AWSTemplateFormatVersion: 2010-09-09
Description: AppSync setup
Parameters:
  FunctionStack:
    Description: The stack name that deploys the Lambda functions to invoke.
    Type: String
Resources:
  DataSourceRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Action: sts:AssumeRole
            Effect: Allow
            Principal:
              Service: appsync.amazonaws.com
      Policies:
        - PolicyName: LambdaInvoker
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Action: lambda:InvokeFunction
                Effect: Allow
                Resource:
                  - Fn::Join:
                    - ''
                    - - 'arn:aws:lambda:'
                      - !Ref AWS::Region
                      - ':'
                      - !Ref AWS::AccountId
                      - ':function:'
                      - Fn::ImportValue:
                          !Sub '${FunctionStack}-functions-Context'
                  - Fn::Join:
                    - ''
                    - - 'arn:aws:lambda:'
                      - !Ref AWS::Region
                      - ':'
                      - !Ref AWS::AccountId
                      - ':function:'
                      - Fn::ImportValue:
                          !Sub '${FunctionStack}-functions-Context'
                      - ':*'
      RoleName: !Sub '${AWS::StackName}-lambda-role'
  GqlApi:
    Type: AWS::AppSync::GraphQLApi
    Properties:
      AuthenticationType:  AWS_IAM
      Name: !Ref AWS::StackName
  GqlSchema:
    Type: AWS::AppSync::GraphQLSchema
    Properties:
      ApiId: !GetAtt GqlApi.ApiId
      Definition: |
        type Mutation {

        }

        type Query {

          getContext(id: String, lang: , cognitoIdentityId__: String): Context

        }

        input ContextInput {
          id: String
        }
        type Context {
          id: String! 
        }


        schema {
          query: Query
          mutation: Mutation
        }
    DependsOn:
      - GqlApi
  ContextDataSource:
    Type: AWS::AppSync::DataSource
    Properties:
      ApiId: !GetAtt GqlApi.ApiId
      LambdaConfig:
        LambdaFunctionArn:
          Fn::Join:
            - ''
            - - 'arn:aws:lambda:'
              - !Ref AWS::Region
              - ':'
              - !Ref AWS::AccountId
              - ':function:'
              - Fn::ImportValue:
                  !Sub '${FunctionStack}-functions-Context'
      Name: context_lambda
      ServiceRoleArn: !GetAtt DataSourceRole.Arn
      Type: AWS_LAMBDA
    DependsOn:
      - DataSourceRole
      - GqlApi
  GetContextResolver:
    Type: AWS::AppSync::Resolver
    Properties:
      ApiId: !GetAtt GqlApi.ApiId
      FieldName: getContext
      TypeName: Query
      DataSourceName: !GetAtt ContextDataSource.Name
      RequestMappingTemplate: |
        #set( $cognitoIdentityId = $context.identity.cognitoIdentityId )
        #if($context.identity.userArn.matches('arn:aws:iam::\d+:user/.*'))
          #if($context.args.cognitoIdentityId__)
            #set( $cognitoIdentityId = $context.args.cognitoIdentityId__ )
          #elseif( $context.source.cognitoIdentityId__ )
            #set( $cognitoIdentityId = $context.source.cognitoIdentityId__ )
          #end
        #end
        #set( $unamepwd = "$util.urlEncode($cognitoIdentityId):" )
        {
          "version" : "2017-02-28",
          "operation": "Invoke",
          "payload": {
            "source": "AppSync",
            "httpMethod": "get",
            "headers": {
              "Authorization": "Basic $util.base64Encode($unamepwd)",
            },
            "pathParameters": {
              "id": "$util.escapeJavaScript($context.args.id)"
            },
            "queryStringParameters": {
              "lang": "$util.escapeJavaScript($context.args.lang)"
            }
          }
        }
      ResponseMappingTemplate: |
        #if($context.result.statusCode >= 200 && $context.result.statusCode <= 299)
          #set( $result = $util.parseJson($context.result.body) )
          #if($context.args.cognitoIdentityId__)
            #set( $result.cognitoIdentityId__ = $context.args.cognitoIdentityId__ )
          #elseif($context.source.cognitoIdentityId__)
            #set( $result.cognitoIdentityId__ = $context.source.cognitoIdentityId__ )
          #end
          $util.toJson($result)
        #else
          $utils.error($util.parseJson($context.result.body).message, $context.result.statusCode.toString(), $util.parseJson($context.result.body))
        #end
    DependsOn:
      - GqlApi
      - GqlSchema
      - ContextDataSource
Outputs:
  ApiEndpoint:
    Description: The endpoint for the AppSync API.
    Value: !GetAtt GqlApi.GraphQLUrl