Code Editor for app.py

import streamlit as st
import random
import time

# Streamed response emulator
def response_generator():
    responses = [
        "Hello there! How can I assist you today?",
        "Hi, human! Is there anything I can help you with?",
        "Do you need help?",
    ]
    response = random.choice(responses)
    response_text = ""
    for word in response.split():
        response_text += word + " "
        time.sleep(0.1)
        yield response_text

st.title("Simple Chat Bot")

# Initialize chat history and input disabled status in session state
if "messages" not in st.session_state:
    st.session_state.messages = []
if "input_disabled" not in st.session_state:
    st.session_state.input_disabled = False
if "response_text" not in st.session_state:
    st.session_state.response_text = ""

# Display chat messages from history on app rerun
for message in st.session_state.messages:
    with st.chat_message(message["role"]):
        st.markdown(message["content"])

# Accept user input if input is not disabled
if prompt := st.chat_input("What is up?", disabled=st.session_state.input_disabled):
    # Add user message to chat history
    st.session_state.messages.append({"role": "user", "content": prompt})
    
    # Display user message in chat message container
    with st.chat_message("user"):
        st.markdown(prompt)
    
    # Disable chat input during response generation and start response generator
    st.session_state.input_disabled = True
    st.session_state.response_text = ""
    st.session_state.generator = response_generator()  # Store generator in session state
    st.experimental_rerun()

# Generate response if input is disabled
if st.session_state.input_disabled and "generator" in st.session_state:
    try:
        # Get the next chunk from the response generator
        chunk = next(st.session_state.generator)
        st.session_state.response_text = chunk  # Update the accumulated response text

        # Display assistant's response incrementally
        with st.chat_message("assistant"):
            st.markdown(st.session_state.response_text)

        # Rerun to display the next chunk
        st.experimental_rerun()

    except StopIteration:
        # Generator has finished, complete the response
        st.session_state.messages.append({"role": "assistant", "content": st.session_state.response_text})
        
        # Clean up and re-enable the input
        st.session_state.input_disabled = False
        del st.session_state.generator
        st.experimental_rerun()