fix(handle_callback): Improve image handling by using iter_content for streaming

Author: Evan Lin

main.py

@@ -132,16 +132,18 @@ async def handle_callback(request: Request):
             print(f"Received image from user: {user_id}")
 
             message_content = await line_bot_api.get_message_content(event.message.id)
-            image_bytes = await message_content.read()
-            image_stream = BytesIO(image_bytes)
+            image_content = b''
+            async for s in message_content.iter_content():
+                image_content += s
+            img_stream = PIL.Image.open(BytesIO(image_content))
 
             file_name = f"{uuid.uuid4()}.jpg"
             gcs_uri = None
             response = "抱歉，處理您的圖片時發生錯誤。"  # Default error message
 
             try:
                 gcs_uri = upload_to_gcs(
-                    image_stream, file_name, google_storage_bucket)
+                    img_stream, file_name, google_storage_bucket)
                 if gcs_uri:
                     print(f"Image uploaded to {gcs_uri}")
                     response = generate_image_description(gcs_uri)