[REFACTOR] Only displayed last active cart in user auth serializer

authentication/serializers.py

+import datetime
 from django.contrib.auth.models import Group
 from rest_framework import serializers, exceptions
 from dj_rest_auth.serializers import LoginSerializer
@@ -23,12 +24,15 @@ class UserAuthSerializer(serializers.ModelSerializer):
         if instance.is_staff:
             result['role'] = 'admin'
 
+        result['transaction_status'] = None
+        result['cart_id'] = None
+
         if instance.cart.exists():
-            result['transaction_status'] = instance.cart.last().transaction_status
-            result['cart_id'] = instance.cart.last().id
-        else:
-            result['transaction_status'] = None
-            result['cart_id'] = None
+            active_carts = instance.cart.filter(program_end_date__gte=datetime.date.today())
+            if len(active_carts) > 0:
+                last_active_cart = active_carts.order_by('-id')[0]
+                result['transaction_status'] = last_active_cart.transaction_status
+                result['cart_id'] = last_active_cart.id
 
         return result