodCountTile extends StatelessWidget {
  const _MoodCountTile({required this.mc});

  final MoodCount mc;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final color =
        AppColors.moodColors[mc.mood.value] ?? theme.colorScheme.primary;

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        children: [
          Text(_moodEmoji(mc.mood), style: const TextStyle(fontSize: 20)),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  _moodLabel(mc.mood),
                  style: theme.textTheme.bodyMedium,
                ),
                const SizedBox(height: 4),
                ClipRRect(
                  borderRadius: BorderRadius.circular(4),
                  child: LinearProgressIndicator(
                    value: mc.percentage / 100,
                    backgroundColor: color.withValues(alpha: 0.15),
                    color: color,
                    minHeight: 6,
                  ),
                ),
              ],
            ),
          ),
          const SizedBox(width: 12),
          SizedBox(
            width: 48,
            child: Text(
              '${mc.count} 篇',
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurface.withValues(alpha: 0.5),
              ),
              textAlign: TextAlign.end,
            ),
          ),
        ],
      ),
    );
  }
}

/// 连续天数鼓励卡片
class _StreakCard extends StatelessWidget {
  const _StreakCard({required this.streakDays});

  final int streakDays;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(22),
      ),
      color: AppColors.tertiary.withValues(alpha: 0.15),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Row(
          children: [
            const Text('🔥', style: TextStyle(fontSize: 32)),
            const SizedBox(width: 16),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    '连续 $streakDays 天',
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                  const SizedBox(height: 4),
                  Text(
                    streakDays >= 7
                        ? '太棒了！你已经坚持了一周 ✨'
                        : '继续加油，坚持就是胜利！',
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.7),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

// ===== 辅助函数 =====

String _moodEmoji(Mood mood) => switch (mood) {
      Mood.happy => '😊',
      Mood.calm => '😌',
      Mood.sad => '😢',
      Mood.angry => '😠',
      Mood.thinking => '🤔',
    };

String _moodLabel(Mood mood) => switch (mood) {
      Mood.happy => '开心',
      Mood.calm => '平静',
      Mood.sad => '难过',
      Mood.angry => '生气',
      Mood.thinking => '思考',
    };