Fix status code: split pipeline load from input parsing

pipeline loading -> 500
input parsing -> 400

Signed-off-by: Raphael Glon <oOraph@users.noreply.github.com>

api_inference_community/routes.py

@@ -95,18 +95,19 @@ async def pipeline_route(request: Request) -> Response:
     ] and already_left(request):
         logger.info("Discarding request as the caller already left")
         return Response(status_code=204)
-
     payload = await request.body()
+
     task = os.environ["TASK"]
+
     if os.getenv("DEBUG", "0") in {"1", "true"}:
         pipe = request.app.get_pipeline()
+
     try:
         pipe = request.app.get_pipeline()
         try:
             sampling_rate = pipe.sampling_rate
         except Exception:
             sampling_rate = None
-        inputs, params = normalize_payload(payload, task, sampling_rate=sampling_rate)
     except ValidationError as e:
         errors = []
         for error in e.errors():
@@ -122,6 +123,16 @@ async def pipeline_route(request: Request) -> Response:
     except Exception as e:
         return JSONResponse({"error": str(e)}, status_code=500)
 
+    try:
+        inputs, params = normalize_payload(payload, task, sampling_rate=sampling_rate)
+    except EnvironmentError as e:
+        logger.error("Error while parsing input %s", e)
+        return JSONResponse({"error": str(e)}, status_code=500)
+    except Exception as e:
+        # We assume the payload is bad -> 400
+        logger.warning("Error while parsing input %s", e)
+        return JSONResponse({"error": str(e)}, status_code=400)
+
     accept = request.headers.get("accept", "")
     lora_adapter = request.headers.get("lora")
     if lora_adapter: