---
AWSTemplateFormatVersion: "2010-09-09"

Description:
  Copies the Lambda Code to your account.

Parameters:

  TemplateBucket:
    Type: String
    Default: code-service-demo-public
    Description: S3 bucket containing the code deployed by this template

  CodeKey:
    Type: String
    Default: Archive.zip
    Description: Key prefix for resources referenced from the TemplateBucket

Resources:
  ImportCode:
    Properties:
      ServiceToken: !GetAtt CopyS3ObjectsFunction.Arn
      SourceBucket: !Ref TemplateBucket
      SourcePrefix: !Ref CodeKey
      LocalBucket: !Ref LocalBucket
      #Prefix: !Ref CodeKey
    Type: "Custom::S3Objects"

  LocalBucket:
    Type: AWS::S3::Bucket
    DeletionPolicy: Retain

  S3CopyRole:
    Type: AWS::IAM::Role
    Properties:

      Path: /assume/
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          -
            Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        -
          PolicyName: S3Access
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              -
                Sid: AllowLogging
                Effect: Allow
                Action:
                  - "logs:CreateLogGroup"
                  - "logs:CreateLogStream"
                  - "logs:PutLogEvents"
                Resource: "*"
              -
                Sid: SourceBucketReadAccess
                Effect: Allow
                Action:
                  - "s3:ListBucket"
                  - "s3:GetObject"
                Resource:
                  - !Sub "arn:aws:s3:::${TemplateBucket}"
                  - !Sub "arn:aws:s3:::${TemplateBucket}/${CodeKey}"
              -
                Sid: DestBucketWriteAccess
                Effect: Allow
                Action:
                  - "s3:ListBucket"
                  - "s3:GetObject"
                  - "s3:PutObject"
                  - "s3:PutObjectAcl"
                  - "s3:PutObjectVersionAcl"
                  - "s3:DeleteObject"
                  - "s3:DeleteObjectVersion"
                  - "s3:CopyObject"
                Resource:
                  - !Sub "arn:aws:s3:::${LocalBucket}"
                  - !Sub "arn:aws:s3:::${LocalBucket}/*"

  CopyS3ObjectsFunction:
    Properties:
      Description: Copies objects from a source S3 bucket to a destination
      Handler: index.handler
      Runtime: python2.7
      Role: !GetAtt S3CopyRole.Arn
      Timeout: 120
      Code:
        ZipFile: |
          import os
          import json
          import cfnresponse
          import boto3
          from botocore.exceptions import ClientError
          client = boto3.client('s3')
          import logging
          logger = logging.getLogger()
          logger.setLevel(logging.INFO)
          def handler(event, context):
            logger.info("Received event: %s" % json.dumps(event))
            source_bucket = event['ResourceProperties']['SourceBucket']
            source_prefix = event['ResourceProperties'].get('SourcePrefix') or ''
            bucket = event['ResourceProperties']['LocalBucket']
            prefix = event['ResourceProperties'].get('Prefix') or ''

            result = cfnresponse.SUCCESS

            try:
              if event['RequestType'] == 'Create' or event['RequestType'] == 'Update':
                result = copy_objects(source_bucket, source_prefix, bucket, prefix)
              elif event['RequestType'] == 'Delete':
                result = delete_objects(bucket, prefix)
            except ClientError as e:
              logger.error('Error: %s', e)
              result = cfnresponse.FAILED

            cfnresponse.send(event, context, result, {})


          def copy_objects(source_bucket, source_prefix, bucket, prefix):
            paginator = client.get_paginator('list_objects_v2')
            page_iterator = paginator.paginate(Bucket=source_bucket, Prefix=source_prefix)
            for key in {x['Key'] for page in page_iterator for x in page['Contents']}:
              dest_key = os.path.join(prefix, os.path.relpath(key, source_prefix))
              print 'copy {} to {}'.format(key, dest_key)
              if not key.endswith('/'):
                print 'copy {} to {}'.format(key, dest_key)
                client.copy_object(CopySource={'Bucket': source_bucket, 'Key': key}, Bucket=bucket, Key = "Archive.zip")
            return cfnresponse.SUCCESS

          def delete_objects(bucket, prefix):
            paginator = client.get_paginator('list_objects_v2')
            page_iterator = paginator.paginate(Bucket=bucket, Prefix=prefix)
            objects = [{'Key': x['Key']} for page in page_iterator for x in page['Contents']]
            client.delete_objects(Bucket=bucket, Delete={'Objects': objects})
            return cfnresponse.SUCCESS


    Type: AWS::Lambda::Function

Outputs:
  S3Bucket:
    Value: !Ref LocalBucket