avoid duplicated classrooms and grant access to access_groups

courses/classroom/views.py

@@ -37,6 +37,7 @@ class BasicClassroomViewSet(viewsets.ReadOnlyModelViewSet):
         if not self.request.user.is_superuser:
             queryset = queryset.filter(
                 Q(group__in=self.request.user.groups.all())
+                | Q(access_groups__in=self.request.user.groups.all())
                 | Q(assistants=self.request.user)
                 | Q(coordinators=self.request.user)
             )
@@ -53,7 +54,7 @@ class BasicClassroomViewSet(viewsets.ReadOnlyModelViewSet):
             'events',
         )
 
-        return queryset
+        return queryset.distinct()
 
 
 class ClassroomViewSet(BasicClassroomViewSet, viewsets.ModelViewSet):