text: # Copyright (c) 2019, CMCC Technologies Co., Ltd.
  #
  # 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.
  
  from rest_framework import serializers
  
  from lcm.nf_pm.counst import CrossingDirectionType
  from lcm.nf_pm.serializers.Link import LinkSerializer
  
  
  class ThresholdCrossedNotificationSerializer(serializers.Serializer):
      id = serializers.CharField(help_text="Identifier of this notification.", required=True, allow_null=False)
      notificationType = serializers.CharField(help_text="Discriminator for the different notification types.",
                                               required=True, allow_null=False)
      subscriptionId = serializers.CharField(help_text="Identifier of the subscription that this notification "
                                                       "relates to", required=True, allow_null=False)
      timeStamp = serializers.DateField(help_text="Date and time of the generation of the notification",
                                        required=True, allow_null=False)
      thresholdId = serializers.CharField(help_text="Identifier of the threshold which has been crossed.",
                                          required=True, allow_null=False)
      crossingDirection = serializers.ChoiceField(help_text="An indication of whether the threshold was "
                                                            "crossed in upward or downward direction.",
                                                  required=True, allow_null=False,
                                                  choices=CrossingDirectionType)
      objectInstanceId = serializers.CharField(help_text="Identifier that identifies a VNF instance.",
                                               required=True, allow_null=False)
      performanceMetric = serializers.CharField(help_text="Performance metric associated with the threshold.",
                                                required=True, allow_null=False)
      performanceValue = serializers.CharField(help_text="Value of the metric that resulted in threshold "
                                                         "crossing.", required=True, allow_null=False)
      _links = LinkSerializer(help_text="Links to resources related to this notification",
                              required=True, allow_null=False)
  