app.py

from langchain_core.messages import AIMessage, HumanMessage
import streamlit as st
from streamlit_chat import message
import os
from agent import ReActAgent

@st.cache_resource
def get_agent():
    return ReActAgent()

agent = get_agent()

#Streamlit app layout
st.title("Bliff AI")
clear_button = st.sidebar.button("Clear Conversation", key="clear")

# Initialise session state variables
if 'generated' not in st.session_state:
    st.session_state['generated'] = ['Quick and Precise Search about just anything']
if 'past' not in st.session_state:
    st.session_state['past'] = []

if 'history' not in st.session_state:
    st.session_state['history'] = []


# reset everything
if clear_button:
    st.session_state['generated'] = ['Quick and Precise Search about just anything']
    st.session_state['past'] = []
    st.session_state['history'] = []


# container for chat history
response_container = st.container()
# container for text box
container = st.container()

with container:
        with st.form(key='my_form', clear_on_submit=True):
            user_input = st.text_area("You:", key='input', height=100)
            submit_button = st.form_submit_button(label='Send')

        if submit_button and user_input:
            if len(st.session_state['history']) > 0 :
                history_string = ""
                for chat in st.session_state['history']:
                    if isinstance(chat, HumanMessage):
                        history_string += f"Human: {chat.content}\n"
                    elif isinstance(chat, AIMessage):
                        history_string += f"AI: {chat.content}\n"
                # Remove trailing newline character if present
                history_string = history_string.rstrip("\n")
                response =  agent.run(user_input, history_string)['output']
            else:
              response = agent.run(user_input)['output']

            st.session_state['generated'].append(response)
            st.session_state['past'].append(user_input)
            st.session_state['history'].extend([HumanMessage(content=user_input), AIMessage(content=response)])

if st.session_state['generated']:
    with response_container:
        for i in range(len(st.session_state['generated'])):
            message(st.session_state["generated"][i], key=str(i))
            if len(st.session_state["past"]) > 0 and i < len(st.session_state["past"]):
                message(st.session_state["past"][i], is_user=True, key=str(i) + '_user')