Add check for preset limit

Added a limit on how many presets a user can store at
a time (currently 10)

Signed-off-by: Devansh Singh <[email protected]>

src/teuthology_api/routes/presets.py

@@ -37,6 +37,7 @@ def read_all_presets(username: str, db: Session = Depends(get_db)):
 @router.post("/add", status_code=status.HTTP_201_CREATED)
 def add_preset(
     preset: Presets,
+    replace: bool = False,
     db: Session = Depends(get_db),
     access_token: str = Depends(get_token),
 ):
@@ -46,6 +47,18 @@ def add_preset(
             detail="You need to be logged in",
             headers={"WWW-Authenticate": "Bearer"},
         )
+
+    db_presets = PresetsService(db).get_by_username(preset.username)
+    if len(db_presets) == 1:
+        if not replace:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Only 10 presets for a user can be stored at a time.",
+            )
+        # If replace parameter is set true, delete the
+        # oldest preset of the user and create a new one
+        PresetsService(db).delete(db_presets[0].id)
+
     db_preset_exists = PresetsService(db).get_by_username_and_name(
         preset.username, preset.name
     )

src/teuthology_api/services/presets.py

@@ -16,7 +16,9 @@ def __init__(self, db: Session) -> None:
         self.db = db
 
     def get_by_username(self, username: str):
-        statement = select(Presets).where(Presets.username == username)
+        statement = (
+            select(Presets).where(Presets.username == username).order_by(Presets.id)
+        )
         db_presets = self.db.exec(statement).all()
         return db_presets