# Copyright 2012-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Amazon Software License (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
# http://aws.amazon.com/asl/
#
# or in the "license" file accompanying this file. This file is distributed
# on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
# express or implied. See the License for the specific language governing
# permissions and limitations under the License.

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  StateMachineLambdaRole: 
    Type: "AWS::IAM::Role"
    Properties: 
      AssumeRolePolicyDocument: 
        Version: "2012-10-17"
        Statement: 
          - 
            Effect: "Allow"
            Principal: 
              Service: 
                - "lambda.amazonaws.com"
            Action: 
              - "sts:AssumeRole"
      Path: "/"
      Policies: 
        - 
          PolicyName: "lambdaexecute"
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - 
                Effect: "Allow"
                Action: 
                  - "logs:*"
                Resource: "arn:aws:logs:*:*:*"
              - 
                Effect: "Allow"
                Action: 
                  - "s3:GetObject"
                  - "s3:GPutbject"
                Resource: "arn:aws:s3:::*"
        - 
          PolicyName: "cloudformation"
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - 
                Effect: "Allow"
                Action:
                  - "cloudformation:*"
                Resource: "*"
        - 
          PolicyName: "iam"
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - 
                Effect: "Allow"
                Action:
                  - "iam:CreateRole"
                  - "iam:PutRolePolicy"
                  - "iam:DeleteRolePolicy"
                  - "iam:DeleteRole"
                  - "iam:GetRole"
                  - "iam:PassRole"
                Resource: "*"
        - 
          PolicyName: "lambda"
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - 
                Effect: "Allow"
                Action:
                  - "lambda:*"
                Resource: "*"
  CreateStackStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: CreateStackStateMachineTask
      Handler: create_stack.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  CheckStackExistsStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: CheckStackExistsStateMachineTask
      Handler: check_stack_exists.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  CreateChangeSetStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: CreateChangeSetStateMachineTask
      Handler: create_change_set.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  CheckStackCreationStatusStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: CheckStackCreationStatusStateMachineTask
      Handler: check_stack_creation_status.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  CheckChangeSetCreationStatusStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: CheckChangeSetCreationStatusStateMachineTask
      Handler: check_change_set_creation_status.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  ExecuteChangeSetStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: ExecuteChangeSetStateMachineTask
      Handler: execute_change_set.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  InspectChangeSetStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: InspectChangeSetStateMachineTask
      Handler: inspect_change_set.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  DeleteChangeSetStateMachineTask:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: DeleteChangeSetStateMachineTask
      Handler: delete_change_set.handler
      Runtime: nodejs10.x
      MemorySize: 128
      Timeout: 30
      Role: !GetAtt StateMachineLambdaRole.Arn
  StepFunctionsStateMachineRole: 
    Type: "AWS::IAM::Role"
    Properties: 
      AssumeRolePolicyDocument: 
        Version: "2012-10-17"
        Statement: 
          - 
            Effect: "Allow"
            Principal: 
              Service: 
                - !Sub "states.${AWS::Region}.amazonaws.com"
            Action: 
              - "sts:AssumeRole"
      Path: "/"
      Policies: 
        - 
          PolicyName: "lambda"
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - 
                Effect: "Allow"
                Action: 
                  - "lambda:InvokeFunction"
                Resource: "*"
  StepFunctionsStateMachine:
    Type: AWS::StepFunctions::StateMachine 
    Properties:
      RoleArn: !GetAtt StepFunctionsStateMachineRole.Arn
      DefinitionString: 
        !Sub |
          {
            "Comment": "A sample state machine called from AWS CodePipeline that deploys a Lambda function through Cloudformation",
            "StartAt": "Check Stack Existence",
            "States": {
              "Check Stack Existence": {
                "Type": "Task",
                "ResultPath": "$.doesStackExists",
                "OutputPath": "$",
                "Resource": "${CheckStackExistsStateMachineTask.Arn}",
                "Next": "Does Stack Exist?"
              },
              "Does Stack Exist?": {
                "Type": "Choice",
                "Choices": [
                  {
                    "Variable": "$.doesStackExists",
                    "BooleanEquals": false,
                    "Next": "Create Stack"
                  }
                ],
                "Default": "Create Change Set"
              },
              "Create Stack": {
                "Type": "Task",
                "ResultPath": "$.stackCreationDetails",
                "OutputPath": "$",
                "Resource": "${CreateStackStateMachineTask.Arn}",
                "Next": "Wait Stack Creation"
              },
              "Wait Stack Creation": {
                "Type": "Wait",
                "Seconds": 10,
                "Next": "Get Stack Creation Status"
              },
              "Get Stack Creation Status": {
                "Type": "Task",
                "ResultPath": "$.stackCreationStatus",
                "OutputPath": "$",
                "Resource": "${CheckStackCreationStatusStateMachineTask.Arn}",
                "Next": "Stack Created?"
              },
              "Stack Created?": {
                "Type": "Choice",
                "Choices": [
                  {
                    "Variable": "$.stackCreationStatus",
                    "StringEquals": "complete",
                    "Next": "Deployment Succeeded"
                  }
                ],
                "Default": "Wait Stack Creation"
              },
              "Create Change Set": {
                "Type": "Task",
                "ResultPath": "$.changeSetName",
                "OutputPath": "$",
                "Resource": "${CreateChangeSetStateMachineTask.Arn}",
                "Next": "Wait Change Set Creation"
              },
              "Wait Change Set Creation": {
                "Type": "Wait",
                "Seconds": 10,
                "Next": "Get Change Set Creation Status"
              },
              "Get Change Set Creation Status": {
                "Type": "Task",
                "ResultPath": "$.changeSetCreationStatus",
                "OutputPath": "$",
                "Resource": "${CheckChangeSetCreationStatusStateMachineTask.Arn}",
                "Next": "Change Set Created?"
              },
              "Change Set Created?": {
                "Type": "Choice",
                "Choices": [
                  {
                    "Variable": "$.changeSetCreationStatus",
                    "StringEquals": "complete",
                    "Next": "Inspect Change Set Changes"
                  }
                ],
                "Default": "Wait Change Set Creation"
              },
              "Inspect Change Set Changes": {
                "Type": "Task",
                "ResultPath": "$.changeSetAction",
                "OutputPath": "$",
                "Resource": "${InspectChangeSetStateMachineTask.Arn}",
                "Next": "Safe to Update Infra?"
              },
              "Safe to Update Infra?": {
                "Type": "Choice",
                "Choices": [
                  {
                    "Variable": "$.changeSetAction",
                    "StringEquals": "CAN-SAFELY-UPDATE-EXISTING-STACK",
                    "Next": "Execute Change Set"
                  }
                ],
                "Default": "Delete Change Set"
              },
              "Execute Change Set": {
                "Type": "Task",
                "ResultPath": "$.changeSetExecutionDetails",
                "OutputPath": "$",
                "Resource": "${ExecuteChangeSetStateMachineTask.Arn}",
                "Next": "Deployment Succeeded"
              },
              "Delete Change Set": {
                "Type": "Task",
                "ResultPath": "$.changeSetDeletionDetails",
                "OutputPath": "$",
                "Resource": "${ExecuteChangeSetStateMachineTask.Arn}",
                "Next": "Deployment Failed"
              },
              "Deployment Succeeded": {
                "Type": "Succeed"
              },
              "Deployment Failed": {
                "Type": "Fail",
                "Cause": "Deployment Failed",
                "Error": "Deployment Failed"
              }
            }
          }
Outputs:
  CodePipelineStepFunctionsStateMachineArn:
    Value: !Ref StepFunctionsStateMachine
    Export:
      Name: !Sub "${AWS::StackName}-CodePipelineStepFunctionsStateMachineArn"
  CodePipelineStepFunctionsStateMachineName:
    Value: !GetAtt StepFunctionsStateMachine.Name
    Export:
      Name: !Sub "${AWS::StackName}-CodePipelineStepFunctionsStateMachineName"