step3.py

import flask
import requests_oauthlib
import os

CLIENT_ID = os.environ.get("CLIENT_ID")
CLIENT_SECRET = os.environ.get("CLIENT_SECRET")

AUTHORIZATION_BASE_URL = "https://app.simplelogin.io/oauth2/authorize"
TOKEN_URL = "https://app.simplelogin.io/oauth2/token"
USERINFO_URL = "https://app.simplelogin.io/oauth2/userinfo"

# This allows us to use a plain HTTP callback
os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"

app = flask.Flask(__name__)


@app.route("/")
def index():
    return """
    <a href="/login">Login with SimpleLogin</a>
    """


@app.route("/login")
def login():
    simplelogin = requests_oauthlib.OAuth2Session(
        CLIENT_ID, redirect_uri="http://localhost:5000/callback"
    )
    authorization_url, _ = simplelogin.authorization_url(AUTHORIZATION_BASE_URL)

    return flask.redirect(authorization_url)


@app.route("/callback")
def callback():
    simplelogin = requests_oauthlib.OAuth2Session(CLIENT_ID)
    simplelogin.fetch_token(
        TOKEN_URL, client_secret=CLIENT_SECRET, authorization_response=flask.request.url
    )

    user_info = simplelogin.get(USERINFO_URL).json()
    return f"""
    User information: <br>
    Name: {user_info["name"]} <br>
    Email: {user_info["email"]} <br>    
    Avatar <img src="{user_info.get('avatar_url')}"> <br>
    <a href="/">Home</a>
    """


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