#### Title : ADS Reference Server
#### Author : Scott Cunningham
####
####

## Parameters - User Input
Parameters: {}

## Resources
Resources:

  #################
  ## S3
  #################
  # S3 Bucket to host code

  S3Bucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256
      Tags:
        - Key: StackName
          Value: !Ref AWS::StackName

  #################
  ## IAM & Permissions
  #################
  ## IAM Role
  LambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - sts:AssumeRole
      Tags:
        - Key: StackName
          Value: !Ref AWS::StackName

  ## IAM Policy
  LambdaBasicExecutionPolicy:
    Type: AWS::IAM::Policy
    Properties:
      Roles:
        - !Ref LambdaRole
      PolicyName: !Sub ${AWS::StackName}-s3-access
      PolicyDocument:
        Statement:
          - Effect: Allow
            Action:
              - logs:CreateLogGroup
            Resource:
              - !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:*
          - Effect: Allow
            Action:
              - logs:CreateLogStream
              - logs:PutLogEvents
            Resource:
              - !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/*
          - Effect: Allow
            Action:
              - s3:*
            Resource:
              - !Sub arn:aws:s3:::${S3Bucket}/*

  LambdaInvokePermissionVAST:
    Type: AWS::Lambda::Permission
    Properties:
      FunctionName: !GetAtt VastProcessor.Arn
      Action: lambda:InvokeFunction
      Principal: apigateway.amazonaws.com
      SourceArn: !Sub "arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${ApiGateway}/*/*/*"
    DependsOn:
      - VastProcessor

  APIGatewayCWatchLoggingRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - apigateway.amazonaws.com
            Action: 'sts:AssumeRole'
      Path: /
      ManagedPolicyArns:
        - >-
          arn:aws:iam::aws:policy/service-role/AmazonAPIGatewayPushToCloudWatchLogs

  #################
  ## Custom Resource
  #################

  FileMover:
    Type: Custom::LambdaInvokerToMoveFiles
    Properties:
      ServiceToken: !GetAtt FileCopier.Arn
      Region: !Ref 'AWS::Region'
    DependsOn:
      - LambdaRole

  #################
  ## Lambda
  #################

  VastProcessor:
    Type: AWS::Lambda::Function
    Properties:
      Description: Lambda to handle VAST requests and build dynamic responses
      Role: !GetAtt LambdaRole.Arn
      Runtime: python3.8
      Handler: index.lambda_handler
      Timeout: 10
      MemorySize: 10240
      Layers:
        - !Ref LambdaLayerXMLtoDict
      Code:
        S3Bucket: !Ref S3Bucket
        S3Key: !GetAtt FileMover.ads-reference-server
      Tags:
        - Key: StackName
          Value: !Ref AWS::StackName
    DependsOn:
      - S3Bucket
      - LambdaRole
      - LambdaLayerXMLtoDict

  FileCopier:
    Type: AWS::Lambda::Function
    Properties:
      Description: Lambda function to copy solution files to destination bucket
      Role: !GetAtt LambdaRole.Arn
      Runtime: python3.8
      Handler: index.lambda_handler
      Timeout: 35
      MemorySize: 10240
      Code:
        ZipFile: |
          '''
          Copyright (c) 2021 Scott Cunningham

          Permission is hereby granted, free of charge, to any person obtaining a copy
          of this software and associated documentation files (the "Software"), to deal
          in the Software without restriction, including without limitation the rights
          to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
          copies of the Software, and to permit persons to whom the Software is
          furnished to do so, subject to the following conditions:

          The above copyright notice and this permission notice shall be included in all
          copies or substantial portions of the Software.

          THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
          IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
          FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
          AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
          LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
          OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
          SOFTWARE.

          Summary: This script is a custom resource to place the HTML pages and Lambda code into the destination bucket.

          Original Author: Scott Cunningham
          '''

          import json
          import logging
          import boto3
          import os
          import urllib3
          from urllib.parse import urlparse
          from zipfile import ZipFile
          import cfnresponse

          LOGGER = logging.getLogger()
          LOGGER.setLevel(logging.INFO)
          MANIFESTMODIFY="True"

          version = 2

          def lambda_handler(event, context):

              ## Log the incoming event
              LOGGER.info("Event : %s " % (event))

              ## Create Response Data Dictionary for the CloudFormationn response
              responseData = dict()

              ## Initialize S3 boto3 client
              s3 = boto3.client('s3')

              # Create urllib3 pool manager
              http = urllib3.PoolManager()

              # Manifest File containning URL's on github
              cloudformation_manifest = "https://raw.githubusercontent.com/scunning1987/ads_reference_server/main/manifest.txt"

              # Pull global env variable to variable
              bucket = os.environ['BUCKET']

              # Get the manifest from GitHub
              get_response = http.request('GET', cloudformation_manifest)

              if get_response.status != 200:
                  # Exit the script with errors
                  responseData['Status'] = "Unable to get file from location : %s " % (file)
                  cfnresponse.send(event, context, "FAILED",responseData)
                  raise Exception("Unable to get file from location : %s " % (file))
              else:
                  # Continue and upload to S3
                  manifest_list = get_response.data.decode("utf-8").split("\n")

              # remove manifest.txt header line
              manifest_list.pop(0)

              LOGGER.info("Files to transfer to S3: %s " % (manifest_list))

              for file in manifest_list:

                  # Get the file from GitHub
                  if "http" in file:
                      get_response = http.request('GET', file)

                  if get_response.status != 200:
                      # Exit the script with errors
                      responseData['Status'] = "Unable to get file from location : %s " % (file)
                      cfnresponse.send(event, context, "FAILED",responseData)
                      raise Exception("Unable to get file from location : %s " % (file))
                  elif "http" in file:

                      # Continue and upload to S3

                      # url string to urllib object
                      file_url_formatted = urlparse(file)
                      file_url_path = file_url_formatted.path

                      # get path after github repo owner name - use this as the path to write to s3
                      path = '/'.join(file_url_path.split("/")[2:]).rsplit("/",1)[0]
                      s3_data = get_response.data


                      file_name = file.rsplit("/",1)[1]
                      file_base_name = os.path.splitext(file_name)[0]
                      s3_key = "%s/%s" % (path,file_name)

                      content_type = ""
                      if ".html" in file_name:
                          content_type = "text/html"
                      elif ".css" in file_name:
                          content_type = "text/css"
                      elif ".js" in file_name:
                          content_type = "text/javascript"
                      elif ".json" in file_name:
                          content_type = "application/json"
                      elif ".zip" in file_name: # this is the zip
                          content_type = "application/zip"
                          s3_key = path + file_name
                      elif ".py" in file_name:
                          # write python file to zip,
                          python_file = open("/tmp/"+file_name,"w")
                          python_file.write(get_response.data.decode("utf-8"))
                          python_file.close()

                          # Zip the file
                          LOGGER.info("Zipping the file : %s " % ("/tmp/"+file_name))
                          zipObj = ZipFile('/tmp/'+file_name.replace(".py",".zip"), 'w')
                          # Add file to the zip
                          zipObj.write('/tmp/'+file_name,"index.py")
                          # close the Zip File
                          zipObj.close()
                          LOGGER.info("Finished zipping file")

                          content_type = "application/zip"
                          s3_data = open("/tmp/"+file_name.replace(".py",".zip"), 'rb')
                          s3_key = s3_key.replace(".py",".zip")

                      # "RequestType": "Create"
                      if event['RequestType'] == "Create" or event['RequestType'] == "Update":
                          # Upload to S3
                          LOGGER.info("Now uploading %s to S3, Bucket: %s , path: %s" % (file_name,bucket,s3_key))
                          try:
                              s3_response = s3.put_object(Body=s3_data, Bucket=bucket, Key=s3_key,ContentType=content_type, CacheControl='no-cache')
                              LOGGER.info("Uploaded %s to S3, got response : %s " % (file_name,s3_response) )
                              responseData[file_base_name] = s3_key
                          except Exception as e:
                              LOGGER.error("Unable to upload %s to S3, got exception: %s" % (file_name,e))
                              responseData['Status'] = "Unable to upload %s to S3, got exception: %s" % (file_name,e)
                              cfnresponse.send(event, context, "FAILED",responseData)
                              raise Exception("Unable to upload %s to S3, got exception: %s" % (file_name,e))

                      else: # DELETE
                          try:
                              s3_response = s3.delete_object(Bucket=bucket,Key=s3_key)
                              LOGGER.info("Deleted %s from S3, got response : %s " % (file_name,s3_response) )
                          except Exception as e:
                              LOGGER.error("Unable to delete %s from S3, got exception: %s" % (file_name,e))
                              responseData['Status'] = "Unable to delete %s from S3, got exception: %s" % (file_name,e)
                              cfnresponse.send(event, context, "FAILED",responseData)
                  else:
                      LOGGER.info("Got line in manifest.txt that isn't a URL: %s " % (file))
              responseData['Status'] = "SUCCESS"
              cfnresponse.send(event, context, "SUCCESS",responseData)
              return responseData

      Environment:
        Variables:
          BUCKET: !Ref S3Bucket
      Tags:
        - Key: StackName
          Value: !Ref AWS::StackName
    DependsOn:
      - S3Bucket
      - LambdaRole
      - LambdaBasicExecutionPolicy

  LambdaLayerXMLtoDict:
    Type: AWS::Lambda::LayerVersion
    Properties:
      Description: Lambda Layer containing Python library XMLtoDict - XML Parser
      CompatibleRuntimes:
        - python3.8
      Content:
        S3Bucket: !Ref S3Bucket
        S3Key: !GetAtt FileMover.xmltodict
      LayerName: xmltodictlibrary
      LicenseInfo: https://raw.githubusercontent.com/martinblech/xmltodict/master/LICENSE

    #################
    ## API Gateway
    #################

  ApiGateway:
    Type: AWS::ApiGateway::RestApi
    Properties:
      Name: ADSReferenceServerAPI
      Description: API for ADS VAST Interactions
      EndpointConfiguration:
        Types:
          - REGIONAL
      Tags:
        - Key: StackName
          Value: !Ref AWS::StackName

  ProxyPlusResourceADS:
    Type: AWS::ApiGateway::Resource
    Properties:
      ParentId: !GetAtt ApiGateway.RootResourceId
      PathPart: '{proxy+}'
      RestApiId: !Ref ApiGateway
    DependsOn:
      - ApiGateway

  ADSResourceMethodAny:
    Type: AWS::ApiGateway::Method
    Properties:
      AuthorizationType: NONE
      HttpMethod: ANY
      Integration:
        IntegrationHttpMethod: POST
        IntegrationResponses:
          - StatusCode: '200'
        Type: AWS_PROXY
        Uri: !Join
          - ''
          - - 'arn:aws:apigateway:'
            - !Ref 'AWS::Region'
            - :lambda:path/2015-03-31/functions/
            - !GetAtt VastProcessor.Arn
            - /invocations
      MethodResponses:
        - StatusCode: 200
          ResponseModels:
            application/json: !Ref EmptyApiModel
      ResourceId: !Ref ProxyPlusResourceADS
      RestApiId: !Ref ApiGateway
    DependsOn:
      - ApiGateway

  OptionsForCors:
    Type: AWS::ApiGateway::Method
    Properties:
      AuthorizationType: NONE
      HttpMethod: OPTIONS
      Integration:
        IntegrationResponses:
          - StatusCode: 200
            ResponseParameters:
              method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
              method.response.header.Access-Control-Allow-Methods: "'GET,PUT,OPTIONS'"
              method.response.header.Access-Control-Allow-Origin: "'*'"
            ResponseTemplates:
              application/json: ''
        PassthroughBehavior: WHEN_NO_MATCH
        RequestTemplates:
          application/json: '{"statusCode": 200}'
        Type: MOCK
      MethodResponses:
        - StatusCode: 200
          ResponseModels:
            application/json: 'Empty'
          ResponseParameters:
            method.response.header.Access-Control-Allow-Headers: false
            method.response.header.Access-Control-Allow-Methods: false
            method.response.header.Access-Control-Allow-Origin: true
      ResourceId: !Ref ProxyPlusResourceADS
      RestApiId: !Ref ApiGateway
    DependsOn:
      - ApiGateway

  EmptyApiModel:
    Type: AWS::ApiGateway::Model
    Properties:
      ContentType: application/xml
      Description: This is a default empty schema model
      RestApiId: !Ref ApiGateway
      Schema: {
        "$schema": "http://json-schema.org/draft-04/schema#",
        "title": "Empty Schema",
        "type": "object"
      }

  Deployment:
    Type: AWS::ApiGateway::Deployment
    Properties:
      Description: Production Deployment of Api Endpoint
      RestApiId: !Ref ApiGateway
    DependsOn:
      - ApiGateway
      - ADSResourceMethodAny
      - ProxyPlusResourceADS

  ApiStage:
    Type: AWS::ApiGateway::Stage
    Properties:
      DeploymentId: !Ref Deployment
      RestApiId: !Ref ApiGateway
      StageName: v1
      MethodSettings:
        - HttpMethod: '*'
          ResourcePath: '/*'
          LoggingLevel: INFO
          DataTraceEnabled: True
    DependsOn:
      - ApiGateway

  APIGatewayCloudWatchLogsAccess:
    Type: AWS::ApiGateway::Account
    Properties:
      CloudWatchRoleArn: !GetAtt APIGatewayCWatchLoggingRole.Arn

#################################
# Outputs
#################################

Outputs:
  ADSVASTURL:
    Description: This is the endpoint to configure as your ADS Server endpoint
    Value: !Sub https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/${ApiStage}/ads
  EXAMPLE1:
    Description: Example 1 - ADS call with duration query parameter
    Value: !Sub https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/${ApiStage}/ads?duration=30
  EXAMPLE2:
    Description: Example 2 - ADS call with assetid query parameter to return VMAP (VOD)
    Value: !Sub https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/${ApiStage}/ads?assetid=scott1
  EXAMPLE3:
    Description: Example 3 - ADS call for wrapped response with ads_url query parameter
    Value: !Sub https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/${ApiStage}/vastwrapper?duration=30&ads_url=this-is-the-real-url.com/v1/ads