# Copyright (C) 2012 - 2014 EMC Corporation.
# 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.

"""The cgsnapshots api."""

from http import HTTPStatus

from oslo_log import log as logging
from oslo_log import versionutils
import webob
from webob import exc

from cinder.api import common
from cinder.api import extensions
from cinder.api.openstack import wsgi
from cinder.api.schemas import cgsnapshots as schema
from cinder.api import validation
from cinder.api.views import cgsnapshots as cgsnapshot_views
from cinder import exception
from cinder import group as group_api
from cinder.i18n import _

LOG = logging.getLogger(__name__)
DEPRECATE_CGSNAP_API_MSG = ("Consistency Group Snapshot APIs are deprecated. "
                            "Use Generic Volume Group Snapshot APIs instead.")


class CgsnapshotsController(wsgi.Controller):
    """The cgsnapshots API controller for the OpenStack API."""

    _view_builder_class = cgsnapshot_views.ViewBuilder

    def __init__(self):
        self.group_snapshot_api = group_api.API()
        super(CgsnapshotsController, self).__init__()

    def show(self, req, id):
        """Return data about the given cgsnapshot."""
        versionutils.report_deprecated_feature(LOG, DEPRECATE_CGSNAP_API_MSG)
        LOG.debug('show called for member %s', id)
        context = req.environ['cinder.context']

        # Not found exception will be handled at the wsgi level
        cgsnapshot = self._get_cgsnapshot(context, id)

        return self._view_builder.detail(req, cgsnapshot)

    def delete(self, req, id):
        """Delete a cgsnapshot."""
        versionutils.report_deprecated_feature(LOG, DEPRECATE_CGSNAP_API_MSG)
        LOG.debug('delete called for member %s', id)
        context = req.environ['cinder.context']

        LOG.info('Delete cgsnapshot with id: %s', id)
        try:
            cgsnapshot = self._get_cgsnapshot(context, id)
            self.group_snapshot_api.delete_group_snapshot(context, cgsnapshot)
        except exception.InvalidGroupSnapshot as e:
            raise exc.HTTPBadRequest(explanation=str(e))
        except (exception.GroupSnapshotNotFound,
                exception.PolicyNotAuthorized):
            # Exceptions will be handled at the wsgi level
            raise
        except Exception:
            msg = _('Failed to delete the cgsnapshot')
            raise exc.HTTPBadRequest(explanation=msg)

        return webob.Response(status_int=HTTPStatus.ACCEPTED)

    def index(self, req):
        """Returns a summary list of cgsnapshots."""
        versionutils.report_deprecated_feature(LOG, DEPRECATE_CGSNAP_API_MSG)
        return self._get_cgsnapshots(req, is_detail=False)

    def detail(self, req):
        """Returns a detailed list of cgsnapshots."""
        versionutils.report_deprecated_feature(LOG, DEPRECATE_CGSNAP_API_MSG)
        return self._get_cgsnapshots(req, is_detail=True)

    def _get_cg(self, context, id):
        # Not found exception will be handled at the wsgi level
        consistencygroup = self.group_snapshot_api.get(context, group_id=id)

        return consistencygroup

    def _get_cgsnapshot(self, context, id):
        # Not found exception will be handled at the wsgi level
        cgsnapshot = self.group_snapshot_api.get_group_snapshot(
            context, group_snapshot_id=id)

        return cgsnapshot

    def _get_cgsnapshots(self, req, is_detail):
        """Returns a list of cgsnapshots, transformed through view builder."""
        context = req.environ['cinder.context']
        grp_snapshots = self.group_snapshot_api.get_all_group_snapshots(
            context)
        grpsnap_limited_list = common.limited(grp_snapshots, req)

        if is_detail:
            grp_snapshots = self._view_builder.detail_list(
                req, grpsnap_limited_list)
        else:
            grp_snapshots = self._view_builder.summary_list(
                req, grpsnap_limited_list)

        return grp_snapshots

    @wsgi.response(HTTPStatus.ACCEPTED)
    @validation.schema(schema.create)
    def create(self, req, body):
        """Create a new cgsnapshot."""
        versionutils.report_deprecated_feature(LOG, DEPRECATE_CGSNAP_API_MSG)
        LOG.debug('Creating new cgsnapshot %s', body)

        context = req.environ['cinder.context']
        cgsnapshot = body['cgsnapshot']

        group_id = cgsnapshot['consistencygroup_id']
        self.clean_name_and_description(cgsnapshot)
        name = cgsnapshot.get('name', None)
        description = cgsnapshot.get('description', None)

        LOG.info("Creating cgsnapshot %(name)s.",
                 {'name': name},
                 context=context)

        # Not found exception will be handled at the wsgi level
        group = self._get_cg(context, group_id)

        try:
            new_cgsnapshot = self.group_snapshot_api.create_group_snapshot(
                context, group, name, description)
        # Not found exception will be handled at the wsgi level
        except (exception.InvalidGroup,
                exception.InvalidGroupSnapshot,
                exception.InvalidVolume) as error:
            raise exc.HTTPBadRequest(explanation=error.msg)

        retval = self._view_builder.summary(req, new_cgsnapshot)

        return retval


class Cgsnapshots(extensions.ExtensionDescriptor):
    """cgsnapshots support."""

    name = 'Cgsnapshots'
    alias = 'cgsnapshots'
    updated = '2014-08-18T00:00:00+00:00'

    def get_resources(self):
        resources = []
        res = extensions.ResourceExtension(
            Cgsnapshots.alias, CgsnapshotsController(),
            collection_actions={'detail': 'GET'})
        resources.append(res)
        return resources
