# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2012 OpenStack LLC.
# 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.

"""Config Drive extension"""

import webob
import webob.exc

from nova.api.openstack.compute import servers
from nova.api.openstack.compute import views
from nova.api.openstack import extensions
from nova.api.openstack import wsgi
from nova.api.openstack import xmlutil
from nova.compute import api as compute_api
from nova import exception
from nova import flags
from nova.openstack.common import log as logging


FLAGS = flags.FLAGS
authorize = extensions.soft_extension_authorizer('compute', 'config_drive')


class ServerConfigDriveTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('server')
        root.set('config_drive', 'config_drive')
        return xmlutil.SlaveTemplate(root, 1)


class ServersConfigDriveTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('servers')
        elem = xmlutil.SubTemplateElement(root, 'server', selector='servers')
        elem.set('config_drive', 'config_drive')
        return xmlutil.SlaveTemplate(root, 1)


class Controller(servers.Controller):

    def _add_config_drive(self, req, servers):
        for server in servers:
            db_server = req.get_db_instance(server['id'])
            # server['id'] is guaranteed to be in the cache due to
            # the core API adding it in its 'show'/'detail' methods.
            server['config_drive'] = db_server['config_drive']

    def _show(self, req, resp_obj):
        if 'server' in resp_obj.obj:
            resp_obj.attach(xml=ServerConfigDriveTemplate())
            server = resp_obj.obj['server']
            self._add_config_drive(req, [server])

    @wsgi.extends
    def show(self, req, resp_obj, id):
        context = req.environ['nova.context']
        if authorize(context):
            self._show(req, resp_obj)

    @wsgi.extends
    def detail(self, req, resp_obj):
        context = req.environ['nova.context']
        if 'servers' in resp_obj.obj and authorize(context):
            resp_obj.attach(xml=ServersConfigDriveTemplate())
            servers = resp_obj.obj['servers']
            self._add_config_drive(req, servers)


class Config_drive(extensions.ExtensionDescriptor):
    """Config Drive Extension"""

    name = "ConfigDrive"
    alias = "os-config_drive"
    namespace = "http://docs.openstack.org/compute/ext/config_drive/api/v1.1"
    updated = "2012-07-16T00:00:00+00:00"

    def get_controller_extensions(self):
        controller = Controller()
        extension = extensions.ControllerExtension(self, 'servers', controller)
        return [extension]
