#!/usr/bin/env python
#
# Copyright 2009 Facebook
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import tornado.auth
import tornado.escape
import tornado.httpserver
import tornado.ioloop
import tornado.web

from tornado import gen
from tornado.options import define, options, parse_command_line

define("port", default=8888, help="run on the given port", type=int)


class Application(tornado.web.Application):
    def __init__(self):
        handlers = [
            (r"/", MainHandler),
            (r"/auth/login", AuthHandler),
            (r"/auth/logout", LogoutHandler),
        ]
        settings = dict(
            cookie_secret="__TODO:_GENERATE_YOUR_OWN_RANDOM_VALUE_HERE__",
            login_url="/auth/login",
        )
        tornado.web.Application.__init__(self, handlers, **settings)


class BaseHandler(tornado.web.RequestHandler):
    def get_current_user(self):
        user_json = self.get_secure_cookie("authdemo_user")
        if not user_json: return None
        return tornado.escape.json_decode(user_json)


class MainHandler(BaseHandler):
    @tornado.web.authenticated
    def get(self):
        name = tornado.escape.xhtml_escape(self.current_user["name"])
        self.write("Hello, " + name)
        self.write("<br><br><a href=\"/auth/logout\">Log out</a>")


class AuthHandler(BaseHandler, tornado.auth.GoogleMixin):
    @gen.coroutine
    def get(self):
        if self.get_argument("openid.mode", None):
            user = yield self.get_authenticated_user()
            self.set_secure_cookie("authdemo_user",
                                   tornado.escape.json_encode(user))
            self.redirect("/")
            return
        self.authenticate_redirect()


class LogoutHandler(BaseHandler):
    def get(self):
        # This logs the user out of this demo app, but does not log them
        # out of Google.  Since Google remembers previous authorizations,
        # returning to this app will log them back in immediately with no
        # interaction (unless they have separately logged out of Google in
        # the meantime).
        self.clear_cookie("authdemo_user")
        self.write('You are now logged out. '
                   'Click <a href="/">here</a> to log back in.')

def main():
    parse_command_line()
    http_server = tornado.httpserver.HTTPServer(Application())
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()


if __name__ == "__main__":
    main()