py: Simple facebook login

fblogin_test.py

import os
import base64
import flask
import urllib.parse
import requests

app = flask.Flask(__name__)

APP_ID = "ID"
APP_SECRET = "SECRET"

loginz = {}


class FacebookLogin:
    """Generic class to handle FB Oauth Login.
    """
    login_url = "https://www.facebook.com/dialog/oauth"
    exchange_url = "https://graph.facebook.com/oauth/access_token"

    def __init__(self, app_id, app_secret):
        self.app_id = app_id
        self.app_secret = app_secret

    def gen_login_url(self, redirect_uri):
        return self.login_url + "?" + urllib.parse.urlencode({
                            "client_id": self.app_id,
                            "redirect_uri": redirect_uri})

    def gen_exchange_url(self, redirect_uri, code):
        return self.excahange_url + "?" + urllib.parse.urlencode({
                            "client_id": self.app_id,
                            "client_secret": self.app_secret,
                            "redirect_uri": redirect_uri,
                            "code": code})


def token(length=8):
    return base64.urlsafe_b64encode(os.urandom(length)).decode()


@app.route("/")
def hello():
    return "Dis is login for Facebookses."


@app.route("/login")
def login():
    login_id = token()
    loginz[login_id] = True
    print("Request:" + login_id)
    url = urllib.parse.urlencode({"client_id": APP_ID,
                    "redirect_uri": flask.url_for('callback',
                                    login_token=login_id, _external=True)})
    return flask.redirect("https://www.facebook.com/dialog/oauth?"+url)


@app.route("/fb/oauth/<login_token>")
def callback(login_token):
    print("Callback:" + login_token)
    if login_token in loginz:
        code = flask.request.args.get('code')
        return code
    else:
        return flask.abort(404)

    #error_reason=user_denied
    #error=access_denied
    #error_description=The+user+denied+your+request.

    return "CALLBACK!"


if __name__ == "__main__":
    app.run(port=9090, debug=True)