math_question/src/services/QuestionGenerator.java

package services;

import interfaces.QuestionInterface;
import models.DifficultyLevel;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;

public class QuestionGenerator {
    private Random random;
    private FileManager fileManager;

    public QuestionGenerator() {
        random = new Random();
        fileManager = new FileManager();
    }

    public String[] generateQuestions(DifficultyLevel level, int count, String username) {
        Set<String> existingQuestions = fileManager.loadExistingQuestions(username);
        Set<String> newQuestions = new HashSet<>();
        String[] questions = new String[count];

        for (int i = 0; i < count; i++) {
            QuestionInterface question;
            int attempts = 0;

            do {
                question = new MathQuestion(level);
                attempts++;
                if (attempts > 100) {
                    return null;
                }
            } while (existingQuestions.contains(question.getQuestionText()) ||
                    newQuestions.contains(question.getQuestionText()) ||
                    !question.isValid());

            newQuestions.add(question.getQuestionText());
            questions[i] = (i + 1) + ". " + question.getQuestionText();
        }

        return questions;
    }
}