Merge branch 'feat/47-sessionregistry-get-by-userid-and-username' into 'main'

Add additional getters to SessionRegistry with UserId and username as key

Closes #47

See merge request cs108-fs26/Gruppe-13!74

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/user/UserRegistry.java

@@ -86,15 +86,38 @@ public class UserRegistry {
     }
 
     /**
-     * Looks up a user by their session ID.
+     * Looks up a user by their {@link SessionId}.
      *
-     * @param sessionId the session ID to look up
-     * @return an Optional containing the user, or empty if no user is associated with this session
+     * @param sessionId the SessionId to look up
+     * @return an Optional containing the {@link User}, or empty if no user is associated with this
+     *     SessionId
      */
-    public Optional<User> findBySessionId(SessionId sessionId) {
+    public Optional<User> getBySessionId(SessionId sessionId) {
         return Optional.ofNullable(bySessionId.get(sessionId));
     }
 
+    /**
+     * Looks up a user by their {@link UserId}.
+     *
+     * @param userId the UserId to look up
+     * @return an Optional containing the {@link User}, or empty if no user is associated with this
+     *     UserId
+     */
+    public Optional<User> getByUserId(UserId userId) {
+        return Optional.ofNullable(byId.get(userId));
+    }
+
+    /**
+     * Looks up a user by their username.
+     *
+     * @param username the username to look up
+     * @return an Optional containing the {@link User}, or empty if no user is associated with this
+     *     username
+     */
+    public Optional<User> getByUsername(String username) {
+        return Optional.ofNullable(byName.get(username));
+    }
+
     /**
      * Returns all currently registered users.
      *