app.py

import gradio as gr
from langchain.embeddings import HuggingFaceEmbeddings
from langchain.vectorstores import Chroma
from langchain.llms import HuggingFacePipeline
from langchain.chains import RetrievalQA
from transformers import AutoConfig, AutoTokenizer, pipeline, AutoModelForCausalLM
from langchain_community.document_loaders import DirectoryLoader
import torch
import re
import requests
from urllib.parse import urlencode
import transformers
import spaces

# Initialize embeddings and ChromaDB
model_name = "sentence-transformers/all-mpnet-base-v2"
device = "cuda" if torch.cuda.is_available() else "cpu"
model_kwargs = {"device": device}
embeddings = HuggingFaceEmbeddings(model_name=model_name, model_kwargs=model_kwargs)

loader = DirectoryLoader('./example', glob="**/*.pdf", recursive=True, use_multithreading=True)
docs = loader.load()
vectordb = Chroma.from_documents(documents=docs, embedding=embeddings, persist_directory="companies_db")
books_db = Chroma(persist_directory="./companies_db", embedding_function=embeddings)
books_db_client = books_db.as_retriever()

# Initialize the model and tokenizer
model_name = "stabilityai/stablelm-zephyr-3b"
model_config = transformers.AutoConfig.from_pretrained(model_name, max_new_tokens=1024)
model = transformers.AutoModelForCausalLM.from_pretrained(
    model_name,
    trust_remote_code=True,
    config=model_config,
    device_map=device,
)

tokenizer = AutoTokenizer.from_pretrained(model_name)

query_pipeline = transformers.pipeline(
    "text-generation",
    model=model,
    tokenizer=tokenizer,
    return_full_text=True,
    torch_dtype=torch.float16,
    device_map=device,
    do_sample=True,
    temperature=0.7,
    top_p=0.9,
    top_k=50,
    max_new_tokens=256
)

llm = HuggingFacePipeline(pipeline=query_pipeline)

books_db_client_retriever = RetrievalQA.from_chain_type(
    llm=llm,
    chain_type="stuff",
    retriever=books_db_client,
    verbose=True
)

# OAuth Configuration
TENANT_ID = 'your-tenant-id'
CLIENT_ID = 'your-client-id'
CLIENT_SECRET = 'your-client-secret'
REDIRECT_URI = 'https://your-chatbot.hf.space/auth/callback'
AUTH_URL = f"https://login.microsoftonline.com/{TENANT_ID}/oauth2/v2.0/authorize"
TOKEN_URL = f"https://login.microsoftonline.com/{TENANT_ID}/oauth2/v2.0/token"

# Function to redirect to Microsoft login
def get_login_url():
    params = {
        'client_id': CLIENT_ID,
        'response_type': 'code',
        'redirect_uri': REDIRECT_URI,
        'response_mode': 'query',
        'scope': 'User.Read',
        'state': '12345'  # Optional state parameter for CSRF protection
    }
    login_url = f"{AUTH_URL}?{urlencode(params)}"
    return login_url

# Function to exchange auth code for an access token
def exchange_code_for_token(auth_code):
    data = {
        'grant_type': 'authorization_code',
        'client_id': CLIENT_ID,
        'client_secret': CLIENT_SECRET,
        'code': auth_code,
        'redirect_uri': REDIRECT_URI
    }
    response = requests.post(TOKEN_URL, data=data)
    token_data = response.json()
    return token_data.get('access_token')

# Function to retrieve answer using the RAG system
@spaces.GPU(duration=60)
def test_rag(query):
    books_retriever = books_db_client_retriever.run(query)
    
    # Extract the relevant answer using regex
    corrected_text_match = re.search(r"Helpful Answer:(.*)", books_retriever, re.DOTALL)
    
    if corrected_text_match:
        corrected_text_books = corrected_text_match.group(1).strip()
    else:
        corrected_text_books = "No helpful answer found."
    
    return corrected_text_books

# Function for RAG Chat
def chat(query, history=None):
    if history is None:
        history = []
    if query:
        answer = test_rag(query)
        history.append((query, answer))
    return history, ""  # Clear input after submission

# Gradio interface
with gr.Blocks() as interface:
    gr.Markdown("## RAG Chatbot")
    gr.Markdown("Ask a question and get answers based on retrieved documents.")
    
    input_box = gr.Textbox(label="Enter your question", placeholder="Type your question here...")
    submit_btn = gr.Button("Submit")
    chat_history = gr.Chatbot(label="Chat History")

    # Add Microsoft OAuth Login
    auth_btn = gr.Button("Login with Microsoft")

    # Action for OAuth login
    def login_action():
        return gr.redirect(get_login_url())

    # Bind login action to button
    auth_btn.click(login_action)
    
    # Submit action
    submit_btn.click(chat, inputs=[input_box, chat_history], outputs=[chat_history, input_box])

interface.launch()