text: # -*- coding: utf-8 -*-
  #
  # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you 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.
  #
  from airflow.contrib.hooks.datastore_hook import DatastoreHook
  from airflow.exceptions import AirflowException
  from airflow.models import BaseOperator
  from airflow.utils.decorators import apply_defaults
  
  
  class DatastoreImportOperator(BaseOperator):
      """
      Import entities from Cloud Storage to Google Cloud Datastore
  
      :param bucket: container in Cloud Storage to store data
      :type bucket: string
      :param file: path of the backup metadata file in the specified Cloud Storage bucket.
          It should have the extension .overall_export_metadata
      :type file: string
      :param namespace: optional namespace of the backup metadata file in
          the specified Cloud Storage bucket.
      :type namespace: str
      :param entity_filter: description of what data from the project is included in
          the export, refer to
          https://cloud.google.com/datastore/docs/reference/rest/Shared.Types/EntityFilter
      :type entity_filter: dict
      :param labels: client-assigned labels for cloud storage
      :type labels: dict
      :param datastore_conn_id: the name of the connection id to use
      :type datastore_conn_id: string
      :param delegate_to: The account to impersonate, if any.
          For this to work, the service account making the request must have domain-wide
          delegation enabled.
      :type delegate_to: string
      :param polling_interval_in_seconds: number of seconds to wait before polling for
          execution status again
      :type polling_interval_in_seconds: int
      :param xcom_push: push operation name to xcom for reference
      :type xcom_push: bool
      """
  
      @apply_defaults
      def __init__(self,
                   bucket,
                   file,
                   namespace=None,
                   entity_filter=None,
                   labels=None,
                   datastore_conn_id='google_cloud_default',
                   delegate_to=None,
                   polling_interval_in_seconds=10,
                   xcom_push=False,
                   *args,
                   **kwargs):
          super(DatastoreImportOperator, self).__init__(*args, **kwargs)
          self.datastore_conn_id = datastore_conn_id
          self.delegate_to = delegate_to
          self.bucket = bucket
          self.file = file
          self.namespace = namespace
          self.entity_filter = entity_filter
          self.labels = labels
          self.polling_interval_in_seconds = polling_interval_in_seconds
          self.xcom_push = xcom_push
  
      def execute(self, context):
          self.log.info('Importing data from Cloud Storage bucket %s', self.bucket)
          ds_hook = DatastoreHook(self.datastore_conn_id, self.delegate_to)
          result = ds_hook.import_from_storage_bucket(bucket=self.bucket,
                                                      file=self.file,
                                                      namespace=self.namespace,
                                                      entity_filter=self.entity_filter,
                                                      labels=self.labels)
          operation_name = result['name']
          result = ds_hook.poll_operation_until_done(operation_name,
                                                     self.polling_interval_in_seconds)
  
          state = result['metadata']['common']['state']
          if state != 'SUCCESSFUL':
              raise AirflowException('Operation failed: result={}'.format(result))
  
          if self.xcom_push:
              return result
  