AWSTemplateFormatVersion: "2010-09-09"


Parameters:
  AlarmAction:
    Type: String
    Default: ""
  Threshold:
    Type: Number
    Description: Number of messages sent before triggering the alarm
    Default: 1


Conditions:
  HasAction: !Not [!Equals [!Ref AlarmAction, ""]]


Resources:
  DeadLetterQueue:
    Type: AWS::SQS::Queue

  DeadLetterQueueAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmActions: !If [ HasAction, [!Ref AlarmAction], !Ref AWS::NoValue ]
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: QueueName
          Value: !GetAtt DeadLetterQueue.QueueName
      EvaluationPeriods: 1
      MetricName: NumberOfMessagesSent
      Namespace: AWS/SQS
      Period: 300
      Statistic: Sum
      Threshold: !Ref Threshold
      TreatMissingData: notBreaching
      Unit: Count


Outputs:
  QueueArn:
    Value: !GetAtt DeadLetterQueue.Arn

  QueueName:
    Value: !GetAtt DeadLetterQueue.QueueName

  QueueURL:
    Value: !Ref DeadLetterQueue