#!/usr/bin/env python

import asyncio
import logging
from tornado import gen
from tornado.iostream import StreamClosedError
from tornado.tcpserver import TCPServer
from tornado.options import options, define

define("port", default=9888, help="TCP port to listen on")
logger = logging.getLogger(__name__)


class EchoServer(TCPServer):
    @gen.coroutine
    def handle_stream(self, stream, address):
        while True:
            try:
                data = yield stream.read_until(b"\n")
                logger.info("Received bytes: %s", data)
                if not data.endswith(b"\n"):
                    data = data + b"\n"
                yield stream.write(data)
            except StreamClosedError:
                logger.warning("Lost client at host %s", address[0])
                break
            except Exception as e:
                print(e)


async def main():
    options.parse_command_line()
    logger.info("Listening on TCP port %d", options.port)
    server = EchoServer()
    server.listen(options.port)
    await asyncio.Event().wait()


if __name__ == "__main__":
    asyncio.run(main())