update[Customer]: update customer class to better suit the application

src/main/java/edu/group5/app/model/user/Customer.java

@@ -14,57 +14,64 @@
 public class Customer extends User {
   private List<Integer> preferences;
 
-  /**
-   * Constructs a Customer object.
-   * Calls the {@link User} superclass constructor to initialize common user fields
-   * and initializes the preferences list.
-   * @param userId the unique identifier for the user, must be a positive integer
-   * @param firstName the first name of the customer
-   * @param lastName the last name of the customer
-   * @param email the email address of the customer
-   * @param passwordHash the hashed password of the customer
-   * @throws IllegalArgumentException if any required field is invalid
-   */
-  public Customer(int userId, String firstName, String lastName,
-                  String email, String passwordHash) {
-
+/**
+ * Constructs a new Customer object for new registrations.
+ * The role is automatically set to "Customer" and the preferences list is initialized empty.
+ *
+ * @param userId the unique identifier for the user, must be positive
+ * @param firstName the first name of the customer
+ * @param lastName the last name of the customer
+ * @param email the email address of the customer
+ * @param passwordHash the hashed password of the customer
+ * @throws IllegalArgumentException if any parameter is invalid (null, empty, or userId ≤ 0)
+ */
+public Customer(int userId, String firstName, String lastName,
+                String email, String passwordHash) {
     super(userId, "Customer", firstName, lastName, email, passwordHash);
     this.preferences = new ArrayList<>();
-  }
+}
+
+/**
+ * Constructs a Customer object for existing users loaded from the database
+ * or for cases where the role is already defined.
+ * The role should normally be "Customer", but this constructor allows flexibility
+ * (e.g., for testing or future user types). Preferences list is initialized empty.
+ *
+ * @param userId the unique identifier for the user, must be positive
+ * @param role the role of the user (should be "Customer" for customer instances)
+ * @param firstName the first name of the customer
+ * @param lastName the last name of the customer
+ * @param email the email address of the customer
+ * @param passwordHash the hashed password of the customer
+ * @throws IllegalArgumentException if any parameter is invalid (null, empty, or userId ≤ 0)
+ */
+public Customer(int userId, String role, String firstName, String lastName,
+                String email, String passwordHash) {
+    super(userId, role, firstName, lastName, email, passwordHash);
+    this.preferences = new ArrayList<>();
+}
 
   public List<Integer> getPreferences() {
     return preferences;
   }
 
-  public boolean addPreference(int orgNumber) {
-    try {
-      if (orgNumber <= 0) {
-        throw new IllegalArgumentException("Organization number must be a positive integer");
-      }
-      if (preferences.contains(orgNumber)) {
-        throw new IllegalStateException("Organization number already in preferences");
-      }
-      preferences.add(orgNumber);
-      return true;
-    } catch (Exception e) {
-      System.out.println("Add preference failed: " + e.getMessage());
-      return false;
+  public void addPreference(int orgNumber) {
+    if (orgNumber <= 0) {
+      throw new IllegalArgumentException("Organization number must be a positive integer");
     }
+    if (preferences.contains(orgNumber)) {
+      throw new IllegalArgumentException("Organization number already in preferences");
+    }
+    preferences.add(orgNumber);
   }
 
-  public boolean removePreference(int orgNumber) {
-    try {
-      if (orgNumber <= 0) {
-        throw new IllegalArgumentException("Organization number must be a positive integer");
-      }
-      if (!preferences.contains(orgNumber)) {
-        throw new IllegalStateException("Organization number not found in preferences");
-      }
-      preferences.remove(Integer.valueOf(orgNumber));
-      return true;
-    } catch (Exception e) {
-      System.out.println("Remove preference failed: " + e.getMessage());
-      return false;
+  public void removePreference(int orgNumber) {
+    if (orgNumber <= 0) {
+      throw new IllegalArgumentException("Organization number must be a positive integer");
+    }
+    if (!preferences.contains(orgNumber)) {
+      throw new IllegalArgumentException("Organization number not found in preferences");
     }
+    preferences.remove(Integer.valueOf(orgNumber));
   }
-}
+}