Enforcing Username Uniqueness (#906)

* Enforcing Username Uniqueness

Changes in UserService.java:

Added a new method findByUsername to allow searching for usernames regardless of case sensitivity.
Added a new method isUsernameValid to validate the username.
Changes in UserController.java:

Updated the changeUsername method to ensure the new username is valid before changing it.
Updated the editUser method to ensure the new username is unique and valid.
Changes in UserRepository.java:

Added a custom JPQL query to search for usernames regardless of case sensitivity.
Changes in HTML templates (account.html and addUsers.html):

Error messages are displayed if a username is invalid or already exists.

* JPAs auto

src/main/java/stirling/software/SPDF/config/security/UserService.java

@@ -176,6 +176,10 @@ public class UserService implements UserServiceInterface {
         return userRepository.findByUsername(username);
     }
 
+    public Optional<User> findByUsernameIgnoreCase(String username) {
+        return userRepository.findByUsernameIgnoreCase(username);
+    }
+
     public void changeUsername(User user, String newUsername) {
         user.setUsername(newUsername);
         userRepository.save(user);
@@ -194,4 +198,8 @@ public class UserService implements UserServiceInterface {
     public boolean isPasswordCorrect(User user, String currentPassword) {
         return passwordEncoder.matches(currentPassword, user.getPassword());
     }
+
+    public boolean isUsernameValid(String username) {
+        return username.matches("[a-zA-Z0-9]+");
+    }
 }

src/main/java/stirling/software/SPDF/controller/api/UserController.java

@@ -61,11 +61,16 @@ public class UserController {
             HttpServletRequest request,
             HttpServletResponse response,
             RedirectAttributes redirectAttributes) {
+
+        if (!userService.isUsernameValid(newUsername)) {
+            return new RedirectView("/account?messageType=invalidUsername");
+        }
+
         if (principal == null) {
             return new RedirectView("/account?messageType=notAuthenticated");
         }
 
-        Optional<User> userOpt = userService.findByUsername(principal.getName());
+        Optional<User> userOpt = userService.findByUsernameIgnoreCase(principal.getName());
 
         if (userOpt == null || userOpt.isEmpty()) {
             return new RedirectView("/account?messageType=userNotFound");
@@ -73,6 +78,10 @@ public class UserController {
 
         User user = userOpt.get();
 
+        if (user.getUsername().equals(newUsername)) {
+            return new RedirectView("/account?messageType=usernameExists");
+        }
+
         if (!userService.isPasswordCorrect(user, currentPassword)) {
             return new RedirectView("/account?messageType=incorrectPassword");
         }
@@ -186,6 +195,18 @@ public class UserController {
             @RequestParam(name = "forceChange", required = false, defaultValue = "false")
                     boolean forceChange) {
 
+        if (!userService.isUsernameValid(username)) {
+            return new RedirectView("/addUsers?messageType=invalidUsername");
+        }
+
+        Optional<User> userOpt = userService.findByUsernameIgnoreCase(username);
+
+        if (userOpt.isPresent()) {
+            User user = userOpt.get();
+            if (user != null && user.getUsername().equalsIgnoreCase(username)) {
+                return new RedirectView("/addUsers?messageType=usernameExists");
+            }
+        }
         if (userService.usernameExists(username)) {
             return new RedirectView("/addUsers?messageType=usernameExists");
         }

src/main/java/stirling/software/SPDF/repository/UserRepository.java

@@ -3,10 +3,14 @@ package stirling.software.SPDF.repository;
 import java.util.Optional;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import stirling.software.SPDF.model.User;
 
 public interface UserRepository extends JpaRepository<User, String> {
+    Optional<User> findByUsernameIgnoreCase(String username);
+
     Optional<User> findByUsername(String username);
 
     User findByApiKey(String apiKey);