Fix Gemini model name and add detailed error handling for sample data loading

app.py

@@ -195,7 +195,11 @@ def load_sample_data():
         
         # Initialize recognizer if needed
         if recognizer is None:
-            recognizer = HandwritingRecognizer(GEMINI_API_KEY)
+            try:
+                recognizer = HandwritingRecognizer(GEMINI_API_KEY)
+            except Exception as e:
+                error_msg = f"❌ Error initializing Gemini API: {str(e)}"
+                return (error_msg, "", error_msg, "")
         
         # Load pre-generated sample images
         try:
@@ -203,20 +207,43 @@ def load_sample_data():
             student_response_img = Image.open("sample_student_response.png")
         except FileNotFoundError:
             # Fallback: use the sample_images module if files don't exist
-            from sample_images import create_sample_answer_key_image, create_sample_student_response_image
-            answer_key_img = create_sample_answer_key_image()
-            student_response_img = create_sample_student_response_image()
+            try:
+                from sample_images import create_sample_answer_key_image, create_sample_student_response_image
+                answer_key_img = create_sample_answer_key_image()
+                student_response_img = create_sample_student_response_image()
+            except Exception as e:
+                error_msg = f"❌ Error creating sample images: {str(e)}"
+                return (error_msg, "", error_msg, "")
         
         # Process through actual OCR
-        answer_key_text = recognizer.extract_text_from_image(answer_key_img)
-        student_response_text = recognizer.extract_text_from_image(student_response_img)
+        try:
+            answer_key_text = recognizer.extract_text_from_image(answer_key_img)
+            if answer_key_text.startswith("Error"):
+                return (
+                    f"❌ Error processing answer key: {answer_key_text}",
+                    "",
+                    f"❌ Error processing answer key: {answer_key_text}",
+                    ""
+                )
+        except Exception as e:
+            error_msg = f"❌ Error processing answer key image: {str(e)}"
+            return (error_msg, "", error_msg, "")
         
-        if answer_key_text.startswith("Error") or student_response_text.startswith("Error"):
+        try:
+            student_response_text = recognizer.extract_text_from_image(student_response_img)
+            if student_response_text.startswith("Error"):
+                return (
+                    "✅ Answer key processed successfully!",
+                    answer_key_text,
+                    f"❌ Error processing student response: {student_response_text}",
+                    ""
+                )
+        except Exception as e:
             return (
-                "❌ Error processing sample images through OCR",
-                answer_key_text if not answer_key_text.startswith("Error") else "",
-                "❌ Error processing sample images through OCR",
-                student_response_text if not student_response_text.startswith("Error") else ""
+                "✅ Answer key processed successfully!",
+                answer_key_text,
+                f"❌ Error processing student response: {str(e)}",
+                ""
             )
         
         return (
@@ -227,7 +254,7 @@ def load_sample_data():
         )
         
     except Exception as e:
-        error_msg = f"❌ Error in demo: {str(e)}"
+        error_msg = f"❌ Unexpected error in demo: {str(e)}"
         return (error_msg, "", error_msg, "")
 
 def process_answer_key(api_key: str, file) -> Tuple[str, str]:

config.py

@@ -30,8 +30,8 @@ SCORE_THRESHOLDS = {
 
 # API settings
 GEMINI_API_KEY = os.getenv('GEMINI_API_KEY', '')
-# Using gemini-2.0-flash-exp (gemini3n series) for all processing including vision (supports 256x256, 512x512, 768x768 images)
-GEMINI_MODEL = os.getenv('GEMINI_MODEL', 'gemma-3n-e4b-it')
+# Using gemini-2.0-flash-exp for vision and text processing
+GEMINI_MODEL = os.getenv('GEMINI_MODEL', 'gemini-2.0-flash-exp')
 ENVIRONMENT = os.getenv('ENVIRONMENT', 'development')
 
 # Image preprocessing settings for gemini3n series models