utility class· schoolcourseenrolmentsystem

Helpers.java

Helpers is a static utility class. It owns the single Scanner, the generic login, the validators, the three menus and the console flows that collect input before calling the entity classes.

public class Helpers

Student session Instructor session Admin session

Type: All static members
Scanner: One shared Scanner on System.in
Generic login: <T extends User<T>> T login(...)
Validators: Predicate<String>-friendly booleans

Responsibilities#

Safe integer input that never crashes on bad text
Validate names, passwords, emails, phone numbers and addresses
One login flow for all three roles, with three password attempts
Print the role menus
Run the multi-step console flows for each menu option
Generate random 10-digit IDs

Fields & enums#

Type Name Modifiers Line

Scanner input public static final L7

	Type	Name	Modifiers	Line
	`Scanner`	`input`	public static final	L7

2 methods

Login#

<T extends User<T>> T login(List<T> usersList, T tempUser)staticL12
Ask for an ID, warn if it is unknown, then hand over to the password check.
- Works for any User subclass through generics
<T extends User<T>> T validatePasswordWithRetries(List<T> usersList, T tempUser, String tempID)staticL38
Up to three password attempts, calling the subclass's own login.
- After three failures: “Too many failed attempts. Returning to main menu.”

5 methods

Validation#

Each returns true or false so callers can loop until input is valid.

boolean ValidatePassword(String password)staticL62
Longer than 8 characters.
boolean ValidateEmail(String email)staticL75
Contains both “@” and “.”.
boolean ValidatePhoneNumber(String phoneNumber)staticL87
Exactly 10 characters.
boolean ValidateAddress(String address)staticL99
Longer than 3 characters.
Boolean ValidateName(String name)staticL112
Longer than 3 characters.

6 methods

Input & prompts#

int getSafeIntInput(String prompt)staticL148
Prompt until an integer is typed; bad input is cleared and asked again.
User.Role checkValidityOfRole()staticL123
Loop until 1, 2 or 3 is chosen and return STUDENT, INSTRUCTOR or ADMIN.
User.Role updateRolePrompt(User.Role currentRole)staticL167
Ask whether to change the role; keep the current one on “No”.
String updateFieldWithPrompt(String fieldName, String currentValue, Predicate<String> validator)staticL181
Ask “Do you want to change your <field>?” and validate the new value with a Predicate.
- Replaces separate updateEmail/updatePassword/… methods
String createUserWithPrompt(String fieldName, Predicate<String> validator)staticL200
Ask for a required field until the Predicate accepts it.
String GenerateRandomID()staticL213
Build a random 10-digit ID from “0123456789”.

3 methods

Menus#

void showStudentMenu()staticL230
Print the 8-option student menu.
void showInstructorMenu()staticL243
Print the 5-option instructor menu.
void showAdminMenu()staticL253
Print the 14-option administrator menu.

3 methods

Student flows#

void enroll_In_Course_Student(List<Course> listOfCourses, Student student)staticL316
List open, non-full courses the student is not in, then enrol in the chosen one.
void dropCourse(List<Course> listOfCourses, Student student)staticL356
Ask for a course code (case-insensitive) and call Student.dropCourse.
void updateStudentProfile(Student specificStudent)staticL382
Walk through password, email, phone and address updates.

2 methods

Instructor flows#

void updateCourseInfo(Instructor instructor, List<Course> listOfCourses)staticL276
Ask for a course code, schedule and description, then call Instructor.updateCourseInfo.
void updateInstructorProfile(Instructor instructor)staticL295
Walk through password, email, phone and address updates.

9 methods

Admin flows#

void addStudent(Administrator administrator, List<Student> listOfStudents)staticL402
Create a student: validated name, unique random ID, validated contact details, credit limit.
void removeStudent(Administrator administrator, List<Student> listOfStudents)staticL452
Ask for an ID and call Administrator.removeStudent.
void addInstructor(Administrator administrator, List<Instructor> listOfInstructors)staticL478
Create an instructor the same way as a student, without a credit limit.
void removeInstructor(Administrator administrator, List<Instructor> listOfInstructors)staticL466
Ask for an ID and call Administrator.removeInstructor.
void addCourse(Administrator administrator, List<Course> listOfCourses, List<Instructor> listOfInstructors)staticL521
Create a course: name, code, capacity, credit hours, optional instructor, Open or Closed.
void adminUpdateStudentProfile(Administrator administrator, List<Student> listOfStudents)staticL587
Find a student by name and ID, then update fields, role and credit limit.
void adminUpdateInstructorProfile(Administrator administrator, List<Instructor> listOfInstructors)staticL649
Find an instructor by name and ID, then update fields and role.
void assignInstructor(Administrator administrator, List<Course> listOfCourses, List<Instructor> listOfInstructors)staticL698
List courses, pick one by number, then assign an instructor by ID.
void closeCourse(Administrator administrator, List<Course> listOfCourses)staticL741
Find a course by name and code, then call Administrator.closeCourse.

2 methods

Reports#

Not called from main(), which uses the dataManager versions instead.

void viewEnrollmentStatistics(List<Course> listOfCourses)staticL768
Per-course enrolment counts, the total, and whether any course is open.
void generateReports(List<Course> listOfCourses)staticL785
Print the course with the most enrolled students.

Known issues#

Helpers.java806 lines · from the project report

1package schoolcourseenrolmentsystem;

3import java.util.*;
4import java.util.function.Predicate;

6public class Helpers {
  public static final Scanner input = new Scanner(System.in);

  /// <T extends User<T>> This method works with any User (Admin, Instructor,
  /// Student). T inherits from User<T>.
  /// The single T will return a single object of type T.
  public static <T extends User<T>> T login(List<T> usersList, T tempUser) {
      T loggedInUser = null;
      try {
          System.out.print("\nPlease enter your ID: ");
          String id = input.next();
          input.nextLine(); // Buffer

          // Check if the ID exists
          boolean idExists = false;
          for (T user : usersList) {
              if (user.getId().equals(id)) {
                  idExists = true;
                  break;
              }
          }
          if (!idExists) {
              System.out.println("No user found with the entered ID.");
          }
          loggedInUser = validatePasswordWithRetries(usersList, tempUser, id);
          return loggedInUser;
      } catch (Exception e) {

          return loggedInUser;
      }
  }

  public static <T extends User<T>> T validatePasswordWithRetries(List<T> usersList, T tempUser, String tempID) {
      T loggedInUser = null;
      int attempts = 0;
      final int maxAttempts = 3;

      while (attempts < maxAttempts) {
          System.out.print("\nPlease enter your password: ");
          String password = input.nextLine();

          loggedInUser = tempUser.login(usersList, tempID, password);

          if (loggedInUser != null) {
              return loggedInUser;
          } else {
              attempts++;
              if (attempts < maxAttempts) {
                  System.out.println("Incorrect password. Try again (" + (maxAttempts - attempts) + " attempts left).");
              }
          }
      }
      System.out.println("Too many failed attempts. Returning to main menu.");
      return null;
  }

  public static boolean ValidatePassword(String password) {
      boolean isValid = false;
      try {
          if (password != null && password != "" && password.length() > 8) {
              isValid = true;
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }

      return isValid;
  }

  public static boolean ValidateEmail(String email) {
      boolean isValid = false;
      try {
          if (email != null && email != "" && email.contains("@") && email.contains(".")) {
              isValid = true;
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
      return isValid;
  }

  public static boolean ValidatePhoneNumber(String phoneNumber) {
      boolean isValid = false;
      try {
          if (phoneNumber != null && phoneNumber != "" && phoneNumber.length() == 10) {
              isValid = true;
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
      return isValid;
  }

  public static boolean ValidateAddress(String address) {
      boolean isValid = false;
      try {
          if (null != address && address != "" && address.length() > 3) {
              isValid = true;
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
      return isValid;

  }

  public static Boolean ValidateName(String name) {
      boolean isValid = false;
      try {
          if (null != name && name != "" && name.length() > 3) {
              isValid = true;
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
      return isValid;
  }
  public static User.Role checkValidityOfRole() {
      while (true) {
          System.out.println("Select a role: \n1. STUDENT \n2. INSTRUCTOR \n3. ADMIN \nOption:");
          try {
              int Option = Helpers.getSafeIntInput("\nOption: ");

              switch (Option) {
                  case 1:
                      return User.Role.STUDENT;
                  case 2:
                      return User.Role.INSTRUCTOR;
                  case 3:
                      return User.Role.ADMIN;
                  default:
                      System.out.println("Invalid selection. Please enter 1, 2, or 3.");
              }
          } catch (InputMismatchException e) {
              System.out.println("Invalid input. Please enter a number.");
              input.nextLine(); // clear the invalid input
          }
      }
  }

  /// Method created to avoid InputMismatchException

  public static int getSafeIntInput(String prompt) {
      try {
          int number = -1; // -1 is typically related to false or not true. This is a default number.
          boolean valid = false;
          while (!valid) {
              System.out.print(prompt);
              //number = Integer.parseInt(input.nextLine());
              number= input.nextInt();
              input.nextLine();
              valid = true;
          }
          return number;
      } catch (Exception e) {
          System.out.println("Invalid input. Please enter a number.");
          input.nextLine(); // Clear the invalid input
          return getSafeIntInput(prompt); // Retry
      }
  }

  public static User.Role updateRolePrompt(User.Role currentRole) {
      System.out.println("\nDo you want to change the role? \n1.Yes \n2.No");
      int choice = getSafeIntInput("\nOption: ");
      input.nextLine();

      if (choice == 1) {
          return checkValidityOfRole(); // Assuming you already have this
      } else {
          System.out.println("Role remains unchanged.");
          return currentRole;
      }
  }

  // Predicate <> helps us use premade validators.
  public static String updateFieldWithPrompt(String fieldName, String currentValue, Predicate<String> validator) {
      System.out.println("\nDo you want to change your " + fieldName + "? \n1.Yes \n2.No");
      int choice = Helpers.getSafeIntInput("\nOption: ");

      if (choice == 1) {
          System.out.print("\nEnter new " + fieldName + ": ");
          String newValue = input.nextLine();
          while (!validator.test(newValue)) {
              System.out.println("Invalid " + fieldName + ". Please try again.");
              System.out.print("\nEnter new " + fieldName + ": ");
              newValue = input.nextLine();
          }
          return newValue;
      } else {
          System.out.println(fieldName + " remains unchanged.");
          return currentValue;
      }
  }

  public static String createUserWithPrompt(String fieldName, Predicate<String> validator) {
      String inputValue;
      while (true) {
          System.out.print("\nEnter " + fieldName + ": ");
          inputValue = input.nextLine();
          if (!validator.test(inputValue)) { // .test() method is just how you invoke the logic inside the Predicate<>
              System.out.println("Invalid " + fieldName + ". Please try again.");
          } else {
              break;
          }
      }
      return inputValue;
  }
  public static String GenerateRandomID() {
      String numbers = "0123456789";
      int ID_Length = 10;
      Random random = new Random();

      StringBuilder id = new StringBuilder(ID_Length);

      for (int i = 0; i < ID_Length; i++) {

          int randomIndex = random.nextInt(numbers.length());
          char randomChar = numbers.charAt(randomIndex);
          id.append(randomChar);
      }
      return id.toString();
  }

  // MENUS
  public static void showStudentMenu() {
      System.out.println("");
      System.out.println("\n---------Student Menu---------");
      System.out.println("1. View avaliable courses.");
      System.out.println("2. Enroll in course.");
      System.out.println("3. View enrolled courses.");
      System.out.println("4. View credit limit.");
      System.out.println("5. Drop course.");
      System.out.println("6. View grades.");
      System.out.println("7. Update personal information.");
      System.out.println("8. Logout.");
  }

  public static void showInstructorMenu() {
      System.out.println("");
      System.out.println("\n---------Instructor Menu---------");
      System.out.println("1. View enrolled students.");
      System.out.println("2. Grade assignments.");
      System.out.println("3. Update course information.");
      System.out.println("4. Update personal information.");
      System.out.println("5. Logout.");
  }

  public static void showAdminMenu() {
      System.out.println("");
      System.out.println("\n---------Administrator Menu---------");
      System.out.println("1. Add Students.");
      System.out.println("2. Remove Students.");
      System.out.println("3. View student list.");

      System.out.println("4. Add Instructors.");
      System.out.println("5. Remove Instructors.");
      System.out.println("6. View instructor list.");
      System.out.println("7. Add Course.");
      System.out.println("8. Close Course.");
      System.out.println("9. Update Student Info.");
      System.out.println("10. Update Instructor Info.");
      System.out.println("11. Assign Instructor to Course.");
      System.out.println("12. View Enrollment Statistics.");
      System.out.println("13. Generate Reports.");
      System.out.println("14. Logout.");
  }

  // CASES

  // INSTRUCTOR CASES
  public static void updateCourseInfo(Instructor instructor, List<Course> listOfCourses) {
      try {
          System.out.println("\n---------Update Course Information---------\nEnter the course code of the course you
                  would like to update: ");
          String courseCode = input.next();
          input.nextLine(); // Buffer

          System.out.print("\nEnter new schedule:");
          String newSchedule = input.nextLine();

          System.out.print("\nEnter new description: ");
          String newDescription = input.nextLine();

          instructor.updateCourseInfo(courseCode, listOfCourses, newSchedule, newDescription);
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void updateInstructorProfile(Instructor instructor) {
      try {

          System.out.println("\n---------Update Personal Profile---------");
          System.out.println("\nPlease fill out the form to update your profile.");

          String updatedPassword = Helpers.updateFieldWithPrompt("password", instructor.getPassword(),
                  Helpers::ValidatePassword); // Helpers::ValidatePassword is like an inhanced for-each loop
          String updateEmail = Helpers.updateFieldWithPrompt("email", instructor.getEmail(), Helpers::ValidateEmail);
          String updatePhone = Helpers.updateFieldWithPrompt("phone number", instructor.getPhoneNumber(),
                  Helpers::ValidatePhoneNumber);
          String updateAddress = Helpers.updateFieldWithPrompt("address", instructor.getAddress(),
                  Helpers::ValidateAddress);
          instructor.updateInstructorPersonalInfo(updatedPassword, updateEmail, updatePhone, updateAddress);
          System.out.println("Instructor " + instructor.getName() + "'s information updated.");
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  // STUDENT CASES
  public static void enroll_In_Course_Student(List<Course> listOfCourses, Student student) {
      try {
          System.out.println("\n---------Enroll In Course---------");

          // Filter available courses
          List<Course> availableCourses = new ArrayList<>();
          for (Course course : listOfCourses) {
              if (!course.isFull() &&
                      course.getEnrollmentStatus() == Course.EnrollmentStatusEnum.Open &&
                      !student.getEnrolledCoursesList().contains(course)) {
                  availableCourses.add(course);
              }
          }

          // Display results
          if (availableCourses.isEmpty()) {
              System.out.println("No available courses to enroll in.");
          } else {
              System.out.println("Courses available to enroll in:");

              for (int i = 0; i < availableCourses.size(); i++) {
                  Course course = availableCourses.get(i);
                  System.out.printf("%d. %s (%s)\n", (i + 1), course.getCourseName(), course.getCourseCode());
              }
              System.out.print("\nEnter the number of the course you would like to enroll in: ");
              int selectedCourse = input.nextInt();
              input.nextLine(); // Consume newline

              if (selectedCourse >= 1 && selectedCourse <= availableCourses.size()) {
                  Course chosenCourse = availableCourses.get(selectedCourse - 1);
                  student.enroll_In_Course(chosenCourse);
              } else {
                  System.out.println("Invalid selection: " + selectedCourse);
              }
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void dropCourse(List<Course> listOfCourses, Student student) {
      try {
          System.out.println("\n---------Unenroll In Course---------");
          System.out.print("\nEnter course code of the course you would like to drop: ");
          String dropCourseCode = input.next();
          input.nextLine(); // Buffer

          Course courseCodeToDrop = null;

          for (Course course : listOfCourses) {
              if (course.getCourseCode().equalsIgnoreCase(dropCourseCode)) {
                  courseCodeToDrop = course;
                  break;
              }
          }
          if (courseCodeToDrop != null) {
              student.dropCourse(courseCodeToDrop);

          } else {
              System.out.println("No course found with the code" + dropCourseCode + "'.");
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void updateStudentProfile(Student specificStudent) {
      try {
          System.out.println("\n---------Update Personal Profile---------");
          System.out.println("\nPlease enter the needed information to update your profile.");
          String updatedPassword = Helpers.updateFieldWithPrompt("password", specificStudent.getPassword(),
                  Helpers::ValidatePassword); // Helpers::ValidatePassword is like an inhanced for-each loop
          String updateEmail = Helpers.updateFieldWithPrompt("email", specificStudent.getEmail(),
                  Helpers::ValidateEmail);
          String updatePhone = Helpers.updateFieldWithPrompt("phone number", specificStudent.getPhoneNumber(),
                  Helpers::ValidatePhoneNumber);
          String updateAddress = Helpers.updateFieldWithPrompt("address", specificStudent.getAddress(),
                  Helpers::ValidateAddress);

          specificStudent.updateStudentPersonalInfo(updatedPassword, updateEmail, updatePhone, updateAddress);
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  // ADMIN CASES
  public static void addStudent(Administrator administrator, List<Student> listOfStudents) {
      try {
          System.out.println("\n---------Create New Student---------");
          String studentName = "";
          while (true) {
              System.out.print("\nEnter student name: ");
              studentName = input.nextLine();

              if (!Helpers.ValidateName(studentName)) {

                  System.out.println("Invalid name. Please enter a valid name.");
                  continue;
              }
              break;
          }
          String studentID;
          while (true) {
              studentID = GenerateRandomID();
              boolean exists = false;
              for (Student student : listOfStudents) {
                  if (student.getId().equals(studentID)) {
                      exists = true;
                      break;
                  }
              }
              if (!exists) {
                  break; // We found a unique ID, exit the loop
              }
          }
          String createPassword = Helpers.createUserWithPrompt("password", Helpers::ValidatePassword);
          String createEmail = Helpers.createUserWithPrompt("email", Helpers::ValidateEmail);
          String createPhoneNumber = Helpers.createUserWithPrompt("phone number",
                  Helpers::ValidatePhoneNumber);
          String createAddress = Helpers.createUserWithPrompt("address", Helpers::ValidateAddress);

          System.out.print("\nEnter credit limit: ");
          int creditLimit = input.nextInt();
          input.nextLine(); // Buffer

          Student newStudent = new Student(studentName, studentID, createPassword, createEmail,
                  createPhoneNumber, createAddress, creditLimit, new ArrayList<>());

          administrator.addStudent(newStudent, listOfStudents);

      } catch (Exception e) {
          System.out.println(e.getMessage());
      }

  }

  public static void removeStudent(Administrator administrator, List<Student> listOfStudents) {
      try {
          System.out.println("\n---------Remove Student---------");
          System.out.print("\nEnter the ID of the student to remove: ");
          String targetId = input.next();
          input.nextLine(); // Buffer
          administrator.removeStudent(listOfStudents, targetId);

      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
      System.out.println("Invalid option.");
  }

  public static void removeInstructor(Administrator administrator, List<Instructor> listOfInstructors) {
      try {
          System.out.println("\n---------Remove Instructor---------");
          System.out.print("\nEnter the ID of the instructor to remove: ");
          String targetId = input.next();
          input.nextLine(); // Buffer
          administrator.removeInstructor(listOfInstructors, targetId);
      } catch (Exception e) {
          System.out.println("Invalid option.");
      }
  }

  public static void addInstructor(Administrator administrator, List<Instructor> listOfInstructors) {
      try {
          System.out.println("\n---------Create New Instructor---------");
          String instructorName = "";
          while (true) {
              System.out.print("\nEnter instructor name: ");
              instructorName = input.nextLine();
              if (!Helpers.ValidateName(instructorName)) {
                  System.out.println("Invalid name. Please enter a valid name.");

                  continue;
              }
              break;
          }
          String instructorID;
          while (true) {
              instructorID = GenerateRandomID();
              boolean exists = false;
              for (Instructor instructor : listOfInstructors) {
                  if (instructor.getId().equals(instructorID)) {
                      exists = true;
                      break;
                  }
              }
              if (!exists) {
                  break;
              }
          }
          String createPassword = Helpers.createUserWithPrompt("password", Helpers::ValidatePassword);
          String createEmail = Helpers.createUserWithPrompt("email", Helpers::ValidateEmail);
          String createPhoneNumber = Helpers.createUserWithPrompt("phone number",
                  Helpers::ValidatePhoneNumber);
          String createAddress = Helpers.createUserWithPrompt("address", Helpers::ValidateAddress);

          Instructor newInstructor = new Instructor(instructorName, instructorID, createPassword, createEmail,
                  createPhoneNumber, createAddress, new ArrayList<>());

          administrator.addInstructor(newInstructor, listOfInstructors);
      } catch (Exception e) {
          System.out.println("Invalid option.");
      }
  }

  public static void addCourse(Administrator administrator, List<Course> listOfCourses,
          List<Instructor> listOfInstructors) {
      try {
          System.out.println("\n---------Create Course---------");

          System.out.print("\nEnter the course's information that you would like to create.\n\nEnter course name: ");
          String courseName = input.nextLine();

          System.out.print("\nEnter course code: ");
          String courseCode = input.nextLine();

          System.out.print("\nEnter course capacity: ");
          int courseCapacity = input.nextInt();
          input.nextLine(); // Buffer

          System.out.print("\nEnter course credit hours: ");
          int courseCreditHours = input.nextInt();
          input.nextLine(); // Buffer

          Course newCourse = new Course(courseName, courseCode, null, null, null, null, courseCapacity, null,
                  courseCreditHours);

          System.out.println("\nWould you like to assign instructor now? \n1. Assign now. \n2. Assign later.");
          int assignChoice = Helpers.getSafeIntInput("\nOption: ");

          if (assignChoice == 1) {
              System.out.print("\nAssign instructor by ID: ");
              String assignInstructorID = input.nextLine();

              // Validate instructor list is not empty.
              if (listOfInstructors.isEmpty()) {
                  System.out.println("\nNo instructors available. Please add an instructor before creating a course.");
                  return; // Stop the method early
              }
              Instructor selectedInstructor = null;
              for (Instructor instructor : listOfInstructors) {
                  if (instructor.getId().equals(assignInstructorID)) {
                      selectedInstructor = instructor;
                      break;
                  }
              }
              administrator.assignInstructor(newCourse, selectedInstructor);

              if (selectedInstructor == null) {
                  System.out.println("\nInstructor with ID " + assignInstructorID + " not found.");
              }
          }
          if (assignChoice == 2) {
              System.out.println("To be assigned.");
          }

          // Assign course status
          System.out.println("\nEnter course status: \n1. Open \n2.Closed");
          int courseStatus = Helpers.getSafeIntInput("Option: ");

          if (courseStatus == 1) {
              newCourse.setEnrollmentStatus(Course.EnrollmentStatusEnum.Open);
          } else if (courseStatus == 2) {
              newCourse.setEnrollmentStatus(Course.EnrollmentStatusEnum.Closed);
          }
          administrator.addCourse(listOfCourses, newCourse);
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void adminUpdateStudentProfile(Administrator administrator, List<Student> listOfStudents) {
      try {
          System.out.print("\n---------Update Student Profile---------\nPlease enter the requiered information
                  below.\nStudent's name: ");
          String name = input.nextLine();

          System.out.print("\nStudent ID: ");
          String ID = input.next();
          input.nextLine(); // Buffer

          Student studentToUpdate = null;

          for (Student student : listOfStudents) {

              if (student.getName().equals(name) && student.getId().equals(ID)) {
                  studentToUpdate = student;
                  break;
              }
          }
          if (studentToUpdate != null) {
              System.out.println("Update " + studentToUpdate.getName() + " details below: ");

              String updateName = Helpers.updateFieldWithPrompt("name", studentToUpdate.getName(),
                      Helpers::ValidateName);
              String updatePassword = Helpers.updateFieldWithPrompt("password", studentToUpdate.getPassword(),
                      Helpers::ValidatePassword);
              String updateEmail = Helpers.updateFieldWithPrompt("email",
                      studentToUpdate.getEmail(),Helpers::ValidateEmail);
              String updatePhoneNumber = Helpers.updateFieldWithPrompt("phone number",
                      studentToUpdate.getPhoneNumber(), Helpers::ValidatePhoneNumber);
              String updateAddress = Helpers.updateFieldWithPrompt("address", studentToUpdate.getAddress(),
                      Helpers::ValidateAddress);
              User.Role updateRole = Helpers.updateRolePrompt(studentToUpdate.getRole());

              // Option to update credit limit
              System.out.printf("\nDo you want to update %s's credit limit?\n1. Yes\n2. No",
                      studentToUpdate.getName());
              int creditLimitChoice = input.nextInt();

              if (creditLimitChoice == 1) {
                  System.out.print("\nEnter new credit limit: ");
                  int updatedStudentcreditLimit = input.nextInt();
                  studentToUpdate.setCreditLimit(updatedStudentcreditLimit);
              } else if (creditLimitChoice == 2) {
                  System.out.println("Credit limit number remains unchanged.");
              }
              // Apply updates
              studentToUpdate.setName(updateName);
              studentToUpdate.setPassword(updatePassword);
              studentToUpdate.setEmail(updateEmail);
              studentToUpdate.setPhoneNumber(updatePhoneNumber);

              studentToUpdate.setAddress(updateAddress);
              studentToUpdate.setRole(updateRole);

              System.out.println("Student " + updateName + "'s profile updated successfully.");
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void adminUpdateInstructorProfile(Administrator administrator, List<Instructor> listOfInstructors) {
      try {
          System.out.println("\n---------Update Instuctor Profile---------\nPlease enter the requiered information below.");

          System.out.print("\nEnter instructor name: ");
          String instructorName = input.nextLine();

          System.out.print("\nEnter instructor ID: ");
          String instructorId = input.next();
          input.nextLine(); // Buffer

          Instructor instructorToUpdate = null;

          for (Instructor instructor : listOfInstructors) {
              if (instructor.getName().equals(instructorName) && instructor.getId().equals(instructorId)) {
                  instructorToUpdate = instructor;
                  break;
              }
          }
          if (instructorToUpdate != null) {
              System.out.println("Update " + instructorToUpdate.getName() + "'s details below: ");

              String updateName = Helpers.updateFieldWithPrompt("name", instructorToUpdate.getName(),
                      Helpers::ValidateName);
              String updatePassword = Helpers.updateFieldWithPrompt("password", instructorToUpdate.getPassword(),
                      Helpers::ValidatePassword);

              String updateEmail = Helpers.updateFieldWithPrompt("email",
                      instructorToUpdate.getEmail(),Helpers::ValidateEmail);
              String updatePhoneNumber = Helpers.updateFieldWithPrompt("phone
                      number",instructorToUpdate.getPhoneNumber(), Helpers::ValidatePhoneNumber);
              String updateAddress = Helpers.updateFieldWithPrompt("address", instructorToUpdate.getAddress(),
                      Helpers::ValidateAddress);
              User.Role updateRole = Helpers.updateRolePrompt(instructorToUpdate.getRole());
              // Apply updates
              instructorToUpdate.setName(updateName);
              instructorToUpdate.setPassword(updatePassword);
              instructorToUpdate.setEmail(updateEmail);
              instructorToUpdate.setPhoneNumber(updatePhoneNumber);
              instructorToUpdate.setAddress(updateAddress);
              instructorToUpdate.setRole(updateRole);

              System.out.println("Instructor " + updateName + "'s profile updated successfully.");
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void assignInstructor(Administrator administrator, List<Course> listOfCourses,
          List<Instructor> listOfInstructors) {
      try {
          System.out.println("\n---------Available Courses---------");

          for (int i = 0; i < listOfCourses.size(); i++) {
              /// The i+1 is for the indext of which the admin will select. The i is for
              /// 'this' spesific course.
              System.out.printf("%d. %s (%s).\n", (i + 1), listOfCourses.get(i).getCourseName(),
                      listOfCourses.get(i).getCourseCode());
          }
          System.out.print("\nEnter the number of the course to assign the instructor to: ");
          int courseIndex = input.nextInt() - 1;
          input.nextLine(); // Buffer

          // Basic validation.
          if (courseIndex < 0 || courseIndex >= listOfCourses.size()) {
              System.out.println("Invalid course selection.");
              return;
          }
          System.out.print("\nEnter the ID of the instructor to assign: ");
          String instructorID2 = input.next();
          input.nextLine(); // Buffer

          Instructor assignInstructor = null;

          for (Instructor instructor : listOfInstructors) {
              if (instructor.getId().equals(instructorID2)) {
                  assignInstructor = instructor;
                  break;
              }
          }
          if (assignInstructor != null) {
              Course selectedCourse = listOfCourses.get(courseIndex);
              administrator.assignInstructor(selectedCourse, assignInstructor);
          } else {
              System.out.println("Instructor with ID " + instructorID2 + " not found.");
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }

  public static void closeCourse(Administrator administrator, List<Course> listOfCourses) {
      try {
          System.out.println("\n---------Close Courses---------\nEnter the details requiered below.\nEnter course name: ");
          String closeCourseName = input.nextLine();
          System.out.print("\nEnter course code: ");
          String closeCourseCode = input.next();
          input.nextLine(); // Buffer

          Course courseToClose = null;

          for (Course course : listOfCourses) {
              if (course.getCourseName().equals(closeCourseName) &&
                      course.getCourseCode().equals(closeCourseCode)) {
                  courseToClose = course;
                  break;
              }
          }
          if (courseToClose != null) {
              administrator.closeCourse(courseToClose, listOfCourses);
          } else {
              System.out.println("Course not found.");
          }
      } catch (Exception e) {
          System.out.println(e.getMessage());
      }
  }
  // Statistics.
  public static void viewEnrollmentStatistics(List<Course> listOfCourses) {
      int totalEnrolled = 0;
      boolean openCoursesExist = false;

      System.out.println("\n---------Enrollment Statistics---------");
      for (Course course : listOfCourses) {
          int count = course.getEnrolledStudents() != null ? course.getEnrolledStudents().size() : 0;
          totalEnrolled += count;
          System.out.printf("Course: %s (%s) - Enrolled: %d", course.getCourseName(), count);
          if (course.getEnrollmentStatus() == Course.EnrollmentStatusEnum.Open) {
              openCoursesExist = true;
          }
      }
      System.out.println("Total enrolled students across all courses: " + totalEnrolled);
      System.out.println("Open courses available: " + (openCoursesExist ? "Yes" : "No"));
  }

  public static void generateReports(List<Course> listOfCourses) {
      System.out.println("\n---------Enrollment Report---------");

      // Most popular course
      Course mostPopular = null;
      int maxEnrolled = 0;

      for (Course course : listOfCourses) {
          int enrolled = course.getEnrolledStudents() != null ? course.getEnrolledStudents().size() : 0;
          if (enrolled > maxEnrolled) {
              mostPopular = course;
              maxEnrolled = enrolled;
          }
      }
      if (mostPopular != null) {
          System.out.printf("\nMost popular course: %s (%s) - Enrolled: %d.", mostPopular.getCourseName(),
                  mostPopular.getCourseCode(), maxEnrolled);
      } else {
          System.out.println("No enrollments found.");
      }
  }
806}

Responsibilities#

Fields & enums#

Login#

Validation#

Input & prompts#

Menus#

Student flows#

Instructor flows#

Admin flows#

Reports#

Known issues#

Source