# (c) Copyright 2014,2015 Hewlett-Packard Development Company, L.P.
#
# 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.


"""
Freezer Backup modes related functions
"""

from oslo_config import cfg
from oslo_log import log

from freezer.utils import utils

CONF = cfg.CONF
LOG = log.getLogger(__name__)


class BackupOs(object):

    def __init__(self, client_manager, container, storage):
        """

        :param client_manager:
        :param container:
        :param storage:
        :type storage: freezer.swift.SwiftStorage
        :return:
        """
        self.client_manager = client_manager
        self.container = container
        self.storage = storage

    def backup_cinder_by_glance(self, volume_id):
        """
        Implements cinder backup:
            1) Gets a stream of the image from glance
            2) Stores resulted image to the swift as multipart object

        :param volume_id: id of volume for backup
        """
        client_manager = self.client_manager
        cinder = client_manager.get_cinder()

        volume = cinder.volumes.get(volume_id)
        LOG.debug("Creation temporary snapshot")
        snapshot = client_manager.provide_snapshot(
            volume, "backup_snapshot_for_volume_%s" % volume_id)
        LOG.debug("Creation temporary volume")
        copied_volume = client_manager.do_copy_volume(snapshot)
        LOG.debug("Creation temporary glance image")
        image = client_manager.make_glance_image(copied_volume.id,
                                                 copied_volume)
        LOG.debug("Download temporary glance image {0}".format(image.id))
        stream = client_manager.download_image(image)
        package = "{0}/{1}".format(volume_id, utils.DateTime.now().timestamp)
        LOG.debug("Saving image to {0}".format(self.storage.type))
        if volume.name is None:
            name = volume_id
        else:
            name = volume.name
        headers = {'x-object-meta-length': str(len(stream)),
                   'volume_name': name,
                   'availability_zone': volume.availability_zone
                   }
        attachments = volume._info['attachments']
        if attachments:
            headers['server'] = attachments[0]['server_id']
        self.storage.add_stream(stream, package, headers=headers)
        LOG.debug("Deleting temporary snapshot")
        client_manager.clean_snapshot(snapshot)
        LOG.debug("Deleting temporary volume")
        cinder.volumes.delete(copied_volume)
        LOG.debug("Deleting temporary image")
        client_manager.get_glance().images.delete(image.id)

    def backup_cinder(self, volume_id, name=None, description=None,
                      incremental=False):
        client_manager = self.client_manager
        cinder = client_manager.get_cinder()
        container = "{0}/{1}/{2}".format(self.container, volume_id,
                                         utils.DateTime.now().timestamp)
        if incremental:
            search_opts = {
                'volume_id': volume_id,
                'status': 'available'
            }
            backups = cinder.backups.list(search_opts=search_opts)
            if len(backups) <= 0:
                cinder.backups.create(volume_id, container, name, description,
                                      incremental=False, force=True)
            else:
                cinder.backups.create(volume_id, container, name, description,
                                      incremental=incremental, force=True)
        else:
            cinder.backups.create(volume_id, container, name, description,
                                  incremental=incremental, force=True)