AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Template to connect DynamoDB Stream to EventBridge

Resources:

  # DynamoDB Stream
  DynamoDBUsersTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: Users
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      ProvisionedThroughput:
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5
      StreamSpecification:
        ## Listen for KEYS_ONLY, NEW_IMAGE, OLD_IMAGE, or NEW_AND_OLD_IMAGES (https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_StreamSpecification.html)
        StreamViewType: NEW_AND_OLD_IMAGES    

  # Event Bus (Target)
  ApplicationEventBus:
    Type: AWS::Events::EventBus
    Properties:
      Name: UserBus

  PipeRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - pipes.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: SourcePolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - "dynamodb:DescribeStream"
                  - "dynamodb:GetRecords"
                  - "dynamodb:GetShardIterator"
                  - "dynamodb:ListStreams"
                Resource: !GetAtt DynamoDBUsersTable.StreamArn
        - PolicyName: TargetPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - 'events:PutEvents'
                Resource: !GetAtt ApplicationEventBus.Arn

  # EventBridge Pipe              
  Pipe:
    Type: AWS::Pipes::Pipe
    Properties:
      Name: ddb-to-eventbridge-suffix
      Description: "Pipe to connect DDB stream to EventBridge event bus with suffix matching"
      RoleArn: !GetAtt PipeRole.Arn
      Source: !GetAtt DynamoDBUsersTable.StreamArn
      SourceParameters:
        FilterCriteria:
          Filters:
            - Pattern: '{"dynamodb": {"NewImage": {"avatarUrl": {"S": [{"suffix": ".png"}]}}}}'
        DynamoDBStreamParameters:
          StartingPosition: LATEST
          BatchSize: 1
      Target: !GetAtt ApplicationEventBus.Arn
      TargetParameters:
        EventBridgeEventBusParameters:
          DetailType: "UserDetailsChanged"
          Source: "myapp.users"