app.py

# from flask import Flask, redirect, request, session, url_for
# import os
# from authlib.integrations.flask_client import OAuth
# from langchain.llms.huggingface_hub import HuggingFaceHub
# from langchain.prompts import ChatPromptTemplate
# from langchain.schema import StrOutputParser
# from langchain.schema.runnable import Runnable
# from langchain.schema.runnable.config import RunnableConfig
# import chainlit as cl

# app = Flask(__name__)
# app.secret_key = 'YourSecretKey'  # Change this to a real secret key for production

# # OAuth setup with Authlib
# oauth = OAuth(app)
# oauth.register(
#     name='oauth_provider',
#     client_id=os.getenv("OAUTH_CLIENT_ID"),
#     client_secret=os.getenv("OAUTH_CLIENT_SECRET"),
#     authorize_url=os.getenv("OPENID_PROVIDER_URL") + '/authorize',
#     access_token_url=os.getenv("OPENID_PROVIDER_URL") + '/token',
#     client_kwargs={'scope': os.getenv("OAUTH_SCOPES").split(',')},
#     redirect_uri=f"https://{os.getenv('SPACE_HOST')}/login/callback"
# )

# print(f"REDIRECT URI: https://{os.getenv('SPACE_HOST')}/login/callback")

# # Instantiate the LLM
# llm = HuggingFaceHub(
#     model_kwargs={"max_length": 500},
#     repo_id="google/flan-t5-xxl",
#     huggingfacehub_api_token=os.getenv("HUGGINGFACE_API_TOKEN"),
# )

# # Initialize ChainLit with LLM
# def initialize_chainlit():
#     add_llm_provider(
#         LangchainGenericProvider(
#             id=llm._llm_type,
#             name="HuggingFaceHub",
#             llm=llm,
#             is_chat=False,
#         )
#     )

# # Setup chainlit callbacks
# @cl.on_chat_start
# async def on_chat_start():
#     prompt = ChatPromptTemplate.from_messages([("human", "{question}")])
#     runnable = prompt | llm | StrOutputParser()
#     cl.user_session.set("runnable", runnable)

# @cl.on_message
# async def on_message(message: cl.Message):
#     runnable = cl.user_session.get("runnable")  # type: Runnable
#     msg = cl.Message(content="")
#     async for chunk in runnable.astream(
#         {"question": message.content},
#         config=RunnableConfig(callbacks=[cl.LangchainCallbackHandler()]),
#     ):
#         await msg.stream_token(chunk)
#     await msg.send()

# @app.route('/')
# def home():
#     return 'Home - <a href="/login">Login with OAuth Provider</a>'

# @app.route('/login')
# def login():
#     redirect_uri = url_for('authorize', _external=True)
#     return oauth.oauth_provider.authorize_redirect(redirect_uri)

# @app.route('/login/callback')
# def authorize():
#     print('Logged in and language model initialized. Proceed with operations.')
#     token = oauth.oauth_provider.authorize_access_token()
#     # Initialize ChainLit or perform actions based on the authenticated user
#     initialize_chainlit()
#     return 'Logged in and language model initialized. Proceed with operations.'

# if __name__ == "__main__":
#     app.run(debug=True)


from flask import Flask, redirect, request, session, url_for, jsonify
import os
import requests
from base64 import b64encode

app = Flask(__name__)
app.secret_key = 'YourSecretKey'  # Change this to a real secret key for production

# OAuth Configuration
CLIENT_ID = os.getenv("OAUTH_CLIENT_ID")
CLIENT_SECRET = os.getenv("OAUTH_CLIENT_SECRET")
REDIRECT_URI = f"https://{os.getenv('SPACE_HOST')}/login/callback"
AUTHORIZE_URL = "https://huggingface.co/oauth/authorize"
TOKEN_URL = "https://huggingface.co/oauth/token"

@app.route('/')
def home():
    # Generate a random state for CSRF protection
    state = os.urandom(16).hex()
    session['state'] = state
    # Redirect URL for "Sign-in with HF"
    return redirect(f"{AUTHORIZE_URL}?redirect_uri={REDIRECT_URI}&scope=openid%20profile&client_id={CLIENT_ID}&state={state}")

@app.route('/login/callback')
def login_callback():
    # Verify state matches
    state = request.args.get('state')
    if state != session.pop('state', None):
        return 'State mismatch', 400

    # Exchange code for token
    code = request.args.get('code')
    headers = {'Authorization': 'Basic ' + b64encode(f"{CLIENT_ID}:{CLIENT_SECRET}".encode()).decode()}
    data = {
        'grant_type': 'authorization_code',
        'code': code,
        'redirect_uri': REDIRECT_URI,
        'client_id': CLIENT_ID
    }
    response = requests.post(TOKEN_URL, headers=headers, data=data)
    response_data = response.json()
    print(response_data)

    if response.status_code != 200:
        return jsonify(response_data), response.status_code

    # At this point, you have access_token and id_token in response_data
    # You can use these tokens to authenticate against the Hugging Face API or your application's backend

    return 'Logged in successfully.', 200

# if __name__ == "__main__":
app.run(debug=True, port=7860)