text: # Copyright The Cloud Custodian Authors.
  # SPDX-License-Identifier: Apache-2.0
  
  
  import base64
  import copy
  import zlib
  
  from .core import EventAction
  from c7n import utils
  from c7n.exceptions import PolicyValidationError
  from c7n.manager import resources as aws_resources
  from c7n.resolver import ValuesFrom
  from c7n.version import version
  
  
  class BaseNotify(EventAction):
  
      batch_size = 250
  
      def expand_variables(self, message):
          """expand any variables in the action to_from/cc_from fields.
          """
          p = copy.deepcopy(self.data)
          if 'to_from' in self.data:
              to_from = self.data['to_from'].copy()
              to_from['url'] = to_from['url'].format(**message)
              if 'expr' in to_from:
                  to_from['expr'] = to_from['expr'].format(**message)
              p.setdefault('to', []).extend(ValuesFrom(to_from, self.manager).get_values())
          if 'cc_from' in self.data:
              cc_from = self.data['cc_from'].copy()
              cc_from['url'] = cc_from['url'].format(**message)
              if 'expr' in cc_from:
                  cc_from['expr'] = cc_from['expr'].format(**message)
              p.setdefault('cc', []).extend(ValuesFrom(cc_from, self.manager).get_values())
          return p
  
      def pack(self, message):
          dumped = utils.dumps(message)
          compressed = zlib.compress(dumped.encode('utf8'))
          b64encoded = base64.b64encode(compressed)
          return b64encoded.decode('ascii')
  
  
  class Notify(BaseNotify):
      """
      Flexible notifications require quite a bit of implementation support
      on pluggable transports, templates, address resolution, variable
      extraction, batch periods, etc.
  
      For expedience and flexibility then, we instead send the data to
      an sqs queue, for processing. ie. actual communications can be enabled
      with the c7n-mailer tool, found under tools/c7n_mailer.
  
      Attaching additional string message attributes are supported on the SNS
      transport, with the exception of the ``mtype`` attribute, which is a
      reserved attribute used by Cloud Custodian.
  
      :example:
  
      .. code-block:: yaml
  
                policies:
                  - name: ec2-bad-instance-kill
                    resource: ec2
                    filters:
                     - Name: bad-instance
                    actions:
                     - terminate
                     - type: notify
                       to:
                        - event-user
                        - resource-creator
                        - email@address
                       owner_absent_contact:
                        - other_email@address
                       # which template for the email should we use
                       template: policy-template
                       transport:
                         type: sqs
                         region: us-east-1
                         queue: xyz
                  - name: ec2-notify-with-attributes
                    resource: ec2
                    filters:
                     - Name: bad-instance
                    actions:
                     - type: notify
                       to:
                        - event-user
                        - resource-creator
                        - email@address
                       owner_absent_contact:
                        - other_email@address
                       # which template for the email should we use
                       template: policy-template
                       transport:
                         type: sns
                         region: us-east-1
                         topic: your-notify-topic
                         attributes:
                            attribute_key: attribute_value
                            attribute_key_2: attribute_value_2
      """
  
      C7N_DATA_MESSAGE = "maidmsg/1.0"
  
      schema_alias = True
      schema = {
          'type': 'object',
          'anyOf': [
              {'required': ['type', 'transport', 'to']},
              {'required': ['type', 'transport', 'to_from']}],
          'properties': {
              'type': {'enum': ['notify']},
              'to': {'type': 'array', 'items': {'type': 'string'}},
              'owner_absent_contact': {'type': 'array', 'items': {'type': 'string'}},
              'to_from': ValuesFrom.schema,
              'cc': {'type': 'array', 'items': {'type': 'string'}},
              'cc_from': ValuesFrom.schema,
              'cc_manager': {'type': 'boolean'},
              'from': {'type': 'string'},
              'subject': {'type': 'string'},
              'template': {'type': 'string'},
              'transport': {
                  'oneOf': [
                      {'type': 'object',
                       'required': ['type', 'queue'],
                       'properties': {
                           'queue': {'type': 'string'},
                           'type': {'enum': ['sqs']}}},
                      {'type': 'object',
                       'required': ['type', 'topic'],
                       'properties': {
                           'topic': {'type': 'string'},
                           'type': {'enum': ['sns']},
                           'attributes': {'type': 'object'},
                       }}]
              },
              'assume_role': {'type': 'boolean'}
          }
      }
  
      def __init__(self, data=None, manager=None, log_dir=None):
          super(Notify, self).__init__(data, manager, log_dir)
          self.assume_role = data.get('assume_role', True)
  
      def validate(self):
          if self.data.get('transport', {}).get('type') == 'sns' and \
                  self.data.get('transport').get('attributes') and \
                  'mtype' in self.data.get('transport').get('attributes').keys():
              raise PolicyValidationError(
                  "attribute: mtype is a reserved attribute for sns transport")
          return self
  
      def get_permissions(self):
          if self.data.get('transport', {}).get('type') == 'sns':
              return ('sns:Publish',)
          if self.data.get('transport', {'type': 'sqs'}).get('type') == 'sqs':
              return ('sqs:SendMessage',)
          return ()
  
      def process(self, resources, event=None):
          alias = utils.get_account_alias_from_sts(
              utils.local_session(self.manager.session_factory))
          message = {
              'event': event,
              'account_id': self.manager.config.account_id,
              'account': alias,
              'version': version,
              'region': self.manager.config.region,
              'execution_id': self.manager.ctx.execution_id,
              'execution_start': self.manager.ctx.start_time,
              'policy': self.manager.data}
          message['action'] = self.expand_variables(message)
  
          for batch in utils.chunks(resources, self.batch_size):
              message['resources'] = self.prepare_resources(batch)
              receipt = self.send_data_message(message)
              self.log.info("sent message:%s policy:%s template:%s count:%s" % (
                  receipt, self.manager.data['name'],
                  self.data.get('template', 'default'), len(batch)))
  
      def prepare_resources(self, resources):
          """Resources preparation for transport.
  
          If we have sensitive or overly large resource metadata we want to
          remove or additional serialization we need to perform, this
          provides a mechanism.
  
          TODO: consider alternative implementations, at min look at adding
          provider as additional discriminator to resource type. One alternative
          would be dynamically adjusting buffer size based on underlying
          transport.
          """
          handler = getattr(self, "prepare_%s" % (
              self.manager.type.replace('-', '_')),
              None)
          if handler is None:
              return resources
          return handler(resources)
  
      def prepare_launch_config(self, resources):
          for r in resources:
              r.pop('UserData', None)
          return resources
  
      def prepare_asg(self, resources):
          for r in resources:
              if 'c7n:user-data' in r:
                  r.pop('c7n:user-data', None)
          return resources
  
      def prepare_ec2(self, resources):
          for r in resources:
              if 'c7n:user-data' in r:
                  r.pop('c7n:user-data')
          return resources
  
      def send_data_message(self, message):
          if self.data['transport']['type'] == 'sqs':
              return self.send_sqs(message)
          elif self.data['transport']['type'] == 'sns':
              return self.send_sns(message)
  
      def send_sns(self, message):
          topic = self.data['transport']['topic'].format(**message)
          user_attributes = self.data['transport'].get('attributes')
          if topic.startswith('arn:'):
              region = region = topic.split(':', 5)[3]
              topic_arn = topic
          else:
              region = message['region']
              topic_arn = utils.generate_arn(
                  service='sns', resource=topic,
                  account_id=message['account_id'],
                  region=message['region'])
          client = self.manager.session_factory(
              region=region, assume=self.assume_role).client('sns')
          attrs = {
              'mtype': {
                  'DataType': 'String',
                  'StringValue': self.C7N_DATA_MESSAGE,
              },
          }
          if user_attributes:
              for k, v in user_attributes.items():
                  if k != 'mtype':
                      attrs[k] = {'DataType': 'String', 'StringValue': v}
          client.publish(
              TopicArn=topic_arn,
              Message=self.pack(message),
              MessageAttributes=attrs
          )
  
      def send_sqs(self, message):
          queue = self.data['transport']['queue'].format(**message)
          if queue.startswith('https://queue.amazonaws.com'):
              region = 'us-east-1'
              queue_url = queue
          elif 'queue.amazonaws.com' in queue:
              region = queue[len('https://'):].split('.', 1)[0]
              queue_url = queue
          elif queue.startswith('https://sqs.'):
              region = queue.split('.', 2)[1]
              queue_url = queue
          elif queue.startswith('arn:'):
              queue_arn_split = queue.split(':', 5)
              region = queue_arn_split[3]
              owner_id = queue_arn_split[4]
              queue_name = queue_arn_split[5]
              queue_url = "https://sqs.%s.amazonaws.com/%s/%s" % (
                  region, owner_id, queue_name)
          else:
              region = self.manager.config.region
              owner_id = self.manager.config.account_id
              queue_name = queue
              queue_url = "https://sqs.%s.amazonaws.com/%s/%s" % (
                  region, owner_id, queue_name)
          client = self.manager.session_factory(
              region=region, assume=self.assume_role).client('sqs')
          attrs = {
              'mtype': {
                  'DataType': 'String',
                  'StringValue': self.C7N_DATA_MESSAGE,
              },
          }
          result = client.send_message(
              QueueUrl=queue_url,
              MessageBody=self.pack(message),
              MessageAttributes=attrs)
          return result['MessageId']
  
      @classmethod
      def register_resource(cls, registry, resource_class):
          if 'notify' in resource_class.action_registry:
              return
  
          resource_class.action_registry.register('notify', cls)
  
  
  aws_resources.subscribe(Notify.register_resource)
  