AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  APIKeyQueryString blog post.
Globals:
  Function:
    Timeout: 10
  Api:
    OpenApiVersion: 3.0.1


Resources:
  MyAuthFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: auth_function/
      Handler: app.lambda_handler
      Runtime: python3.8
  BackendFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: hello_world/
      Handler: app.lambda_handler
      Runtime: python3.8
      Events:
        HelloWorld:
          Type: Api 
          Properties:
            RestApiId: 
              Ref: MyApi
            Path: /auth
            Method: get
            
  MyApi:
      DependsOn: MyAuthFunction
      Type: AWS::Serverless::Api
      Properties:
        StageName: prod
        Auth:
            DefaultAuthorizer: MyLambdaRequestAuthorizer
            ApiKeyRequired: true
            Authorizers:
              MyLambdaRequestAuthorizer:
                FunctionPayloadType: REQUEST
                FunctionArn: !GetAtt MyAuthFunction.Arn
                Identity:
                  ReauthorizeEvery: 0
                  QueryStrings:
                    - apiKey
        DefinitionBody:
          swagger: "2.0"
          info:
            version: "2021-08-10T13:18:57Z"
            title: "API-Key-QueryString"
          basePath: "/prod"
          x-amazon-apigateway-api-key-source: "AUTHORIZER" #important
          schemes:
          - "https"
          paths:
            /auth:
              get:
                produces:
                - "application/json"
                responses:
                  "200":
                    description: "200 response"
                    schema:
                      $ref: "#/definitions/Empty"
                x-amazon-apigateway-integration:
                  type: "aws_proxy"
                  httpMethod: "POST"
                  uri: 
                    Fn::Sub: "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${BackendFunction.Arn}/invocations"
                  responses:
                    default:
                      statusCode: "200"
                  passthroughBehavior: "when_no_match"
                  contentHandling: "CONVERT_TO_TEXT"
          definitions:
            Empty:
              type: "object"
              title: "Empty Schema"
            
  ApiKey:
    Type: AWS::ApiGateway::ApiKey
    DependsOn: MyApiprodStage
    Properties:
      Name: !Join ["", [{"Ref": "AWS::StackName"}, "-apikey"]]
      Enabled: true
      StageKeys:
        - RestApiId: !Ref MyApi
          StageName: prod
      Value: !Join ["", [{"Ref": "AWS::StackName"}, "-abcdefhijk1234567890"]]
          
  UsagePlan:
    DependsOn: MyApiprodStage
    Type: AWS::ApiGateway::UsagePlan
    Properties:
      ApiStages:
        - ApiId: !Ref MyApi
          Stage: prod
      Throttle:
        BurstLimit: 50
        RateLimit: 100
      UsagePlanName: MyUsagePlan
      
  UsagePlanKey:
    Type: AWS::ApiGateway::UsagePlanKey
    Properties:
      KeyId: !Ref ApiKey
      KeyType: API_KEY
      UsagePlanId: !Ref UsagePlan


Outputs:
  HelloWorldApi:
    Description: "API Gateway endpoint URL for Prod stage for Hello World function"
    Value: !Sub "https://${MyApi}.execute-api.${AWS::Region}.amazonaws.com/prod/auth?apiKey=${AWS::StackName}-abcdefhijk1234567890"