"""An example service authenticating with the Hub.

This example service serves `/services/whoami/`,
authenticated with the Hub,
showing the user their own info.
"""
import json
import os
from urllib.parse import urlparse

from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop
from tornado.web import Application
from tornado.web import authenticated
from tornado.web import RequestHandler

from jupyterhub.services.auth import HubOAuthCallbackHandler
from jupyterhub.services.auth import HubOAuthenticated
from jupyterhub.utils import url_path_join


class WhoAmIHandler(HubOAuthenticated, RequestHandler):
    # hub_users can be a set of users who are allowed to access the service
    # `getuser()` here would mean only the user who started the service
    # can access the service:

    # from getpass import getuser
    # hub_users = {getuser()}

    @authenticated
    def get(self):
        user_model = self.get_current_user()
        self.set_header('content-type', 'application/json')
        self.write(json.dumps(user_model, indent=1, sort_keys=True))


def main():
    app = Application(
        [
            (os.environ['JUPYTERHUB_SERVICE_PREFIX'], WhoAmIHandler),
            (
                url_path_join(
                    os.environ['JUPYTERHUB_SERVICE_PREFIX'], 'oauth_callback'
                ),
                HubOAuthCallbackHandler,
            ),
            (r'.*', WhoAmIHandler),
        ],
        cookie_secret=os.urandom(32),
    )

    http_server = HTTPServer(app)
    url = urlparse(os.environ['JUPYTERHUB_SERVICE_URL'])

    http_server.listen(url.port, url.hostname)

    IOLoop.current().start()


if __name__ == '__main__':
    main()