Implement questionnaire history

feudal/backend/models/serializers/clients.py

 # we don't need to deserialize, so we do not implement the abstract methods
 # pylint: disable=abstract-method
 
+import logging
+
 from django_mysql.models import JSONField
 from rest_framework.serializers import Serializer, ModelSerializer, DictField, ListField, CharField
 from rest_polymorphic.serializers import PolymorphicSerializer
@@ -10,6 +12,8 @@ from feudal.backend.models.users import User, SSHPublicKey
 from feudal.backend.models.deployments import Deployment, VODeployment, ServiceDeployment, DeploymentState, CredentialState
 from feudal.backend.models.auth.serializers.clients import VOSerializer
 
+LOGGER = logging.getLogger(__name__)
+
 
 class ServiceSerializer(ModelSerializer):
     class Meta:
@@ -132,3 +136,29 @@ class DeploymentStateSerializer(ModelSerializer):
         read_only_fields = (
             'answers',
         )
+
+
+    def update(self, instance, validated_data):
+        LOGGER.debug('Updating %s', instance)
+        instance.state = validated_data.get('state', instance.state)
+        instance.message = validated_data.get('message', instance.message)
+        instance.credentials = validated_data.get('credentials', instance.credentials)
+
+        # merge new questionnaire / answers value into the existing dictionary
+        if 'questionnaire' in validated_data:
+            new_questionnaire = validated_data.get('questionnaire')
+            for key in new_questionnaire:
+                question = new_questionnaire[key]
+                if instance.questionnaire.get(key, None) != question:
+                    LOGGER.debug('Question %s = %s', key, question)
+                    instance.questionnaire[key] = question
+
+        if 'questionnaire_answers' in validated_data:
+            new_questionnaire_answers = validated_data.get('questionnaire_answers')
+            for key in new_questionnaire_answers:
+                new_answer = new_questionnaire_answers[key]
+                if instance.questionnaire_answers.get(key, None) != new_answer:
+                    LOGGER.debug('Questionnaire answer %s = %s', key, new_answer)
+                    instance.questionnaire_answers[key] = new_answer
+
+        return instance