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

import '../../core/app_colors.dart';
import '../../core/app_design_tokens.dart';
import '../../core/app_module_visuals.dart';
import '../../core/app_theme.dart';
import '../../core/navigation_provider.dart';
import '../../providers/data_providers.dart';
import '../../widgets/app_toast.dart';

class MedicationEditPage extends ConsumerStatefulWidget {
  final String? id;

  const MedicationEditPage({super.key, this.id});

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

class _MedicationEditPageState extends ConsumerState<MedicationEditPage> {
  static const _visual = AppModuleVisuals.medication;

  final _nameCtrl = TextEditingController();
  final _dosageCtrl = TextEditingController();
  final _notesCtrl = TextEditingController();
  int _timesPerDay = 2;
  List<TimeOfDay> _times = [
    const TimeOfDay(hour: 8, minute: 0),
    const TimeOfDay(hour: 18, minute: 0),
  ];
  DateTime _start = DateTime.now();
  DateTime? _end;
  bool _loading = false;

  @override
  void initState() {
    super.initState();
    if (widget.id != null) _load();
  }

  @override
  void dispose() {
    _nameCtrl.dispose();
    _dosageCtrl.dispose();
    _notesCtrl.dispose();
    super.dispose();
  }

  Future<void> _load() async {
    final srv = ref.read(medicationServiceProvider);
    final list = await srv.getList();
    final m = list.cast<Map<String, dynamic>?>().firstWhere(
      (x) => x?['id']?.toString() == widget.id,
      orElse: () => null,
    );
    if (m == null || !mounted) return;
    _nameCtrl.text = m['name']?.toString() ?? '';
    _dosageCtrl.text = m['dosage']?.toString() ?? '';
    _notesCtrl.text = m['notes']?.toString() ?? '';
    final tod =
        (m['timeOfDay'] as List?)?.map((t) {
          final parts = t.toString().split(':');
          return TimeOfDay(
            hour: int.tryParse(parts[0]) ?? 8,
            minute: int.tryParse(parts.length > 1 ? parts[1] : '0') ?? 0,
          );
        }).toList() ??
        [
          const TimeOfDay(hour: 8, minute: 0),
          const TimeOfDay(hour: 18, minute: 0),
        ];
    _timesPerDay = tod.length;
    _times = tod;
    if (m['startDate'] != null) {
      _start = DateTime.tryParse(m['startDate'].toString()) ?? DateTime.now();
    }
    if (m['endDate'] != null) _end = DateTime.tryParse(m['endDate'].toString());
    setState(() {});
  }

  Future<void> _save() async {
    final name = _nameCtrl.text.trim();
    if (name.isEmpty) {
      AppToast.show(context, '请输入药品名称', type: AppToastType.warning);
      return;
    }
    setState(() => _loading = true);
    final data = {
      'name': name,
      'dosage': _dosageCtrl.text.trim(),
      'frequency': 'Daily',
      'notes': _notesCtrl.text.trim(),
      'timeOfDay': _times
          .map(
            (t) =>
                '${t.hour.toString().padLeft(2, '0')}:${t.minute.toString().padLeft(2, '0')}',
          )
          .toList(),
      'startDate':
          '${_start.year}-${_start.month.toString().padLeft(2, '0')}-${_start.day.toString().padLeft(2, '0')}',
      if (_end != null)
        'endDate':
            '${_end!.year}-${_end!.month.toString().padLeft(2, '0')}-${_end!.day.toString().padLeft(2, '0')}',
      'source': 'Manual',
    };
    final srv = ref.read(medicationServiceProvider);
    try {
      if (widget.id != null) {
        await srv.update(widget.id!, data);
      } else {
        await srv.create(data);
      }
      ref.invalidate(medicationListProvider);
      ref.invalidate(medicationReminderProvider);
      if (mounted) popRoute(ref);
    } catch (_) {
      if (mounted) {
        AppToast.show(context, '保存失败', type: AppToastType.error);
      }
    }
    if (mounted) setState(() => _loading = false);
  }

  void _updateTimes(int n) {
    setState(() {
      _timesPerDay = n;
      while (_times.length < n) {
        _times.add(const TimeOfDay(hour: 12, minute: 0));
      }
      while (_times.length > n) {
        _times.removeLast();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return GradientScaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: const Icon(Icons.arrow_back),
          onPressed: () => popRoute(ref),
        ),
        title: Text(widget.id != null ? '编辑用药' : '添加用药'),
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Row(
            children: [
              Expanded(
                flex: 3,
                child: _field('药品名称', _nameCtrl, hint: '如：阿司匹林'),
              ),
              const SizedBox(width: 12),
              Expanded(
                flex: 2,
                child: _field('剂量', _dosageCtrl, hint: '如：100mg'),
              ),
            ],
          ),
          const SizedBox(height: 16),
          _label('每日服药次数'),
          const SizedBox(height: 8),
          GestureDetector(
            onTap: () async {
              final n = await showAppCountPicker(
                context,
                initialValue: _timesPerDay,
                min: 1,
                max: 4,
                label: '次',
              );
              if (n != null) _updateTimes(n);
            },
            child: _PickerBox(
              child: Text('$_timesPerDay 次/天', style: AppTextStyles.formValue),
            ),
          ),
          const SizedBox(height: 16),
          _label('服药时间'),
          const SizedBox(height: 8),
          Wrap(
            spacing: 8,
            runSpacing: 8,
            children: List.generate(
              _timesPerDay,
              (i) => GestureDetector(
                onTap: () async {
                  final t = await showAppTimePicker(
                    context,
                    initialTime: _times[i],
                  );
                  if (t != null) setState(() => _times[i] = t);
                },
                child: Container(
                  padding: const EdgeInsets.symmetric(
                    horizontal: 14,
                    vertical: 10,
                  ),
                  decoration: BoxDecoration(
                    color: Colors.white,
                    borderRadius: AppRadius.mdBorder,
                    border: Border.all(color: _visual.borderColor, width: 1),
                  ),
                  child: Text(
                    '${_times[i].hour.toString().padLeft(2, '0')}:${_times[i].minute.toString().padLeft(2, '0')}',
                    style: AppTextStyles.formValue,
                  ),
                ),
              ),
            ),
          ),
          const SizedBox(height: 16),
          Row(
            children: [
              Expanded(
                child: _dateField(
                  '开始日期',
                  _start,
                  (d) => setState(() => _start = d),
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: _dateFieldOpt(
                  '结束日期（可选）',
                  _end,
                  (d) => setState(() => _end = d),
                ),
              ),
            ],
          ),
          const SizedBox(height: 16),
          _field('备注', _notesCtrl, hint: '如：饭后服用、睡前'),
          const SizedBox(height: 32),
          SizedBox(
            width: double.infinity,
            child: ElevatedButton(
              onPressed: _loading ? null : _save,
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.white,
                foregroundColor: _visual.color,
                side: BorderSide(color: _visual.color, width: 1.5),
                shape: RoundedRectangleBorder(borderRadius: AppRadius.lgBorder),
                padding: const EdgeInsets.symmetric(vertical: 14),
              ),
              child: Text(_loading ? '保存中...' : '保存', style: AppTextStyles.button),
            ),
          ),
          const SizedBox(height: 20),
        ],
      ),
    );
  }

  Widget _label(String text) => Text(text, style: AppTextStyles.formLabel);

  Widget _field(String label, TextEditingController ctrl, {String? hint}) =>
      Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _label(label),
          const SizedBox(height: 6),
          TextField(
            controller: ctrl,
            decoration: InputDecoration(
              hintText: hint,
              filled: true,
              fillColor: AppTheme.surface,
              border: _inputBorder(AppColors.border),
              enabledBorder: _inputBorder(AppColors.border),
              focusedBorder: _inputBorder(_visual.color),
              contentPadding: const EdgeInsets.symmetric(
                horizontal: 12,
                vertical: 12,
              ),
            ),
            style: AppTextStyles.formValue,
          ),
        ],
      );

  Widget _dateField(String label, DateTime val, ValueChanged<DateTime> cb) =>
      Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _label(label),
          const SizedBox(height: 6),
          GestureDetector(
            onTap: () async {
              final d = await showAppDatePicker(
                context,
                initialDate: val,
                firstDate: DateTime(2024),
                lastDate: DateTime(2030),
              );
              if (d != null) cb(d);
            },
            child: _PickerBox(
              child: Text(_displayDate(val), style: AppTextStyles.formValue),
            ),
          ),
        ],
      );

  Widget _dateFieldOpt(
    String label,
    DateTime? val,
    ValueChanged<DateTime?> cb,
  ) => Column(
    crossAxisAlignment: CrossAxisAlignment.start,
    children: [
      _label(label),
      const SizedBox(height: 6),
      GestureDetector(
        onTap: () async {
          final d = await showAppDatePicker(
            context,
            initialDate: val ?? DateTime.now(),
            firstDate: DateTime(2024),
            lastDate: DateTime(2030),
          );
          if (d != null) cb(d);
        },
        child: _PickerBox(
          child: Row(
            children: [
              Expanded(
                child: Text(
                  val != null ? _displayDate(val) : '不设置',
                  style: AppTextStyles.formValue.copyWith(
                    color: val != null ? null : AppTheme.textHint,
                  ),
                ),
              ),
              if (val != null)
                GestureDetector(
                  onTap: () => cb(null),
                  child: const Icon(
                    Icons.close,
                    size: 19,
                    color: AppColors.textHint,
                  ),
                ),
            ],
          ),
        ),
      ),
    ],
  );

  OutlineInputBorder _inputBorder(Color color) => OutlineInputBorder(
    borderRadius: AppRadius.mdBorder,
    borderSide: BorderSide(color: color),
  );
}

class _PickerBox extends StatelessWidget {
  final Widget child;

  const _PickerBox({required this.child});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: AppTheme.surface,
        borderRadius: AppRadius.mdBorder,
        border: Border.all(color: AppColors.border),
      ),
      child: child,
    );
  }
}

String _displayDate(DateTime date) {
  return '${date.year}/${date.month.toString().padLeft(2, '0')}/${date.day.toString().padLeft(2, '0')}';
}