Untitled

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    public User findByEmail(String email) {
        return userRepository.findByEmail(email);
    }

    public List<User> findAll() {
        return userRepository.findAll();
    }

    public User save(User user) {
        return userRepository.save(user);
    }

    public void delete(Long id) {
        userRepository.deleteById(id);
    }

    public ExamResult takeExam(User user, int level) {
        // Check if the user has already passed this level
        if (user.getPassedLevels() >= level) {
            throw new IllegalArgumentException("User has already passed this level.");
        }

        // Load questions for the given level
        List<Question> questions = loadQuestionsForLevel(level);

        // Create a new exam session
        ExamSession examSession = new ExamSession(user, level, questions);

        // Start the exam session
        ExamResult examResult = examSession.start();

        // Check if the user passed the exam
        if (examResult.getScore() >= getMinimumPassingScore(level)) {
            // Update the user's passed levels
            user.setPassedLevels(level);
            userRepository.save(user);

            // Generate and return a report card
            return generateReportCard(user, examResult);
        } else {
            // User failed the exam, log them out and return the result
            user.setLoggedIn(false);
            userRepository.save(user);
            return examResult;
        }
    }

    private List<Question> loadQuestionsForLevel(int level) {
        // Load questions from the database or a file
        // ...
    }

    private int getMinimumPassingScore(int level) {
        // Load the minimum passing score for the given level from the database or a configuration file
        // ...
    }

    private ExamResult generateReportCard(User user, ExamResult examResult) {
        // Create a new report card and save it to the database
        ReportCard reportCard = new ReportCard(user, examResult);
        // ...

        // Return the report card
        return examResult;
    }
}