import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/navigation_provider.dart';
import '../../providers/data_providers.dart';

class _MedicationItem {
  String name = '';
  String dosage = '';
  String frequency = '每日1次';
  List<TimeOfDay> times = [const TimeOfDay(hour: 8, minute: 0)];
  DateTime startDate = DateTime.now();
  DateTime? endDate;
  int weekday = 1;
}

const _frequencies = ['每日1次', '每日2次', '每日3次', '每周1次', '按需服用'];
const _weekdays = ['周一', '周二', '周三', '周四', '周五', '周六', '周日'];

class MedicationEditPage extends ConsumerStatefulWidget {
  final String? medicationId;
  const MedicationEditPage({super.key, this.medicationId});

  @override
  ConsumerState<MedicationEditPage> createState() => _MedicationEditPageState();
}

class _MedicationEditPageState extends ConsumerState<MedicationEditPage> {
  final _items = <_MedicationItem>[];
  final _nameCtrls = <TextEditingController>[];
  final _doseCtrls = <TextEditingController>[];

  @override
  void initState() {
    super.initState();
    _addItem();
  }

  @override
  void dispose() {
    for (final c in _nameCtrls) {
      c.dispose();
    }
    for (final c in _doseCtrls) {
      c.dispose();
    }
    super.dispose();
  }

  void _addItem() {
    setState(() {
      _items.add(_MedicationItem());
      _nameCtrls.add(TextEditingController());
      _doseCtrls.add(TextEditingController());
    });
  }

  void _removeItem(int index) {
    setState(() {
      _nameCtrls[index].dispose();
      _doseCtrls[index].dispose();
      _nameCtrls.removeAt(index);
      _doseCtrls.removeAt(index);
      _items.removeAt(index);
    });
  }

  void _onSave() async {
    for (int i = 0; i < _items.length; i++) {
      _items[i].name = _nameCtrls[i].text.trim();
      _items[i].dosage = _doseCtrls[i].text.trim();
    }
    final allValid = _items.every(
      (item) => item.name.isNotEmpty && item.dosage.isNotEmpty,
    );
    if (!allValid) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请填写所有药品的名称和剂量')),
      );
      return;
    }
    final service = ref.read(medicationServiceProvider);
    try {
      for (final item in _items) {
        final timesStr = item.frequency == '按需服用'
            ? []
            : item.times.map((t) => t.format(context)).toList();
        await service.create({
          'name': item.name,
          'dosage': item.dosage,
          'frequency': 'Daily',
          'timeOfDay': timesStr,
          'startDate': item.startDate.toIso8601String().split('T')[0],
          if (item.endDate != null)
            'endDate': item.endDate!.toIso8601String().split('T')[0],
          'source': 'Manual',
        });
      }
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('已添加 ${_items.length} 种药品'),
          backgroundColor: const Color(0xFF14B8A6),
        ),
      );
      ref.invalidate(medicationListProvider);
      ref.invalidate(medicationReminderProvider);
      popRoute(ref);
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('保存失败：$e'),
          backgroundColor: Colors.red,
        ),
      );
      // 仍然返回上一页，避免卡在黑屏
      popRoute(ref);
    }
  }

  int _timeCount(String frequency) {
    switch (frequency) {
      case '每日1次':
        return 1;
      case '每日2次':
        return 2;
      case '每日3次':
        return 3;
      case '每周1次':
        return 1;
      default:
        return 0;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFFF6F9FB),
      appBar: AppBar(
        backgroundColor: Colors.white,
        elevation: 0,
        leading: IconButton(
          icon: const Icon(Icons.chevron_left),
          onPressed: () => popRoute(ref),
        ),
        title: const Text(
          '添加用药',
          style: TextStyle(
            color: Color(0xFF1A1A1A),
            fontWeight: FontWeight.w600,
          ),
        ),
        centerTitle: true,
        actions: [
          TextButton(
            onPressed: _onSave,
            child: const Text(
              '保存',
              style: TextStyle(
                color: Color(0xFF14B8A6),
                fontWeight: FontWeight.w600,
              ),
            ),
          ),
        ],
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            ...List.generate(_items.length, (i) => _buildCard(i)),
            const SizedBox(height: 12),
            _buildAddButton(),
            const SizedBox(height: 40),
          ],
        ),
      ),
    );
  }

  Widget _buildCard(int index) {
    final item = _items[index];
    final count = _timeCount(item.frequency);

    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFFEEEEEE)),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Header
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text(
                '药品 ${index + 1}',
                style: const TextStyle(
                  fontSize: 13,
                  fontWeight: FontWeight.w600,
                  color: Color(0xFF14B8A6),
                ),
              ),
              if (_items.length > 1)
                GestureDetector(
                  onTap: () => _removeItem(index),
                  child: const Icon(Icons.close, size: 18, color: Color(0xFFBDBDBD)),
                ),
            ],
          ),
          const SizedBox(height: 8),
          Divider(height: 1, color: const Color(0xFFF0F0F0)),
          const SizedBox(height: 8),

          // Name
          _buildLabel('药品名称'),
          const SizedBox(height: 4),
          TextField(
            controller: _nameCtrls[index],
            style: const TextStyle(fontSize: 14),
            decoration: _inputDecoration('请输入药品名称'),
          ),
          const SizedBox(height: 8),

          // Dosage
          _buildLabel('剂量'),
          const SizedBox(height: 4),
          TextField(
            controller: _doseCtrls[index],
            style: const TextStyle(fontSize: 14),
            decoration: _inputDecoration('如：100mg'),
          ),
          const SizedBox(height: 8),

          // Frequency
          _buildLabel('服用频率'),
          const SizedBox(height: 4),
          GestureDetector(
            onTap: () => _pickFrequency(index),
            child: Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(8),
                border: Border.all(color: const Color(0xFFE0E0E0)),
                color: const Color(0xFFFAFAFA),
              ),
              child: Row(
                children: [
                  Text(item.frequency, style: const TextStyle(fontSize: 14, color: Color(0xFF1A1A1A))),
                  const Spacer(),
                  const Icon(Icons.keyboard_arrow_down, size: 20, color: Color(0xFF9E9E9E)),
                ],
              ),
            ),
          ),
          const SizedBox(height: 8),

          // Times (dynamic)
          if (count > 0) ...[
            _buildLabel('服药时间'),
            const SizedBox(height: 4),
            Wrap(
              spacing: 8,
              runSpacing: 6,
              children: List.generate(count, (t) => _buildTimePicker(index, t)),
            ),
            if (item.frequency == '每周1次') ...[
              const SizedBox(height: 8),
              _buildLabel('选择星期'),
              const SizedBox(height: 4),
              GestureDetector(
                onTap: () => _pickWeekday(index),
                child: Container(
                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(8),
                    border: Border.all(color: const Color(0xFFE0E0E0)),
                    color: const Color(0xFFFAFAFA),
                  ),
                  child: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Text(_weekdays[item.weekday - 1], style: const TextStyle(fontSize: 14, color: Color(0xFF1A1A1A))),
                      const SizedBox(width: 4),
                      const Icon(Icons.keyboard_arrow_down, size: 18, color: Color(0xFF9E9E9E)),
                    ],
                  ),
                ),
              ),
            ],
            const SizedBox(height: 8),
          ],

          // Start date
          _buildLabel('开始日期'),
          const SizedBox(height: 4),
          GestureDetector(
            onTap: () => _pickDate(index, isStart: true),
            child: Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(8),
                border: Border.all(color: const Color(0xFFE0E0E0)),
                color: const Color(0xFFFAFAFA),
              ),
              child: Row(
                children: [
                  Text(
                    '${item.startDate.year}-${item.startDate.month.toString().padLeft(2, '0')}-${item.startDate.day.toString().padLeft(2, '0')}',
                    style: const TextStyle(fontSize: 14, color: Color(0xFF1A1A1A)),
                  ),
                  const Spacer(),
                  const Icon(Icons.calendar_today, size: 18, color: Color(0xFF9E9E9E)),
                ],
              ),
            ),
          ),
          const SizedBox(height: 8),

          // End date (optional)
          _buildLabel('结束日期（可选）'),
          const SizedBox(height: 4),
          GestureDetector(
            onTap: () => _pickDate(index, isStart: false),
            child: Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(8),
                border: Border.all(color: const Color(0xFFE0E0E0)),
                color: const Color(0xFFFAFAFA),
              ),
              child: Row(
                children: [
                  Text(
                    item.endDate != null
                        ? '${item.endDate!.year}-${item.endDate!.month.toString().padLeft(2, '0')}-${item.endDate!.day.toString().padLeft(2, '0')}'
                        : '不设置',
                    style: TextStyle(
                      fontSize: 14,
                      color: item.endDate != null ? const Color(0xFF1A1A1A) : const Color(0xFFBDBDBD),
                    ),
                  ),
                  const Spacer(),
                  GestureDetector(
                    onTap: item.endDate != null ? () => setState(() => item.endDate = null) : null,
                    child: Icon(
                      item.endDate != null ? Icons.close : Icons.calendar_today,
                      size: 18,
                      color: const Color(0xFF9E9E9E),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildLabel(String text) {
    return Text(
      text,
      style: const TextStyle(fontSize: 12, color: Color(0xFF757575)),
    );
  }

  Widget _buildTimePicker(int itemIndex, int timeIndex) {
    final item = _items[itemIndex];
    final time = item.times[timeIndex];

    return GestureDetector(
      onTap: () => _pickTime(itemIndex, timeIndex),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(8),
          border: Border.all(color: const Color(0xFFE0E0E0)),
          color: const Color(0xFFFAFAFA),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Icon(Icons.access_time, size: 16, color: Color(0xFF14B8A6)),
            const SizedBox(width: 6),
            Text(
              time.format(context),
              style: const TextStyle(fontSize: 14, color: Color(0xFF1A1A1A)),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildAddButton() {
    return SizedBox(
      width: double.infinity,
      child: OutlinedButton.icon(
        onPressed: _addItem,
        icon: const Icon(Icons.add, size: 18),
        label: const Text('添加', style: TextStyle(fontSize: 14)),
        style: OutlinedButton.styleFrom(
          foregroundColor: const Color(0xFF14B8A6),
          side: const BorderSide(color: Color(0xFFC0E8E2)),
          padding: const EdgeInsets.symmetric(vertical: 12),
          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
          backgroundColor: const Color(0xFFF2FAF9),
        ),
      ),
    );
  }

  InputDecoration _inputDecoration(String hint) {
    return InputDecoration(
      hintText: hint,
      hintStyle: const TextStyle(color: Color(0xFFBDBDBD), fontSize: 14),
      filled: true,
      fillColor: const Color(0xFFFAFAFA),
      contentPadding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      isDense: true,
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8),
        borderSide: const BorderSide(color: Color(0xFFE0E0E0)),
      ),
      enabledBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8),
        borderSide: const BorderSide(color: Color(0xFFE0E0E0)),
      ),
      focusedBorder: OutlineInputBorder(
        borderRadius: BorderRadius.circular(8),
        borderSide: const BorderSide(color: Color(0xFF14B8A6)),
      ),
    );
  }

  void _pickFrequency(int index) async {
    final selected = await showModalBottomSheet<String>(
      context: context,
      builder: (ctx) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: _frequencies
              .map((f) => ListTile(
                    title: Text(f),
                    onTap: () => Navigator.pop(ctx, f),
                  ))
              .toList(),
        ),
      ),
    );
    if (selected != null && mounted) {
      setState(() {
        final item = _items[index];
        item.frequency = selected;
        final newCount = _timeCount(selected);
        if (newCount > 0 && item.times.length != newCount) {
          item.times = List.generate(
            newCount,
            (i) => TimeOfDay(hour: 8 + i * 4, minute: 0),
          );
        }
      });
    }
  }

  void _pickWeekday(int index) async {
    final item = _items[index];
    final selected = await showModalBottomSheet<int>(
      context: context,
      builder: (ctx) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: List.generate(7, (i) {
            return ListTile(
              title: Text(_weekdays[i]),
              selected: item.weekday == i + 1,
              onTap: () => Navigator.pop(ctx, i + 1),
            );
          }),
        ),
      ),
    );
    if (selected != null && mounted) {
      setState(() => _items[index].weekday = selected);
    }
  }

  void _pickTime(int itemIndex, int timeIndex) async {
    final item = _items[itemIndex];
    final time = await showTimePicker(
      context: context,
      initialTime: item.times[timeIndex],
    );
    if (time != null && mounted) {
      setState(() => item.times[timeIndex] = time);
    }
  }

  void _pickDate(int index, {required bool isStart}) async {
    final item = _items[index];
    final initial = isStart ? item.startDate : (item.endDate ?? DateTime.now());
    final date = await showDatePicker(
      context: context,
      firstDate: DateTime(2020),
      lastDate: DateTime(2030),
      initialDate: initial,
    );
    if (date != null && mounted) {
      setState(() {
        if (isStart) {
          item.startDate = date;
        } else {
          item.endDate = date;
        }
      });
    }
  }
}