Mathlearn/src/QuizController.java

import java.util.*;

public class QuizController {
    private QuestionGenerator questionGenerator;
    private List<Question> currentQuiz;
    private int currentQuestionIndex;
    private int score;
    private Map<Integer, Integer> userAnswers;

    public static class Question {
        private int id;
        private String content;
        private String[] options;
        private int correctAnswer;
        private String difficulty;

        public Question(int id, String content, String[] options, int correctAnswer, String difficulty) {
            this.id = id;
            this.content = content;
            this.options = options;
            this.correctAnswer = correctAnswer;
            this.difficulty = difficulty;
        }

        public int getId() { return id; }
        public String getContent() { return content; }
        public String[] getOptions() { return options; }
        public int getCorrectAnswer() { return correctAnswer; }
        public String getDifficulty() { return difficulty; }

        public boolean checkAnswer(int userAnswer) {
            return userAnswer == correctAnswer;
        }
    }

    public QuizController() {
        this.questionGenerator = new QuestionGenerator();
        this.userAnswers = new HashMap<>();
    }

    public void startNewQuiz(String difficulty, int questionCount) {
        this.currentQuiz = questionGenerator.generateQuestionSet(questionCount, difficulty);
        this.currentQuestionIndex = 0;
        this.score = 0;
        this.userAnswers.clear();
    }

    public Question getCurrentQuestion() {
        if (currentQuiz == null || currentQuestionIndex >= currentQuiz.size()) {
            return null;
        }
        return currentQuiz.get(currentQuestionIndex);
    }

    public boolean submitAnswer(int answer) {
        if (currentQuiz == null || currentQuestionIndex >= currentQuiz.size()) {
            return false;
        }

        Question current = currentQuiz.get(currentQuestionIndex);
        userAnswers.put(currentQuestionIndex, answer);

        if (current.checkAnswer(answer)) {
            score++;
        }

        return true;
    }

    public boolean nextQuestion() {
        if (currentQuiz == null || currentQuestionIndex >= currentQuiz.size() - 1) {
            return false;
        }
        currentQuestionIndex++;
        return true;
    }

    public boolean hasNextQuestion() {
        return currentQuiz != null && currentQuestionIndex < currentQuiz.size() - 1;
    }

    public int getCurrentQuestionNumber() {
        return currentQuestionIndex + 1;
    }

    public int getTotalQuestions() {
        return currentQuiz != null ? currentQuiz.size() : 0;
    }

    public int getScore() {
        return score;
    }

    public double getPercentage() {
        return currentQuiz != null ? (double) score / currentQuiz.size() * 100 : 0;
    }
}