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

import '../models/models.dart';
import '../services/auth_controller.dart';
import '../theme/app_theme.dart';
import '../ui/feedback.dart';
import 'dealer_stock_screen.dart';
import 'stock_form_screen.dart';

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

  @override
  State<StockScreen> createState() => _StockScreenState();
}

class _StockScreenState extends State<StockScreen> {
  List<Dealer> _dealers = [];
  List<StockItem> _stocks = [];
  bool _loading = true;

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

  Future<void> _load() async {
    final api = context.read<AuthController>().api;
    try {
      final results = await Future.wait([
        api.dealers(),
        api.stocks(),
      ]);
      if (!mounted) return;
      setState(() {
        _dealers = results[0] as List<Dealer>;
        _stocks = results[1] as List<StockItem>;
        _loading = false;
      });
    } catch (error) {
      if (!mounted) return;
      setState(() => _loading = false);
      showError(context, error);
    }
  }

  int _count(String dealerId, String badge) {
    return _stocks.where((item) => item.currentDealerId == dealerId && item.badge == badge).length;
  }

  @override
  Widget build(BuildContext context) {
    final role = context.watch<AuthController>().user?.role;
    final canAdd = role == 'dealer' || role == 'salesRep' || role == 'superAdmin';

    if (_loading && _dealers.isEmpty && _stocks.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }

    return Scaffold(
      floatingActionButton: canAdd
          ? FloatingActionButton.extended(
              onPressed: () async {
                final created = await Navigator.of(context).push<bool>(
                  MaterialPageRoute(builder: (_) => StockFormScreen(dealers: _dealers)),
                );
                if (created == true) _load();
              },
              icon: const Icon(Icons.add),
              label: const Text('Add stock'),
            )
          : null,
      body: RefreshIndicator(
        onRefresh: _load,
        child: ListView(
          padding: const EdgeInsets.fromLTRB(16, 12, 16, 96),
          children: [
            if (_dealers.isEmpty)
              const Padding(
                padding: EdgeInsets.symmetric(vertical: 32),
                child: Center(child: Text('No dealers to show.')),
              ),
            for (final dealer in _dealers)
              Card(
                clipBehavior: Clip.antiAlias,
                child: InkWell(
                  onTap: () async {
                    await Navigator.of(context).push<bool>(
                      MaterialPageRoute(
                        builder: (_) => DealerStockScreen(dealer: dealer, dealers: _dealers),
                      ),
                    );
                    if (mounted) _load();
                  },
                  child: Padding(
                    padding: const EdgeInsets.all(16),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(dealer.name, style: Theme.of(context).textTheme.titleMedium),
                        const SizedBox(height: 2),
                        Text(
                          dealer.district == null || dealer.district!.isEmpty
                              ? dealer.code
                              : '${dealer.code} · ${dealer.district}',
                          style: Theme.of(context).textTheme.bodySmall,
                        ),
                        const SizedBox(height: 12),
                        Row(
                          children: [
                            Expanded(
                              child: _AgeCount(
                                label: 'Under 30',
                                count: _count(dealer.id, 'green'),
                                badge: 'green',
                              ),
                            ),
                            Expanded(
                              child: _AgeCount(
                                label: '30–45',
                                count: _count(dealer.id, 'yellow'),
                                badge: 'yellow',
                              ),
                            ),
                            Expanded(
                              child: _AgeCount(
                                label: 'Over 45',
                                count: _count(dealer.id, 'red'),
                                badge: 'red',
                              ),
                            ),
                          ],
                        ),
                      ],
                    ),
                  ),
                ),
              ),
          ],
        ),
      ),
    );
  }
}

class _AgeCount extends StatelessWidget {
  const _AgeCount({required this.label, required this.count, required this.badge});

  final String label;
  final int count;
  final String badge;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text(
          '$count',
          style: Theme.of(context).textTheme.headlineSmall?.copyWith(color: badgeColor(badge)),
        ),
        const SizedBox(height: 2),
        Text(label, style: Theme.of(context).textTheme.bodySmall, textAlign: TextAlign.center),
      ],
    );
  }
}