import 'package:flutter/material.dart';

class DurationPicker extends StatefulWidget {
  const DurationPicker({super.key, required this.onChangedCallback});

  final void Function(Duration duration) onChangedCallback;

  @override
  State<DurationPicker> createState() => _DurationPickerState();
}

class _DurationPickerState extends State<DurationPicker> {
  String _timeString = '';

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: 400,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Row(
            mainAxisSize: MainAxisSize.max,
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              Text(
                _timeString.padLeft(4, '0').substring(0, 2),
                style: Theme.of(context).textTheme.displayMedium,
              ),
              Padding(padding: EdgeInsets.only(left: 5)),
              Text(
                'h',
                style:
                    Theme.of(context).textTheme.bodyLarge!.copyWith(height: 2),
              ),
              Padding(padding: EdgeInsets.only(left: 10)),
              Text(
                _timeString.padLeft(4, '0').substring(2, 4),
                style: Theme.of(context).textTheme.displayMedium,
              ),
              Padding(padding: EdgeInsets.only(left: 5)),
              Text(
                'm',
                style:
                    Theme.of(context).textTheme.bodyLarge!.copyWith(height: 2),
              ),
            ],
          ),
          Padding(padding: EdgeInsets.only(top: 10)),
          Expanded(
            child: GridView.count(
              crossAxisSpacing: 10,
              mainAxisSpacing: 10,
              crossAxisCount: 3,
              physics: NeverScrollableScrollPhysics(),
              children: [
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(7),
                  child: _getTextWidget('7'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(8),
                  child: _getTextWidget('8'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(9),
                  child: _getTextWidget('9'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(4),
                  child: _getTextWidget('4'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(5),
                  child: _getTextWidget('5'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(6),
                  child: _getTextWidget('6'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(1),
                  child: _getTextWidget('1'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(2),
                  child: _getTextWidget('2'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(3),
                  child: _getTextWidget('3'),
                ),
                Padding(padding: EdgeInsets.all(0)),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: () => _addTime(0),
                  child: _getTextWidget('0'),
                ),
                ElevatedButton(
                  style: _buttonTheme,
                  onPressed: _removeTime,
                  child: Icon(
                    Icons.backspace,
                    size: 24,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Text _getTextWidget(String text) {
    return Text(text);
  }

  void _addTime(int time) {
    if (_timeString.length >= 4) return;

    setState(() {
      _timeString += time.toString();
    });

    widget.onChangedCallback(_duration);
  }

  void _removeTime() {
    if (_timeString.isEmpty) return;
    setState(() {
      _timeString = _timeString.substring(0, _timeString.length - 1);
    });

    widget.onChangedCallback(_duration);
  }

  Duration get _duration {
    return Duration(
      hours: int.parse(_timeString.padLeft(4, '0').substring(0, 2)),
      minutes: int.parse(_timeString.padLeft(4, '0').substring(2, 4)),
    );
  }

  ButtonStyle get _buttonTheme => ElevatedButton.styleFrom(
        textStyle: Theme.of(context).textTheme.displaySmall,
      );
}