AWSTemplateFormatVersion: '2010-09-09'

Transform: 'AWS::Serverless-2016-10-31'

Description: An AWS Serverless Specification template describing your function.

Parameters:
  AmazonMQHost:
    Type: String
    Default: ''
    Description: Host name of your Amazon MQ instance

  AmazonMQLogin:
    Type: String
    Default: ''
    Description: Login / username for your Amazon MQ instance

  AmazonMQPassword:
    Type: String
    Default: ''
    NoEcho: true
    Description: Password for your Amazon MQ instance

  AmazonMQQueueName:
    Type: String
    Default: SAMPLE_QUEUE
    Description: Name of queue

  AmazonMQSecurityGroupId:
    Type: AWS::EC2::SecurityGroup::Id
    Description: Security Group ID for Amazon MQ broker

Resources:
  SubscriberFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      CodeUri: subscriber/
      Handler: index.handler
      Runtime: nodejs6.10
      Role: !GetAtt SubscriberRole.Arn
      Description: 'Polls Amazon MQ broker for messages and pushes to worker function'
      Timeout: 15
      Environment:
        Variables:
          HOST: !Ref AmazonMQHost
          LOGIN: !Ref AmazonMQLogin
          PASSWORD: !Ref AmazonMQPassword
          QUEUE_NAME: !Ref AmazonMQQueueName
          WORKER_FUNCTION: !Ref WorkerFunction
      Events:
        Timer:
          Type: Schedule
          Properties:
            Schedule: rate(5 minutes)

  WorkerFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      CodeUri: worker/
      Handler: index.handler
      Runtime: nodejs6.10
      Role: !GetAtt WorkerRole.Arn
      Description: 'Writes incoming message to DynamoDB'
      Environment:
        Variables:
          TABLE_NAME: !Ref MessagesTable

  MessagesTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        Name: uuid
        Type: String

  # --------------
  
  # add inbound to STOMP for provided security group
  BrokerSGIngressFromLambda:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      GroupId: !Ref AmazonMQSecurityGroupId
      IpProtocol: tcp
      FromPort: 61614
      ToPort: 61614
      CidrIp: '0.0.0.0/0'

  # --------------
  
  SubscriberRole:
    Type: AWS::IAM::Role
    Properties:
      Path: "/AmazonMQLambda/"
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
        - arn:aws:iam::aws:policy/service-role/AWSLambdaVPCAccessExecutionRole
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Sid: AllowLambdaServiceToAssumeRole
            Effect: Allow
            Action: 
              - sts:AssumeRole
            Principal:
              Service: 
                - lambda.amazonaws.com

  SubscriberPolicy:
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: AmazonMQLambdaSubscriberPolicy
      Roles:
        - !Ref SubscriberRole
      PolicyDocument:
        Version: "2012-10-17"
        Statement: 
          -
            Effect:   "Allow"
            Resource: !GetAtt WorkerFunction.Arn
            Action:
              - "lambda:InvokeFunction"

  WorkerRole:
    Type: AWS::IAM::Role
    Properties:
      Path: "/AmazonMQLambda/"
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
        - arn:aws:iam::aws:policy/service-role/AWSLambdaVPCAccessExecutionRole
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Sid: AllowLambdaServiceToAssumeRole
            Effect: Allow
            Action: 
              - sts:AssumeRole
            Principal:
              Service: 
                - lambda.amazonaws.com

  WorkerPolicy:
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: AmazonMQLambdaWorkerPolicy
      Roles:
        - !Ref WorkerRole
      PolicyDocument:
        Version: "2012-10-17"
        Statement: 
          -
            Effect:   "Allow"
            Resource: !GetAtt MessagesTable.Arn
            Action:
              - "dynamodb:PutItem"

Outputs:
  MessagesTable:
    Description: Name of messages table
    Value: !Ref MessagesTable