import 'package:flutter/material.dart';

import '../../../../extensions/date_time.dart';

/// Returns the "depart at / arrive by" time and the AB/AN-toggle. `null` for
/// [value] means "now" — the API treats an empty `when` parameter as the
/// current time.
class WhenPicker extends StatelessWidget {
  final DateTime? value;
  final bool byArrival;
  final ValueChanged<DateTime?> onValueChanged;
  final ValueChanged<bool> onByArrivalChanged;

  const WhenPicker({
    super.key,
    required this.value,
    required this.byArrival,
    required this.onValueChanged,
    required this.onByArrivalChanged,
  });

  @override
  Widget build(BuildContext context) {
    final label = value == null
        ? 'Jetzt'
        : value!.formatDateRelativeShort() == 'Heute'
        ? value!.formatHm()
        : '${value!.formatDateRelativeShort()} ${value!.formatHm()}';
    return Row(
      children: [
        Expanded(
          child: OutlinedButton.icon(
            icon: const Icon(Icons.schedule),
            label: Text(label),
            onPressed: () => _pick(context),
          ),
        ),
        const SizedBox(width: 8),
        SegmentedButton<bool>(
          segments: const [
            ButtonSegment(value: false, label: Text('Ab')),
            ButtonSegment(value: true, label: Text('An')),
          ],
          selected: {byArrival},
          onSelectionChanged: (s) => onByArrivalChanged(s.first),
        ),
        if (value != null) ...[
          const SizedBox(width: 4),
          IconButton(
            icon: const Icon(Icons.close),
            tooltip: 'Zurück auf "Jetzt"',
            onPressed: () => onValueChanged(null),
          ),
        ],
      ],
    );
  }

  Future<void> _pick(BuildContext context) async {
    final now = DateTime.now();
    final initial = value ?? now;
    final date = await showDatePicker(
      context: context,
      initialDate: initial,
      firstDate: now.subtract(const Duration(days: 7)),
      lastDate: now.add(const Duration(days: 365)),
    );
    if (date == null) return;
    if (!context.mounted) return;
    final time = await showTimePicker(
      context: context,
      initialTime: TimeOfDay(hour: initial.hour, minute: initial.minute),
    );
    if (time == null) return;
    onValueChanged(
      DateTime(date.year, date.month, date.day, time.hour, time.minute),
    );
  }
}