import javax.swing.;
import java.awt.;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Random;

public class MathQuizApp extends JFrame {
private static final int QUIZ_TIME = 3 * 60; // 3
private static final int QUESTION_COUNT = 40; // Ŀ
private Random rand = new Random();
private HashMap<String, Integer> questions = new HashMap<>();
private JTextField[] answerFields;
private Timer timer;
private JLabel timerLabel;
private int remainingTime;

public MathQuizApp() {
    setTitle("Math Quiz");
    setLayout(new GridLayout(QUESTION_COUNT + 2, 1)); 
    setSize(400, 800);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    timerLabel = new JLabel("Time left: 3:00", SwingConstants.CENTER);
    timerLabel.setFont(new Font("Arial", Font.BOLD, 30));
    add(timerLabel);
    answerFields = new JTextField[QUESTION_COUNT];

    generateQuestions();
    displayQuestions();

    JButton submitButton = new JButton("Submit");
    submitButton.addActionListener(e -> checkAnswers());
    add(submitButton);

    startQuiz();
    setVisible(true);
}

private void startQuiz() {
    remainingTime = QUIZ_TIME;
    timer = new Timer(1000, e -> {
        remainingTime--;
        timerLabel.setText("    ʱ: " + formatTime(remainingTime));
        if (remainingTime <= 0) endQuiz();
    });
    timer.start();
}

private void generateQuestions() {
    HashSet<String> generatedQuestions = new HashSet<>();

    while (generatedQuestions.size() < QUESTION_COUNT) {
        int num1 = rand.nextInt(51);
        int num2 = rand.nextInt(51);
        char op = "+-*/".charAt(rand.nextInt(4));
        String question = "";

        switch (op) {
            case '+':
                question = String.format("%d + %d =", num1, num2);
                if (generatedQuestions.add(question))
                    questions.put(question, num1 + num2);
                break;
            case '-':
                if (num1 >= num2) {
                    question = String.format("%d - %d =", num1, num2);
                    if (generatedQuestions.add(question))
                        questions.put(question, num1 - num2);
                }
                break;
            case '*':
                if (num1 * num2 < 1000) {
                    question = String.format("%d * %d =", num1, num2);
                    if (generatedQuestions.add(question))
                        questions.put(question, num1 * num2);
                }
                break;
            case '/':
                if (num2 != 0 && (num1 % num2 == 0)) {
                    question = String.format("%d / %d =", num1, num2);
                    if (generatedQuestions.add(question))
                        questions.put(question, num1 / num2);
                }
                break;
        }
    }
}

private void displayQuestions() {
    for (int i = 0; i < QUESTION_COUNT; i++) {
        String question = (String) questions.keySet().toArray()[i];
        answerFields[i] = new JTextField(10);
        answerFields[i].setPreferredSize(new Dimension(60, 25));
        answerFields[i].setHorizontalAlignment(JTextField.CENTER);

        JPanel linePanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        linePanel.add(new JLabel(question + " "));
        linePanel.add(answerFields[i]);

        add(linePanel);
    }
}

private void checkAnswers() {
    int score = 0;
    int wrongCount = 0;

    for (int i = 0; i < QUESTION_COUNT; i++) {
        String question = (String) questions.keySet().toArray()[i];
        int correctAnswer = questions.get(question);

        int userAnswer;
        try {
            userAnswer = Integer.parseInt(answerFields[i].getText());
        } catch (NumberFormatException e) {
            userAnswer = Integer.MIN_VALUE;
        }

        if (userAnswer == correctAnswer) {
            score++;
        } else {
            wrongCount++;
        }
    }

    double accuracy = (double) score / QUESTION_COUNT * 100;
    String resultMessage = String.format("Score: %d/%d\nWrong Count: %d\nAccuracy: %.2f%%",
            score, QUESTION_COUNT, wrongCount, accuracy);
    JOptionPane.showMessageDialog(this, resultMessage);
    System.exit(0);
}

private void endQuiz() {
    timer.stop();
    JOptionPane.showMessageDialog(this, "Time's up! Please submit your answers.");
    checkAnswers();
}

private String formatTime(int seconds) {
    int minutes = seconds / 60;
    int secs = seconds % 60;
    return String.format("%02d:%02d", minutes, secs);
}

public static void main(String[] args) {
    SwingUtilities.invokeLater(MathQuizApp::new);
}

}