From ed28a4090054a0853652c17e93db75a7c66c0a33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=A8=E6=98=8E=E8=A8=80?=
 <292125771+hazelp343@users.noreply.github.com>
Date: Mon, 31 Aug 2026 02:19:49 +0800
Subject: [PATCH] fix: return 404 for not-found session in ideas_api.py cancel
 endpoint

---
 backend/app/modules/idea/ideas_api.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/backend/app/modules/idea/ideas_api.py b/backend/app/modules/idea/ideas_api.py
index f524697a..a0be3c50 100644
--- a/backend/app/modules/idea/ideas_api.py
+++ b/backend/app/modules/idea/ideas_api.py
@@ -520,9 +520,15 @@ async def cancel_session(session_id: str) -> SessionResponse:
         session = service.cancel_session(session_id)
         return _session_to_response(session)
     except ValueError as e:
+        msg = str(e)
+        if "not found" in msg:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=msg
+            )
         raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=str(e)
+            status_code=status.HTTP_409_CONFLICT,
+            detail=msg
         )