import 'package:flutter/material.dart';

import '../../../../api/connect/rmv/rmv_models.dart';
import '../../../../api/errors/error_mapper.dart';
import '../../../../extensions/date_time.dart';
import '../../../../state/app/modules/rmv/repository/rmv_repository.dart';
import '../../../../widget/app_progress_indicator.dart';
import '../widgets/product_chip.dart';
import '../widgets/realtime_time.dart';

class JourneyDetailView extends StatefulWidget {
  final String journeyRef;
  final DateTime? date;

  const JourneyDetailView({super.key, required this.journeyRef, this.date});

  @override
  State<JourneyDetailView> createState() => _JourneyDetailViewState();
}

class _JourneyDetailViewState extends State<JourneyDetailView> {
  final RmvRepository _repo = RmvRepository();
  JourneyDetail? _detail;
  bool _loading = true;
  Object? _error;

  @override
  void initState() {
    super.initState();
    _load();
  }

  Future<void> _load() async {
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final detail = await _repo.journeyDetail(
        widget.journeyRef,
        date: widget.date,
      );
      if (!mounted) return;
      setState(() {
        _detail = detail;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _error = e;
        _loading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final detail = _detail;
    return Scaffold(
      appBar: AppBar(
        title: Row(
          children: [
            ProductChip(product: detail?.product),
            const SizedBox(width: 8),
            Expanded(
              child: Text(
                detail?.direction ?? 'Fahrt',
                overflow: TextOverflow.ellipsis,
              ),
            ),
          ],
        ),
      ),
      body: _body(),
    );
  }

  Widget _body() {
    if (_loading) {
      return const Center(child: AppProgressIndicator.large());
    }
    final err = _error;
    if (err != null) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Text(
            errorToUserMessage(err),
            textAlign: TextAlign.center,
          ),
        ),
      );
    }
    final stops = _detail?.stops ?? const <JourneyStop>[];
    if (stops.isEmpty) {
      return const Center(child: Text('Keine Halte verfügbar.'));
    }
    return RefreshIndicator(
      onRefresh: _load,
      child: ListView.separated(
        itemCount: stops.length,
        separatorBuilder: (_, _) => const Divider(height: 1),
        itemBuilder: (_, i) => _stopTile(stops[i], i, stops.length),
      ),
    );
  }

  Widget _stopTile(JourneyStop stop, int idx, int total) {
    final isFirst = idx == 0;
    final isLast = idx == total - 1;
    final arrival = stop.realArrival ?? stop.scheduledArrival;
    final departure = stop.realDeparture ?? stop.scheduledDeparture;
    final track = (stop.realDepTrack?.isNotEmpty ?? false)
        ? stop.realDepTrack
        : stop.depTrack;
    return ListTile(
      leading: SizedBox(
        width: 24,
        child: Icon(
          isFirst
              ? Icons.trip_origin
              : (isLast ? Icons.place : Icons.fiber_manual_record),
          size: isFirst || isLast ? 20 : 10,
          color: stop.cancelled
              ? Colors.red
              : Theme.of(context).colorScheme.primary,
        ),
      ),
      title: Text(
        stop.name,
        style: TextStyle(
          decoration: stop.cancelled ? TextDecoration.lineThrough : null,
          fontWeight: (isFirst || isLast) ? FontWeight.bold : null,
        ),
      ),
      subtitle: (track == null || track.isEmpty)
          ? null
          : Text('Gleis $track'),
      trailing: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.end,
        children: [
          if (stop.scheduledArrival != null)
            RealtimeTime(
              scheduled: stop.scheduledArrival!,
              realtime: stop.realArrival,
              cancelled: stop.cancelledArrival,
              style: Theme.of(context).textTheme.bodyMedium,
            ),
          if (stop.scheduledDeparture != null &&
              stop.scheduledDeparture != stop.scheduledArrival)
            RealtimeTime(
              scheduled: stop.scheduledDeparture!,
              realtime: stop.realDeparture,
              cancelled: stop.cancelledDeparture,
              style: Theme.of(context).textTheme.bodyMedium,
            ),
          if (arrival == null && departure == null) const Text('-'),
        ],
      ),
      isThreeLine: arrival != null && departure != null && arrival != departure,
    );
  }
}

/// Allows showing "departure 14:35" as a tooltip in the journey timeline.
String formatStopMoment(DateTime t) => t.formatHm();