"""Basic message consumer example"""
import functools
import logging
import pika

LOG_FORMAT = ('%(levelname) -10s %(asctime)s %(name) -30s %(funcName) '
              '-35s %(lineno) -5d: %(message)s')
LOGGER = logging.getLogger(__name__)

logging.basicConfig(level=logging.DEBUG, format=LOG_FORMAT)

def on_message(chan, method_frame, _header_frame, body, userdata=None):
    """Called when a message is received. Log message and ack it."""
    LOGGER.info('Userdata: %s Message body: %s', userdata, body)
    chan.basic_ack(delivery_tag=method_frame.delivery_tag)

def main():
    """Main method."""
    credentials = pika.PlainCredentials('guest', 'guest')
    parameters = pika.ConnectionParameters('localhost', credentials=credentials)
    connection = pika.BlockingConnection(parameters)

    channel = connection.channel()
    channel.exchange_declare(exchange="test_exchange",
                             exchange_type="direct",
                             passive=False,
                             durable=True,
                             auto_delete=False)
    channel.queue_declare(queue="standard", auto_delete=True)
    channel.queue_bind(queue="standard", exchange="test_exchange", routing_key="standard_key")
    channel.basic_qos(prefetch_count=1)

    on_message_callback = functools.partial(on_message, userdata='on_message_userdata')
    channel.basic_consume(on_message_callback, 'standard')

    try:
        channel.start_consuming()
    except KeyboardInterrupt:
        channel.stop_consuming()

    connection.close()

if __name__ == '__main__':
    main()