ch.py

import streamlit as st
import langchain_google_genai as l
import time
from streamlit_option_menu import option_menu
with st.sidebar:
    s=option_menu("select from start",options=["select title","enter chat bot","download chat history"])
if s=="select title":
    b=st.selectbox(label="select the topic",options=["Python","SQL","Power BI","Exploratory Data Analysis (EDA)","Machine Learning (ML)","Deep Learning (DL)","Generative AI (Gen AI)","Agentic AI"])
    if not st.session_state:
        st.session_state["topic"]=b
    elif "topic" in st.session_state:
        st.session_state["topic"]=b
elif s=="enter chat bot":
    api="AIzaSyCaw1tgfw_90aB3R2R6lfxAJMXjBSLqE8o"
    time.sleep(5)
    model=l.GoogleGenerativeAI(model="gemini-2.5-flash-lite",api_key=api,max_tokens=10,temperature=0.2)
    if st.session_state:
        var="behave like a 1 year experice chat model trainer of"+ st.session_state.get("topic")+"Topic you strictly should not discuss anything other that specified topic"
        st.session_state["messages"]=[["system",var]]
        prompt=st.chat_input("Type your message")
        if prompt:
            st.session_state["messages"].append(["user",prompt])
            st.session_state.update({"topic":""})
            ai_mess=model.invoke(st.session_state["messages"])
            st.session_state["messages"].append(["ai",ai_mess])
            if "bytes" not in st.session_state:
                st.session_state["bytes"]=0
            else:
                with open("chat.txt","w") as f:
                    f.seek(st.session_state["bytes"])
                    for role,mess in st.session_state["messages"]:
                        bytes=f.write("\n"+role+f": {mess}"+"\n")
                        st.session_state["bytes"]=bytes
                    
            for user,message in st.session_state["messages"]:
                if user=="user":
                    with st.chat_message("user"):
                        st.write(message)
                elif user=="ai":
                    with st.chat_message("assistant"):
                        st.write(st.session_state["messages"][-1][-1])
elif s=="download chat history":
    with open("chat.txt","r") as f:
        st.download_button(label="download chat history",data= f,file_name="chat.txt")
    
    #else:
        #st.markdown("please go and select the title to access the chatbot")