QuizApplication.java

import java.util.*;
import java.io.*;
public class QuizApplication {
    static Scanner input = new Scanner(System.in);
    static boolean isUserLogin = false;
    static boolean isAdminLogin = false;
    static int age;
    static String currentUser ;
    public static boolean isStrong(String password){
        if (password.length() < 8){
            return false;
        }
        boolean hasDigit = false;
        boolean hasUpper = false;
        boolean hasLetter = false;
        boolean hasSpecial = false;

        //loop for checking the password
        for(int i = 0 ; i < password.length() ; i++ ){
            //storing character of password to check
            char character = password.charAt(i);
            if(Character.isDigit(character)){
                hasDigit = true;
            }
            if(Character.isLetter(character)){
                hasLetter = true;
            }
            if(Character.isUpperCase(character)){
                hasUpper = true;
            }
            if (!(Character.isDigit(character) && Character.isLetter(character))) {
                hasSpecial = true;
            }
        }
        return hasDigit && hasLetter && hasSpecial && hasUpper;
    }
    public static boolean duplicateUsers(String userName , String password){

        //opening the registration file
        File file = new File("registrations.txt");
        try{
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();
                String[] registrationDetails = line.trim().split("\\|");

                if(userName.equals(registrationDetails[0]) &&
                        password.equals(registrationDetails[1])){
                    return true;
                }
            }
            reader.close();
        }
        catch (FileNotFoundException e){
            System.out.println("File Does Not Exists!");
        }
        return false;
    }
    public static boolean duplicateUsers(String userName ){

        //opening the registration file
        File file = new File("registrations.txt");
        try{
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();
                String[] registrationDetails = line.trim().split("\\|");

                if(userName.equals(registrationDetails[0])){
                    return true;
                }
            }
            reader.close();
        }
        catch (FileNotFoundException e){
            System.out.println("File Does Not Exists!");
        }
        return false;
    }
    public static void registerUser() throws InputMismatchException{
        String userName;
        String password;


        while (true) {
            //prompting user to enter user-name & password
            System.out.print("Enter Your Name: ");
            userName = input.nextLine();

            //checking if user-name already taken
            if(duplicateUsers(userName)){
                System.out.println("User Name Already Taken");
                System.out.println("Kindly Use Another User-Name");
                continue;
            }
            while (true) {
                try {
                    System.out.print("Enter Your Age: ");
                    age = input.nextInt();
                    break;
                } catch (InputMismatchException e) {
                    System.out.println("Only Integers are Accepted....Try Again");
                    input.nextLine();
                }
            }

            //validating age
            if( age < 15){
                return;
            }
            //clearing buffer
            input.nextLine();
            System.out.print("Enter a strong Password: ");
            password = input.nextLine();
            //checking if user already exists
            if(duplicateUsers(userName,password)){
                System.out.println("User Already Exists Kindly Login");
                return;
            }

            if (!isStrong(password)) {
                System.out.println("Weak Password! .... Kindly Enter a Strong Password");
            }
            else {
                //if password is strong then exit the loop
                System.out.println("***** Registered Successfully *******");
                break;
            }
        }
        try {
            // opening file for storing registration records
            FileWriter writer = new FileWriter("registrations.txt", true);
            writer.write(userName + "|" + password + "|" + age +  "\n");
            //closing writer
            writer.close();
        }catch (FileNotFoundException e){
            System.out.println("File Does Not Exist");
        }
        catch (IOException e){
            System.out.println("Error While Writing to the file");
        }
    }
    public static void loginUser() {
        int attempts = 3;
        while (true) {
            System.out.print("Enter Name: ");
            String userName = input.nextLine();

            while (true) {
                try {
                    System.out.print("Enter Your Age: ");
                    age = input.nextInt();
                    break;
                } catch (InputMismatchException e) {
                    System.out.println("Only Integers are Accepted....Try Again");
                    input.nextLine();
                }
            }

            //clearing buffer
            input.nextLine();
            System.out.print("Enter Your Password: ");
            String password = input.nextLine();

            File file = new File("registrations.txt");

            try  {
                Scanner reader = new Scanner(file);
                while (reader.hasNext()) {
                    String line = reader.nextLine();
                    String[] details = line.trim().split("\\|");
                    //storing age in registration file in a variable so to verify
                    int registeredAge = Integer.parseInt(details[2]);
                    if (userName.equals(details[0]) && password.equals(details[1]) &&
                            age == registeredAge) {
                        currentUser = userName;
                        isUserLogin = true;
                        break;
                    }
                }
            } catch (FileNotFoundException e) {
                System.out.println("File not found.");
            }
            attempts --;
            if(attempts == 0){
                System.out.println("-------------------------------------");
                System.out.println("|    Better Luck Next Time!!         |");
                System.out.println("| You Have Wasted All Your Attempts  |");
                System.out.println("-------------------------------------");

                break;
            }
            if (isUserLogin) {
                System.out.println("******** User Login Successful ********");
                break;
            } else {
                System.out.println("Invalid Credentials. Try Again!");
                System.out.println("Attempts left: " + attempts);

            }
        }
    }
    public static void loginAdmin() {
        int attempts = 3;

        do{
            System.out.print("Enter Name: ");
            String userName = input.nextLine();
            System.out.print("Enter Your Password: ");
            String password = input.nextLine();

            //opening the registration file to read data so to verify login
            File file = new File("adminlogin.txt");
            try {
                Scanner reader = new Scanner(file);
                while (reader.hasNext()) {
                    //storing line from the file in a variable
                    String line = reader.nextLine();
                    String[] details = line.trim().split("\\|");

                    //checking if the login details matches
                    if (userName.equals(details[0]) && password.equals(details[1])) {
                        isAdminLogin = true;
                    }
                }
                reader.close();
            } catch (FileNotFoundException e) {
                System.out.println("Can not Find the File");
            }
            if (isAdminLogin) {
                System.out.println("********    Admin Login Successfully     ********");

                //getting out of loop if login successfully
                break;
            }

            else {
                System.out.println("Invalid Credentials  ....... Try Again!");
                System.out.println("You Have " +(attempts - 1) + ((attempts > 2)?" attempts":" attempt") + " left");
            }
            attempts --;
        }while (attempts != 0 );
    }
    public static void showUserQuizMenu() {
        System.out.println("=======================================");
        System.out.println("|  Welcome to User Quiz Section       |");
        System.out.println("=======================================");
        System.out.println("|  1: Take Quiz                       |");
        System.out.println("|  2: View Results                    |");
        System.out.println("|  3: Exit                            |");
        System.out.println("========================================");

        //variable that will store user selected option
        int userMenuOption;

        while (true) {
            try {
                System.out.print("Kindly Select an Option from the User-Menu: ");
                userMenuOption = input.nextInt();

                if (userMenuOption < 1 || userMenuOption > 3){
                    System.out.println("Invalid Option....Try Again");
                    continue;
                }
                //getting out of loop when valid input received
                break;
            } catch (InputMismatchException e) {
                System.out.println("Only Integers are Allowed! .... Try Again");
                input.nextLine();
            }
        }
        //checking what user selected from the MENU
        switch (userMenuOption) {

            case 1 -> startQuiz();

            case 2 -> viewResults();

            case 3 -> {
                System.out.println("Logging Out......");
            }
        }
    }
    public static void showAdminQuizMenu() {

        System.out.println("=======================================");
        System.out.println("|  Welcome to Admin Quiz Section      |");
        System.out.println("=======================================");
        System.out.println("|  1: Add Quiz                        |");
        System.out.println("|  2: View All Results                |");
        System.out.println("|  3: Edit Quiz                       |");
        System.out.println("|  4: Delete Quiz                     |");
        System.out.println("|  5: Exit                            |");
        System.out.println("=======================================");

        int adminChoice = 0;

        while (true) {
            try {
                System.out.print("Kindly Select an option from the MENU: ");
                adminChoice = input.nextInt();
                if(adminChoice < 1 || adminChoice > 5){
                    System.out.println("Invalid Choice.... Try Again");
                    continue;
                }
                //clearing buffer
                input.nextLine();
                //getting out of loop if correct input is provided
                break;
            } catch (InputMismatchException e) {
                System.out.println("Only Integers are Accepted.....Try Again");
                input.nextLine();
            }
        }
        switch (adminChoice) {
            case 1 -> addQuiz();

            case 2 -> viewAllResults();

            case 3 -> editQuiz();

            case 4 -> deleteQuiz();

            case 5 -> {
                System.out.println("Logging Out....");
                isAdminLogin = false;
            }
        }
    }
    public static void subjects(){
        File file = new File("Subjects.txt");
        try{
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();
                System.out.println(line);
            }
        }catch (FileNotFoundException e){
            System.out.println("File Does Not Exists");
        }
    }
    public static void startQuiz() {
        char userWants;
        //checking what difficulty level is selected by the user
        String difficulty = difficultyLevel().toUpperCase();

        //setting timer for the quiz based on the difficulty
        int totalTimeInSeconds = switch (difficulty.toUpperCase()){
            //setting quiz time 2.5 minutes if user selected easy
            case "EASY" -> 150;
            //setting quiz time 5 minutes if user selected medium
            case "MEDIUM" -> 5 * 60;
            //setting quiz time 10 minutes if user selected hard
            case "HARD" -> 10 * 60;
            //setting timer randomly between 1 - 10
            case "SURPRISE" -> (int)(1 + Math.random() * 10 ) * 60;
            default -> 300;
        };

        if(difficulty.equals("SURPRISE")){
            takeQuiz("SurpriseQuiz.txt","SurpriseKey.txt",currentUser,totalTimeInSeconds);
            System.out.print("Want to Go Back to Menu (Y/N)?");
            userWants = input.next().toUpperCase().charAt(0);
            if(userWants == 'Y'){
                showUserQuizMenu();
                return;
            }
            else {
                System.out.println("Logging Out.....");
                return;
            }
        }

        // if user selects surprise then quiz menu will not be shown to the user
        System.out.println("===========   QUIZ MENU    =============");
        subjects();
        System.out.println("=========================================");

        //variable that will store what user selected from the QUIZ-MENU
        String subjectName;
        input.nextLine();
        System.out.print("Enter the Subject Name to Attempt Quiz: ");
        subjectName = input.nextLine();

        String questionFile = subjectName + difficulty + "Quiz.txt";
        String keyFile = subjectName + difficulty + "Key.txt";

        takeQuiz(questionFile,keyFile,currentUser,totalTimeInSeconds);

        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                    "press any other key to exit");
        userWants = input.next().toUpperCase().charAt(0);
        if (userWants != 'Y') {
            System.out.println("Logging Out........");
        }
        else {
            showUserQuizMenu();
        }
    }
    //method to get total question that will help in compiling the result
    public static int lineCounter(String File){
        int counter = 0;
        File file = new File(File);
        try{
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();
                counter ++;
            }
            reader.close();
        }catch (FileNotFoundException e){
            System.out.println("File Does Not Exists");
        }
        return counter;
    }
    public static void takeQuiz(String questionFile , String key,String userName, int totalTimeInSeconds) {
        int score = 0;
        //getting how many total questions are there in the file
        int questions = lineCounter(questionFile);

        File file = new File(questionFile);
        File file2 = new File(key);

        try {
            //for writing results in user file
            FileWriter writer = new FileWriter(userName + ".txt", true);

            //for writing result in a file accessible by admin
            FileWriter resultWriter = new FileWriter("AllResults.txt",true);
            // for reading questions
            Scanner reader = new Scanner(file);
            // for reading key
            Scanner keyReader = new Scanner(file2);

            // Start timer
            long startTime = System.currentTimeMillis();
            long lastMinuteUpdate = 0;

            //giving user message that how much time user have to attempt the quiz
            System.out.println("=======================  NOTE!    =======================");
            System.out.println("| You Have " + (totalTimeInSeconds/60) + " minutes and "
                    + (totalTimeInSeconds % 60) + " seconds to complete the Quiz |");
            System.out.println("==========================================================");
            while (reader.hasNext() && keyReader.hasNext()) {

                //checking how much time has passed
                long elapsedTime = (System.currentTimeMillis() - startTime) / 1000;
                //checking how much time is left
                long timeLeft = totalTimeInSeconds - elapsedTime;

                if (timeLeft <= 0) {
                    System.out.println("\n Time's up! Quiz ended automatically.");
                    break;
                }

                // Showing user how much time is left for completing the quiz
                if (elapsedTime - lastMinuteUpdate >= 30) {
                    System.out.println(" Time Left: " + (timeLeft / 60) + " minutes " + (timeLeft % 60) + " seconds");
                    lastMinuteUpdate = elapsedTime;
                }

                String line = reader.nextLine();
                String[] mcq = line.trim().split("\\$");

                char correctAnswer = keyReader.next().charAt(0);

                for (String question : mcq) {
                    System.out.println(question);
                }
                char userAnswer;
                while (true) {
                    System.out.print("Enter Your Answer: ");
                    userAnswer = input.next().toUpperCase().charAt(0);
                    if(userAnswer != 'A' && userAnswer != 'B'
                            && userAnswer != 'C'&& userAnswer != 'D'){
                        System.out.println("Select option(A,B,C or D)");
                    }
                    else {
                        //clearing buffer
                        input.nextLine();
                        break;
                    }

                }

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

            System.out.println("You Scored " + score + " out of " + questions);

            //writing data in user results file
            writer.write(userName + " Scored " + score + " out of " + questions + " in "
                    + questionFile.substring(0, questionFile.indexOf(".")) + "\n");

            //writing data in allResults file
            resultWriter.write(userName  + " scored " + score + "/"
                    + lineCounter(questionFile) + " in " + questionFile.substring(0,questionFile.indexOf("Q")) + "\n" );

            writer.close();
            reader.close();
            keyReader.close();
            resultWriter.close();
        } catch (FileNotFoundException e) {
            System.out.println("File Not Found Exception");
        } catch (IOException e) {
            System.out.println("Error while reading/writing the file");
        }
    }
    public static void viewResults() {
        char userWants;
        //opening the file in which result is stores
        File file = new File(currentUser + ".txt");
        if(!(file.exists())){
            System.out.println("There is no Previous Record of " + currentUser);
            System.out.println("*THANKS!*");

            System.out.print("Do You Want to go back to USER-MENU(Y/N)? : ");
            userWants = input.next().toUpperCase().charAt(0);
            if(userWants != 'Y'){
                System.out.println("Logging Out..........");
                isUserLogin = false;
            }
            else {
                showUserQuizMenu();
            }
            return;
        }
        try{
            //creating scanner object to read from the file
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();
                System.out.println(line);
            }
            reader.close();
        }
        catch (FileNotFoundException e){
            System.out.println("File Does Not Exist!");
        }
        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                "press any other key to exit");
        userWants = input.next().toUpperCase().charAt(0);
        if (userWants != 'Y') {
            System.out.println("Logging Out........");
            isUserLogin = false;
        }
        else {
            showUserQuizMenu();
        }
    }
    public static void viewAllResults(){
        File file = new File("AllResults.txt");
        try{
            Scanner reader = new Scanner(file);
            while (reader.hasNext()){
                String line = reader.nextLine();

                System.out.println(line);
            }
        }catch (IOException e){
            System.out.println("Error While Reading data from the file");
        }

        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                "press any other key to exit");
        char adminWants = input.next().toUpperCase().charAt(0);
        if (adminWants != 'Y') {
            System.out.println("Logging Out........");
            isAdminLogin = false;
        }
    }
    public static void addQuiz() {
        System.out.print("Enter the Subject Name to Add: ");
        String subjectName = input.nextLine();

        //Now allowing admin to select the difficulty
        System.out.println("=================================");
        System.out.println("| 1: EASY                        |");
        System.out.println("| 2: MEDIUM                      |");
        System.out.println("| 3: HARD                        |");
        System.out.println("==================================");
        int difficultyOption;
        while (true){
            try{
                System.out.printf("Select a Difficulty Level for %s",subjectName);
                difficultyOption = input.nextInt();
                if(difficultyOption <1 || difficultyOption>3){
                    System.out.println("Kindly Select a Valid Option");
                }
                else {
                    break;
                }
            }catch (InputMismatchException e){
                System.out.println("Only Integers Are Accepted.....Try Again");
            }
        }
        String difficulty = "";
        switch (difficultyOption){
            case 1 -> difficulty = "EASY";
            case 2 -> difficulty = "MEDIUM";
            case 3 -> difficulty = "HARD";
        }

        int lineNumber = lineCounter("Subjects.txt");

        //creating files
        File file1 = new File(subjectName + difficulty + "Quiz.txt");
        File file2 = new File(subjectName + difficulty + "Key.txt");

        try {
            //creating file writer Object to append data
            FileWriter writer = new FileWriter("Subjects.txt",true);
            
            //creating Print Writer so we can format data in a specific way
            PrintWriter writer1 = new PrintWriter(writer);
            
            //counting line number in subject file
            lineNumber ++;
            
            writer1.printf("|  %d: %-34s|\n",lineNumber,subjectName);

            System.out.println(subjectName + " Added to the Subjects Successfully!");
            if(file1.createNewFile()){
                System.out.println( "Quiz File " + file1.getName() + " Created Successfully");
            }
            else {
                System.out.println("Quiz File " + file1.getName() + " Already Exists");
            }
            if(file2.createNewFile()){
                System.out.println("Key File " + file2.getName() + " Created Successfully");
            }
            else {
                System.out.println("Key File " + file1.getName() + " Already Exists");
            }
            writer.close();
            writer1.close();
        }catch (FileNotFoundException e){
            System.out.println("File Does Not exists");
        }
        catch (IOException e){
            System.out.println("Error Occurred Writing or creating the files");
        }

        char adminWants;
        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                "press any other key to exit");
        adminWants = input.next().toUpperCase().charAt(0);
        if (adminWants != 'Y') {
            System.out.println("Logging Out........");
            isAdminLogin = false;
        }
    }
    public static void deleteQuiz(){
        System.out.print("Enter the Subject Name to Delete: ");
        String subjectName = input.nextLine();

        //Now allowing admin to select the difficulty
        System.out.println("=================================");
        System.out.println("| 1: EASY                        |");
        System.out.println("| 2: MEDIUM                      |");
        System.out.println("| 3: HARD                        |");
        System.out.println("==================================");
        int difficultyOption;
        while (true){
            try{
                System.out.printf("Select a Difficulty Level for: %s\n",subjectName);
                difficultyOption = input.nextInt();
                if(difficultyOption <1 || difficultyOption>3){
                    System.out.print("Kindly Select a Valid Option: ");
                }
                else {
                    break;
                }
            }catch (InputMismatchException e){
                System.out.println("Only Integers Are Accepted.....Try Again");
            }
        }
        String difficulty = "";
        switch (difficultyOption){
            case 1 -> difficulty = "EASY";
            case 2 -> difficulty = "MEDIUM";
            case 3 -> difficulty = "HARD";
        }
        String quizFile = subjectName + difficulty + "Quiz.txt";
        String keyFile = subjectName + difficulty + "Key.txt";

        File file1 = new File(quizFile);
        File file2 = new File(keyFile);

        if(file1.delete() && file2.delete()){
            System.out.println("All the files of " + subjectName + " deleted Successfully!");
        }

        //now logic for updating the subjects file
        File subjects = new File("Subjects.txt");
        File tempFile = new File("temp.txt");
        
        try{
            tempFile.createNewFile();
            Scanner reader = new Scanner(subjects);
            PrintWriter writer = new PrintWriter(tempFile);

            while (reader.hasNext()) {
                String line = reader.nextLine();
                if (!line.contains(subjectName)) {
                    writer.println(line);
                }
            }
            reader.close();
            writer.close();
        }catch (IOException e){
            System.out.println("Error while reading or writing to the file");
        }

        //now deleting the subject file & renaming temp file with subject file
        if(subjects.delete() && tempFile.renameTo(subjects)){
            System.out.println(subjectName + " Subject removed from the Subject File Successfully");
        }
        else {
            System.out.println("Error while updating the subjects file");
        }

        char adminWants;
        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                "press any other key to exit");
        adminWants = input.next().toUpperCase().charAt(0);
        if (adminWants != 'Y') {
            System.out.println("Logging Out........");
            isAdminLogin = false;
        }
    }
    public static void editQuiz() {
        char wantToAddQuestion;
        System.out.println("===========   EDIT QUIZ   ==============");
        System.out.println("----------------------------------------");
        System.out.println("|              SUBJECTS                 |");
        System.out.println("----------------------------------------");
        subjects();
        System.out.println("=========================================");

        System.out.print("Enter Subject Name to Edit Quiz: ");
        String quizSelection = input.nextLine();

        // Prompt admin to select a subject to edit
        System.out.println("=================================");
        System.out.println("| 1: Easy                        |");
        System.out.println("| 2: Medium                      |");
        System.out.println("| 3: Hard                        |");
        System.out.println("==================================");


        int difficultyOption;
        // Prompt admin to select difficulty level for editing quiz
        while (true){
            try{
                System.out.print("Select a difficulty: ");
                difficultyOption = input.nextInt();
                if(difficultyOption <1 || difficultyOption>3){
                    System.out.println("Kindly Select a Valid Option");
                }
                else {
                    break;
                }
            }catch (InputMismatchException e){
                System.out.println("Only Integers Are Accepted.....Try Again");
            }
        }
        String difficulty = "";
        switch (difficultyOption){
            case 1 -> difficulty = "Easy";
            case 2 -> difficulty = "Medium";
            case 3 -> difficulty = "Hard";
        }

        String subjectName = quizSelection + difficulty;

        try{
            //creating file writer object to edit the  question file
            FileWriter questionWriter = new FileWriter(subjectName + "Quiz.txt", true);
            FileWriter keyWriter = new FileWriter(subjectName + "Key.txt",true);
            do {
                //prompting admin to enter the question to add
                System.out.println("Enter the Questions that you want to add along with the options: ");
                input.nextLine(); // consume leftover newline
                String question = input.nextLine();
                //storing questions in the file
                questionWriter.write(question + "\n");
                //prompting admin to enter the key for the asked question
                System.out.print("Now Enter the Key: ");
                char key = input.next().toUpperCase().charAt(0);
                //clearing buffer
                input.nextLine();
                //storing answer in the key file
                keyWriter.write(key + "\n");

                //asking admin if want to add more question , otherwise exit from loop
                System.out.println("Do You want to Add More Questions?(Y/N): ");
                wantToAddQuestion = input.next().toUpperCase().charAt(0);
            } while (wantToAddQuestion == 'Y');
            //closing resources
            System.out.println("Questions Added Successfully!");
            questionWriter.close();
            keyWriter.close();
        }
        catch (FileNotFoundException e){
            System.out.println("File Does Not exits");
        }
        catch (IOException e){
            System.out.println("Error while Writing to the file");
        }
        char adminWants;
        System.out.println("Do You Want to Go to back to MENU then press Y otherwise " +
                "press any other key to exit");
        adminWants = input.next().toUpperCase().charAt(0);
        if (adminWants != 'Y') {
            System.out.println("Logging Out........");
            isAdminLogin = false;
        }
    }
    public static String difficultyLevel() {
        System.out.println("================================");
        System.out.println("| 1: Easy                        |");
        System.out.println("| 2: Medium                      |");
        System.out.println("| 3: Hard                        |");
        System.out.println("| 4: Surprise Me                 |");
        System.out.println("=================================");

        int optionSelected = 0;
        while (true) {
            try {
                System.out.println("Kindly Select a Difficulty Level: ");
                optionSelected = input.nextInt();
                // getting out of loop if input is valid
                if (optionSelected >= 1 && optionSelected <= 4) {
                    break;
                } else {
                    System.out.println("Kindly Select Option 1, 2, 3, or 4");
                }
            } catch (InputMismatchException e) {
                System.out.println("Only Integers are Accepted....Try Again");
                input.nextLine();  // clear invalid input
            }
        }

        String difficultySelected = "";
        switch (optionSelected) {
            case 1 -> difficultySelected = "Easy";
            case 2 -> difficultySelected = "Medium";
            case 3 -> difficultySelected = "Hard";
            case 4 -> difficultySelected = "Surprise";

        }
        return difficultySelected;
    }

    public static void userLoginMenu(){
        System.out.println("=======================================");
        System.out.println("|  Welcome to User Login Section       |");
        System.out.println("=======================================");
        System.out.println("|  1: Register                         |");
        System.out.println("|  2: Login                            |");
        System.out.println("=======================================");
        //variable that will store user's choice
        int userOption;
        //loop that will run till valid input is not given
        while (true){
            try {
                System.out.print("Kindly Select an Option: ");
                userOption = input.nextInt();
                //clearing buffer
                input.nextLine();
                //getting out of loop if got the desired input
                break;
            }
            catch (InputMismatchException e){
                System.out.println("Only Integers are Accepted...... Try Again");
                input.nextLine();
            }
        }
        //checking which option user selected from the USER-MENU
        switch (userOption) {
            case 1 -> {
                registerUser();
                if(age < 15){
                    input.nextLine();
                    System.out.println("You Can't Take This Quiz");
                    System.out.println("Good Bye!");

                    System.out.print("Press Enter to Exit: ");
                    input.nextLine();
                    return;
                }
                else {
                    System.out.println("***** Kindly Enter Details to Now Login ******");
                    //after registration prompting user to login
                    loginUser();
                }
            }
            case 2 -> {
                loginUser();
            }
        }
        //if user login successfully then show userQuizMenu
        if (isUserLogin) {
            showUserQuizMenu();
        }
    }
    public static void adminLoginMenu(){
        System.out.println("=======================================");
        System.out.println("|  Welcome to Admin Login Section      |");
        System.out.println("=======================================");
        loginAdmin();

        while (isAdminLogin) {
            showAdminQuizMenu();
        }
    }
    public static void main(String[] args) {
        //declaring & initializing variables
        int userChoice;
        //displaying welcome message & prompting user to register or login accordingly
        System.out.println("\n/==================================================\\");
        System.out.println("|                                                  |");
        System.out.println("|    !        <<   Q U I Z   A P P   >>        !   |");
        System.out.println("|    !        =========================        !   |");
        System.out.println("|    !        |      W E L C O M E     |       !   |");
        System.out.println("|    !        =========================        !   |");
        System.out.println("|    !                                         !   |");
        System.out.println("|--------------------------------------------------|");
        System.out.println("|                                                  |");
        System.out.println("|    !        +----------------------+         !   |");
        System.out.println("|    !        |   1. USER            |         !   |");
        System.out.println("|    !        |   2. ADMIN           |         !   |");
        System.out.println("|    !        +----------------------+         !   |");
        System.out.println("|    !                                         !   |");
        System.out.println("\\==================================================/");

        while (true) {
            try{
                System.out.print(">> Select an Option[1-2]: ");
                userChoice = input.nextInt();
                //clearing buffer
                input.nextLine();

                //verifying whether user selected valid option
                if(userChoice != 1 && userChoice != 2){
                    System.out.println("> Invalid Option.... Try Again");
                    continue;
                }
                //if input is valid then getting out of the loop
                break;
            }
            catch (InputMismatchException e){
                System.out.println("> Only Integers are Accepted....... Try Again");
                //clearing buffer
                input.nextLine();
            }
        }

        // checking what user selected
        if (userChoice == 1) {
            userLoginMenu();
        }
        else  {
            adminLoginMenu();
        }
        //closing scanner input
        input.close();
    }
}