refactor(core): simplify code for price aggregation and formatting

Improve readability by removing unnecessary parentheses in `min_price` and `max_price` methods in `models.py`. Enhance JSON serialization error formatting in `views.py` and adjustment of field formatting in serializers. No functional changes, purely stylistic updates for code maintainability.

engine/core/models.py

@@ -470,21 +470,15 @@ class Category(NiceModel, MPTTModel):
 
     @cached_property
     def min_price(self) -> Decimal:
-        return (
+        return self.products.filter(is_active=True, stocks__is_active=True).aggregate(
-            self.products.filter(is_active=True, stocks__is_active=True).aggregate(
             Min("stocks__price")
-            )["stocks__price__min"]
+        )["stocks__price__min"] or Decimal("0.00")
-            or Decimal("0.00")
-        )
 
     @cached_property
     def max_price(self) -> Decimal:
-        return (
+        return self.products.filter(is_active=True, stocks__is_active=True).aggregate(
-            self.products.filter(is_active=True, stocks__is_active=True).aggregate(
             Max("stocks__price")
-            )["stocks__price__max"]
+        )["stocks__price__max"] or Decimal("0.00")
-            or Decimal("0.00")
-        )
 
     @cached_property
     def seo_description(self) -> str:

engine/core/serializers/detail.py

@@ -112,7 +112,6 @@ class CategoryDetailSerializer(ModelSerializer):
         return []
 
 
-
 class BrandDetailSerializer(ModelSerializer):
     categories = CategorySimpleSerializer(many=True)
     description = SerializerMethodField()
@@ -286,7 +285,10 @@ class ProductDetailSerializer(ModelSerializer):
     quantity = SerializerMethodField()
     feedbacks_count = SerializerMethodField()
     discount_price = DecimalField(
-        max_digits=12, decimal_places=2, read_only=True, allow_null=True,
+        max_digits=12,
+        decimal_places=2,
+        read_only=True,
+        allow_null=True,
         coerce_to_string=False,
     )
     personal_orders_only = SerializerMethodField()

engine/core/serializers/simple.py

@@ -147,7 +147,10 @@ class ProductSimpleSerializer(ModelSerializer):
     feedbacks_count = SerializerMethodField()
     personal_orders_only = SerializerMethodField()
     discount_price = DecimalField(
-        max_digits=12, decimal_places=2, read_only=True, allow_null=True,
+        max_digits=12,
+        decimal_places=2,
+        read_only=True,
+        allow_null=True,
         coerce_to_string=False,
     )
 

engine/core/views.py

@@ -144,7 +144,9 @@ class CustomGraphQLView(FileUploadGraphQLView):
         def _default(obj):
             if isinstance(obj, Decimal):
                 return float(obj)
-            raise TypeError(f"Object of type {type(obj).__name__} is not JSON serializable")
+            raise TypeError(
+                f"Object of type {type(obj).__name__} is not JSON serializable"
+            )
 
         opts = orjson.OPT_NON_STR_KEYS
         if pretty or request.GET.get("pretty"):