AWSTemplateFormatVersion: '2010-09-09'
Description: Serverless demo

Resources:
  # SNS Topic
  MySNSTopic:
    Type: AWS::SNS::Topic

  # SQS Queue
  MySQSQueue:
    Type: AWS::SQS::Queue

  # SNS Subscription to SQS
  SNSToSQSSubscription:
    Type: AWS::SNS::Subscription
    Properties:
      TopicArn: !Ref MySNSTopic
      Protocol: sqs
      Endpoint: !GetAtt MySQSQueue.Arn
      RawMessageDelivery: true

  # SQS Queue Policy to Allow SNS to Send Messages
  SQSPolicy:
    Type: AWS::SQS::QueuePolicy
    Properties:
      Queues:
        - !Ref MySQSQueue
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service: sns.amazonaws.com
            Action: sqs:SendMessage
            Resource: !GetAtt MySQSQueue.Arn
            Condition:
              ArnEquals:
                aws:SourceArn: !Ref MySNSTopic

  # API Gateway
  ApiGatewayRestApi:
    Type: AWS::ApiGateway::RestApi
    Properties:
      Name: SNSInvokeAPI
      Parameters:
        endpointConfigurationTypes: REGIONAL
      EndpointConfiguration:
        Types:
        - REGIONAL

  # API Gateway Resource
  ApiGatewayResource:
    Type: AWS::ApiGateway::Resource
    Properties:
      ParentId: !GetAtt ApiGatewayRestApi.RootResourceId
      PathPart: invoke
      RestApiId: !Ref ApiGatewayRestApi

  # API Gateway Method to integrate directly with SNS
  ApiGatewayMethod:
    Type: AWS::ApiGateway::Method
    Properties:
      RestApiId: !Ref ApiGatewayRestApi
      ResourceId: !Ref ApiGatewayResource
      HttpMethod: POST
      AuthorizationType: NONE
      Integration:
        IntegrationHttpMethod: POST
        Type: AWS
        Uri: !Sub arn:aws:apigateway:${AWS::Region}:sns:path/Publish
        Credentials: "arn:aws:iam::920372985147:role/AWSAPIGateway"
        RequestParameters:
          integration.request.header.Content-Type: "'application/x-www-form-urlencoded'"
        RequestTemplates:
          application/json: !Sub |
            Action=Publish&TopicArn={!Ref MySNSTopic}&Message=$util.urlEncode($input.body)
        IntegrationResponses:
          - StatusCode: 200
            ResponseTemplates:
              application/json: '{"status": "Message published to SNS"}'
      MethodResponses:
        - StatusCode: 200

  # API Gateway Deployment
  ApiGatewayDeployment:
    Type: AWS::ApiGateway::Deployment
    DependsOn: ApiGatewayMethod
    Properties:
      RestApiId: !Ref ApiGatewayRestApi
      StageName: prod

Outputs:
  ApiEndpoint:
    Description: "Endpoint URL for POST /invoke"
    Value: !Sub "https://${ApiGatewayRestApi}.execute-api.${AWS::Region}.amazonaws.com/prod/invoke"