Add backend for set all viewed and delete all

backend/backend.py

@@ -242,6 +242,41 @@ def list_subscription_notifications(
     ]
 
 
+@app.post("/subscriptions/{subscription_id}/notifications")
+def set_all_notifications_viewed(
+    subscription_id: int,
+    current_user: User = Depends(get_current_user),
+):
+    db = SessionLocal()
+    notifications = (
+        db.query(Notification)
+        .filter(Notification.subscription_id == subscription_id)
+        .all()
+    )
+    for notification in notifications:
+        notification.viewed = True
+    db.commit()
+    db.close()
+    return {"message": "Notifications marked as viewed"}
+
+
+@app.delete("/subscriptions/{subscription_id}/notifications")
+def remove_subscription_notifications(
+    subscription_id: int, current_user: User = Depends(get_current_user)
+):
+    db = SessionLocal()
+    notifications = (
+        db.query(Notification)
+        .filter(Notification.subscription_id == subscription_id)
+        .all()
+    )
+    for notification in notifications:
+        db.delete(notification)
+    db.commit()
+    db.close()
+    return {"message": "Notifications removed"}
+
+
 @app.get("/notifications")
 def list_notifications(current_user: User = Depends(get_current_user)):
     db = SessionLocal()