import socket
import ssl
import tornado.gen
import tornado.ioloop
import tornado.iostream
import tornado.tcpclient
import tornado.test.iostream_test


@tornado.gen.coroutine
def case1(host, port):
    ssl_context = ssl.create_default_context()
    try:
        stream = yield tornado.tcpclient.TCPClient().connect(
            host=host, port=port, ssl_options=ssl_context)
    except ValueError as e:
        print(e)  # check_hostname requires server_hostname
        raise


@tornado.gen.coroutine
def case2(stream_future):
    stream = yield stream_future
    try:
        sslstream = yield stream.start_tls(
            server_side=False,
            ssl_options=ssl.create_default_context(),
            server_hostname='example.com')
    except ValueError as e:
        print(e)  # check_hostname requires server_hostname
        raise


if __name__ == '__main__':
    ioloop = tornado.ioloop.IOLoop.current()

    # Case 1
    #ioloop.add_callback(lambda: case1('example.com', 443))

    # Case 2
    stream = tornado.iostream.IOStream(socket.socket())
    ioloop.add_future(stream.connect(('example.com', 443)), case2)

    ioloop.start()