Handle grace period days

crates/component_subsystem/billing/src/stripe/webhook_event_handlers/customer_subscription/calculate_subscription_end_date.rs

@@ -1,9 +1,19 @@
 use chrono::{Duration, NaiveDateTime};
 use crate::stripe::webhook_event_handlers::customer_subscription::subscription_event_extractor::SubscriptionSummary;
+use once_cell::sync::Lazy;
 use std::ops::Add;
 
+const SUBSCRIPTION_GRACE_DAYS: Lazy<Duration> = Lazy::new(|| {
+  Duration::days(2)
+});
+
 #[inline]
 pub fn calculate_subscription_end_date(subscription_summary: &SubscriptionSummary) -> NaiveDateTime {
-  let SUBSCRIPTION_GRACE_DAYS = Duration::days(2);
-  subscription_summary.current_billing_period_end.add(SUBSCRIPTION_GRACE_DAYS)
+  let mut subscription_end = subscription_summary.current_billing_period_end;
+
+  if !subscription_summary.cancel_at_period_end {
+    subscription_end = subscription_end.add(*SUBSCRIPTION_GRACE_DAYS);
+  }
+
+  subscription_end
 }