From 658e7990762b99cfb28a33b1f2da7e948f1e209e Mon Sep 17 00:00:00 2001
From: Egor fureunoir Gorbunov <contact@fureunoir.com>
Date: Thu, 19 Jun 2025 10:49:56 +0300
Subject: [PATCH] Features: 1) Add ordered filtering logic for `filter_name`
 methods across products, categories, and brands; 2) Enhance query processing
 with `Case` and `When` operations for precise ordering;

Fixes: 1) Ensure queryset returns `none()` when no valid UUIDs are found in filters;

Extra: 1) Refactor import statements for readability; 2) Clean up and consolidate redundant filter logic across multiple `filter_name` methods;
---
 core/filters.py | 79 +++++++++++++++++++++++++++++++------------------
 1 file changed, 51 insertions(+), 28 deletions(-)

diff --git a/core/filters.py b/core/filters.py
index bc9929c4..35076d9e 100644
--- a/core/filters.py
+++ b/core/filters.py
@@ -3,7 +3,18 @@ import logging
 import uuid
 
 from django.core.exceptions import BadRequest
-from django.db.models import Avg, Exists, FloatField, OuterRef, Q, Subquery, Value
+from django.db.models import (
+    Avg,
+    Case,
+    Exists,
+    FloatField,
+    IntegerField,
+    OuterRef,
+    Q,
+    Subquery,
+    Value,
+    When,
+)
 from django.db.models.functions import Coalesce
 from django.utils.http import urlsafe_base64_decode
 from django.utils.translation import gettext_lazy as _
@@ -131,15 +142,19 @@ class ProductFilter(FilterSet):
 
     def filter_name(self, queryset, _name, value):
         search_results = process_query(query=value, request=self.request)["products"]
-        if search_results:
-            queryset = queryset.filter(
-                uuid__in=[
-                    result.get("uuid")
-                    for result in search_results
-                    if result.get("uuid") is not None
-                ]
-            )
-        return queryset
+        uuids = [res["uuid"] for res in search_results if res.get("uuid")]
+
+        if not uuids:
+            return queryset.none()
+
+        ordering = Case(
+            *[When(uuid=uuid_, then=pos) for pos, uuid_ in enumerate(uuids)],
+            output_field=IntegerField(),
+        )
+
+        return (
+            queryset.filter(uuid__in=uuids).annotate(_order=ordering).order_by("_order")
+        )
 
     def filter_include_flag(self, queryset, **_kwargs):
         if not self.data.get("category_uuid"):
@@ -397,15 +412,19 @@ class CategoryFilter(FilterSet):
 
     def filter_name(self, queryset, _name, value):
         search_results = process_query(query=value, request=self.request)["categories"]
-        if search_results:
-            queryset = queryset.filter(
-                uuid__in=[
-                    result.get("uuid")
-                    for result in search_results
-                    if result.get("uuid") is not None
-                ]
-            )
-        return queryset
+        uuids = [res["uuid"] for res in search_results if res.get("uuid")]
+
+        if not uuids:
+            return queryset.none()
+
+        ordering = Case(
+            *[When(uuid=uuid_, then=pos) for pos, uuid_ in enumerate(uuids)],
+            output_field=IntegerField(),
+        )
+
+        return (
+            queryset.filter(uuid__in=uuids).annotate(_order=ordering).order_by("_order")
+        )
 
     def filter_whole_categories(self, queryset, _name, value):
         has_own_products = Exists(Product.objects.filter(category=OuterRef("pk")))
@@ -455,15 +474,19 @@ class BrandFilter(FilterSet):
 
     def filter_name(self, queryset, _name, value):
         search_results = process_query(query=value, request=self.request)["brands"]
-        if search_results:
-            queryset = queryset.filter(
-                uuid__in=[
-                    result.get("uuid")
-                    for result in search_results
-                    if result.get("uuid") is not None
-                ]
-            )
-        return queryset
+        uuids = [res["uuid"] for res in search_results if res.get("uuid")]
+
+        if not uuids:
+            return queryset.none()
+
+        ordering = Case(
+            *[When(uuid=uuid_, then=pos) for pos, uuid_ in enumerate(uuids)],
+            output_field=IntegerField(),
+        )
+
+        return (
+            queryset.filter(uuid__in=uuids).annotate(_order=ordering).order_by("_order")
+        )
 
 
 class FeedbackFilter(FilterSet):