only ensure user exists on login

Author: cyclotruc

src/backend/dependencies.py

@@ -12,7 +12,7 @@
 from domain.user import User
 from domain.pad import Pad
 from coder import CoderAPI
-from database.database import async_session, get_session
+from database.database import get_session
 
 # oidc_config for session creation and user sessions
 oidc_config = {
@@ -49,19 +49,12 @@ def __init__(self, access_token: str, token_data: dict, session_domain: Session,
                 algorithms=["RS256"],
                 audience=oidc_config['client_id']
             )
-
-            # Ensure user exists in database
-            async def ensure_user():
-                async with async_session() as session:
-                    await User.ensure_exists(session, self.token_data)
-            asyncio.create_task(ensure_user())
 
-
         except jwt.InvalidTokenError as e:
             # Log the error and raise an appropriate exception
             print(f"Invalid token: {str(e)}")
             raise ValueError(f"Invalid authentication token: {str(e)}")
-        
+
     @property
     def is_authenticated(self) -> bool:
         """Check if the session is authenticated"""

src/backend/routers/auth_router.py

@@ -12,6 +12,8 @@
 from coder import CoderAPI
 from dependencies import optional_auth, UserSession
 from domain.session import Session
+from database.database import async_session
+from domain.user import User
 
 auth_router = APIRouter()
 
@@ -81,6 +83,17 @@ async def callback(
         access_token = token_data['access_token']
         user_info = jwt.decode(access_token, options={"verify_signature": False})
 
+        # Ensure user exists in database (only during login)
+        async with async_session() as db_session:
+            try:
+                await User.ensure_exists(db_session, user_info)
+            except Exception as e:
+                # Handle duplicate key violations gracefully - this means user already exists
+                if "duplicate key value violates unique constraint" in str(e) or "already exists" in str(e):
+                    print(f"User {user_info.get('sub')} already exists in database (race condition handled)")
+                else:
+                    raise e
+        
         try:
             user_data, _ = coder_api.ensure_user_exists(
                 user_info