import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'training_detail_screen.dart';

class FavoritesTab extends StatelessWidget {
  const FavoritesTab({super.key});

  @override
  Widget build(BuildContext context) {
    final user = FirebaseAuth.instance.currentUser;
    if (user == null) {
      return const Center(child: Text('Nicht eingeloggt'));
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text('Favoriten'),
      ),
      body: StreamBuilder<DocumentSnapshot>(
        stream: FirebaseFirestore.instance.collection('User').doc(user.uid).snapshots(),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          }
          if (!snapshot.hasData || !snapshot.data!.exists) {
            return const Center(child: Text('Keine Favoriten gefunden'));
          }
          final data = snapshot.data!.data() as Map<String, dynamic>;
          final favorites = List<String>.from(data['favorites'] ?? []);

          if (favorites.isEmpty) {
            return const Center(child: Text('Keine Favoriten gefunden'));
          }

          return ListView.builder(
            itemCount: favorites.length,
            itemBuilder: (context, index) {
              return FutureBuilder<DocumentSnapshot>(
                future: FirebaseFirestore.instance.collection('Training').doc(favorites[index]).get(),
                builder: (context, trainingSnapshot) {
                  if (!trainingSnapshot.hasData || !trainingSnapshot.data!.exists) {
                    return const ListTile(title: Text('Training nicht gefunden'));
                  }
                  final trainingData = trainingSnapshot.data!.data() as Map<String, dynamic>;
                  return Card(
                    margin: const EdgeInsets.all(8.0),
                    child: InkWell(
                      onTap: () {
                        Navigator.push(
                          context,
                          MaterialPageRoute(
                            builder: (context) => TrainingDetailScreen(trainingId: favorites[index]),
                          ),
                        );
                      },
                      child: Padding(
                        padding: const EdgeInsets.all(16.0),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              trainingData['title'] ?? 'Unbekannt',
                              style: const TextStyle(
                                fontSize: 18,
                                fontWeight: FontWeight.bold,
                              ),
                            ),
                            const SizedBox(height: 8),
                            Text(
                              trainingData['description'] ?? 'Keine Beschreibung',
                              style: TextStyle(color: Colors.grey[600]),
                            ),
                            const SizedBox(height: 8),
                            Text(
                              'Dauer: ${trainingData['duration'] ?? '-'} Minuten',
                              style: TextStyle(color: Colors.grey[600]),
                            ),
                            const SizedBox(height: 8),
                            Row(
                              mainAxisAlignment: MainAxisAlignment.spaceBetween,
                              children: [
                                Text(
                                  'Level: ${trainingData['year'] ?? '-'}',
                                  style: TextStyle(color: Colors.grey[600]),
                                ),
                                IconButton(
                                  icon: const Icon(Icons.favorite, color: Colors.red),
                                  onPressed: () async {
                                    await FirebaseFirestore.instance.collection('User').doc(user.uid).update({
                                      'favorites': FieldValue.arrayRemove([favorites[index]]),
                                    });
                                  },
                                ),
                              ],
                            ),
                          ],
                        ),
                      ),
                    ),
                  );
                },
              );
            },
          );
        },
      ),
    );
  }
}