fmassive/lib/days.dart

import 'package:flutter/material.dart';

class Days extends StatefulWidget {
  final ValueChanged<String> onChanged;
  final String days;

  const Days({required this.onChanged, required this.days, super.key});

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

class _DaysState extends State<Days> {
  final List<String> _days = [
    'Monday',
    'Tuesday',
    'Wednesday',
    'Thursday',
    'Friday',
    'Saturday',
    'Sunday'
  ];
  late List<bool> _selections;

  @override
  void initState() {
    super.initState();
    final dayList = widget.days.split(',');
    _selections = _days.map((day) => dayList.contains(day)).toList();
  }

  String _getSelectedDaysString() {
    List<String> selectedDays = [];
    for (int i = 0; i < _selections.length; i++)
      if (_selections[i]) selectedDays.add(_days[i]);
    return selectedDays.join(",");
  }

  void _updateSelections(int index) {
    setState(() {
      _selections[index] = !_selections[index];
      widget.onChanged(_getSelectedDaysString());
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(children: [
      Text('Days', style: Theme.of(context).textTheme.headlineSmall),
      Expanded(
        child: ListView(
          children: List.generate(7, (index) {
            return SwitchListTile(
              title: Text(_days[index]),
              value: _selections[index],
              onChanged: (value) => _updateSelections(index),
            );
          }),
        ),
      ),
    ]);
  }
}