AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Pattern that will remove one-time schedules based on a given expiry time

Resources:
  # Queue to hold schedules to remove, Lambda will process them in batches of 10
  ScheduleQueue:
    Type: AWS::SQS::Queue
    Properties:
      QueueName: !Sub ${AWS::StackName}-removal-queue
      VisibilityTimeout: 350
      RedrivePolicy:
        deadLetterTargetArn: !GetAtt ScheduleQueueDLQ.Arn
        maxReceiveCount: 5

  #DLQ for source
  ScheduleQueueDLQ:
    Type: AWS::SQS::Queue

  # Lambda function to query schedules and put the onto a queue for processing
  FindSchedules:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: src/
      Handler: find-schedules.handler
      Runtime: nodejs18.x
      Policies:
        - AWSLambdaBasicExecutionRole
        - Version: 2012-10-17
          Statement:
            - Effect: Allow
              Action:
                - 'scheduler:ListSchedules'
                - 'scheduler:GetSchedule'
              Resource: '*'
            - Effect: Allow
              Action:
                - 'sqs:SendMessage'
                - 'sqs:SendMessageBatch'
              Resource: !GetAtt ScheduleQueue.Arn
      Architectures:
        - x86_64
      Timeout: 300
      Environment:
        Variables:
          QUEUE_URL: !Ref ScheduleQueue
    Metadata: # Manage esbuild properties
      BuildMethod: esbuild
      BuildProperties:
        Minify: true
        Target: 'es2020'
        # Sourcemap: true # Enabling source maps will create the required NODE_OPTIONS environment variables on your lambda function during sam build
        EntryPoints:
          - find-schedules.ts

  # Lambda function to check schedule and remove it if its one-time and expired.
  ProcessSchedules:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: src/
      Handler: process-schedule-batch.handler
      Runtime: nodejs18.x
      Policies:
        - AWSLambdaBasicExecutionRole
        - Version: 2012-10-17
          Statement:
            - Effect: Allow
              Action:
                - 'scheduler:GetSchedule'
                - 'scheduler:DeleteSchedule'
              Resource: '*'
            - Effect: Allow
              Action:
                - 'sqs:ReceiveMessage'
                - 'sqs:DeleteMessage'
                - 'sqs:GetQueueAttributes'
              Resource: !GetAtt ScheduleQueue.Arn

      Architectures:
        - x86_64
      Timeout: 300
      Events:
        MySQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt ScheduleQueue.Arn
            BatchSize: 10
    Metadata: # Manage esbuild properties
      BuildMethod: esbuild
      BuildProperties:
        Minify: true
        Target: 'es2020'
        # Sourcemap: true # Enabling source maps will create the required NODE_OPTIONS environment variables on your lambda function during sam build
        EntryPoints:
          - process-schedule-batch.ts

  # Schedule that will run every day at 00:00 to trigger process
  CleanUpOneTimeSchedules:
    Type: AWS::Scheduler::Schedule
    Properties:
      Description: Schedule the runs every day to clean up one time schedules
      FlexibleTimeWindow:
        Mode: 'OFF'
      ScheduleExpression: 'cron(0 0 * * ? *)'
      Target:
        Arn: !GetAtt FindSchedules.Arn
        RoleArn: !GetAtt CleanUpOneTimeSchedulesRole.Arn

  CleanUpOneTimeSchedulesRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - scheduler.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: InvokeLambda
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - 'lambda:InvokeFunction'
                Resource:
                  - !GetAtt FindSchedules.Arn