import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

import '../../../../api/connect/rmv/rmv_models.dart';
import '../../../../api/errors/error_mapper.dart';
import '../../../../routing/app_routes.dart';
import '../../../../state/app/modules/rmv/repository/rmv_repository.dart';
import '../../../../state/app/modules/settings/bloc/settings_cubit.dart';
import '../../../../widget/app_progress_indicator.dart';
import '../favorites_controller.dart';
import '../widgets/departure_arrival_tile.dart';

enum _Direction { departures, arrivals }

class StationDetailView extends StatefulWidget {
  final StopLocation station;
  const StationDetailView({super.key, required this.station});

  @override
  State<StationDetailView> createState() => _StationDetailViewState();
}

class _StationDetailViewState extends State<StationDetailView> {
  final RmvRepository _repo = RmvRepository();
  _Direction _direction = _Direction.departures;
  List<Departure>? _departures;
  List<Arrival>? _arrivals;
  bool _loading = false;
  Object? _error;

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

  Future<void> _load() async {
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      if (_direction == _Direction.departures) {
        final result = await _repo.departures(widget.station.id);
        if (!mounted) return;
        setState(() {
          _departures = result;
          _loading = false;
        });
      } else {
        final result = await _repo.arrivals(widget.station.id);
        if (!mounted) return;
        setState(() {
          _arrivals = result;
          _loading = false;
        });
      }
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _error = e;
        _loading = false;
      });
    }
  }

  void _switch(_Direction d) {
    if (d == _direction) return;
    setState(() {
      _direction = d;
      _departures = null;
      _arrivals = null;
    });
    _load();
  }

  @override
  Widget build(BuildContext context) {
    final settings = context.watch<SettingsCubit>();
    final favCtrl = RmvFavoritesController(settings);
    final isFav = favCtrl.isFavorite(widget.station);
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.station.name),
        actions: [
          IconButton(
            tooltip: isFav ? 'Favorit entfernen' : 'Als Favorit speichern',
            icon: Icon(isFav ? Icons.star : Icons.star_border),
            onPressed: () => favCtrl.toggleFavorite(widget.station),
          ),
        ],
      ),
      body: Column(
        children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(16, 12, 16, 8),
            child: SegmentedButton<_Direction>(
              segments: const [
                ButtonSegment(
                  value: _Direction.departures,
                  icon: Icon(Icons.north_east),
                  label: Text('Abfahrten'),
                ),
                ButtonSegment(
                  value: _Direction.arrivals,
                  icon: Icon(Icons.south_west),
                  label: Text('Ankünfte'),
                ),
              ],
              selected: {_direction},
              onSelectionChanged: (s) => _switch(s.first),
            ),
          ),
          Expanded(child: _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: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text(
                errorToUserMessage(err),
                textAlign: TextAlign.center,
                style: TextStyle(color: Theme.of(context).colorScheme.error),
              ),
              const SizedBox(height: 12),
              FilledButton.icon(
                icon: const Icon(Icons.refresh),
                onPressed: _load,
                label: const Text('Erneut versuchen'),
              ),
            ],
          ),
        ),
      );
    }
    if (_direction == _Direction.departures) {
      final list = _departures ?? const <Departure>[];
      if (list.isEmpty) return _emptyState('Keine Abfahrten gefunden.');
      return RefreshIndicator(
        onRefresh: _load,
        child: ListView.separated(
          itemCount: list.length,
          separatorBuilder: (_, _) => const Divider(height: 1),
          itemBuilder: (_, i) => DepartureArrivalTile.fromDeparture(
            list[i],
            onTap: () => _openJourney(list[i].journeyRef),
          ),
        ),
      );
    }
    final list = _arrivals ?? const <Arrival>[];
    if (list.isEmpty) return _emptyState('Keine Ankünfte gefunden.');
    return RefreshIndicator(
      onRefresh: _load,
      child: ListView.separated(
        itemCount: list.length,
        separatorBuilder: (_, _) => const Divider(height: 1),
        itemBuilder: (_, i) => DepartureArrivalTile.fromArrival(
          list[i],
          onTap: () => _openJourney(list[i].journeyRef),
        ),
      ),
    );
  }

  Widget _emptyState(String text) => RefreshIndicator(
    onRefresh: _load,
    child: ListView(
      physics: const AlwaysScrollableScrollPhysics(),
      children: [
        Padding(
          padding: const EdgeInsets.symmetric(vertical: 80, horizontal: 24),
          child: Center(
            child: Text(text, style: Theme.of(context).textTheme.bodyLarge),
          ),
        ),
      ],
    ),
  );

  void _openJourney(String? ref) {
    if (ref == null) return;
    AppRoutes.openRmvJourneyDetail(context, ref);
  }
}