import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../models/health.dart';
import '../../providers/health_provider.dart';
import 'diet_page.dart';
import 'goal_setup_page.dart';
import 'weight_page.dart';
import 'widgets/health_card.dart';

/// 「强宝健康」模块入口页。
///
/// 三个卡片就是三件事，按用户关心的顺序排：
///   ① 减肥进度（目标层面：还差多少、节奏对不对）
///   ② 当前体重（日常层面：今天称了没、趋势如何）
///   ③ 今日饮食（执行层面：吃了多少）
class HealthHomePage extends ConsumerWidget {
  const HealthHomePage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Scaffold(
      backgroundColor: const Color(0xFFF7F4F1),
      appBar: AppBar(
        title: const Text('强宝健康'),
        backgroundColor: const Color(0xFFF7F4F1),
        elevation: 0,
        scrolledUnderElevation: 0,
        foregroundColor: const Color(0xFF5D4037),
      ),
      body: RefreshIndicator(
        color: const Color(0xFFC8956E),
        onRefresh: () async {
          ref.invalidate(weightGoalProvider);
          ref.invalidate(weightChartProvider);
          ref.invalidate(dietTodayProvider);
          // 等目标那一路拉完再收起转圈 —— 它是三个卡片里最先渲染的
          try {
            await ref.read(weightGoalProvider.future);
          } catch (_) {
            // 失败就失败，RefreshIndicator 该收起来
          }
        },
        child: ListView(
          padding: const EdgeInsets.fromLTRB(14, 6, 14, 24),
          children: const [
            _GoalCard(),
            SizedBox(height: 12),
            _WeightCard(),
            SizedBox(height: 12),
            _DietCard(),
          ],
        ),
      ),
    );
  }
}

// ==================================================================
// ① 减肥进度
// ==================================================================

class _GoalCard extends ConsumerWidget {
  const _GoalCard();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final async = ref.watch(weightGoalProvider);
    final goal = async.value;

    // 加载中和出错都退化成「还没设目标」的形态 —— 卡片不该变成一块错误提示，
    // 用户想做的只是点进去设个目标
    if (goal == null || !goal.hasGoal) {
      return HealthCard(
        title: '减肥进度',
        onTap: () => _openGoal(context, ref),
        child: async.isLoading
            ? const _CardLoading()
            : const _GoalEmpty(),
      );
    }

    final current = goal.currentWeight;
    final lost = goal.lostWeight;
    final remain = goal.remainWeight;

    return HealthCard(
      title: '减肥进度',
      onTap: () => _openGoal(context, ref),
      trailing: Text(
        '目标 ${_num(goal.targetWeight)} kg',
        style: const TextStyle(fontSize: 12, color: Color(0xFF8D6E63)),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.baseline,
            textBaseline: TextBaseline.alphabetic,
            children: [
              Text(
                current == null ? '--' : _num(current),
                style: const TextStyle(
                  fontSize: 30,
                  fontWeight: FontWeight.bold,
                  color: Color(0xFF5D4037),
                ),
              ),
              const SizedBox(width: 3),
              const Text('kg',
                  style: TextStyle(fontSize: 13, color: Color(0xFF8D6E63))),
              const SizedBox(width: 8),
              // Expanded + 右对齐：小屏上「已减 x kg」会被压窄，
              // 但不能把左边的体重数字顶出去
              Expanded(
                child: Text(
                  lost == null ? '' : '已减 ${_num(lost)} kg',
                  textAlign: TextAlign.right,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w600,
                    color: Color(0xFF4FA98A),
                  ),
                ),
              ),
            ],
          ),
          const SizedBox(height: 10),
          HealthProgressBar(value: goal.weightProgress),
          const SizedBox(height: 10),
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Text(
                  remain == null
                      ? '还没记体重，记一次就能看进度'
                      : '还差 ${_num(remain)} kg',
                  maxLines: 2,
                  style: const TextStyle(
                      fontSize: 12, color: Color(0xFF8D6E63)),
                ),
              ),
              const SizedBox(width: 8),
              // 单独一行放「每周应减」，不和「还差」挤同一个方向
              Flexible(
                child: Text(
                  '每周应减 ${_num(goal.weeklyLoss)} kg',
                  textAlign: TextAlign.right,
                  maxLines: 2,
                  style: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.w600,
                    // 每周超过 1kg 通常是掉肌肉和水，标黄提示
                    color: goal.weeklyLossUnhealthy
                        ? const Color(0xFFD9A93C)
                        : const Color(0xFF8D6E63),
                  ),
                ),
              ),
            ],
          ),
          if (goal.weeklyLossUnhealthy) ...[
            const SizedBox(height: 8),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 7),
              decoration: BoxDecoration(
                color: const Color(0xFFF8ECD2),
                borderRadius: BorderRadius.circular(8),
              ),
              child: const Row(
                children: [
                  Icon(Icons.info_outline, size: 14, color: Color(0xFFD9A93C)),
                  SizedBox(width: 6),
                  Expanded(
                    child: Text(
                      '节奏偏快，每周超过 1kg 掉的往往是肌肉和水分',
                      style: TextStyle(fontSize: 11.5, color: Color(0xFF8D6E63)),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ],
      ),
    );
  }

  Future<void> _openGoal(BuildContext context, WidgetRef ref) async {
    await Navigator.of(context).push(
      MaterialPageRoute(builder: (_) => const GoalSetupPage()),
    );
    ref.invalidate(weightGoalProvider);
    ref.invalidate(weightChartProvider);
  }
}

class _GoalEmpty extends StatelessWidget {
  const _GoalEmpty();

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        const Expanded(
          child: Text(
            '还没设目标\n设一个，就有每周该减多少了',
            style: TextStyle(
                fontSize: 13, height: 1.6, color: Color(0xFFBCAAA4)),
          ),
        ),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 7),
          decoration: BoxDecoration(
            color: const Color(0xFFC8956E).withValues(alpha: 0.12),
            borderRadius: BorderRadius.circular(20),
          ),
          child: const Text(
            '去设置',
            style: TextStyle(
              fontSize: 13,
              fontWeight: FontWeight.w600,
              color: Color(0xFFC8956E),
            ),
          ),
        ),
      ],
    );
  }
}

// ==================================================================
// ② 当前体重
// ==================================================================

class _WeightCard extends ConsumerWidget {
  const _WeightCard();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final async = ref.watch(weightChartProvider);
    final chart = async.value;

    final delta = chart?.delta;

    return HealthCard(
      title: '当前体重',
      onTap: () => _openWeight(context, ref),
      trailing: delta == null
          ? null
          : Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Icon(
                  delta > 0 ? Icons.arrow_upward : Icons.arrow_downward,
                  size: 13,
                  // 涨了用红、掉了用绿 —— 这个模块的语境就是「掉是好事」
                  color: delta > 0
                      ? const Color(0xFFE0725C)
                      : const Color(0xFF4FA98A),
                ),
                Text(
                  '${_num(delta.abs())} kg',
                  style: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.w600,
                    color: delta > 0
                        ? const Color(0xFFE0725C)
                        : const Color(0xFF4FA98A),
                  ),
                ),
              ],
            ),
      child: async.isLoading
          ? const _CardLoading()
          : chart == null || !chart.hasData
              ? const _WeightEmpty()
              : _WeightBody(chart: chart),
    );
  }

  Future<void> _openWeight(BuildContext context, WidgetRef ref) async {
    await Navigator.of(context).push(
      MaterialPageRoute(builder: (_) => const WeightPage()),
    );
    ref.invalidate(weightChartProvider);
    ref.invalidate(weightGoalProvider);
  }
}

class _WeightBody extends StatelessWidget {
  const _WeightBody({required this.chart});

  final WeightChart chart;

  @override
  Widget build(BuildContext context) {
    final current = chart.currentWeight;
    final points = chart.points;
    final last = points.isEmpty ? null : points.last;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          crossAxisAlignment: CrossAxisAlignment.baseline,
          textBaseline: TextBaseline.alphabetic,
          children: [
            Text(
              current == null ? '--' : _num(current),
              style: const TextStyle(
                fontSize: 30,
                fontWeight: FontWeight.bold,
                color: Color(0xFF5D4037),
              ),
            ),
            const SizedBox(width: 3),
            const Text('kg',
                style: TextStyle(fontSize: 13, color: Color(0xFF8D6E63))),
            const SizedBox(width: 8),
            if (last != null)
              Expanded(
                child: Text(
                  '最近 ${_shortDate(last.date)}',
                  textAlign: TextAlign.right,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                      fontSize: 12, color: Color(0xFFBCAAA4)),
                ),
              ),
          ],
        ),
        const SizedBox(height: 10),
        // 卡片里只给迷你趋势，看完整图表点进详情页
        _MiniTrend(points: points),
      ],
    );
  }
}

/// 卡片内嵌的迷你折线（不引图表库：这里只要一条走势线，
/// fl_chart 在这么小的尺寸里坐标轴反而占掉一半空间）
class _MiniTrend extends StatelessWidget {
  const _MiniTrend({required this.points});

  final List<WeightPoint> points;

  @override
  Widget build(BuildContext context) {
    if (points.length < 2) {
      return const SizedBox(
        height: 46,
        child: Center(
          child: Text(
            '再记一次就能看出趋势了',
            style: TextStyle(fontSize: 12, color: Color(0xFFBCAAA4)),
          ),
        ),
      );
    }
    return SizedBox(
      height: 46,
      width: double.infinity,
      child: CustomPaint(
        painter: _MiniTrendPainter(
          values: points.map<double>((p) => p.weight).toList(),
        ),
      ),
    );
  }
}

class _MiniTrendPainter extends CustomPainter {
  _MiniTrendPainter({required this.values});

  final List<double> values;

  @override
  void paint(Canvas canvas, Size size) {
    if (values.length < 2) return;

    var min = values.first;
    var max = values.first;
    for (final v in values) {
      if (v < min) min = v;
      if (v > max) max = v;
    }
    // 上下各留 20% 余量，否则线会贴着边框
    final span = (max - min).abs() < 0.1 ? 1.0 : (max - min);
    final pad = span * 0.2;

    final dx = size.width / (values.length - 1);
    final path = Path();
    for (var i = 0; i < values.length; i++) {
      // 体重掉下去应该往下走 —— Y 轴要翻转（屏幕坐标 y 向下增长）
      final ratio = (values[i] - (min - pad)) / (span + pad * 2);
      final y = size.height - ratio * size.height;
      final x = dx * i;
      if (i == 0) {
        path.moveTo(x, y);
      } else {
        path.lineTo(x, y);
      }
    }

    canvas.drawPath(
      path,
      Paint()
        ..color = const Color(0xFFC8956E)
        ..strokeWidth = 2
        ..style = PaintingStyle.stroke
        ..strokeCap = StrokeCap.round
        ..strokeJoin = StrokeJoin.round,
    );

    // 末端点一个实心圆，提示「这里是现在」
    final lastRatio = (values.last - (min - pad)) / (span + pad * 2);
    canvas.drawCircle(
      Offset(size.width, size.height - lastRatio * size.height),
      3.2,
      Paint()..color = const Color(0xFFC8956E),
    );
  }

  @override
  bool shouldRepaint(covariant _MiniTrendPainter old) =>
      old.values != values;
}

class _WeightEmpty extends StatelessWidget {
  const _WeightEmpty();

  @override
  Widget build(BuildContext context) {
    return const Row(
      children: [
        Expanded(
          child: Text(
            '还没记过体重\n点这里记一下，就能看趋势',
            style: TextStyle(
                fontSize: 13, height: 1.6, color: Color(0xFFBCAAA4)),
          ),
        ),
        Icon(Icons.add_circle_outline, size: 26, color: Color(0xFFC8956E)),
      ],
    );
  }
}

// ==================================================================
// ③ 今日饮食
// ==================================================================

class _DietCard extends ConsumerWidget {
  const _DietCard();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final async = ref.watch(dietTodayProvider);
    final day = async.value;

    final kcal = day?.totals.energyKcal ?? 0;
    final count = day?.totals.itemCount ?? 0;

    return HealthCard(
      title: '今日饮食',
      onTap: () => _openDiet(context, ref),
      trailing: count == 0
          ? null
          : Text(
              '$count 条',
              style: const TextStyle(fontSize: 12, color: Color(0xFF8D6E63)),
            ),
      action: GestureDetector(
        onTap: () => _openDiet(context, ref),
        child: Container(
          width: double.infinity,
          padding: const EdgeInsets.symmetric(vertical: 9),
          decoration: BoxDecoration(
            color: const Color(0xFFC8956E).withValues(alpha: 0.1),
            borderRadius: BorderRadius.circular(10),
          ),
          child: const Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(Icons.add, size: 16, color: Color(0xFFC8956E)),
              SizedBox(width: 4),
              Text(
                '记一笔',
                style: TextStyle(
                  fontSize: 13,
                  fontWeight: FontWeight.w600,
                  color: Color(0xFFC8956E),
                ),
              ),
            ],
          ),
        ),
      ),
      child: async.isLoading
          ? const _CardLoading()
          : Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  crossAxisAlignment: CrossAxisAlignment.baseline,
                  textBaseline: TextBaseline.alphabetic,
                  children: [
                    Text(
                      _num(kcal),
                      style: const TextStyle(
                        fontSize: 30,
                        fontWeight: FontWeight.bold,
                        color: Color(0xFF5D4037),
                      ),
                    ),
                    const SizedBox(width: 3),
                    const Text('kcal',
                        style: TextStyle(
                            fontSize: 13, color: Color(0xFF8D6E63))),
                  ],
                ),
                const SizedBox(height: 10),
                if (day == null || count == 0)
                  const Text(
                    '今天还没记，点这里加一条',
                    style:
                        TextStyle(fontSize: 13, color: Color(0xFFBCAAA4)),
                  )
                else
                  // 只列有内容的餐次，空餐次不占位
                  ...day.meals
                      .where((m) => m.items.isNotEmpty)
                      .map((m) => _MealLine(group: m)),
              ],
            ),
    );
  }

  Future<void> _openDiet(BuildContext context, WidgetRef ref) async {
    await Navigator.of(context).push(
      MaterialPageRoute(builder: (_) => const DietPage()),
    );
    ref.invalidate(dietTodayProvider);
  }
}

class _MealLine extends StatelessWidget {
  const _MealLine({required this.group});

  final MealGroup group;

  @override
  Widget build(BuildContext context) {
    final names = group.items
        .map((e) => '${e.foodName}(${_num(e.amountGrams)}g)')
        .join('、');

    return Padding(
      padding: const EdgeInsets.only(bottom: 6),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Container(
            margin: const EdgeInsets.only(top: 1),
            padding:
                const EdgeInsets.symmetric(horizontal: 6, vertical: 1.5),
            decoration: BoxDecoration(
              color: const Color(0xFFF0EAE4),
              borderRadius: BorderRadius.circular(4),
            ),
            child: Text(
              _mealLabel(group.mealType),
              style: const TextStyle(
                  fontSize: 10.5, color: Color(0xFF8D6E63)),
            ),
          ),
          const SizedBox(width: 7),
          Expanded(
            child: Text(
              names,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              style: const TextStyle(
                  fontSize: 12.5, height: 1.5, color: Color(0xFF5D4037)),
            ),
          ),
          const SizedBox(width: 6),
          Text(
            '${_num(group.totals.energyKcal)} kcal',
            style: const TextStyle(
              fontSize: 11.5,
              color: Color(0xFF8D6E63),
            ),
          ),
        ],
      ),
    );
  }
}

// ==================================================================

class _CardLoading extends StatelessWidget {
  const _CardLoading();

  @override
  Widget build(BuildContext context) {
    return const SizedBox(
      height: 56,
      child: Center(
        child: SizedBox(
          width: 20,
          height: 20,
          child: CircularProgressIndicator(
              strokeWidth: 2, color: Color(0xFFC8956E)),
        ),
      ),
    );
  }
}

/// 数字去掉多余的小数位：65.0 → 65，65.5 → 65.5
String _num(num value) {
  if (value == value.roundToDouble()) return value.round().toString();
  return value.toStringAsFixed(1);
}

String _shortDate(DateTime date) {
  final m = date.month.toString().padLeft(2, '0');
  final d = date.day.toString().padLeft(2, '0');
  return '$m-$d';
}

String _mealLabel(String mealType) {
  switch (mealType) {
    case 'breakfast':
      return '早';
    case 'lunch':
      return '午';
    case 'dinner':
      return '晚';
    default:
      return '加';
  }
}