Some django manager methods for the Order model

managers.py

class OrderManager(Manager):
    def add_available_count(self, qs):
        available_count = qs.annotate(
            available_count=Count('user_order_availability', filter=Q(user_order_availability__is_accepted=False))
                                ).filter(user_order_availability__order_id=OuterRef('id'))

        qs = qs.annotate(
            available_count=Subquery(available_count.values('available_count'), output_field=IntegerField()),
        )

        return qs

    def add_assigned_count(self, qs):
        assigned_count = qs.annotate(assigned_count=Count('assigned_orders')).filter(
            assigned_orders__order_id=OuterRef('id'))
        qs = qs.annotate(
            assigned_count=Subquery(assigned_count.values('assigned_count'), output_field=IntegerField()),
        )

        return qs

    def get_order_type_counts(self, order_types, year):
        def get_order_type_count_annotation(order_type_key, order_type_text):
            return {
                order_type_key: Sum(
                    Case(
                        When(order_type_lower=order_type_text, then=Value(1)),
                        default=Value(0),
                        output_field=IntegerField(),
                   ),
                )
            }

        def get_aggregate_annotation(key, order_type_key):
            return {
                key: Sum(order_type_key)
            }

        qs = super().get_queryset().filter(start_date__year=year)
        qs = qs.annotate(order_type_lower=Lower('order_type'))
        qs = qs.order_by().values('order_type_lower')

        order_types_norm = []

        for order_type in order_types:
            order_type_norm = order_type.replace(' ', '_').lower()
            order_types_norm.append(order_type_norm)
            qs = qs.annotate(**get_order_type_count_annotation(order_type_norm, order_type.lower()))

        qs = (
            qs.annotate(Total=Count("order_type"))
            .order_by("-Total", *order_types_norm)
            .values('Total', *order_types_norm)
        )

        aggregate_annotations = {
            'sum_total': Sum('Total')
        }

        for order_type_norm in order_types_norm:
            aggregate_annotations.update(get_aggregate_annotation('sum_{0}'.format(order_type_norm), order_type_norm))

        # aggregate and add percentages
        qs = qs.aggregate(**aggregate_annotations)
        qs.update({'{0}_perc'.format(key): round((qs[key] / qs['sum_total'])*100, 2) for key in qs.keys() if key != 'sum_total'})

        return qs

    def get_count_per_month(self, year):
        qs = super().get_queryset().filter(start_date__year=year)
        return qs.annotate(month=TruncMonth('start_date')).values('month').annotate(c=Count('id')).values('month', 'c')

    def get_within_range(self, from_point: Point, radius: int):
        return self.get_base_qs().filter(geo_location__distance_lt=(from_point, MeasureDistance(km=radius)))

    def get_by_distance(self, point: Point):
        qs = self.get_base_qs().annotate(distance=Distance('geo_location', point))
        qs = qs.order_by('distance')

        return qs