refactor: views and srzs of business-statement api

api_v1/views/business/statements/views.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from collections import OrderedDict
 from decimal import Decimal, ROUND_HALF_UP
 from typing import Iterable, List
 
@@ -67,7 +68,6 @@ class StatementViewBase(StockChangeViewMixin, views.APIView):
         extra: dict | None = None,
     ) -> dict:
         items = items or []
-        print(items)
         record = {
             'counterparty': counterparty_id,
             'counterparty_name': counterparty_name,
@@ -86,6 +86,27 @@ class StatementViewBase(StockChangeViewMixin, views.APIView):
             record['extra'] = extra
         return record
 
+    def _aggregate_items(self, order_items) -> List[dict]:
+        """Merge duplicate order items without changing the response schema."""
+
+        aggregated = OrderedDict()
+        for item in order_items:
+            product_id = getattr(item, 'product_id', None)
+            product_name = getattr(getattr(item, 'product', None), 'name', '')
+            unit = getattr(item, 'unit', '')
+            price = getattr(item, 'price', Decimal('0'))
+            key = (product_id, product_name, unit, price)
+            if key not in aggregated:
+                aggregated[key] = {
+                    'product_id': product_id,
+                    'product_name': product_name,
+                    'quantity': Decimal('0'),
+                    'price': price,
+                    'unit': unit,
+                }
+            aggregated[key]['quantity'] += Decimal(getattr(item, 'quantity', 0))
+        return list(aggregated.values())
+
     def _sort_records(self, records: Iterable[dict]) -> List[dict]:
         return sorted(
             records,
@@ -168,17 +189,7 @@ class CustomerStatementView(StatementViewBase):
         )
         records = []
         for order in qs:
-            items = [
-                {
-                    'product_id': item.product_id,
-                    'product_name': item.product.name,
-                    'quantity': item.quantity,
-                    'price': item.price,
-                    'unit': item.unit,
-                }
-                for item in order.items.all()
-            ]
-            print(items)
+            items = self._aggregate_items(order.items.all())
             records.append(
                 self._build_record(
                     counterparty_id=order.customer_id,
@@ -209,16 +220,7 @@ class CustomerStatementView(StatementViewBase):
         )
         records = []
         for order in qs:
-            items = [
-                {
-                    'product_id': item.product_id,
-                    'product_name': item.product.name,
-                    'quantity': item.quantity,
-                    'price': item.price,
-                    'unit': item.unit,
-                }
-                for item in order.items.all()
-            ]
+            items = self._aggregate_items(order.items.all())
             records.append(
                 self._build_record(
                     counterparty_id=order.customer_id,
@@ -309,19 +311,11 @@ class SupplierStatementView(StatementViewBase):
                 status=business_models.PurchaseOrderStatusEnum.APPROVED,
             )
             .select_related('supplier')
+            .prefetch_related('items__product')
         )
         records = []
         for order in qs:
-            items = [
-                {
-                    'product_id': item.product_id,
-                    'product_name': item.product.name,
-                    'quantity': item.quantity,
-                    'price': item.price,
-                    'unit': item.unit,
-                }
-                for item in order.items.all()
-            ]
+            items = self._aggregate_items(order.items.all())
             records.append(
                 self._build_record(
                     counterparty_id=order.supplier_id,
@@ -348,19 +342,11 @@ class SupplierStatementView(StatementViewBase):
                 status=business_models.PurchaseReturnStatusEnum.APPROVED,
             )
             .select_related('supplier')
+            .prefetch_related('items__product')
         )
         records = []
         for order in qs:
-            items = [
-                {
-                    'product_id': item.product_id,
-                    'product_name': item.product.name,
-                    'quantity': item.quantity,
-                    'price': item.price,
-                    'unit': item.unit,
-                }
-                for item in order.items.all()
-            ]
+            items = self._aggregate_items(order.items.all())
             records.append(
                 self._build_record(
                     counterparty_id=order.supplier_id,