Add device existence check in CreatePaymentView to handle invalid device IDs

billing/views.py

@@ -1,5 +1,6 @@
 # Create your views here.
 # billing/views.py
+from django.shortcuts import get_object_or_404
 from .models import Payment, Device
 from datetime import datetime, timedelta
 import requests
@@ -29,6 +30,13 @@ class CreatePaymentView(StaffEditorPermissionMixin, generics.CreateAPIView):
         device_ids = data.get("device_ids", [])
         print(amount, number_of_months, device_ids)
 
+        for device_id in device_ids:
+            device = get_object_or_404(Device, id=device_id)
+            if not device:
+                return Response(
+                    {"message": f"Device with id {device_id} not found."},
+                    status=status.HTTP_400_BAD_REQUEST,
+                )
         if not amount or not number_of_months:
             return Response(
                 {"message": "amount and number_of_months are required."},