refactor: Change variable definition

Author: calvin-codecov

services/billing.py

@@ -158,11 +158,13 @@ def cancel_and_refund(
     ):
         stripe.Subscription.cancel(owner.stripe_subscription_id)
 
-        start_of_last_period = (
-            current_subscription_datetime - relativedelta(months=1)
-            if subscription_plan_interval == "month"
-            else current_subscription_datetime - relativedelta(years=1)
-        )
+        start_of_last_period = current_subscription_datetime - relativedelta(months=1)
+        invoice_grace_period_start = current_subscription_datetime - relativedelta(days=1)
+
+        if subscription_plan_interval == "year":
+            start_of_last_period = current_subscription_datetime - relativedelta(years=1)
+            invoice_grace_period_start = current_subscription_datetime - relativedelta(days=3)
+
         invoices_list = stripe.Invoice.list(
             subscription=owner.stripe_subscription_id,
             status="paid",
@@ -171,11 +173,7 @@ def cancel_and_refund(
                 "created.lt": int(current_subscription_datetime.timestamp()),
             },
         )
-        invoice_grace_period_start = (
-            current_subscription_datetime - relativedelta(days=1)
-            if subscription_plan_interval == "month"
-            else current_subscription_datetime - relativedelta(days=3)
-        )
+
         # we only want to refund the invoices for the latest, current period
         recently_paid_invoices_list = [
             invoice