AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: S3-to-Lambda video - Example 4.

Parameters:
  InputBucketName:
    Type: String
    Default: 'svs214-ex4-workflow'

Globals:
  Function:
    Timeout: 10

Resources:
  ## S3 buckets
  InputBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Ref InputBucketName

  ## Lambda functions
  ProcessFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: processFunction/
      Handler: app.handler
      Runtime: nodejs12.x
      MemorySize: 128
      Environment:
        Variables:
          stateMachineArn: !Ref 'DogOrCatStateMachine'
      Policies:
        - S3CrudPolicy:
            BucketName: !Ref InputBucketName
        - Statement:
          - Effect: Allow
            Resource: '*'
            Action:
              - states:*
      Events:
        FileUpload:
          Type: S3
          Properties:
            Bucket: !Ref InputBucket
            Events: s3:ObjectCreated:*
            Filter: 
              S3Key:
                Rules:
                  - Name: suffix
                    Value: '.jpg'            

  DogFoundFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: foundFunction/
      Handler: dog.handler
      Runtime: nodejs12.x
      MemorySize: 128

  CatFoundFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: foundFunction/
      Handler: cat.handler
      Runtime: nodejs12.x
      MemorySize: 128      

  ## Step Functions state machine
  DogOrCatStateMachine:
    Type: 'AWS::StepFunctions::StateMachine'
    Properties:
      DefinitionString: !Sub |
        {
          "Comment": "Is it a dog or a cat?",
          "StartAt": "IsDogOrCat",
          "States": {
            "IsDogOrCat": {
              "Type": "Task",
              "Resource": "arn:aws:lambda:us-west-2:763653534548:function:dogCatFunction",
              "Next": "ChoiceState"
            },
            "ChoiceState": {
              "Type" : "Choice",
              "Choices": [
                {
                  "Variable": "$",
                  "StringEquals": "Dog",
                  "Next": "DogFound"
                },
                {
                  "Variable": "$",
                  "StringEquals": "Cat",
                  "Next": "CatFound"
                }
              ],
              "Default": "UnknownAnimal"
            },

            "DogFound": {
              "Type" : "Task",
              "Resource": "${DogFoundFunction.Arn}",
              "Next": "NextState"
            },

            "CatFound": {
              "Type" : "Task",
              "Resource": "${CatFoundFunction.Arn}",
              "Next": "NextState"
            },

            "UnknownAnimal": {
              "Type": "Fail",
              "Error": "DefaultStateError",
              "Cause": "No Matches!"
            },

            "NextState": {
              "Type": "Pass",
              "End": true
            }
          }
        }
      RoleArn: !GetAtt 'StateMachineRole.Arn'

  # IAM roles
  StateMachineRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Effect: Allow
          Principal:
            Service: !Sub 'states.${AWS::Region}.amazonaws.com'
          Action: 'sts:AssumeRole'
      Policies:
      - PolicyName: lambda
        PolicyDocument:
          Statement:
          - Effect: Allow
            Action: 'lambda:InvokeFunction'
            Resource:
            - '*'