Requests-OAuthlib

import os
from requests_oauthlib import OAuth2Session

# Replace with your actual client ID and secret from your OAuth provider
CLIENT_ID = os.environ.get('OAUTH_CLIENT_ID', 'your_client_id')
CLIENT_SECRET = os.environ.get('OAUTH_CLIENT_SECRET', 'your_client_secret')

# These URLs are specific to your OAuth provider (e.g., GitHub, Google)
AUTHORIZATION_BASE_URL = 'https://github.com/login/oauth/authorize'
TOKEN_URL = 'https://github.com/login/oauth/access_token'
REDIRECT_URI = 'http://localhost:5000/callback'
SCOPE = ['user'] # Example scope for GitHub

def get_authorization_url():
    """Step 1: Get the authorization URL to redirect the user."""
    github = OAuth2Session(CLIENT_ID, redirect_uri=REDIRECT_URI, scope=SCOPE)
    authorization_url, state = github.authorization_url(AUTHORIZATION_BASE_URL)
    print(f"Please go to {authorization_url} and authorize access.")
    print(f"Store this state parameter for callback validation: {state}")
    return authorization_url, state

def fetch_token_from_callback(authorization_response_url, stored_state):
    """Step 2 & 3: Exchange the authorization code for an access token.
       In a real web app, authorization_response_url comes from the redirect callback.
    """
    github = OAuth2Session(CLIENT_ID, state=stored_state, redirect_uri=REDIRECT_URI)
    try:
        token = github.fetch_token(TOKEN_URL,
                                   client_secret=CLIENT_SECRET,
                                   authorization_response=authorization_response_url)
        print(f"Access Token obtained: {token}")
        # Now you can use the 'github' session to make API calls
        user_info = github.get('https://api.github.com/user').json()
        print(f"Authenticated user info: {user_info}")
        return token, user_info
    except Exception as e:
        print(f"Error fetching token: {e}")
        return None, None

if __name__ == "__main__":
    auth_url, initial_state = get_authorization_url()
    # In a real application, you would redirect the user to auth_url
    # and then capture the full redirect URL (authorization_response_url)
    # from their browser after they authorize your application.
    print("\n--- Manual Step Required ---")
    print("1. Open the URL printed above in your browser.")
    print("2. Authorize the application.")
    print("3. After authorization, copy the full URL from your browser's address bar.")
    print("   (It will likely be http://localhost:5000/callback?code=...&state=...)")
    authorization_response = input("\nEnter the full redirect URL here: ")

    # Simulate callback handling
    if authorization_response:
        fetch_token_from_callback(authorization_response, initial_state)
    else:
        print("No authorization response provided. Exiting.")