import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:mileograph_flutter/components/traction/traction_card.dart';
import 'package:mileograph_flutter/objects/objects.dart';
import 'package:mileograph_flutter/services/api_service.dart';
import 'package:provider/provider.dart';

class TractionPendingPage extends StatefulWidget {
  const TractionPendingPage({super.key});

  @override
  State<TractionPendingPage> createState() => _TractionPendingPageState();
}

class _TractionPendingPageState extends State<TractionPendingPage> {
  bool _isLoading = false;
  String? _error;
  List<LocoSummary> _locos = const [];

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _load());
  }

  Future<void> _load() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      final api = context.read<ApiService>();
      final params = '?limit=200&offset=0';
      final json = await api.get('/loco/pending$params');
      if (json is List) {
        setState(() {
          _locos = json
              .whereType<Map>()
              .map((e) => LocoSummary.fromJson(
                    e.map((k, v) => MapEntry(k.toString(), v)),
                  ))
              .toList();
        });
      } else {
        setState(() {
          _error = 'Unexpected response';
          _locos = const [];
        });
      }
    } catch (e) {
      setState(() {
        _error = e.toString();
        _locos = const [];
      });
    } finally {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: const Icon(Icons.arrow_back),
          onPressed: () => Navigator.of(context).maybePop(),
        ),
        title: const Text('Pending traction'),
      ),
      body: RefreshIndicator(
        onRefresh: _load,
        child: _buildBody(context),
      ),
    );
  }

  Widget _buildBody(BuildContext context) {
    if (_isLoading && _locos.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }
    if (_error != null) {
      return ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Text(
            'Failed to load pending traction: $_error',
            style: Theme.of(context)
                .textTheme
                .bodyMedium
                ?.copyWith(color: Theme.of(context).colorScheme.error),
          ),
          const SizedBox(height: 12),
          FilledButton.icon(
            onPressed: _load,
            icon: const Icon(Icons.refresh),
            label: const Text('Retry'),
          ),
        ],
      );
    }
    if (_locos.isEmpty) {
      return ListView(
        padding: const EdgeInsets.all(16),
        children: const [
          Text('No pending traction found.'),
        ],
      );
    }
    return ListView.builder(
      padding: const EdgeInsets.all(12),
      itemCount: _locos.length,
      itemBuilder: (context, index) {
        final loco = _locos[index];
        return Padding(
          padding: const EdgeInsets.symmetric(vertical: 6.0),
          child: TractionCard(
            loco: loco,
            selectionMode: false,
            isSelected: false,
            onShowInfo: () => showTractionDetails(
              context,
              loco,
              onActionComplete: _load,
            ),
            onOpenTimeline: () => context.push(
              '/traction/${loco.id}/timeline',
              extra: {'label': '${loco.locoClass} ${loco.number}'.trim()},
            ),
            onOpenLegs: () => context.push('/traction/${loco.id}/legs'),
            onActionComplete: _load,
          ),
        );
      },
    );
  }
}