text: # 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 alibabacloud.signer.algorithm import NoHandle, ShaHmac1
  from alibabacloud.signer.composer import SIGNER_MAP
  
  
  class Signer(object):
  
      @staticmethod
      def sign(credentials, context):
          signer = ShaHmac1
          if getattr(credentials, 'bearer_token') is not None:
              signer = NoHandle
  
          request = context.api_request
          region_id = context.config.region_id
          version = context.client.api_version
          # which token
          cls = SIGNER_MAP[request.style]
          auth = cls(credentials, request, region_id, version, signer=signer)
          signature, headers, params = auth.signature, auth.headers, auth.params
          return signature, headers, params
  