AWSTemplateFormatVersion: "2010-09-09"
Description: "An example template with an IAM role for a Lambda state machine."
Resources:
  StatesExecutionRole:
    Type: "AWS::IAM::Role"
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - !Sub states.${AWS::Region}.amazonaws.com
            Action: "sts:AssumeRole"
      Path: "/"
      Policies:
        - PolicyName: StatesExecutionPolicy
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              - Effect: Allow
                Action:
                  - "lambda:InvokeFunction"
                Resource: "*"

  CallCenterStateMachine:
    Type: "AWS::StepFunctions::StateMachine"
    Properties:
      StateMachineName: "CallCenter"
      DefinitionString:
        !Sub
          - |-
                {
                  "Comment": "AWS Step Functions state machine that automates a call center support session.",
                  "StartAt": "Open Case",
                  "States": {
                    "Open Case": {
                      "Type": "Task",
                      "Resource": "arn:aws:lambda:us-east-2:AWS_ACCOUNT_ID:function:OpenCase",
                      "Next": "Assign Case"
                    }, 
                    "Assign Case": {
                      "Type": "Task",
                      "Resource": "arn:aws:lambda:us-east-2:AWS_ACCOUNT_ID:function:AssignCase",
                      "Next": "Work on Case"
                    },
                    "Work on Case": {
                      "Type": "Task",
                      "Resource": "arn:aws:lambda:us-east-2:AWS_ACCOUNT_ID:function:WorkOnCase",
                      "Next": "Is Case Resolved"
                    },
                    "Is Case Resolved": {
                        "Type" : "Choice",
                        "Choices": [ 
                          {
                            "Variable": "$.Status",
                            "NumericEquals": 1,
                            "Next": "Close Case"
                          },
                          {
                            "Variable": "$.Status",
                            "NumericEquals": 0,
                            "Next": "Escalate Case"
                          }
                      ]
                    },
                     "Close Case": {
                      "Type": "Task",
                      "Resource": "arn:aws:lambda:us-east-2:AWS_ACCOUNT_ID:function:CloseCase",
                      "End": true
                    },
                    "Escalate Case": {
                      "Type": "Task",
                      "Resource": "arn:aws:lambda:us-east-2:AWS_ACCOUNT_ID:function:EscalateCase",
                      "Next": "Fail"
                    },
                    "Fail": {
                      "Type": "Fail",
                      "Cause": "Engage Tier 2 Support."    }   
                  }
                }
          - {}
      RoleArn: !GetAtt [ StatesExecutionRole, Arn ]