free sale of inventory entry system deployment - add dhi state to rancher

apps/warehouse/services/services.py

@@ -1,8 +1,14 @@
 from apps.herd.services.services import rancher_quota_weight, get_rancher_statistics
-from apps.warehouse.models import InventoryEntry, InventoryQuotaSaleTransaction
+from apps.warehouse.models import (
+    InventoryEntry,
+    InventoryQuotaSaleTransaction,
+    InventoryQuotaSaleItem,
+    ExtraSale
+)
 from apps.product.models import QuotaDistribution
 from apps.core.models import SystemConfig
 from django.db.models import Sum
+import typing
 
 
 def get_total_sold(rancher, inventory_entry: InventoryEntry = None, distribution: QuotaDistribution = None):
@@ -53,3 +59,35 @@ def can_buy_from_inventory(rancher, inventory_entry: InventoryEntry = None, dist
     total_sold = get_total_sold(inventory_entry, rancher)
 
     return total_sold < total_allowed
+
+
+def create_extra_sale(
+        sale_item: InventoryQuotaSaleItem,
+        transaction: InventoryQuotaSaleTransaction
+) -> typing.Any:
+    """
+    :param sale_item
+    :param transaction
+    create extra sale for items that weight are
+    more than distribution warehouse balance
+    """
+
+    if sale_item.quota_distribution.free_sale:
+        if sale_item.weight > sale_item.quota_distribution.warehouse_balance:
+            # calculate extra weight between item weight and warehouse balance
+            extra_weight = sale_item.weight - sale_item.quota_distribution.warehouse_balance
+            extra_sale = ExtraSale.objects.create(  # create extra sale
+                transaction=transaction,
+                sale_item=sale_item,
+                distribution=sale_item.quota_distribution,
+                weight=extra_weight
+            )
+
+            # set distribution warehouse balance to 0 because we have extra sale
+            sale_item.quota_distribution.warehouse_balance = 0
+            sale_item.quota_distribution.save()
+
+            return extra_sale
+        pass
+    pass
+