feat: improve exception handlers

Author: edwardzjl

api/chatbot/exception_handlers.py

@@ -1,32 +1,64 @@
 import logging
 
 from fastapi import FastAPI, status
-from fastapi.encoders import jsonable_encoder
 from fastapi.requests import Request
 from fastapi.responses import JSONResponse
-
-from sqlalchemy.exc import NoResultFound
-
+from sqlalchemy.exc import IntegrityError, NoResultFound
 
 logger = logging.getLogger(__name__)
 
 
 def register_exception_handlers(app: FastAPI):
-    app.add_exception_handler(NoResultFound, not_found_error_handler)
-    app.add_exception_handler(Exception, exception_handler)
+    app.add_exception_handler(NoResultFound, handle_no_result_found)
+    app.add_exception_handler(IntegrityError, handle_integrity_error)
+    app.add_exception_handler(ValueError, handle_value_error)
+    app.add_exception_handler(PermissionError, handle_permission_error)
+    app.add_exception_handler(ConnectionError, handle_connection_error)
+    app.add_exception_handler(Exception, handle_generic_exception)
 
 
-def not_found_error_handler(request: Request, exc: NoResultFound):
+def handle_no_result_found(request: Request, exc: NoResultFound):
     return JSONResponse(
         status_code=status.HTTP_404_NOT_FOUND,
-        content=jsonable_encoder({"detail": str(exc)}),
+        content={"message": "Resource not found", "detail": str(exc)},
+    )
+
+
+def handle_integrity_error(request: Request, exc: IntegrityError):
+    return JSONResponse(
+        status_code=status.HTTP_409_CONFLICT,
+        content={"message": "Resource already exists", "detail": str(exc)},
+    )
+
+
+def handle_value_error(request: Request, exc: ValueError):
+    logger.exception("Unhandled ValueError: %s", exc)
+    return JSONResponse(
+        status_code=status.HTTP_400_BAD_REQUEST,
+        content={"message": "Invalid input", "detail": str(exc)},
+    )
+
+
+def handle_permission_error(request: Request, exc: PermissionError):
+    logger.exception("Unhandled PermissionError: %s", exc)
+    return JSONResponse(
+        status_code=status.HTTP_403_FORBIDDEN,
+        content={"message": "Permission denied", "detail": str(exc)},
+    )
+
+
+def handle_connection_error(request: Request, exc: ConnectionError):
+    logger.exception("Unhandled ConnectionError: %s", exc)
+    return JSONResponse(
+        status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+        content={"message": "Service unavailable", "detail": str(exc)},
     )
 
 
-def exception_handler(request: Request, exc: Exception):
-    """Global exception handler."""
-    logger.exception("Unhandled error during request %s", request)
+def handle_generic_exception(request: Request, exc: Exception):
+    logger.exception("Unhandled exception: %s", exc)
     return JSONResponse(
         status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-        content={"detail": "server error"},
+        # Do not expose error details
+        content={"message": "Server error"},
     )