✅ Robust file handling: fixed NamedString and fallback logic

app.py

@@ -65,20 +65,19 @@ def process_file(file):
     try:
         ext = os.path.splitext(file.name)[1].lower()
         with tempfile.NamedTemporaryFile(delete=False, suffix=ext) as tmp:
-            # Ensure we always write bytes regardless of file type
-	# Ensure we always write bytes regardless of file type
-if hasattr(file, "read"):
-    file_bytes = file.read()
-elif isinstance(file, str):
-    with open(file, "rb") as f:
-        file_bytes = f.read()
-elif isinstance(file, bytes):
-    file_bytes = file
-else:
-    file_bytes = bytes(str(file), encoding='utf-8')  # fallback for NamedString
-
-tmp.write(file_bytes)
-
+            # ✅ Robust handling for file types: file-like, string path, bytes, NamedString
+            if hasattr(file, "read"):
+                file_bytes = file.read()
+            elif isinstance(file, str) and os.path.exists(file):
+                with open(file, "rb") as f:
+                    file_bytes = f.read()
+            elif isinstance(file, bytes):
+                file_bytes = file
+            else:
+                # Fallback for Hugging Face NamedString or other str-like types
+                file_bytes = bytes(str(file), encoding='utf-8')
+
+            tmp.write(file_bytes)
             tmp.flush()
             full_text = extract_text(tmp.name, ext)
 
@@ -92,6 +91,7 @@ tmp.write(file_bytes)
     except Exception as e:
         return f"❌ Error: {str(e)}"
 
+
 def generate_prompt(context, question):
     return f"""
 You are a helpful academic tutor assisting a student strictly based on course slides or textbook material.