class MasterDataElementFilterViewSet(ViewSetActionPermissionMixin, viewsets.ModelViewSet):
    permission_classes = [permissions.IsAuthenticated]
    pagination_class = CustomPageNumberPagination
    serializer_class = MasterDataFilterSerializer

    def get_queryset(self):
        active_project_id = self.request.user.active_project_id

        if not active_project_id:
            raise UserHasNoActiveProjectSet(language_code=self.request.user.language.code)

        try:
            parent_id = int(self.request.query_params.get('parent_id'))
        except TypeError:
            parent_id = None

        hierarchy = get_object_or_404(
            MasterDataHierarchy.objects.all(),
            id=self.kwargs.get('pk'),
            project_id=active_project_id
        )

        if parent_id:
            return MasterDataElement.objects.filter(
                level__hierarchy_id=hierarchy.id,
                parent_id=parent_id,
                is_archived=False
            ).annotate(Count('children', distinct=True))
        else:

            try:
                statuses = loads(self.request.query_params.get('statuses', ''))
            except JSONDecodeError:
                statuses = None

            last_hierarchy_level = MasterDataLevel.get_levels_in_hierarchical_order_for_hierarchy(hierarchy.id)

            logger = logging.getLogger(__name__)

            queryset = MasterDataElement.objects.filter(
                level__id=last_hierarchy_level.last().id,
                is_archived=False,
                level__hierarchy_id=hierarchy.id,
            )

            if statuses:
                level_count = range(last_hierarchy_level.count()-1)
                field_query = '__'.join(['children' for _ in level_count]) + '__info__calculated_status_id'
                query_string = Q(**{field_query: statuses[0]})

                for status in statuses[1:]:
                    query_string.add(Q(**{field_query: status}), Q.OR)

                queryset = queryset.filter(query_string)

            return queryset.select_related(
                'info__calculated_status',
                'info__manual_status',
            ).annotate(
                Count('children', distinct=True)
            ).order_by('-id')