// lib/screens/daily_quiz_screen.dart
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:math';

import 'package:kzeduca_app/services/i18n_service.dart';
import 'package:kzeduca_app/services/firebase_service.dart';
import 'package:kzeduca_app/models/app_models.dart';

class DailyQuizScreen extends StatefulWidget {
  final FinancialChallenge dailyChallenge;

  const DailyQuizScreen({super.key, required this.dailyChallenge});

  @override
  State<DailyQuizScreen> createState() => _DailyQuizScreenState();
}

class _DailyQuizScreenState extends State<DailyQuizScreen> {
  List<QuizQuestion> _questions = [];
  bool _isLoading = true;
  String _error = '';
  int _currentQuestionIndex = 0;
  int _score = 0;
  String? _selectedOption;
  bool _showAnswerFeedback = false;
  bool _quizFinished = false;

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

  Future<void> _loadDailyQuizQuestions() async {
    final firebaseService = Provider.of<FirebaseService>(context, listen: false);
    setState(() {
      _isLoading = true;
    });

    try {
      final querySnapshot = await firebaseService.firestore
          .collection('artifacts')
          .doc('default-kzeduca-app')
          .collection('public')
          .doc('data')
          .collection('quizQuestions')
          .get();
      
      final allQuestions = querySnapshot.docs.map((doc) => QuizQuestion.fromFirestore(doc)).toList();
      
      if (allQuestions.length < 10) {
        throw Exception('Não há perguntas suficientes para o quiz diário.');
      }
      
      allQuestions.shuffle();
      _questions = allQuestions.take(10).toList();

    } catch (e) {
      setState(() {
        _error = "Erro ao carregar o quiz diário: $e";
      });
    } finally {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
      }
    }
  }

  void _showAlertDialog(String message, {bool isError = false}) {
    final i18n = Provider.of<I18nService>(context, listen: false);
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text(isError ? i18n.t('error_prefix') : 'Info'),
        content: Text(message),
        actions: <Widget>[
          TextButton(
            child: const Text('Ok'),
            onPressed: () {
              Navigator.of(ctx).pop();
            },
          )
        ],
      ),
    );
  }

  Future<void> _handleAnswer(String option) async {
    if (_showAnswerFeedback) return;

    setState(() {
      _selectedOption = option;
      _showAnswerFeedback = true;
      if (option == _questions[_currentQuestionIndex].answer) {
        _score++;
      }
    });
    
    await Future.delayed(const Duration(seconds: 2));
    if (mounted) {
      _handleNextQuestion();
    }
  }

  Future<void> _handleNextQuestion() async {
    setState(() {
      _selectedOption = null;
      _showAnswerFeedback = false;
    });

    if (_currentQuestionIndex < _questions.length - 1) {
      setState(() {
        _currentQuestionIndex++;
      });
    } else {
      await _saveDailyQuizResult();
      setState(() {
        _quizFinished = true;
      });
    }
  }
  
  Future<void> _saveDailyQuizResult() async {
    final i18n = Provider.of<I18nService>(context, listen: false);
    final firebaseService = Provider.of<FirebaseService>(context, listen: false);
    final userId = FirebaseAuth.instance.currentUser?.uid;

    if (userId == null) {
      _showAlertDialog(i18n.t('quiz_save_error'), isError: true);
      return;
    }

    try {
      await firebaseService.saveQuizResult(userId, {
        'score': _score,
        'totalQuestions': _questions.length,
        'timestamp': DateTime.now().toIso8601String(),
        'isDailyQuiz': true, // Marcar como quiz diário
      });
      
      final prefs = await SharedPreferences.getInstance();
      await prefs.setString('daily_quiz_completion_date', DateFormat('yyyy-MM-dd').format(DateTime.now()));
      
      final double scorePercentage = _score / _questions.length;
      if (scorePercentage >= 0.8) {
        _showBonusChallengeDialog();
      }
      _showAlertDialog(i18n.t('quiz_saved'));

    } catch (e) {
      _showAlertDialog(i18n.t('quiz_save_error'), isError: true);
    }
  }

  void _showBonusChallengeDialog() {
    final i18n = Provider.of<I18nService>(context, listen: false);
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text(i18n.t('bonus_daily_challenge'), style: TextStyle(color: Colors.amber)),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text('Parabéns, você acertou ${_score} de 10 perguntas e desbloqueou um desafio bônus!'),
            SizedBox(height: 10),
            Text(widget.dailyChallenge.nome, style: TextStyle(fontWeight: FontWeight.bold)),
            Text(widget.dailyChallenge.meta),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(),
            child: const Text('OK'),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final i18n = Provider.of<I18nService>(context);

    return Scaffold(
      extendBodyBehindAppBar: true,
      appBar: AppBar(
        title: Text('Quiz Diário'),
        backgroundColor: Colors.purple[900]?.withOpacity(0.5),
        foregroundColor: Colors.white,
        elevation: 0,
      ),
      body: Stack(
        children: [
          Container(
            decoration: const BoxDecoration(
              image: DecorationImage(
                image: AssetImage('assets/images/quiz_background.png'),
                fit: BoxFit.cover,
              ),
            ),
          ),
          Center(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(16.0),
              child: Container(
                padding: const EdgeInsets.all(32.0),
                decoration: BoxDecoration(
                  color: Colors.black.withOpacity(0.7),
                  borderRadius: BorderRadius.circular(24.0),
                  border: Border.all(color: Colors.white.withOpacity(0.2)),
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black.withOpacity(0.5),
                      blurRadius: 32,
                      offset: const Offset(0, 8),
                    ),
                  ],
                ),
                constraints: const BoxConstraints(maxWidth: 600),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    if (_isLoading)
                      const Center(child: CircularProgressIndicator())
                    else if (_questions.isEmpty)
                      Text(
                        'Não foi possível carregar o quiz diário.',
                        style: TextStyle(color: Colors.white.withOpacity(0.8)),
                        textAlign: TextAlign.center,
                      )
                    else if (!_quizFinished)
                      Column(
                        children: [
                          LinearProgressIndicator(
                            value: (_currentQuestionIndex + 1) / _questions.length,
                            backgroundColor: Colors.white.withOpacity(0.3),
                            color: Colors.teal[400],
                            minHeight: 10,
                            borderRadius: BorderRadius.circular(5),
                          ),
                          const SizedBox(height: 16),
                          Text(
                            'Questão ${_currentQuestionIndex + 1} de ${_questions.length}',
                            style: TextStyle(fontSize: 14, color: Colors.white.withOpacity(0.6)),
                            textAlign: TextAlign.center,
                          ),
                          const SizedBox(height: 16),
                          Text(
                            _questions[_currentQuestionIndex].question,
                            style: const TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: Colors.white),
                            textAlign: TextAlign.center,
                          ),
                          const SizedBox(height: 24),
                          ..._questions[_currentQuestionIndex].options.map((option) {
                            bool isCorrect = option == _questions[_currentQuestionIndex].answer;
                            bool isSelected = option == _selectedOption;
                            return Padding(
                              padding: const EdgeInsets.symmetric(vertical: 8.0),
                              child: ElevatedButton(
                                onPressed: _showAnswerFeedback ? null : () => _handleAnswer(option),
                                style: ElevatedButton.styleFrom(
                                  backgroundColor: _showAnswerFeedback
                                      ? (isCorrect ? Colors.green[500] : Colors.red[500])
                                      : Colors.black.withOpacity(0.4),
                                  foregroundColor: Colors.white,
                                  side: BorderSide(
                                    color: _showAnswerFeedback
                                        ? (isCorrect ? Colors.green[400]! : Colors.red[400]!)
                                        : Colors.white.withOpacity(0.3),
                                    width: 1,
                                  ),
                                  padding: const EdgeInsets.all(16),
                                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                                  elevation: isSelected ? 4 : 2,
                                ),
                                child: Align(
                                  alignment: Alignment.centerLeft,
                                  child: Text(option, style: const TextStyle(fontSize: 16)),
                                ),
                              ),
                            );
                          }),
                          if (_showAnswerFeedback) ...[
                            const SizedBox(height: 16),
                            Card(
                              elevation: 4,
                              shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                              color: _selectedOption == _questions[_currentQuestionIndex].answer
                                  ? Colors.green[900]?.withOpacity(0.6)
                                  : Colors.red[900]?.withOpacity(0.6),
                              child: Padding(
                                padding: const EdgeInsets.all(16.0),
                                child: Column(
                                  crossAxisAlignment: CrossAxisAlignment.start,
                                  children: [
                                    Text(
                                      _selectedOption == _questions[_currentQuestionIndex].answer
                                          ? i18n.t('correct')
                                          : i18n.t('incorrect'),
                                      style: const TextStyle(
                                        fontSize: 18,
                                        fontWeight: FontWeight.bold,
                                        color: Colors.white,
                                      ),
                                    ),
                                    const SizedBox(height: 8),
                                    Text(
                                      _questions[_currentQuestionIndex].explanation,
                                      style: TextStyle(fontSize: 16, color: Colors.white.withOpacity(0.9)),
                                    ),
                                  ],
                                ),
                              ),
                            ),
                          ],
                          const SizedBox(height: 24),
                          ElevatedButton.icon(
                            onPressed: _showAnswerFeedback ? _handleNextQuestion : null,
                            icon: Icon(_currentQuestionIndex < _questions.length - 1 ? Icons.arrow_forward : Icons.bar_chart),
                            label: Text(
                              _currentQuestionIndex < _questions.length - 1
                                  ? i18n.t('next_question')
                                  : i18n.t('view_results'),
                            ),
                            style: ElevatedButton.styleFrom(
                              backgroundColor: Colors.blue[500],
                              foregroundColor: Colors.white,
                              padding: const EdgeInsets.symmetric(vertical: 16),
                              shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                              elevation: 8,
                              shadowColor: Colors.blue[300]?.withOpacity(0.5),
                            ),
                          ),
                        ],
                      )
                    else if (_quizFinished)
                      Column(
                        children: [
                          Icon(Icons.emoji_events, size: 80, color: Colors.amber[600]),
                          const SizedBox(height: 16),
                          Text(
                            'Quiz Diário Concluído!',
                            style: TextStyle(fontSize: 22, fontWeight: FontWeight.bold, color: Colors.white),
                            textAlign: TextAlign.center,
                          ),
                          const SizedBox(height: 10),
                          Text(
                            'Você acertou ${_score} de ${_questions.length} perguntas!',
                            style: TextStyle(fontSize: 20, color: Colors.teal[300], fontWeight: FontWeight.bold),
                            textAlign: TextAlign.center,
                          ),
                          const SizedBox(height: 24),
                          ElevatedButton.icon(
                            onPressed: () {
                              Navigator.of(context).pop();
                            },
                            icon: const Icon(Icons.arrow_back),
                            label: const Text('Voltar para o Quiz Normal'),
                            style: ElevatedButton.styleFrom(
                              backgroundColor: Colors.teal[500],
                              foregroundColor: Colors.white,
                              padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 30),
                              shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                              elevation: 8,
                            ),
                          ),
                        ],
                      ),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}