app.py

import os
from langchain_core.prompts import ChatPromptTemplate
from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_core.prompts import MessagesPlaceholder
from langchain.memory import ConversationBufferWindowMemory
from operator import itemgetter
from langchain_core.runnables import RunnableLambda,RunnablePassthrough
import streamlit as st

genai_key = os.getenv("gen_key")

model = ChatGoogleGenerativeAI(temperature=0,model='gemini-1.5-pro',max_output_tokens=150,convert_system_message_to_human=True,google_api_key=genai_key)

prompt=ChatPromptTemplate.from_messages([
     ("system","you are a good assistant that give information about mentioned topic."),
     MessagesPlaceholder(variable_name="history"),
     ("human","{input}")])

# Initialize memory in session state
if 'memory' not in st.session_state:
    st.session_state.memory = ConversationBufferWindowMemory(k=10, return_messages=True)

# Define the chain
chain = (RunnablePassthrough.assign(history=RunnableLambda(st.session_state.memory.load_memory_variables) | itemgetter("history")) |
         prompt | model)

# Streamlit app
st.title("Interactive Chatbot")

# Initialize session state for user input
if 'user_input' not in st.session_state:
    st.session_state.user_input = ""

# Input from user
user_input = st.text_area("User: ", st.session_state.user_input, height=100)

if st.button("Submit"):
    response = chain.invoke({"input": user_input})
    st.write(f"Assistant: {response.content}")
    st.session_state.memory.save_context({"input": user_input}, {"output": response.content})
    st.session_state.user_input = ""  # Clear the input box

# Display chat history
if st.checkbox("Show Chat History"):
    chat_history = st.session_state.memory.load_memory_variables({})
    st.write(chat_history)