Untitled

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Scanner;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class QuizSystem {
    private static final String USERS_FILE_PATH = "users.json";
    private static final String QUESTIONS_FILE_PATH = "quiz.json";

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        JSONParser parser = new JSONParser();
        Scanner scanner = new Scanner(System.in);

        List<JSONObject> users = new ArrayList<>();
        List<JSONObject> questions = new ArrayList<>();

        try {
            // Load users from JSON file
            JSONArray usersArray = (JSONArray) parser.parse(new FileReader(USERS_FILE_PATH));
            for (Object obj : usersArray) {
                users.add((JSONObject) obj);
            }

            // Load questions from JSON file
            JSONArray questionsArray = (JSONArray) parser.parse(new FileReader(QUESTIONS_FILE_PATH));
            for (Object obj : questionsArray) {
                questions.add((JSONObject) obj);
            }
        } catch (IOException | ParseException e) {
            e.printStackTrace();
            return;
        }

        while (true) {
            System.out.println("System:> Enter your username");
            String username = scanner.nextLine();
            System.out.println("System:> Enter password");
            String password = scanner.nextLine();

            JSONObject user = null;
            for (JSONObject u : users) {
                if (u.get("username").equals(username) && u.get("password").equals(password)) {
                    user = u;
                    break;
                }
            }

            if (user != null) {
                System.out.println("System:> Welcome " + user.get("username") + "!");

                if (user.get("role").equals("admin")) {
                    System.out.println("System:> Please create new questions in the question bank.");
                    while (true) {
                        JSONObject question = addQuestion(scanner);
                        questions.add(question);
                        saveQuestions(questions);
                        System.out.println("System:> Saved successfully! Do you want to add more questions? (press 's' for start and 'q' for quit)");
                        String choice = scanner.nextLine();
                        if (choice.equalsIgnoreCase("q")) {
                            break;
                        }
                    }
                } else if (user.get("role").equals("student")) {
                    System.out.println("System:> Welcome to the quiz! We will throw you 10 questions. Each MCQ mark is 1 and no negative marking. Are you ready? Press 's' for start.");
                    String choice = scanner.nextLine();
                    if (choice.equalsIgnoreCase("s")) {
                        generateQuiz(questions, scanner);
                        System.out.println("Would you like to start again? Press 's' for start or 'q' for quit");
                        choice = scanner.nextLine();
                        if (choice.equalsIgnoreCase("q")) {
                            break;
                        }
                    } else {
                        System.out.println("Invalid choice. Exiting...");
                        break;
                    }
                }
            } else {
                System.out.println("Invalid username or password. Please try again.");
            }
        }

        scanner.close();
    }

    @SuppressWarnings("unchecked")
    private static JSONObject addQuestion(Scanner scanner) {
        JSONObject question = new JSONObject();

        System.out.println("System:> Input your question");
        question.put("question", scanner.nextLine());

        for (int i = 1; i <= 4; i++) {
            System.out.println("System:> Input option " + i + ": Admin:>");
            question.put("option " + i, scanner.nextLine());
        }

        System.out.println("System:> What is the answer key? Admin:>");
        question.put("answerkey", Integer.parseInt(scanner.nextLine()));

        return question;
    }

    private static void saveQuestions(List<JSONObject> questions) {
        try (FileWriter file = new FileWriter(QUESTIONS_FILE_PATH)) {
            JSONArray jsonArray = new JSONArray();
            jsonArray.addAll(questions);
            file.write(jsonArray.toJSONString());
            file.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void generateQuiz(List<JSONObject> questions, Scanner scanner) {
        Random random = new Random();
        int score = 0;

        for (int i = 0; i < 10; i++) {
            JSONObject question = questions.get(random.nextInt(questions.size()));
            System.out.println("\n[Question " + (i + 1) + "] " + question.get("question"));
            for (int j = 1; j <= 4; j++) {
                System.out.println(j + ". " + question.get("option " + j));
            }
            int answer = 0;
            try {
                answer = Integer.parseInt(scanner.nextLine());
            } catch (NumberFormatException e) {
                System.out.println("Invalid input! 0 mark awarded for this question.");
            }
            if (answer == (long) question.get("answerkey")) {
                score++;
            }
        }

        System.out.println("\nQuiz complete! Score: " + score + " out of 10.");
        if (score >= 8) {
            System.out.println("Excellent!");
        } else if (score >= 5) {
            System.out.println("Good.");
        } else if (score >= 2) {
            System.out.println("Very poor!");
        } else {
            System.out.println("Very sorry, you have failed.");
        }
    }
}