import 'package:flutter/material.dart';

import '../../../../api/connect/rmv/rmv_models.dart';
import '../../../../extensions/date_time.dart';
import 'product_chip.dart';
import 'realtime_time.dart';

/// Renders a single [Leg] of a trip with header (line/direction), origin and
/// destination times and (optionally) the list of intermediate stops.
class LegTile extends StatelessWidget {
  final Leg leg;
  final VoidCallback? onShowJourneyDetail;

  const LegTile({super.key, required this.leg, this.onShowJourneyDetail});

  @override
  Widget build(BuildContext context) {
    final isWalk =
        leg.type == LegType.walk || leg.type == LegType.transfer;
    final cancelled = leg.cancelled || leg.partCancelled;
    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _header(context, isWalk: isWalk, cancelled: cancelled),
          _endpoint(
            context,
            label: leg.origin.name,
            scheduled: leg.origin.scheduledTime,
            realtime: leg.origin.realTime,
            delayMinutes: leg.origin.delayMinutes?.toInt(),
            track: (leg.origin.realTrack?.isNotEmpty ?? false)
                ? leg.origin.realTrack
                : leg.origin.track,
            icon: Icons.trip_origin,
            cancelled: cancelled,
          ),
          if (leg.stops.length > 2)
            _stopsExpander(context, leg.stops),
          _endpoint(
            context,
            label: leg.destination.name,
            scheduled: leg.destination.scheduledTime,
            realtime: leg.destination.realTime,
            delayMinutes: leg.destination.delayMinutes?.toInt(),
            track: (leg.destination.realTrack?.isNotEmpty ?? false)
                ? leg.destination.realTrack
                : leg.destination.track,
            icon: Icons.place,
            cancelled: cancelled,
          ),
        ],
      ),
    );
  }

  Widget _header(
    BuildContext context, {
    required bool isWalk,
    required bool cancelled,
  }) {
    final headlineStyle = Theme.of(context).textTheme.titleSmall?.copyWith(
      decoration: cancelled ? TextDecoration.lineThrough : null,
    );
    final title = isWalk
        ? 'Fußweg'
        : (leg.direction != null
              ? '${leg.name ?? ''}  →  ${leg.direction}'
              : (leg.name ?? '—'));
    final canOpenJourney = leg.journeyRef != null && !isWalk;
    return Container(
      color: Theme.of(context).colorScheme.surfaceContainerHighest,
      padding: const EdgeInsets.fromLTRB(12, 8, 8, 8),
      child: Row(
        children: [
          if (!isWalk) ProductChip(product: leg.product, fallbackLabel: leg.name),
          if (!isWalk) const SizedBox(width: 8),
          if (isWalk)
            const Padding(
              padding: EdgeInsets.only(right: 8),
              child: Icon(Icons.directions_walk),
            ),
          Expanded(
            child: Text(
              title,
              style: headlineStyle,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
            ),
          ),
          if (leg.duration != null)
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 4),
              child: Text(
                '${leg.duration!.inMinutes} min',
                style: Theme.of(context).textTheme.bodySmall,
              ),
            ),
          if (canOpenJourney)
            IconButton(
              icon: const Icon(Icons.list_alt),
              tooltip: 'Alle Halte',
              onPressed: onShowJourneyDetail,
            ),
        ],
      ),
    );
  }

  Widget _endpoint(
    BuildContext context, {
    required String label,
    required DateTime scheduled,
    DateTime? realtime,
    int? delayMinutes,
    String? track,
    required IconData icon,
    required bool cancelled,
  }) => ListTile(
    leading: Icon(icon, size: 20),
    title: Text(
      label,
      style: TextStyle(
        decoration: cancelled ? TextDecoration.lineThrough : null,
      ),
    ),
    subtitle: (track != null && track.isNotEmpty)
        ? Text('Gleis $track')
        : null,
    trailing: RealtimeTime(
      scheduled: scheduled,
      realtime: realtime,
      delayMinutes: delayMinutes,
      cancelled: cancelled,
    ),
    dense: true,
  );

  Widget _stopsExpander(BuildContext context, List<JourneyStop> stops) {
    final intermediate = stops.length > 2
        ? stops.sublist(1, stops.length - 1)
        : const <JourneyStop>[];
    if (intermediate.isEmpty) return const SizedBox.shrink();
    return ExpansionTile(
      tilePadding: const EdgeInsets.symmetric(horizontal: 16),
      childrenPadding: const EdgeInsets.symmetric(horizontal: 16),
      title: Text(
        '${intermediate.length} Zwischenhalt${intermediate.length > 1 ? 'e' : ''}',
        style: Theme.of(context).textTheme.bodySmall,
      ),
      children: intermediate
          .map(
            (s) => ListTile(
              dense: true,
              visualDensity: VisualDensity.compact,
              leading: const Icon(Icons.fiber_manual_record, size: 10),
              title: Text(s.name),
              trailing: Text(_stopTime(s)),
            ),
          )
          .toList(),
    );
  }

  String _stopTime(JourneyStop s) {
    final dep = s.realDeparture ?? s.scheduledDeparture;
    final arr = s.realArrival ?? s.scheduledArrival;
    if (arr != null && dep != null && arr != dep) {
      return '${arr.formatHm()} / ${dep.formatHm()}';
    }
    final t = dep ?? arr;
    return t?.formatHm() ?? '';
  }
}