app.py

import json
import os
import streamlit as st
from cassandra.auth import PlainTextAuthProvider
from cassandra.cluster import Cluster
from llama_index import ServiceContext
from llama_index import set_global_service_context
from llama_index import VectorStoreIndex, SimpleDirectoryReader, StorageContext
from llama_index.embeddings import GradientEmbedding
from llama_index.llms import GradientBaseModelLLM
from llama_index.vector_stores import CassandraVectorStore
from copy import deepcopy
from tempfile import NamedTemporaryFile

os.environ['GRADIENT_ACCESS_TOKEN'] = "sevG6Rqb0ztaquM4xjr83SBNSYj91cux"
os.environ['GRADIENT_WORKSPACE_ID'] = "4de36c1f-5ee6-41da-8f95-9d2fb1ded33a_workspace"

@st.cache_resource
def create_datastax_connection():

    cloud_config= {'secure_connect_bundle': 'secure-connect-temp-db.zip'}

    with open("temp_db-token.json") as f:
        secrets = json.load(f)

    CLIENT_ID = secrets["clientId"]
    CLIENT_SECRET = secrets["secret"]

    auth_provider = PlainTextAuthProvider(CLIENT_ID, CLIENT_SECRET)
    cluster = Cluster(cloud=cloud_config, auth_provider=auth_provider)
    astra_session = cluster.connect()
    return astra_session

def main():

    index_placeholder = None
    st.set_page_config(page_title = "NyayMitra", page_icon="🦙")
    st.header('NyayMitra')
    
    if "conversation" not in st.session_state:
        st.session_state.conversation = None

    if "activate_chat" not in st.session_state:
        st.session_state.activate_chat = False

    if "messages" not in st.session_state:
        st.session_state.messages = []

    for message in st.session_state.messages:
        with st.chat_message(message["role"], avatar = message['avatar']):
            st.markdown(message["content"])

    session = create_datastax_connection()

    os.environ['GRADIENT_ACCESS_TOKEN'] = "sevG6Rqb0ztaquM4xjr83SBNSYj91cux"
    os.environ['GRADIENT_WORKSPACE_ID'] = "4de36c1f-5ee6-41da-8f95-9d2fb1ded33a_workspace"

    llm = GradientBaseModelLLM(base_model_slug="llama2-7b-chat", max_tokens=400)
    
    embed_model = GradientEmbedding(
        gradient_access_token = os.environ["GRADIENT_ACCESS_TOKEN"],
        gradient_workspace_id = os.environ["GRADIENT_WORKSPACE_ID"],
        gradient_model_slug="bge-large")

    service_context = ServiceContext.from_defaults(
    llm = llm,
    embed_model = embed_model,
    chunk_size=256)

    set_global_service_context(service_context)

    with st.sidebar:
        st.subheader('Start your chat here')
        if st.button('Process'):
            with st.spinner('Processing'):
                reader = 'data'
                
                documents = SimpleDirectoryReader(reader).load_data()
                index = VectorStoreIndex.from_documents(documents,
                                                        service_context=service_context)
                query_engine = index.as_query_engine()
                if "query_engine" not in st.session_state:
                    st.session_state.query_engine = query_engine
                st.session_state.activate_chat = True

    if st.session_state.activate_chat == True:
        if prompt := st.chat_input("Ask your question"):
            with st.chat_message("user", avatar = '👨🏻'):
                st.markdown(prompt)
            st.session_state.messages.append({"role": "user", 
                                              "avatar" :'👨🏻',
                                              "content": prompt})

            query_index_placeholder = st.session_state.query_engine
            pdf_response = query_index_placeholder.query(prompt)
            cleaned_response = pdf_response.response
            with st.chat_message("assistant", avatar='🤖'):
                st.markdown(cleaned_response)
            st.session_state.messages.append({"role": "assistant", 
                                              "avatar" :'🤖',
                                              "content": cleaned_response})
        else:
            st.markdown(
                ' '
                )


if __name__ == '__main__':
    main()