From 2fb338bc59af5b2ce5eef297b3106e900e3261f2 Mon Sep 17 00:00:00 2001
From: Anatoly <a.feteleu@spider.ru>
Date: Mon, 23 Dec 2019 12:59:39 +0300
Subject: [PATCH] refactored method to get similar list on entities (see todo:
 establishment/models.py)

---
 apps/establishment/models.py    |  8 +++++---
 apps/establishment/views/web.py |  8 ++++----
 apps/product/views/common.py    | 28 ++++++++++++++++++++--------
 3 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/apps/establishment/models.py b/apps/establishment/models.py
index e5514bb8..8ad1663c 100644
--- a/apps/establishment/models.py
+++ b/apps/establishment/models.py
@@ -253,8 +253,9 @@ class EstablishmentQuerySet(models.QuerySet):
         return Subquery(
             self.similar_base(establishment)
                 .filter(**filters)
-                .order_by('distance')[:settings.LIMITING_QUERY_OBJECTS]
-                .values('id')
+                .order_by('distance')
+                .distinct()
+                .values_list('id', flat=True)[:settings.LIMITING_QUERY_OBJECTS]
         )
 
     def similar_restaurants(self, restaurant):
@@ -271,7 +272,8 @@ class EstablishmentQuerySet(models.QuerySet):
                 'establishment_gallery__is_main': True,
             }
         )
-        return self.filter(id__in=ids_by_subquery) \
+        # todo: fix this - replace ids_by_subquery.queryset on ids_by_subquery
+        return self.filter(id__in=ids_by_subquery.queryset) \
                    .annotate_intermediate_public_mark() \
                    .annotate_mark_similarity(mark=restaurant.public_mark) \
                    .order_by('mark_similarity') \
diff --git a/apps/establishment/views/web.py b/apps/establishment/views/web.py
index d94be1d5..b4e6f776 100644
--- a/apps/establishment/views/web.py
+++ b/apps/establishment/views/web.py
@@ -44,7 +44,7 @@ class EstablishmentListView(EstablishmentMixinView, generics.ListAPIView):
 class EstablishmentSimilarView(EstablishmentListView):
     """Resource for getting a list of similar establishments."""
     serializer_class = serializers.EstablishmentSimilarSerializer
-    pagination_class = PortionPagination
+    pagination_class = None
 
     def get_base_object(self):
         """
@@ -105,7 +105,7 @@ class RestaurantSimilarListView(EstablishmentSimilarView):
         base_establishment = self.get_base_object()
 
         if base_establishment:
-            return qs.similar_restaurants(base_establishment)
+            return qs.similar_restaurants(base_establishment)[:settings.QUERY_OUTPUT_OBJECTS]
         else:
             return EstablishmentMixinView.get_queryset(self) \
                                          .none()
@@ -120,7 +120,7 @@ class WinerySimilarListView(EstablishmentSimilarView):
         base_establishment = self.get_base_object()
 
         if base_establishment:
-            return qs.similar_wineries(base_establishment)
+            return qs.similar_wineries(base_establishment)[:settings.QUERY_OUTPUT_OBJECTS]
         else:
             return qs.none()
 
@@ -134,7 +134,7 @@ class ArtisanProducerSimilarListView(EstablishmentSimilarView):
         base_establishment = self.get_base_object()
 
         if base_establishment:
-            return qs.similar_artisans_producers(base_establishment)
+            return qs.similar_artisans_producers(base_establishment)[:settings.QUERY_OUTPUT_OBJECTS]
         else:
             return qs.none()
 
diff --git a/apps/product/views/common.py b/apps/product/views/common.py
index dbb24e53..5eeaccf2 100644
--- a/apps/product/views/common.py
+++ b/apps/product/views/common.py
@@ -1,12 +1,13 @@
 """Product app views."""
-from rest_framework import generics, permissions
+from django.conf import settings
 from django.shortcuts import get_object_or_404
-from product.models import Product
+from rest_framework import generics, permissions
+
 from comment.models import Comment
-from product import filters, serializers
 from comment.serializers import CommentRUDSerializer
+from product import filters, serializers
+from product.models import Product
 from utils.views import FavoritesCreateDestroyMixinView
-from utils.pagination import PortionPagination
 
 
 class ProductBaseView(generics.GenericAPIView):
@@ -35,7 +36,15 @@ class ProductListView(ProductBaseView, generics.ListAPIView):
 class ProductSimilarView(ProductListView):
     """Resource for getting a list of similar product."""
     serializer_class = serializers.ProductBaseSerializer
-    pagination_class = PortionPagination
+    pagination_class = None
+
+    def get_base_object(self):
+        """
+        Return base product instance for a getting list of similar products.
+        """
+        product = get_object_or_404(Product.objects.all(),
+                                    slug=self.kwargs.get('slug'))
+        return product
 
 
 class ProductDetailView(ProductBaseView, generics.RetrieveAPIView):
@@ -95,7 +104,10 @@ class SimilarListView(ProductSimilarView):
 
     def get_queryset(self):
         """Overridden get_queryset method."""
-        return super().get_queryset() \
-                      .has_location() \
-                      .similar(slug=self.kwargs.get('slug'))
+        qs = super(SimilarListView, self).get_queryset()
+        base_product = self.get_base_object()
 
+        if base_product:
+            return qs.has_location().similar(slug=self.kwargs.get('slug'))[:settings.QUERY_OUTPUT_OBJECTS]
+        else:
+            return qs.none()