From 32e66c7ef9976cad7baa8d9e0656d539f68b89f2 Mon Sep 17 00:00:00 2001
From: moonlitgrace <moonlitgrace.gaia@gmail.com>
Date: Fri, 27 Dec 2024 16:49:16 +0530
Subject: [PATCH] refactor: use annotated ratio property on comment model for
 optimzation

---
 backend/apps/comment/api/v1/serializers.py |  2 +-
 backend/apps/comment/managers.py           | 11 +++++++++++
 backend/apps/comment/models.py             |  4 ++--
 backend/apps/quib/api/v1/viewsets.py       |  2 +-
 backend/common/mixins/model_mixins.py      |  9 ---------
 5 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/backend/apps/comment/api/v1/serializers.py b/backend/apps/comment/api/v1/serializers.py
index eef8793c..49ce5e42 100644
--- a/backend/apps/comment/api/v1/serializers.py
+++ b/backend/apps/comment/api/v1/serializers.py
@@ -34,7 +34,7 @@ def create(self, validated_data):
 
 class CommentDetailSerializer(serializers.ModelSerializer):
     quibbler = ProfileBasicSerializer(allow_null=True)
-    ratio = serializers.ReadOnlyField()
+    ratio = serializers.IntegerField()
 
     class Meta:
         model = Comment
diff --git a/backend/apps/comment/managers.py b/backend/apps/comment/managers.py
index db9d4b13..ab254007 100644
--- a/backend/apps/comment/managers.py
+++ b/backend/apps/comment/managers.py
@@ -1,3 +1,4 @@
+from django.db.models import Count, ExpressionWrapper, F, IntegerField
 from django_ltree.managers import TreeManager
 
 
@@ -18,3 +19,13 @@ def clean_up_soft_deleted(self):
         for comment in self.filter(deleted=True):
             if comment.children_count == 0:
                 comment.delete()
+
+    def with_annotated_ratio(self):
+        # returns annotated ratio property
+        return self.annotate(
+            upvote_count=Count('upvotes'),
+            downvote_count=Count('downvotes'),
+            ratio=ExpressionWrapper(
+                F('upvote_count') - F('downvote_count'), output_field=IntegerField()
+            ),
+        )
diff --git a/backend/apps/comment/models.py b/backend/apps/comment/models.py
index 57de1d46..afcc916a 100644
--- a/backend/apps/comment/models.py
+++ b/backend/apps/comment/models.py
@@ -4,14 +4,14 @@
 from django_ltree.models import TreeModel
 
 from apps.user.models import Profile
-from common.mixins.model_mixins import CreatedAtMixin, RatioMixin
+from common.mixins.model_mixins import CreatedAtMixin
 
 from .managers import CommentManager
 
 # Create your models here.
 
 
-class Comment(CreatedAtMixin, RatioMixin, TreeModel):
+class Comment(CreatedAtMixin, TreeModel):
     quibbler = models.ForeignKey(
         Profile, on_delete=models.SET_NULL, null=True, verbose_name=_('quibbler')
     )
diff --git a/backend/apps/quib/api/v1/viewsets.py b/backend/apps/quib/api/v1/viewsets.py
index 6536538e..70596e8a 100644
--- a/backend/apps/quib/api/v1/viewsets.py
+++ b/backend/apps/quib/api/v1/viewsets.py
@@ -32,7 +32,7 @@ def comments(self, request, pk=None):
         context = {'request': request}
 
         if request.method == HTTPMethod.GET:
-            comments = quib_instance.comments.all()
+            comments = quib_instance.comments.with_annotated_ratio()  # pyright: ignore
             serializer = CommentDetailSerializer(comments, many=True, context=context)
 
             return response.Response(serializer.data, status=status.HTTP_200_OK)
diff --git a/backend/common/mixins/model_mixins.py b/backend/common/mixins/model_mixins.py
index 31580ec1..cb4897b3 100644
--- a/backend/common/mixins/model_mixins.py
+++ b/backend/common/mixins/model_mixins.py
@@ -49,12 +49,3 @@ class ShortUUIDMixin(models.Model):
 
     class Meta:  # pyright: ignore
         abstract = True
-
-
-class RatioMixin(models.Model):
-    @property
-    def ratio(self):
-        return self.upvotes.count() - self.downvotes.count()  # type: ignore
-
-    class Meta:
-        abstract = True