AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Custom Domain

Parameters:
  DomainName:
    Type: String
    Description: Domain name for api
  ZoneId:
    Type: String
    Description: Zone ID if exists. If not leave as none.
    Default: none
  CertArn:
    Type: String
    Description: Certificate ARN if exists. If not leave as none.
    Default: none

Conditions:
  CreateZone:
    !Equals [!Ref ZoneId, 'none']
  CreateCert:
    !Equals [!Ref CertArn, 'none']

Resources:
  GeneratedZone: # If a Zone ID is not passed in the parameteres, then a new zone is created for the domain
    Type: AWS::Route53::HostedZone
    Condition: CreateZone
    Properties: 
      Name: !Ref DomainName

  GeneratedCert: # If a Certificate ARN is not passed in the parameters, then a new cert is created and will required validation during the deploy
    Type: AWS::CertificateManager::Certificate
    Condition: CreateCert
    Properties:
      DomainName: !Ref DomainName
      ValidationMethod: DNS

  HttpApiGateway: # Creates a HTTP API endpoint under the customm domain
    Type: AWS::Serverless::HttpApi
    Properties:
      Domain:
        DomainName: !Ref DomainName
        CertificateArn: !If [CreateCert, !Ref GeneratedCert, !Ref CertArn]
        Route53:
          HostedZoneId: !If [CreateZone, !Ref GeneratedZone, !Ref ZoneId]

  HttpApiFunction: # Integration Lambda function for the HTTP API 
    Type: AWS::Serverless::Function
    Properties:
      InlineCode: exports.handler = async (event) => JSON.stringify(event)
      Handler: index.handler
      Runtime: nodejs12.x
      Timeout: 30
      Events:
        FetchHttp:
          Type: HttpApi
          Properties:
            ApiId: !Ref HttpApiGateway
            Method: GET
            Path: /