AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::Serverless-2016-10-31'
Description: >
  Create resources for a project that generate transcript of video file. 
  Uses Step Functions, S3, EventBridge, Transcribe.
Resources:
  TranscriptMediaBucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Sub 'bucket-${AWS::AccountId}-${AWS::Region}-transcript-media'
      NotificationConfiguration:
        EventBridgeConfiguration:
          EventBridgeEnabled: true
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256
    Metadata:
      SamResourceId: TranscriptMediaBucket
  TranscriptMediaBucketPolicy:
    Type: 'AWS::S3::BucketPolicy'
    Properties:
      PolicyDocument:
        Id: MyPolicy
        Statement:
          - Sid: TranscriptMediaReadPolicy
            Effect: Allow
            Principal:
              Service: transcribe.amazonaws.com
            Action:
              - 's3:GetObject'
            Resource: !Join 
              - ''
              - - 'arn:aws:s3:::'
                - !Ref TranscriptMediaBucket
                - /*
          - Sid: TranscriptMediaReadPolicy
            Effect: Allow
            Principal:
              Service: states.amazonaws.com
            Action:
              - 's3:GetObject'
            Resource: !Join 
              - ''
              - - 'arn:aws:s3:::'
                - !Ref TranscriptMediaBucket
                - /*
          - Sid: HttpsOnly
            Action: 's3:*'
            Effect: Deny
            Principal: '*'
            Resource:
              - !Join 
                - ''
                - - 'arn:aws:s3:::'
                  - !Ref TranscriptMediaBucket
                  - /*
              - !Join 
                - ''
                - - 'arn:aws:s3:::'
                  - !Ref TranscriptMediaBucket
            Condition:
              Bool:
                'aws:SecureTransport': false
      Bucket: !Ref TranscriptMediaBucket
    Metadata:
      SamResourceId: TranscriptMediaBucketPolicy
  TranscriptResultsBucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Sub 'bucket-${AWS::AccountId}-${AWS::Region}-transcript-results'
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256
    Metadata:
      SamResourceId: TranscriptResultsBucket
  TranscriptResultsBucketPolicy:
    Type: 'AWS::S3::BucketPolicy'
    Properties:
      PolicyDocument:
        Id: MyPolicy
        Version: 2012-10-17
        Statement:
          - Sid: TranscriptMediaWritePolicy
            Effect: Allow
            Principal:
              Service: transcribe.amazonaws.com
            Action:
              - 's3:PutObject'
            Resource: !Join 
              - ''
              - - 'arn:aws:s3:::'
                - !Ref TranscriptResultsBucket
                - /*
          - Sid: HttpsOnly
            Action: 's3:*'
            Effect: Deny
            Principal: '*'
            Resource:
              - !Join 
                - ''
                - - 'arn:aws:s3:::'
                  - !Ref TranscriptResultsBucket
                  - /*
              - !Join 
                - ''
                - - 'arn:aws:s3:::'
                  - !Ref TranscriptResultsBucket
            Condition:
              Bool:
                'aws:SecureTransport': false
      Bucket: !Ref TranscriptResultsBucket
    Metadata:
      SamResourceId: TranscriptResultsBucketPolicy
      
  
  ##########################################################################
  #   STEP FUNCTION                                                        #
  ##########################################################################  
    
  ScriptGeneratorStateMachine:
    Type: 'AWS::Serverless::StateMachine'
    Properties:
      Tracing:
        Enabled: true
      Events:
        S3MediaTrigger:
          Type: EventBridgeRule
          Properties:
            EventBusName: default
            Pattern:
              source:
                - aws.s3
              detail-type:
                - Object Created
              detail:
                bucket:
                  name:
                    - !Ref TranscriptMediaBucket
      Definition:
        Comment: >-
          Invoke Transcribe on a media file, when complete execute the results
          query Step Function and output the results
        StartAt: StartTranscriptionJob
        TimeoutSeconds: 900
        States:
          StartTranscriptionJob:
            Type: Task
            Comment: Start a transcribe job on the provided media file
            Parameters:
              Media:
                MediaFileUri.$: States.Format('s3://{}/{}', $.detail.bucket.name, $.detail.object.key)
              TranscriptionJobName.$: "$$.Execution.Name"
              IdentifyLanguage: true
              OutputBucketName: !Ref TranscriptResultsBucket
              OutputKey: temp.json
            Resource: !Sub >-
              arn:${AWS::Partition}:states:${AWS::Region}:${AWS::AccountId}:aws-sdk:transcribe:startTranscriptionJob
            Next: Wait
          Wait:
            Type: Wait
            Seconds: 10
            Next: GetTranscriptionJob
          GetTranscriptionJob:
            Type: Task
            Comment: Retrieve the status of an Amazon Transcribe job
            Parameters:
              TranscriptionJobName.$: $.TranscriptionJob.TranscriptionJobName
            Resource: !Sub >-
              arn:${AWS::Partition}:states:${AWS::Region}:${AWS::AccountId}:aws-sdk:transcribe:getTranscriptionJob
            Next: TranscriptionJobStatus
          TranscriptionJobStatus:
            Type: Choice
            Choices:
              - Variable: $.TranscriptionJob.TranscriptionJobStatus
                StringEquals: COMPLETED
                Next: GetObject
              - Variable: $.TranscriptionJob.TranscriptionJobStatus
                StringEquals: FAILED
                Next: Failed
            Default: Wait
          Failed:
            Type: Fail
            Cause: transcription job failed
            Error: FAILED
          GetObject:
            Type: Task
            Comment: >-
              Get Transcribed json file
            Resource: !Sub >-
              arn:${AWS::Partition}:states:${AWS::Region}:${AWS::AccountId}:aws-sdk:s3:getObject
            Parameters:
              Bucket: !Sub 'bucket-${AWS::AccountId}-${AWS::Region}-transcript-results'
              Key: temp.json
            Next: PutObject
            ResultSelector: 
              filecontent.$: >-
                States.StringToJson($.Body)
            ResultPath: $.transcription
          PutObject:
            Type: Task
            Comment: extract transcription text in json file
            Resource: !Sub >-
              arn:${AWS::Partition}:states:${AWS::Region}:${AWS::AccountId}:aws-sdk:s3:putObject
            Parameters:
              Body.$: $.transcription.filecontent.results.transcripts[0].transcript
              Bucket: !Sub 'bucket-${AWS::AccountId}-${AWS::Region}-transcript-results'
              Key: script.txt
            End: true

      Policies:
        - S3ReadPolicy:
            BucketName: !Ref TranscriptMediaBucket
        - S3ReadPolicy:
            BucketName: !Ref TranscriptResultsBucket
        - S3WritePolicy:
            BucketName: !Ref TranscriptResultsBucket
        - CloudWatchPutMetricPolicy: {}
        - Version: 2012-10-17
          Statement:
            - Sid: XrayAccessPolicy
              Effect: Allow
              Action:
                - 'xray:PutTraceSegments'
                - 'xray:PutTelemetryRecords'
                - 'xray:GetSamplingRules'
                - 'xray:GetSamplingTargets'
                - 'xray:GetSamplingStatisticSummaries'
              Resource: '*'
            - Sid: TranscriptJobPolicy
              Effect: Allow
              Action:
                - 'transcribe:GetTranscriptionJob'
                - 'transcribe:StartTranscriptionJob'
              Resource: '*'
    Metadata:
      SamResourceId: ScriptGeneratorStateMachine