code.py

def get_jobs_queryset(self) -> QuerySet:
    """
    Get QuerySet from production.Job (for subquery in ProductionOrderJob queryset)
    :return: QuerySet
    """
    return apps.get_model("production.Job").objects.filter(
        (
            Q(version_end_date__gt=OuterRef("production_order__created_at"))
            | Q(version_end_date__isnull=True)
        )
        & Q(version_start_date__lte=OuterRef("production_order__created_at"))
        & Q(identity=OuterRef("production_job__identity"))
    )

def get_jobs_subquery_with_price(self) -> dict:
    """Get 'price' values from versioned ProductionOrderJob's queryset"""
    return self.get_jobs_queryset().values("price")

def get_orders_with_prefetch(self, year: int, month: int):
    """TODO Main"""
    # Conditions for count ProductionOrderJob's for each ProductionOrder's
    created_jobs_count_case = Case(
        When(
            Q(
                poj_productionorder__created_at__month=month,
                poj_productionorder__created_at__year=year,
                poj_productionorder__finish_at__isnull=True,
            )
            | Q(
                poj_productionorder__finish_at__month=month,
                poj_productionorder__finish_at__year=year,
            ),
            then=1,
        ),
        output_field=IntegerField(),
    )
    #
    finished_jobs_cost_subquery = (
        apps.get_model("production.ProductionOrderJob")
        .objects_clear.select_related("production_job")
        .filter(
            finish_at__year=year,
            finish_at__month=month,
            production_order=OuterRef("id")
        )
        .annotate(
            job_price=Subquery(
                self.get_jobs_subquery_with_price(), output_field=DecimalField()
            )
        )
        .annotate(price=Sum("job_price"))
        .values("price")[:1]
    )

    return (
        apps.get_model("production.ProductionOrder")
        .objects_clear.filter(created_at__month=month, created_at__year=year,)
        .annotate(
            finished_jobs_count=Count(
                Case(
                    When(
                        Q(
                            poj_productionorder__finish_at__month=month,
                            poj_productionorder__finish_at__year=year,
                        ),
                        then=1,
                    )
                )
            ),
            total_jobs_count=Count("poj_productionorder"),
            created_jobs_count=Count(created_jobs_count_case),
            created_jobs_cost=Coalesce(
                Sum("poj_productionorder__production_job__price"),
                Decimal("0.00")
            ),
            finished_jobs_cost=Coalesce(
                Sum(
                    Subquery(finished_jobs_cost_subquery),
                    output_field=DecimalField()
                ),
                Decimal("0.00")
            ),
        )
        .values(
            "pk",
            "finished_jobs_count",
            "total_jobs_count",
            "created_jobs_count",
            "created_jobs_cost",
            "finished_jobs_cost",
        )
    )