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

class TrainingDetailScreen extends StatefulWidget {
  final String trainingId;

  const TrainingDetailScreen({super.key, required this.trainingId});

  @override
  State<TrainingDetailScreen> createState() => _TrainingDetailScreenState();
}

class _TrainingDetailScreenState extends State<TrainingDetailScreen> {
  double? _userRating;
  bool _isLoading = false;
  bool _isPlayer = false;
  bool _userRoleChecked = false;

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

  Future<void> _checkUserRole() async {
    final user = FirebaseAuth.instance.currentUser;
    if (user == null) return;

    try {
      final userDoc = await FirebaseFirestore.instance.collection('User').doc(user.uid).get();
      if (userDoc.exists) {
        setState(() {
          _isPlayer = userDoc.data()?['role'] == 'player';
          _userRoleChecked = true;
        });
      }
    } catch (e) {
      print('Error checking user role: $e');
    }
  }

  Future<void> _submitRating(double rating) async {
    if (!_isPlayer) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Nur Spieler können Übungen bewerten')),
      );
      return;
    }

    setState(() => _isLoading = true);
    try {
      final user = FirebaseAuth.instance.currentUser;
      if (user == null) {
        throw Exception('Nicht eingeloggt');
      }

      final trainingRef = FirebaseFirestore.instance.collection('Training').doc(widget.trainingId);
      final trainingDoc = await trainingRef.get();
      
      if (!trainingDoc.exists) {
        throw Exception('Training nicht gefunden');
      }

      final data = trainingDoc.data() as Map<String, dynamic>;
      List<dynamic> ratings = List<dynamic>.from(data['ratings'] ?? []);
      
      // Entferne alte Bewertung des Users falls vorhanden
      ratings.removeWhere((r) => r['userId'] == user.uid);
      
      // Füge neue Bewertung hinzu
      ratings.add({
        'userId': user.uid,
        'rating': rating,
        'timestamp': DateTime.now().toIso8601String(), // Verwende ISO-String statt FieldValue
      });

      // Berechne neue Gesamtbewertung
      double overallRating = 0;
      if (ratings.isNotEmpty) {
        overallRating = ratings.map((r) => (r['rating'] as num).toDouble()).reduce((a, b) => a + b) / ratings.length;
      }

      // Aktualisiere das Dokument
      await trainingRef.update({
        'ratings': ratings,
        'rating overall': overallRating,
      });

      setState(() => _userRating = rating);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Bewertung erfolgreich gespeichert')),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Fehler beim Speichern der Bewertung: ${e.toString()}')),
        );
      }
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Training Details'),
      ),
      body: FutureBuilder<DocumentSnapshot>(
        future: FirebaseFirestore.instance.collection('Training').doc(widget.trainingId).get(),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          }
          if (!snapshot.hasData || !snapshot.data!.exists) {
            return const Center(child: Text('Training nicht gefunden'));
          }
          final data = snapshot.data!.data() as Map<String, dynamic>;
          
          // Hole die Bewertung des aktuellen Users
          final user = FirebaseAuth.instance.currentUser;
          if (user != null && _userRating == null) {
            final ratings = List<dynamic>.from(data['ratings'] ?? []);
            final userRating = ratings.firstWhere(
              (r) => r['userId'] == user.uid,
              orElse: () => {'rating': null},
            )['rating'];
            if (userRating != null) {
              _userRating = (userRating as num).toDouble();
            }
          }

          return SingleChildScrollView(
            padding: const EdgeInsets.all(16.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Container(
                  width: double.infinity,
                  height: 200,
                  color: Colors.grey[300],
                  child: (data['picture'] is String && data['picture'] != '')
                      ? Image.network(
                          data['picture'],
                          fit: BoxFit.cover,
                        )
                      : const Center(
                          child: Icon(Icons.image, size: 64, color: Colors.grey),
                        ),
                ),
                const SizedBox(height: 16),
                Text(
                  data['title'] ?? 'Unbekannt',
                  style: const TextStyle(
                    fontSize: 24,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 8),
                Text(
                  data['description'] ?? 'Keine Beschreibung',
                  style: TextStyle(color: Colors.grey[600]),
                ),
                const SizedBox(height: 16),
                Text(
                  'Dauer: ${data['duration'] ?? '-'} Minuten',
                  style: TextStyle(color: Colors.grey[600]),
                ),
                const SizedBox(height: 8),
                Text(
                  'Level: ${data['year'] ?? '-'}',
                  style: TextStyle(color: Colors.grey[600]),
                ),
                const SizedBox(height: 16),
                Row(
                  children: [
                    const Icon(Icons.star, color: Colors.amber),
                    const SizedBox(width: 8),
                    Text(
                      'Durchschnittliche Bewertung: ${(data['rating overall'] ?? 0.0).toStringAsFixed(1)}',
                      style: const TextStyle(fontSize: 16),
                    ),
                  ],
                ),
                const SizedBox(height: 8),
                Text(
                  'Anzahl Bewertungen: ${(data['ratings'] ?? []).length}',
                  style: TextStyle(color: Colors.grey[600]),
                ),
                if (_userRoleChecked && _isPlayer) ...[
                  const SizedBox(height: 16),
                  const Text(
                    'Deine Bewertung:',
                    style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
                  ),
                  const SizedBox(height: 8),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: List.generate(5, (index) {
                      return IconButton(
                        icon: Icon(
                          index < (_userRating ?? 0) ? Icons.star : Icons.star_border,
                          color: Colors.amber,
                          size: 32,
                        ),
                        onPressed: _isLoading
                            ? null
                            : () => _submitRating(index + 1.0),
                      );
                    }),
                  ),
                  if (_isLoading)
                    const Padding(
                      padding: EdgeInsets.all(8.0),
                      child: Center(child: CircularProgressIndicator()),
                    ),
                ],
                const SizedBox(height: 8),
                Text(
                  'Kategorie: ${data['category'] ?? '-'}',
                  style: TextStyle(color: Colors.grey[600]),
                ),
              ],
            ),
          );
        },
      ),
    );
  }
}