fix: improve error handling and logging in OpenAI client and chat message processing

src/app.py

@@ -12,22 +12,29 @@ def display_chat_messages():
 
 def handle_user_input():
     if prompt := st.chat_input("Type your message..."):
+        print(f"User input received: {prompt}")  # Debug log
         st.session_state.messages.append({"role": "user", "content": prompt})
         with st.chat_message("user"):
             st.markdown(prompt)
         
-        with st.chat_message("assistant"):
-            response_placeholder = st.empty()
-            full_response = ""
-            
-            client = OpenAIClient()
-            for chunk in client.get_chat_response(st.session_state.messages):
-                if chunk.choices[0].delta.content:
-                    full_response += chunk.choices[0].delta.content
-                    response_placeholder.markdown(full_response + "▌")
-            
-            response_placeholder.markdown(full_response)
-            st.session_state.messages.append({"role": "assistant", "content": full_response})
+        try:
+            with st.chat_message("assistant"):
+                response_placeholder = st.empty()
+                full_response = ""
+                
+                client = OpenAIClient()
+                print("Calling OpenAI API...")  # Debug log
+                for chunk in client.get_chat_response(st.session_state.messages):
+                    if chunk.choices[0].delta.content:
+                        full_response += chunk.choices[0].delta.content
+                        response_placeholder.markdown(full_response + "▌")
+                
+                response_placeholder.markdown(full_response)
+                st.session_state.messages.append({"role": "assistant", "content": full_response})
+                print("API call completed successfully")  # Debug log
+        except Exception as e:
+            st.error(f"Error processing message: {str(e)}")
+            print(f"Error details: {str(e)}")  # Debug log
 
 def main():
     st.title("Streamlit Chat App")