# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: MIT-0

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Description: >
  step-functions

  Sample SAM Template for step-functions

Resources:
  AnalyticsStateMachine:
    Type: AWS::Serverless::StateMachine # More info about State Machine Resource: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-statemachine.html
    Properties:
      DefinitionUri: statemachine/analytics.asl.json
      DefinitionSubstitutions:
        SNSTopicArn: !Ref AnalyticsTopic
        StackOverflowWorkflowArn: !Ref GatherStackOverflowMetrics
        TwitchWorkflowArn: !Ref GatherTwitchMetrics
      Events:
        DailySchedule:
          Type: Schedule # More info about Schedule Event Source: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-statemachine-schedule.html
          Properties:
            Description: Schedule to run the analytics state machine every day
            Enabled: true # This schedule is disabled by default to avoid incurring charges.
            Schedule: "rate(1 day)"
      Role: !GetAtt AnalyticsWorkflowRole.Arn

  GatherStackOverflowMetrics:
    Type: AWS::Serverless::StateMachine
    Properties:
      DefinitionUri: statemachine/stackoverflow.asl.json
      DefinitionSubstitutions:
        DDBPutItem: !Sub arn:${AWS::Partition}:states:::dynamodb:putItem
        DDBTable: !Ref AnalyticsTable
      Type: EXPRESS
      Policies: # Find out more about SAM policy templates: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-policy-templates.html
        - DynamoDBWritePolicy:
            TableName: !Ref AnalyticsTable

  GatherTwitchMetrics:
    Type: AWS::Serverless::StateMachine
    Properties:
      DefinitionUri: statemachine/twitch.asl.json
      DefinitionSubstitutions:
        DDBPutItem: !Sub arn:${AWS::Partition}:states:::dynamodb:putItem
        DDBTable: !Ref AnalyticsTable
      Type: EXPRESS
      Policies:
        - DynamoDBWritePolicy:
            TableName: !Ref AnalyticsTable

  AnalyticsTable:
    Type: AWS::Serverless::SimpleTable # More info about SimpleTable Resource: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-simpletable.html
    Properties:
      PrimaryKey:
        Name: Id
        Type: String
      ProvisionedThroughput:
        ReadCapacityUnits: 1
        WriteCapacityUnits: 1

  AnalyticsTopic:
    Type: AWS::SNS::Topic

  ##############################################################################
  # Parent IAM role
  ##############################################################################
  AnalyticsWorkflowRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - !Sub states.${AWS::Region}.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        - PolicyName: ParentWorkflowExecutionPolicy
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              # The following stanzas are required to invoke nested workflows
              - Effect: Allow
                Action:
                  - states:StartExecution
                Resource:
                  - !Ref GatherStackOverflowMetrics
                  - !Ref GatherTwitchMetrics
              # The following additional stanzas are required for .sync invocations of nested workflows
              - Effect: Allow
                Action:
                  - states:DescribeExecution
                  - states:StopExecution
                Resource:
                  - !Ref GatherStackOverflowMetrics
                  - !Ref GatherTwitchMetrics
              - Effect: Allow
                Action:
                  - events:PutTargets
                  - events:PutRule
                  - events:DescribeRule
                Resource:
                  - !Sub "arn:aws:events:${AWS::Region}:${AWS::AccountId}:rule/StepFunctionsGetEventsForStepFunctionsExecutionRule"
              # The following stanzas are required to publish messages to SNS topics
              - Effect: Allow
                Action:
                  - sns:Publish
                Resource:
                  - !Ref AnalyticsTopic

Outputs:
  AnalyticsStateMachineArn:
    Description: "Analytics state machine ARN"
    Value: !Ref AnalyticsStateMachine