#!/usr/bin/env python
# pylint: disable=C0103
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    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.

"""Starter script for Nova Direct API."""

import eventlet
eventlet.monkey_patch()

import os
import sys

# If ../nova/__init__.py exists, add ../ to Python search path, so that
# it will override what happens to be installed in /usr/(local/)lib/python...
possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
                                   os.pardir,
                                   os.pardir))
if os.path.exists(os.path.join(possible_topdir, 'nova', '__init__.py')):
    sys.path.insert(0, possible_topdir)


from nova import compute
from nova import flags
from nova import log as logging
from nova import network
from nova.openstack.common import cfg
from nova import service
from nova import utils
from nova import volume
from nova import wsgi
from nova.api import direct


direct_api_opts = [
    cfg.IntOpt('direct_port',
               default=8001,
               help='Direct API port'),
    cfg.StrOpt('direct_host',
               default='0.0.0.0',
               help='Direct API host'),
    ]

FLAGS = flags.FLAGS
FLAGS.register_cli_opts(direct_api_opts)


# An example of an API that only exposes read-only methods.
# In this case we're just limiting which methods are exposed.
class ReadOnlyCompute(direct.Limited):
    """Read-only Compute API."""

    _allowed = ['get', 'get_all', 'get_console_output']


# An example of an API that provides a backwards compatibility layer.
# In this case we're overwriting the implementation to ensure
# compatibility with an older version. In reality we would want the
# "description=None" to be part of the actual API so that code
# like this isn't even necessary, but this example shows what one can
# do if that isn't the situation.
class VolumeVersionOne(direct.Limited):
    _allowed = ['create', 'delete', 'update', 'get']

    def create(self, context, size, name):
        self.proxy.create(context, size, name, description=None)


if __name__ == '__main__':
    utils.default_flagfile()
    FLAGS(sys.argv)
    logging.setup()

    direct.register_service('compute', compute.API())
    direct.register_service('volume', volume.API())
    direct.register_service('network', network.API())
    direct.register_service('reflect', direct.Reflection())

    # Here is how we could expose the code in the examples above.
    #direct.register_service('compute-readonly',
    #                        ReadOnlyCompute(compute.API()))
    #direct.register_service('volume-v1', VolumeVersionOne(volume.API()))

    router = direct.Router()
    with_json = direct.JsonParamsMiddleware(router)
    with_req = direct.PostParamsMiddleware(with_json)
    with_auth = direct.DelegatedAuthMiddleware(with_req)

    server = wsgi.Server("Direct API",
                         with_auth,
                         host=FLAGS.direct_host,
                         port=FLAGS.direct_port)

    service.serve(server)
    service.wait()