fix(app): raise error if no audio selected

src/emotion_analysis/app/on_callback.py

@@ -1,11 +1,15 @@
 from pathlib import Path
 
+from gradio import Error
+
 from ..services import Classifier
 
 
 def on_classify(model: Classifier):
     def fn(audio: Path | str):
-        probs: dict[int, float] = model.predict(audio, return_probs=True)  # type: ignore
-        return list(probs.values())
+        if not audio:
+            Error("No Audio selected")
+            return [None] * len(model.id2label.keys())
+        return [f"{prob:.03%}" for prob in model.predict(audio)]
 
     return fn