Code Editor for app.py

import streamlit as st
import random
import time

# Function to generate a response text
def get_response():
    responses = [
        "Hello there! How can I assist you today?",
        "Hi, human! Is there anything I can help you with?",
        "Do you need help?",
    ]
    return random.choice(responses)

st.title("Simple Chat Bot")

# Initialize chat history and control flags 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 = ""
if "full_response" not in st.session_state:
    st.session_state.full_response = ""
if "response_complete" not in st.session_state:
    st.session_state.response_complete = True

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

# Check for user input only if response generation is complete
if st.session_state.response_complete and (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
    with st.chat_message("user"):
        st.markdown(prompt)
    
    # Initialize response generation process
    st.session_state.input_disabled = True
    st.session_state.response_complete = False
    st.session_state.response_text = ""
    st.session_state.full_response = get_response()  # Generate the full response
    st.rerun()  # Rerun to start incremental response display

# Display the response incrementally if response generation is in progress
if not st.session_state.response_complete:
    words = st.session_state.full_response.split()
    next_word_index = len(st.session_state.response_text.split())
    
    # Add the next word to the response text if there are remaining words
    if next_word_index < len(words):
        st.session_state.response_text += words[next_word_index] + " "
        time.sleep(0.1)  # Simulate typing delay
        st.rerun()  # Rerun to display the next word
    else:
        # Complete the response, add it to message history
        st.session_state.messages.append({"role": "assistant", "content": st.session_state.response_text})
        st.session_state.input_disabled = False
        st.session_state.response_complete = True
        st.rerun()  # Rerun to re-enable the input

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