update main.py createuser foutafhandeling

backend/main.py

@@ -76,21 +76,26 @@ def database_status():
 
 # users
 
-
 @app.post("/create-user")
 def api_create_user(user: UserCreate):
 
+    try:
         user_id = create_user(
             user.username,
             user.password
         )
 
+    except sqlite3.IntegrityError:
+        raise HTTPException(
+            status_code=409,
+            detail="username already exists"
+        )
+
     return {
         "status": "created",
         "user_id": user_id
     }
 
-
 @app.post("/login")
 def api_login(login: Login):