AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Serverless pattern API Gateway to EventBridge

Parameters:
  Stage:
    Type: String
    Default: dev
  Service:
    Type: String
    Default: apigw2eb
  SubDomainName:
    Type: String
    # Create a custom domain name at
    # https://<REGION>.console.aws.amazon.com/apigateway/main/publish/domain-names
    Default: dev-events
  DomainName:
    Type: String
    # Replace example.com with your domain
    Default: example.com

# Resources declares the AWS resources that you want to include in the stack
# https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resources-section-structure.html
Resources:
  # Resource creates or updates a partner event bus or custom event bus
  # https://docs.aws.amazon.com/ja_jp/AWSCloudFormation/latest/UserGuide/aws-resource-events-eventbus.html
  ApplicationEventBus:
    Type: AWS::Events::EventBus
    Properties:
      Name: !Sub ${Service}-${Stage}

  # Resource reates an API
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigatewayv2-api.html
  HttpApi:
    Type: AWS::ApiGatewayV2::Api
    Properties:
      Name: !Sub ${Service}-http-api-${Stage}
      ProtocolType: HTTP
      DisableExecuteApiEndpoint: true

  # Resource creates an API mapping
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigatewayv2-apimapping.html
  HttpApiMapping:
    DependsOn:
      - HttpApiStage
    Type: AWS::ApiGatewayV2::ApiMapping
    Properties:
      ApiId:
        Ref: HttpApi
      DomainName: !Sub ${SubDomainName}.${DomainName}
      Stage: !Sub ${Stage}
      ApiMappingKey: !Sub ${Service}

  # Resource updates a stage for an API
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigatewayv2-stage.html
  HttpApiStage:
    Type: AWS::ApiGatewayV2::Stage
    Properties:
      ApiId:
        Ref: HttpApi
      StageName: !Sub ${Stage}
      AutoDeploy: true

  # Resource creates a route for an API
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigatewayv2-route.html
  HttpApiRoute:
    DependsOn:
      - HttpApiIntegrationEventBridge
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId:
        Ref: HttpApi
      RouteKey: POST /{source}/{detailType}
      Target:
        Fn::Join:
          - /
          - - integrations
            - Ref: HttpApiIntegrationEventBridge

  # Resource creates an integration for an API
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigatewayv2-integration.html
  HttpApiIntegrationEventBridge:
    DependsOn:
      - HttpApiIntegrationEventBridgeRole
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId:
        Ref: HttpApi
      IntegrationType: AWS_PROXY
      IntegrationSubtype: EventBridge-PutEvents
      CredentialsArn:
        Fn::GetAtt: [HttpApiIntegrationEventBridgeRole, Arn]
      RequestParameters:
        # Replace `mycompany` with your needs
        Source: com.mycompany.$request.path.source
        DetailType: $request.path.detailType
        Detail: $request.body
        EventBusName:
          Fn::GetAtt: [ApplicationEventBus, Arn]
      PayloadFormatVersion: "1.0"
      TimeoutInMillis: 10000

  # Resource creates a new role for your AWS account
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-iam-role.html
  HttpApiIntegrationEventBridgeRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - apigateway.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: !Sub ${Service}-${Stage}-eventBridge
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              - Effect: Allow
                Action: 'events:*'
                Resource:
                  Fn::GetAtt: [ApplicationEventBus, Arn]
      RoleName:
        Fn::Join:
          - "-"
          - - !Sub ${Service}-${Stage}
            - Ref: AWS::Region
            - eventBridgeRole

Outputs:
  ApplicationEventBusName:
    Description: Application EventBus Name
    Value:
      Ref: ApplicationEventBus

  ApplicationEventBusArn:
    Description: Application EventBus ARN
    Value:
      Fn::GetAtt:
        - ApplicationEventBus
        - Arn