How to use the authlib.integrations.flask_client.OAuth function in Authlib

def test_openid_authorize(self):
        app = Flask(__name__)
        app.secret_key = '!'
        oauth = OAuth(app)
        client = oauth.register(
            'dev',
            client_id='dev',
            api_base_url='https://i.b/api',
            access_token_url='https://i.b/token',
            authorize_url='https://i.b/authorize',
            client_kwargs={'scope': 'openid profile'},
        )

        with app.test_request_context():
            resp = client.authorize_redirect('https://b.com/bar')
            self.assertEqual(resp.status_code, 302)
            nonce = session['_dev_authlib_nonce_']
            self.assertIsNotNone(nonce)
            url = resp.headers.get('Location')
            self.assertIn('nonce={}'.format(nonce), url)

def test_register_oauth2_remote_app(self):
        app = Flask(__name__)
        oauth = OAuth(app)
        oauth.register(
            'dev',
            client_id='dev',
            client_secret='dev',
            api_base_url='https://i.b/api',
            access_token_url='https://i.b/token',
            refresh_token_url='https://i.b/token',
            authorize_url='https://i.b/authorize',
            update_token=lambda name: 'hi'
        )
        self.assertEqual(oauth.dev.name, 'dev')
        session = oauth.dev._get_oauth_client()
        self.assertIsNotNone(session.update_token)

def test_init_app_later(self):
        app = Flask(__name__)
        app.config.update({
            'DEV_CLIENT_ID': 'dev',
            'DEV_CLIENT_SECRET': 'dev',
        })
        oauth = OAuth()
        remote = oauth.register('dev')
        self.assertRaises(RuntimeError, lambda: oauth.dev.client_id)
        oauth.init_app(app)
        self.assertEqual(oauth.dev.client_id, 'dev')
        self.assertEqual(remote.client_id, 'dev')

        self.assertIsNone(oauth.cache)
        self.assertIsNone(oauth.fetch_token)
        self.assertIsNone(oauth.update_token)

def test_oauth1_authorize(self):
        app = Flask(__name__)
        app.secret_key = '!'
        oauth = OAuth(app, cache=SimpleCache())
        client = oauth.register(
            'dev',
            client_id='dev',
            client_secret='dev',
            request_token_url='https://i.b/reqeust-token',
            api_base_url='https://i.b/api',
            access_token_url='https://i.b/token',
            authorize_url='https://i.b/authorize'
        )

        with app.test_request_context():
            with mock.patch('requests.sessions.Session.send') as send:
                send.return_value = mock_send_value('oauth_token=foo&oauth_verifier=baz')
                resp = client.authorize_redirect('https://b.com/bar')
                self.assertEqual(resp.status_code, 302)
                url = resp.headers.get('Location')

def test_oauth2_authorize(self):
        app = Flask(__name__)
        app.secret_key = '!'
        oauth = OAuth(app)
        client = oauth.register(
            'dev',
            client_id='dev',
            client_secret='dev',
            api_base_url='https://i.b/api',
            access_token_url='https://i.b/token',
            authorize_url='https://i.b/authorize'
        )

        with app.test_request_context():
            resp = client.authorize_redirect('https://b.com/bar')
            self.assertEqual(resp.status_code, 302)
            url = resp.headers.get('Location')
            self.assertIn('state=', url)
            state = session['_dev_authlib_state_']
            self.assertIsNotNone(state)

def test_oauth2_access_token_with_post(self):
        app = Flask(__name__)
        app.secret_key = '!'
        oauth = OAuth(app)
        client = oauth.register(
            'dev',
            client_id='dev',
            client_secret='dev',
            api_base_url='https://i.b/api',
            access_token_url='https://i.b/token',
            authorize_url='https://i.b/authorize'
        )
        payload = {'code': 'a', 'state': 'b'}
        with app.test_request_context(data=payload, method='POST'):
            session['_dev_authlib_state_'] = 'b'
            with mock.patch('requests.sessions.Session.send') as send:
                send.return_value = mock_send_value(get_bearer_token())
                token = client.authorize_access_token()
                self.assertEqual(token['access_token'], 'a')

from ..libs.exceptions import MsgException, APIFailure, APIForbidden, APIClosed
from ..libs.helper import is_accept_json
from ..models.bgp import TBBGP
from ..models.user import TBUser, TBRole


class LoginManager(_LoginManager):
    """特定场景返回登录失效提示"""

    def unauthorized(self):
        if is_accept_json():
            raise APIFailure('登录状态过期, 请刷新')
        return super(LoginManager, self).unauthorized()


oauth = OAuth()
oauth.register('OA')

login_manager = LoginManager()
login_manager.session_protection = 'strong'
login_manager.login_view = 'web.web_login'
login_manager.login_message = '请先登录'
login_manager.login_message_category = 'info'


@login_manager.user_loader
def load_user(user_id):
    """Flask-login 获取用户信息"""
    try:
        user = pickle.loads(session['load_user'])
    except Exception:
        user = None

def create_oauth_app(service_config, name):
  service_oauth = OAuth(app)
  service_app = service_oauth.register(name, **service_config)
  return service_app

import jwt
import json
import base64
import logging
from urllib.request import urlopen
from authlib.integrations.flask_client import OAuth
from cryptography.x509 import load_pem_x509_certificate
from cryptography.hazmat.backends import default_backend

from aleph import signals, settings

oauth = OAuth()
log = logging.getLogger(__name__)


def configure_oauth(app, cache):
    if settings.OAUTH:
        oauth.provider = oauth.register(
            name=settings.OAUTH_NAME,
            client_id=settings.OAUTH_KEY,
            client_secret=settings.OAUTH_SECRET,
            client_kwargs={'scope': settings.OAUTH_SCOPE},
            request_token_url=settings.OAUTH_REQUEST_TOKEN_URL,
            access_token_method=settings.OAUTH_TOKEN_METHOD,
            access_token_url=settings.OAUTH_TOKEN_URL,
            api_base_url=settings.OAUTH_BASE_URL,
            authorize_url=settings.OAUTH_AUTHORIZE_URL
        )

from data.models import User

bp = Blueprint("auth", __name__, url_prefix="/auth")
db = DEFAULT_DATABASE.db


def fetch_google_token():
    return session.get('google_token')


def update_google_token(token):
    session['google_token'] = token
    return session['google_token']


oauth = OAuth()  # pylint: disable=invalid-name
oauth.register(
    name='google',  # nosec
    api_base_url='https://www.googleapis.com/',
    server_metadata_url=
    'https://accounts.google.com/.well-known/openid-configuration',
    fetch_token=fetch_google_token,
    update_token=update_google_token,
    client_kwargs={'scope': 'openid email profile'})


@bp.route("/login", methods=["GET"])
def login():
    if is_authenticated():
        return redirect("/")

    # Allow OAuth bypass on local dev environment.