Optimize query for supervision events

aleksis/apps/chronos/models.py

@@ -505,7 +505,7 @@ class SupervisionEvent(LessonEvent):
         cls, request: HttpRequest | None = None, params: dict[str, any] | None = None, **kwargs
     ) -> Iterable:
         """Return all objects that should be included in the calendar."""
-        objs = super().get_objects(request, params, no_effect=True, **kwargs)
+        q = Q()
         if params:
             obj_id = int(params.get("id", 0))
             type_ = params.get("type", None)
@@ -514,21 +514,30 @@ class SupervisionEvent(LessonEvent):
             amending = params.get("amending", False)
 
             if not_amended:
-                objs = objs.not_amended()
+                q = q & SupervisionEventQuerySet.not_amended_q()
 
             if not_amending:
-                objs = objs.not_amending()
+                q = q & SupervisionEventQuerySet.not_amending_q()
 
             if amending:
-                objs = objs.amending()
+                q = q & SupervisionEventQuerySet.amending_q()
 
             if type_ and obj_id:
                 if type_ == "TEACHER":
-                    return objs.for_teacher(obj_id)
+                    q = q & SupervisionEventQuerySet.for_teacher_q(obj_id)
                 elif type_ == "GROUP":
-                    return objs.for_group(obj_id)
+                    q = q & SupervisionEventQuerySet.for_group_q(obj_id)
                 elif type_ == "ROOM":
-                    return objs.for_room(obj_id)
-        if request:
-            return objs.for_person(request.user.person)
-        return objs
+                    q = q & SupervisionEventQuerySet.for_room_q(obj_id)
+        elif request:
+            q = q & SupervisionEventQuerySet.for_person_q(request.user.person)
+
+        return super().get_objects(
+            request,
+            params,
+            no_effect=True,
+            additional_filter=q,
+            select_related=["subject"],
+            prefetch_related=["teachers", "rooms"],
+            **kwargs,
+        )