# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: MIT-0

AWSTemplateFormatVersion: '2010-09-09'
Description: DynamoDB Stream event filtering for Lambda demo stack

Transform: AWS::Serverless-2016-10-31

Globals:
  Function:
    Handler: app.handler
    Runtime: nodejs18.x
    CodeUri: ./src
    Timeout: 10
    MemorySize: 128
    Architectures:
      - arm64

Resources:

  DemoDynamoDBTable:
    Type: AWS::DynamoDB::Table
    Properties:
      BillingMode: PAY_PER_REQUEST
      TableName: table-lambda-esm-filter
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      StreamSpecification:
        StreamViewType: NEW_AND_OLD_IMAGES # Both the new and the old item images of the item are written to the stream.

  # 1. this Lambda is invoked for all messages, regardless of the payload format and contents
  NoFilterFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-esm-no-filter
      Description: No filter
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
  NoFilterFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${NoFilterFunction}"
      RetentionInDays: 3

  # 2. this Lambda is invoked for:
  # {
  #   "kind": "Event"
  # }
  FilterEventsFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-events
      Description: Demo filtering in a single field
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"dynamodb":{"NewImage":{"kind":{"S":["Event"]}}}}'
  FilterEventsFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterEventsFunction}"
      RetentionInDays: 3

  # 3. this Lambda is invoked for:
  # {
  #   "kind": "Event"
  #   "responseStatus": {
  #     "code": 300
  #   }
  # }
  FilterEventsAndResponseCodeFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-events-and-response-code
      Description: Demo filtering on multiple fields
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"dynamodb":{"NewImage":{"kind":{"S":["Event"]},"responseStatus":{"M":{"code":{"N":["300"]}}}}}}'
  FilterEventsAndResponseCodeFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterEventsAndResponseCodeFunction}"
      RetentionInDays: 3

  # 4. this Lambda is invoked for either of the following messages:
  # - option 1 - code is >= 300
  #   {
  #     "responseStatus": {
  #       "code": 300
  #     }
  #   }
  # - option 2 - RBAC flag is set to true
  #   {
  #     "RBAC": true
  #   }
  FilterMultiplePatternsFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-multiple-patterns
      Description: Demo multiple patterns
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"dynamodb":{"NewImage":{"responseStatus":{"M":{"code":{"N":["300"]}}}}}}'
                - Pattern: '{"dynamodb":{"OldImage":{"RBAC":{"BOOL":[true]}}}}'
  FilterMultiplePatternsFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterMultiplePatternsFunction}"
      RetentionInDays: 3

  # 5. this Lambda is invoked for the messages having kind set to anything other than Event
  FilterNotEventKindFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-not-event-kind
      Description: Demo Not filter
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"dynamodb":{"NewImage":{"kind":{"S":[{"anything-but":["Event"]}]}}}}'
  FilterNotEventKindFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterNotEventKindFunction}"
      RetentionInDays: 3

  # 6. this Lambda is invoked for the messages having region property starting with `us-`
  FilterStartsWithFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-starts-with
      Description: Demo prefix filter
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"dynamodb":{"NewImage":{"region":{"S":[{"prefix":"us-"}]}}}}'
  FilterStartsWithFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterStartsWithFunction}"
      RetentionInDays: 3

  # 7. this Lambda is invoked for INSERT and REMOVE events matching a specific Keys filter
  # {
  #   "kind": "Event"
  # }
  FilterOnKeysAndMetadataFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: fn-ddb-filter-key
      Description: Demo inclusive range filter
      Events:
        DDBEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DemoDynamoDBTable.StreamArn
            StartingPosition: LATEST
            FilterCriteria:
              Filters:
                - Pattern: '{"eventName":["INSERT","REMOVE"],"dynamodb":{"Keys":{"id":{"S":["rbac-is-set"]}}}}'
  FilterOnKeysAndMetadataFunctionLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FilterOnKeysAndMetadataFunction}"
      RetentionInDays: 3