import 'dart:math';

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: CalendarPage(),
    );
  }
}

class CalendarPage extends StatefulWidget {
  @override
  _CalendarPageState createState() => _CalendarPageState();
}

class _CalendarPageState extends State<CalendarPage> {
  DateTime currentDate = DateTime.now();
  late List<DateTime> dateList;

  @override
  void initState() {
    super.initState();
    dateList = _generateDateList(currentDate);
  }

  List<DateTime> _generateDateList(DateTime date) {
    List<DateTime> list = [];
    DateTime firstOfMonth = DateTime(date.year, date.month, 1);
    int dayOfWeek = firstOfMonth.weekday;

    // Adjust to Monday start
    int startDay = dayOfWeek - 1;
    if (startDay < 0) startDay = 6;

    // Dates from previous month
    for (int i = startDay; i > 0; i--) {
      list.add(firstOfMonth.subtract(Duration(days: i)));
    }

    // Dates of current month
    int daysInMonth = DateUtils.getDaysInMonth(date.year, date.month);
    for (int i = 0; i < daysInMonth; i++) {
      list.add(DateTime(date.year, date.month, i + 1));
    }

    return list;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Calendar"),
      ),
      body: GridView.builder(
        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: 7,
        ),
        itemBuilder: (context, index) {
          double radius =
              (Random().nextInt(50).toDouble() + 20) / 2; // Reduced by 50%
          DateTime date = dateList[index];
          return Center(
            child: Container(
              width: radius * 2,
              height: radius * 2,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                border: Border.all(color: Colors.black, width: 2),
              ),
              child: Center(
                child: Container(
                  width: radius,
                  height: radius,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: Colors.lightGreen,
                  ),
                  child: Center(
                    child: Text(
                      DateFormat("d").format(date),
                      style: TextStyle(color: Colors.black),
                    ),
                  ),
                ),
              ),
            ),
          );
        },
        itemCount: dateList.length,
      ),
    );
  }
}