chore(): small improvements

src/backend/apps/notifications/services.py

@@ -82,11 +82,15 @@ def rule_create(
     event_type: str,
     channel: NotificationChannel,
     experiment: Any | None = None,
+    rate_limit_window_seconds: int = 60,
+    rate_limit_max_notifications: int = 1,
 ) -> NotificationRule:
     rule = NotificationRule(
         event_type=event_type,
         channel=channel,
         experiment=experiment,
+        rate_limit_window_seconds=rate_limit_window_seconds,
+        rate_limit_max_notifications=rate_limit_max_notifications,
     )
     rule.save()
     return rule
@@ -97,7 +101,12 @@ def rule_update(
     rule: NotificationRule,
     **fields: Any,
 ) -> NotificationRule:
-    allowed = {"event_type", "is_active"}
+    allowed = {
+        "event_type",
+        "is_active",
+        "rate_limit_window_seconds",
+        "rate_limit_max_notifications",
+    }
     for key in fields:
         if key not in allowed:
             raise ValueError(f"Field '{key}' cannot be updated.")
@@ -149,12 +158,17 @@ def notification_enqueue(
 
     logs: list[NotificationLog] = []
     for rule in rules:
-        event_key = _build_event_key(event_type, payload)
-        if NotificationLog.objects.filter(
+        event_key = _build_event_key(
+            event_type,
+            payload,
+            rule.rate_limit_window_seconds,
+        )
+        sent_or_pending = NotificationLog.objects.filter(
             event_key=event_key,
             channel=rule.channel,
             status__in=[NotificationStatus.PENDING, NotificationStatus.SENT],
-        ).exists():
+        ).count()
+        if sent_or_pending >= rule.rate_limit_max_notifications:
             continue
 
         log = NotificationLog.objects.create(
@@ -176,8 +190,13 @@ def notification_enqueue(
     return logs
 
 
-def _build_event_key(event_type: str, payload: NotificationPayload) -> str:
-    bucket = int(timezone.now().timestamp()) // 60
+def _build_event_key(
+    event_type: str,
+    payload: NotificationPayload,
+    window_seconds: int,
+) -> str:
+    normalized_window = max(window_seconds, 1)
+    bucket = int(timezone.now().timestamp()) // normalized_window
     return f"{event_type}:{payload.experiment_id}:{bucket}"