Features: 1) Add logging for saving vendor responses and processing attributes; 2) Update process_attribute to return AttributeValue upon success.

Fixes: 1) Replace missing return values with `None` in `process_attribute` for clarity; 2) Correct typo in debug log messaging.

Extra: 1) Update method definitions for readability; 2) Improve logging granularity and structure.

engine/core/vendors/__init__.py

@@ -155,8 +155,12 @@ class AbstractVendor:
                     filename = f"response_{timestamp}.json"
                     content = ContentFile(json_bytes)
 
+                self.log(LogLevel.DEBUG, f"Saving vendor's response to {filename}")
+
                 vendor_instance.last_processing_response.save(filename, content, save=True)
 
+                self.log(LogLevel.DEBUG, f"Saved vendor's response to {filename} successfuly!")
+
                 return
         raise VendorDebuggingError("Could not save response")
 
@@ -451,17 +455,23 @@ class AbstractVendor:
 
         return attr
 
-    def process_attribute(self, key: str, value: Any, product: Product, attr_group: AttributeGroup) -> None:
+    def process_attribute(
+        self, key: str, value: Any, product: Product, attr_group: AttributeGroup
+    ) -> AttributeValue | None:
+        self.log(
+            LogLevel.DEBUG, f"Trying to save attribute {key} with value {value} to {attr_group.name} of {product.pk}"
+        )
+
         if not value:
             self.log(LogLevel.WARNING, f"No value for attribute {key!r} at {product.name!r}...")
-            return
+            return None
 
         if not attr_group:
             self.log(LogLevel.WARNING, f"No group for attribute {key!r} at {product.name!r}...")
-            return
+            return None
 
         if key in self.blocked_attributes:
-            return
+            return None
 
         value, attr_value_type = self.auto_convert_value(value)
 
@@ -498,18 +508,25 @@ class AbstractVendor:
                         raise
         except IntegrityError:
             self.log(LogLevel.WARNING, f"IntegrityError while processing attribute {key!r}...")
-            return
+            return None
 
         if not is_created:
-            return
+            return None
 
-        AttributeValue.objects.get_or_create(
+        av, _ = AttributeValue.objects.get_or_create(
             attribute=attribute,
             value=value,
             product=product,
             defaults={"is_active": True},
         )
 
+        self.log(
+            LogLevel.DEBUG,
+            f"Succesfully saved attribute {key} with value {value} to {attr_group.name} of {product.pk} into {av.uuid}",
+        )
+
+        return av
+
     def update_stock(self) -> None:
         pass