Queryset annotation refactor (#3117)

* Refactor out 'ordering' serializer annotation field

* Refactor BomItem serializer annotations

* Factor out MPTT OuterRef query

* Add 'available_stock' annotation to SalesOrderLineItem serializer

- Allows for better rendering of stock availability in sales order table

* Improve 'available quantity' rendering of salesorderlineitem table

* Bump API version

* Add docstring

InvenTree/order/api.py

@@ -788,6 +788,8 @@ class SalesOrderLineItemList(generics.ListCreateAPIView):
             'order__stock_items',
         )
 
+        queryset = serializers.SalesOrderLineItemSerializer.annotate_queryset(queryset)
+
         return queryset
 
     filter_backends = [
@@ -835,6 +837,14 @@ class SalesOrderLineItemDetail(generics.RetrieveUpdateDestroyAPIView):
     queryset = models.SalesOrderLineItem.objects.all()
     serializer_class = serializers.SalesOrderLineItemSerializer
 
+    def get_queryset(self, *args, **kwargs):
+        """Return annotated queryset for this endpoint"""
+        queryset = super().get_queryset(*args, **kwargs)
+
+        queryset = serializers.SalesOrderLineItemSerializer.annotate_queryset(queryset)
+
+        return queryset
+
 
 class SalesOrderContextMixin:
     """Mixin to add sales order object as serializer context variable."""

InvenTree/order/models.py

@@ -887,14 +887,6 @@ class OrderLineItem(models.Model):
         target_date: An (optional) date for expected shipment of this line item.
     """
 
-    """
-    Query filter for determining if an individual line item is "overdue":
-    - Amount received is less than the required quantity
-    - Target date is not None
-    - Target date is in the past
-    """
-    OVERDUE_FILTER = Q(received__lt=F('quantity')) & ~Q(target_date=None) & Q(target_date__lt=datetime.now().date())
-
     class Meta:
         """Metaclass options. Abstract ensures no database table is created."""
 
@@ -953,6 +945,9 @@ class PurchaseOrderLineItem(OrderLineItem):
         order: Reference to a PurchaseOrder object
     """
 
+    # Filter for determining if a particular PurchaseOrderLineItem is overdue
+    OVERDUE_FILTER = Q(received__lt=F('quantity')) & ~Q(target_date=None) & Q(target_date__lt=datetime.now().date())
+
     @staticmethod
     def get_api_url():
         """Return the API URL associated with the PurchaseOrderLineItem model"""
@@ -1076,6 +1071,9 @@ class SalesOrderLineItem(OrderLineItem):
         shipped: The number of items which have actually shipped against this line item
     """
 
+    # Filter for determining if a particular SalesOrderLineItem is overdue
+    OVERDUE_FILTER = Q(shipped__lt=F('quantity')) & ~Q(target_date=None) & Q(target_date__lt=datetime.now().date())
+
     @staticmethod
     def get_api_url():
         """Return the API URL associated with the SalesOrderLineItem model"""

InvenTree/order/serializers.py

@@ -14,6 +14,7 @@ from rest_framework.serializers import ValidationError
 from sql_util.utils import SubqueryCount
 
 import order.models
+import part.filters
 import stock.models
 import stock.serializers
 from common.settings import currency_code_mappings
@@ -248,7 +249,7 @@ class PurchaseOrderLineItemSerializer(InvenTreeModelSerializer):
         queryset = queryset.annotate(
             overdue=Case(
                 When(
-                    Q(order__status__in=PurchaseOrderStatus.OPEN) & order.models.OrderLineItem.OVERDUE_FILTER, then=Value(True, output_field=BooleanField())
+                    Q(order__status__in=PurchaseOrderStatus.OPEN) & order.models.PurchaseOrderLineItem.OVERDUE_FILTER, then=Value(True, output_field=BooleanField())
                 ),
                 default=Value(False, output_field=BooleanField()),
             )
@@ -790,17 +791,36 @@ class SalesOrderLineItemSerializer(InvenTreeModelSerializer):
     def annotate_queryset(queryset):
         """Add some extra annotations to this queryset:
 
-        - "Overdue" status (boolean field)
+        - "overdue" status (boolean field)
+        - "available_quantity"
         """
+
         queryset = queryset.annotate(
             overdue=Case(
                 When(
-                    Q(order__status__in=SalesOrderStatus.OPEN) & order.models.OrderLineItem.OVERDUE_FILTER, then=Value(True, output_field=BooleanField()),
+                    Q(order__status__in=SalesOrderStatus.OPEN) & order.models.SalesOrderLineItem.OVERDUE_FILTER, then=Value(True, output_field=BooleanField()),
                 ),
                 default=Value(False, output_field=BooleanField()),
             )
         )
 
+        # Annotate each line with the available stock quantity
+        # To do this, we need to look at the total stock and any allocations
+        queryset = queryset.alias(
+            total_stock=part.filters.annotate_total_stock(reference='part__'),
+            allocated_to_sales_orders=part.filters.annotate_sales_order_allocations(reference='part__'),
+            allocated_to_build_orders=part.filters.annotate_build_order_allocations(reference='part__'),
+        )
+
+        queryset = queryset.annotate(
+            available_stock=ExpressionWrapper(
+                F('total_stock') - F('allocated_to_sales_orders') - F('allocated_to_build_orders'),
+                output_field=models.DecimalField()
+            )
+        )
+
+        return queryset
+
     def __init__(self, *args, **kwargs):
         """Initializion routine for the serializer:
 
@@ -825,7 +845,9 @@ class SalesOrderLineItemSerializer(InvenTreeModelSerializer):
     part_detail = PartBriefSerializer(source='part', many=False, read_only=True)
     allocations = SalesOrderAllocationSerializer(many=True, read_only=True, location_detail=True)
 
+    # Annotated fields
     overdue = serializers.BooleanField(required=False, read_only=True)
+    available_stock = serializers.FloatField(read_only=True)
 
     quantity = InvenTreeDecimalField()
 
@@ -853,6 +875,7 @@ class SalesOrderLineItemSerializer(InvenTreeModelSerializer):
             'pk',
             'allocated',
             'allocations',
+            'available_stock',
             'quantity',
             'reference',
             'notes',