transaction system deploying

apps/warehouse/models.py

@@ -88,14 +88,8 @@ class InventoryQuotaSaleTransaction(BaseModel):
         related_name='inventory_sales',
         null=True
     )
-    weight = models.DecimalField(max_digits=12, decimal_places=2, null=True)
+    weight = models.PositiveBigIntegerField(default=0)
     delivery_address = models.TextField(blank=True, null=True)
-    product = models.ForeignKey(
-        product_models.Product,
-        on_delete=models.CASCADE,
-        related_name='sale_transactions',
-        null=True
-    )
     transaction_price = models.PositiveBigIntegerField(default=0)
     price_paid = models.PositiveBigIntegerField(default=0)
     type_of_price = (
@@ -121,17 +115,43 @@ class InventoryQuotaSaleTransaction(BaseModel):
     payer_cart = models.CharField(max_length=50, null=True)
     additional = models.JSONField(default=dict)
 
-    def buyers_count(self):
-        """ number of buyers from specific inventory """
-
-        unique_buyers_count = self.objects.filter(
-            inventory_entry=self.inventory_entry
-        ).values('buyer_user').distinct().count()
-
-        return unique_buyers_count
+    @property
+    def total_weight(self):
+        """ summation of total sold product weight """
+        return sum(item.weight for item in self.items.all)
 
     def __str__(self):
         return f"Inventory Sale: {self.transaction_id}-{self.quota_distribution.distribution_id}"
 
     def save(self, *args, **kwargs):
         super(InventoryQuotaSaleTransaction, self).save(*args, **kwargs)
+
+
+class InventoryQuotaSaleItem(BaseModel):
+    transaction = models.ForeignKey(
+        InventoryQuotaSaleTransaction,
+        on_delete=models.CASCADE,
+        related_name='items',
+        null=True
+    )
+    quota_distribution = models.ForeignKey(
+        product_models.QuotaDistribution,
+        on_delete=models.CASCADE,
+        related_name='sale_items',
+        null=True
+    )
+    product = models.ForeignKey(
+        product_models.Product,
+        on_delete=models.CASCADE,
+        related_name='sale_items',
+        null=True
+    )
+    weight = models.PositiveBigIntegerField(default=0)
+    unit_price = models.PositiveBigIntegerField(default=0)
+    total_price = models.PositiveBigIntegerField(default=0)
+
+    def __str__(self):
+        return f'Item {self.product} - {self.weight} Kg - {self.total_price}'
+
+    def save(self, *args, **kwargs):
+        return super(InventoryQuotaSaleItem, self).save(*args, **kwargs)