AWSTemplateFormatVersion: 2010-09-09

Outputs:
  LambdaFunction:
    Value: !Ref LambdaReadFromDynamoDB
  LambdaFunctionArn:
    Value: !GetAtt LambdaReadFromDynamoDB.Arn

Parameters:
  TargetedDynamoDBTable:
    Type: String

Resources:
  IAMRole:
      Type: 'AWS::IAM::Role'
      Properties:
        AssumeRolePolicyDocument:
          Version: 2012-10-17
          Statement:
            - Effect: Allow
              Principal:
                Service:
                  - lambda.amazonaws.com
              Action:
                - 'sts:AssumeRole'
        Path: /
        ManagedPolicyArns:
          - arn:aws:iam::aws:policy/AmazonDynamoDBFullAccess
          - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

  LambdaReadFromDynamoDB:
    Type: 'AWS::Lambda::Function'
    Properties:
      Code:
        ZipFile: |
          import json
          import os
          import boto3

          def lambda_handler(event, context):
              dynamodb = boto3.client("dynamodb")
              tableName = os.environ["table_name"]
              reviewId = event["reviewId"]
              print("reviewId:{}".format(reviewId))
              print("tableName:{}".format(tableName))
              
              data = dynamodb.query(
                  ExpressionAttributeValues={
                      ':reviewId': {
                          'S': reviewId,
                      },
                  },
                  KeyConditionExpression='reviewId = :reviewId',
                  TableName=tableName,
              )    
              
              response = {
                    'statusCode': 200,
                    'body': data,
                    'headers': {
                      'Content-Type': 'application/json',
                      'Access-Control-Allow-Headers': 'Content-Type',
                      'Access-Control-Allow-Origin': '*',
                      'Access-Control-Allow-Methods': 'OPTIONS,POST,GET'
                    },
                }
                
              return response

      FunctionName: "cf-read-from-dynamodb-lambda"
      Handler: index.lambda_handler
      Runtime: python3.8
      Role: !GetAtt IAMRole.Arn
      Tags:
        - "Key": "Project"
          "Value": "Realtime Sentiment Blog"
      Environment:
        Variables:
          table_name: !Ref TargetedDynamoDBTable
    DependsOn:
      - IAMRole