#   Copyright 2013 Rackspace Hosting
#
#   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.

"""The shelved mode extension."""

from oslo_log import log as logging
from webob import exc

from nova.api.openstack import api_version_request
from nova.api.openstack import common
from nova.api.openstack.compute.schemas import shelve as shelve_schemas
from nova.api.openstack import wsgi
from nova.api import validation
from nova.compute import api as compute
from nova import exception
from nova.policies import shelve as shelve_policies

LOG = logging.getLogger(__name__)


class ShelveController(wsgi.Controller):
    def __init__(self):
        super(ShelveController, self).__init__()
        self.compute_api = compute.API()

    @wsgi.response(202)
    @wsgi.expected_errors((404, 403, 409, 400))
    @wsgi.action('shelve')
    def _shelve(self, req, id, body):
        """Move an instance into shelved mode."""
        context = req.environ["nova.context"]

        instance = common.get_instance(self.compute_api, context, id)
        context.can(shelve_policies.POLICY_ROOT % 'shelve',
                    target={'user_id': instance.user_id,
                            'project_id': instance.project_id})
        try:
            self.compute_api.shelve(context, instance)
        except (
            exception.InstanceIsLocked,
            exception.UnexpectedTaskStateError,
        ) as e:
            raise exc.HTTPConflict(explanation=e.format_message())
        except exception.InstanceInvalidState as state_error:
            common.raise_http_conflict_for_instance_invalid_state(state_error,
                                                                  'shelve', id)
        except exception.ForbiddenPortsWithAccelerator as e:
            raise exc.HTTPBadRequest(explanation=e.format_message())

    @wsgi.response(202)
    @wsgi.expected_errors((400, 404, 409))
    @wsgi.action('shelveOffload')
    def _shelve_offload(self, req, id, body):
        """Force removal of a shelved instance from the compute node."""
        context = req.environ["nova.context"]
        instance = common.get_instance(self.compute_api, context, id)
        context.can(shelve_policies.POLICY_ROOT % 'shelve_offload',
                    target={'user_id': instance.user_id,
                            'project_id': instance.project_id})
        try:
            self.compute_api.shelve_offload(context, instance)
        except exception.InstanceIsLocked as e:
            raise exc.HTTPConflict(explanation=e.format_message())
        except exception.InstanceInvalidState as state_error:
            common.raise_http_conflict_for_instance_invalid_state(state_error,
                                                              'shelveOffload',
                                                              id)

        except exception.ForbiddenPortsWithAccelerator as e:
            raise exc.HTTPBadRequest(explanation=e.format_message())

    @wsgi.response(202)
    @wsgi.expected_errors((400, 404, 409))
    @wsgi.action('unshelve')
    # In microversion 2.77 we support specifying 'availability_zone' to
    # unshelve a server. But before 2.77 there is no request body
    # schema validation (because of body=null).
    @validation.schema(
        shelve_schemas.unshelve_v277,
        min_version='2.77',
        max_version='2.90'
    )
    # In microversion 2.91 we support specifying 'host' to
    # unshelve an instance to a specific hostself.
    # 'availability_zone' = None is supported as well to unpin the
    # availability zone of an instance bonded to this availability_zone
    @validation.schema(shelve_schemas.unshelve_v291, min_version='2.91')
    def _unshelve(self, req, id, body):
        """Restore an instance from shelved mode."""
        context = req.environ["nova.context"]
        instance = common.get_instance(self.compute_api, context, id)
        context.can(
            shelve_policies.POLICY_ROOT % 'unshelve',
            target={'project_id': instance.project_id}
        )

        unshelve_args = {}

        unshelve_dict = body.get('unshelve')
        support_az = api_version_request.is_supported(
            req, '2.77')
        support_host = api_version_request.is_supported(
            req, '2.91')
        if unshelve_dict:
            if support_az and 'availability_zone' in unshelve_dict:
                unshelve_args['new_az'] = (
                    unshelve_dict['availability_zone']
                )
            if support_host:
                unshelve_args['host'] = unshelve_dict.get('host')

        try:
            self.compute_api.unshelve(
                context,
                instance,
                **unshelve_args,
            )
        except (
            exception.InstanceIsLocked,
            exception.UnshelveInstanceInvalidState,
            exception.UnshelveHostNotInAZ,
            exception.MismatchVolumeAZException,
        ) as e:
            raise exc.HTTPConflict(explanation=e.format_message())
        except exception.InstanceInvalidState as state_error:
            common.raise_http_conflict_for_instance_invalid_state(
                state_error, 'unshelve', id)
        except (
            exception.InvalidRequest,
            exception.ExtendedResourceRequestOldCompute,
            exception.ComputeHostNotFound,
        ) as e:
            raise exc.HTTPBadRequest(explanation=e.format_message())
