# Copyright (c) 2013 Rackspace Hosting, Inc.
#
# 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 functools
import sys

from oslo_config import cfg
from oslo_log import log as logging


CONF = cfg.CONF

LOG = logging.getLogger(__name__)


def _fail(returncode, ex):
    """Handles terminal errors.

    :param returncode: process return code to pass to sys.exit
    :param ex: the error that occurred
    """

    print(ex, file=sys.stderr)

    LOG.exception('Exception encountered:')
    sys.exit(returncode)


def runnable(func):
    """Entry point wrapper.

    Note: This call blocks until the process is killed
          or interrupted.
    """

    @functools.wraps(func)
    def _wrapper():
        try:
            logging.register_options(CONF)
            logging.setup(CONF, 'zaqar')
            func()
        except KeyboardInterrupt:
            LOG.info(u'Terminating')
        except Exception as ex:
            _fail(1, ex)

    return _wrapper
