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

class HDatePickerDialog extends StatefulWidget {
  final DateTime initialDate;
  final VoidCallback onCancel;
  final ValueChanged<DateTime> onConfirm;

  const HDatePickerDialog({
    Key? key,
    required this.initialDate,
    required this.onCancel,
    required this.onConfirm,
  }) : super(key: key);

  @override
  _HDatePickerDialogState createState() => _HDatePickerDialogState();
}

class _HDatePickerDialogState extends State<HDatePickerDialog> {
  late DateTime _displayedMonth;
  late DateTime _selectedDate;

  @override
  void initState() {
    super.initState();
    _selectedDate = widget.initialDate;
    _displayedMonth = DateTime(widget.initialDate.year, widget.initialDate.month);
  }

  void _prevMonth() {
    setState(() {
      _displayedMonth = DateTime(_displayedMonth.year, _displayedMonth.month - 1);
    });
  }

  void _nextMonth() {
    setState(() {
      _displayedMonth = DateTime(_displayedMonth.year, _displayedMonth.month + 1);
    });
  }

  @override
  Widget build(BuildContext context) {
    final daysInMonth = DateUtils.getDaysInMonth(_displayedMonth.year, _displayedMonth.month);
    final firstWeekday = DateTime(_displayedMonth.year, _displayedMonth.month, 1).weekday;

    return GestureDetector(
      onTap: widget.onCancel,
      child: Material(
        color: Colors.black54,
        child: Center(
          child: GestureDetector(
            onTap: () {}, // 拦截点击
            child: Container(
              width: 320,
              padding: const EdgeInsets.all(16),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(8),
              ),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  // 顶部显示选中日期
                  Text(
                    DateFormat('yyyy-MM-dd').format(_selectedDate),
                    style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                  ),
                  const SizedBox(height: 16),

                  // 月份选择
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      IconButton(
                        icon: const Icon(Icons.chevron_left),
                        onPressed: _prevMonth,
                      ),
                      Text(
                        DateFormat('yyyy 年 MM 月').format(_displayedMonth),
                        style: const TextStyle(fontSize: 16),
                      ),
                      IconButton(
                        icon: const Icon(Icons.chevron_right),
                        onPressed: _nextMonth,
                      ),
                    ],
                  ),

                  // 星期标题
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceAround,
                    children: ['一', '二', '三', '四', '五', '六', '日']
                        .map((d) => Expanded(
                      child: Center(child: Text(d)),
                    ))
                        .toList(),
                  ),
                  SizedBox(height: 10,),
                  // 日历网格
                  GridView.builder(
                    shrinkWrap: true,
                    physics: const NeverScrollableScrollPhysics(),
                    gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                      crossAxisCount: 7,
                      childAspectRatio: 1.2,
                      crossAxisSpacing: 4,
                      mainAxisSpacing: 4,
                    ),
                    itemCount: daysInMonth + firstWeekday - 1,
                    itemBuilder: (context, index) {
                      if (index < firstWeekday - 1) {
                        return const SizedBox();
                      }
                      final day = index - firstWeekday + 2;
                      final date = DateTime(_displayedMonth.year, _displayedMonth.month, day);
                      final isSelected = DateUtils.isSameDay(date, _selectedDate);

                      return GestureDetector(
                        onTap: () {
                          setState(() {
                            _selectedDate = date;
                          });
                        },
                        child: Container(
                          decoration: BoxDecoration(
                            color: isSelected ? Theme.of(context).primaryColor : null,
                            shape: BoxShape.circle,
                          ),
                          child: Center(
                            child: Text(
                              '$day',
                              style: TextStyle(
                                color: isSelected ? Colors.white : Colors.black87,
                              ),
                            ),
                          ),
                        ),
                      );
                    },
                  ),

                  const SizedBox(height: 16),

                  // 按钮
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                    children: [
                      TextButton(
                        onPressed: widget.onCancel,
                        child: const Text('取消'),
                      ),
                      ElevatedButton(
                        onPressed: () => widget.onConfirm(_selectedDate),
                        child: const Text('确定'),
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}