AWSTemplateFormatVersion: '2010-09-09'
Description: 'CloudFormation template to create a lambda function.'

Parameters:
    LambdaName:
        Type: String
        Description: Lambda function name
        Default: 'activity-detection-lambda'

    LambdaCodeBucket:
        Type: String
        Description: "Lambda SourceCode bucket name."
        Default: 'activity-detection-data-bucket'

    TriggerBucketName:
        Type: String
        Description: "S3 bucket name used to create a trigger."
        Default: 'activity-detection-livestream-bucket'
        
    DetectionTableName: 
        Type: String
        Description: DynamoDB table to save prediction results
        Default: "activity-detection-table"

    EndpointName: 
        Type: String
        Description: SageMaker endpoint for model deployment
        Default: "activity-detection-endpoint"

    ModelMaxFrames: 
        Type: Number
        Description: Maximum number of frames used for activity detection model
        Default: 32
        
Resources:
    LivestreamLambdaFunction:
        Type: AWS::Lambda::Function
        Properties:
            FunctionName: !Ref LambdaName
            Runtime: python3.6
            Role: !GetAtt LivestreamLambdaRole.Arn
            Code: 
                S3Bucket: !Ref LambdaCodeBucket
                S3Key: "artifacts/amazon-sagemaker-activity-detection/deployment/lambda/lambda_function.zip"
            Handler: lambda_function.lambda_handler
            Timeout: 180
            MemorySize: 1024
            Environment:
                Variables:
                    DETECTION_TABLE_NAME: !Ref DetectionTableName
                    ENDPOINT_NAME: !Ref EndpointName
                    MODEL_MAX_FRAMES: !Ref ModelMaxFrames

    LivestreamLambdaPermission:
        Type: AWS::Lambda::Permission
        Properties:
            Action: lambda:InvokeFunction
            FunctionName: !Ref LivestreamLambdaFunction
            Principal: s3.amazonaws.com
            SourceArn: 
                Fn::Sub: "arn:aws:s3:::${TriggerBucketName}"
            SourceAccount: !Ref AWS::AccountId
            
    LambdaTrigger:
       Type: AWS::S3::Bucket
       DependsOn: LivestreamLambdaPermission
       Properties:
           BucketName: !Ref TriggerBucketName
           NotificationConfiguration:
               LambdaConfigurations:
                   - Event: s3:ObjectCreated:*
                     Filter:
                       S3Key:
                           Rules:
                               - Name: prefix
                                 Value: "livestream_pipe/"
                               - Name: suffix
                                 Value: ".ts"
                     Function: !GetAtt LivestreamLambdaFunction.Arn
                     
    LivestreamLambdaRole:
        Type: 'AWS::IAM::Role'
        Properties:
            RoleName: 'LivestreamLambdaRole'
            AssumeRolePolicyDocument:
                Version: 2012-10-17
                Statement:
                  - Effect: Allow
                    Principal:
                      Service:
                      - "lambda.amazonaws.com"
                    Action:
                      - 'sts:AssumeRole'
            ManagedPolicyArns:
                - 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
                - 'arn:aws:iam::aws:policy/AmazonS3FullAccess'
                - 'arn:aws:iam::aws:policy/AmazonSageMakerFullAccess'