Merge pull request #2048 from jelanmathewjames/dev

refactor: optimize leaderboard ranking query

api/launchpad/launchpad_views.py

@@ -1,6 +1,5 @@
-from django.db.models import Sum, Max, Prefetch, F, OuterRef, Subquery, Window, IntegerField
-from django.db.models.functions import Rank
-from django.db import connection
+from django.db.models import Sum, Max, Prefetch, F, OuterRef, Subquery, IntegerField
+
 from rest_framework.views import APIView
 
 from .serializers import LaunchpadLeaderBoardSerializer
@@ -50,13 +49,6 @@ def get(self, request):
             time_=Max("karma_activity_log_user__created_at"),
         ).order_by("-karma", "time_")
 
-        users = users.annotate(
-            rank=Window(
-                expression=Rank(),
-                order_by=F("karma").desc(),
-            )
-        )
-
         paginated_queryset = CommonUtils.get_paginated_queryset(
             users,
             request,

api/launchpad/serializers.py

@@ -1,9 +1,14 @@
+from django.db.models import Sum, Max, Prefetch, F, OuterRef, Subquery, Window, IntegerField
+from django.db.models.functions import Rank
+
 from rest_framework import serializers
 
 from db.user import User
+from db.organization import UserOrganizationLink
+from db.task import KarmaActivityLog
 
 class LaunchpadLeaderBoardSerializer(serializers.ModelSerializer):
-    rank = serializers.IntegerField()
+    rank = serializers.SerializerMethodField()
     karma = serializers.IntegerField()
     org = serializers.CharField()
     district_name = serializers.CharField()
@@ -12,3 +17,45 @@ class LaunchpadLeaderBoardSerializer(serializers.ModelSerializer):
     class Meta:
         model = User
         fields = ("rank", "full_name", "karma", "org", "district_name", "state")
+
+    def get_rank(self, obj):
+        total_karma_subquery = KarmaActivityLog.objects.filter(
+            user=OuterRef('id'),
+            task__event='launchpad',
+            appraiser_approved=True,
+        ).values('user').annotate(
+            total_karma=Sum('karma')
+        ).values('total_karma')
+        allowed_org_types = ["College", "School", "Company"]
+
+        intro_task_completed_users = KarmaActivityLog.objects.filter(
+            task__event='launchpad',
+            appraiser_approved=True,
+            task__hashtag='#lp24-introduction',
+        ).values('user')
+
+        users = User.objects.filter(
+            karma_activity_log_user__task__event="launchpad",
+            karma_activity_log_user__appraiser_approved=True,
+            id__in=intro_task_completed_users
+        ).prefetch_related(
+            Prefetch(
+                "user_organization_link_user",
+                queryset=UserOrganizationLink.objects.filter(org__org_type__in=allowed_org_types),
+            )
+        ).filter(
+            user_organization_link_user__id__in=UserOrganizationLink.objects.filter(
+                org__org_type__in=allowed_org_types
+            ).values("id")
+        ).annotate(
+            karma=Subquery(total_karma_subquery, output_field=IntegerField()),
+            time_=Max("karma_activity_log_user__created_at"),
+        ).order_by("-karma", "time_").annotate(
+            rank=Window(
+                expression=Rank(),
+                order_by=[F("karma").desc(), F("time_").asc()]
+            )
+        )
+
+        return users.get(id=obj.id).rank
+