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

AWSTemplateFormatVersion: 2010-09-09
Description: Amazon Kendra FAQ Refresher

Parameters:
  BucketNamePrefix:
    Description: S3 Bucket name
    Type: String
    Default: kendra-faq

  EmailAddress:
    Type: String
    Description: Email that receives notifications when FAQs have been successfully added

Resources:

  FAQBucket:
    DependsOn: BucketPermission
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Join ['-', [!Ref BucketNamePrefix, !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      NotificationConfiguration:
        LambdaConfigurations:
          - Event: s3:ObjectCreated:*
            Filter:
              S3Key:
                Rules:
                  - Name: suffix
                    Value: .json
            Function: !GetAtt FAQRefresherLambda.Arn
          - Event: s3:ObjectCreated:*
            Filter:
              S3Key:
                Rules:
                  - Name: suffix
                    Value: .csv
            Function: !GetAtt FAQRefresherLambda.Arn
          - Event: s3:ObjectCreated:*
            Filter:
              S3Key:
                Rules:
                  - Name: suffix
                    Value: .JSON
            Function: !GetAtt FAQRefresherLambda.Arn
          - Event: s3:ObjectCreated:*
            Filter:
              S3Key:
                Rules:
                  - Name: suffix
                    Value: .CSV
            Function: !GetAtt FAQRefresherLambda.Arn
      PublicAccessBlockConfiguration:
        BlockPublicAcls: true
        BlockPublicPolicy: true
        IgnorePublicAcls: true
        RestrictPublicBuckets: true
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256
      VersioningConfiguration:
        Status: Enabled
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W35
            reason: S3 access logging is not required since no sensitive faqs are used for this blog

  FAQBucketPolicy:
    Type: AWS::S3::BucketPolicy
    Properties:
      Bucket: !Ref FAQBucket
      PolicyDocument:
        Statement:
          - Sid: AllowSSLRequestsOnly
            Action:
              - s3:*
            Effect: Deny
            Resource:
              - !Join ['-', [!Sub 'arn:${AWS::Partition}:s3:::${BucketNamePrefix}', !Select [2, !Split ['/', !Ref AWS::StackId]]]]
              - !Join ['/', [!Join ['-', [!Sub 'arn:${AWS::Partition}:s3:::${BucketNamePrefix}', !Select [2, !Split ['/', !Ref AWS::StackId]]]], '*']]
            Principal: '*'
            Condition:
              Bool:
                'aws:SecureTransport': false

  BucketPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !Ref FAQRefresherLambda
      Principal: s3.amazonaws.com
      SourceAccount: !Ref AWS::AccountId
      SourceArn: !Join ['-', [!Sub 'arn:${AWS::Partition}:s3:::${BucketNamePrefix}', !Select [2, !Split ['/', !Ref AWS::StackId]]]]

  FAQRefresherLambdaLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: /aws/lambda/kendra-faq-refresher-lambda
      RetentionInDays: 60
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W84
            reason: The data stored in CloudWatch Logs does not contain sensitive information, using default protections provided by CloudWatch logs

  FAQRefresherLambdaExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          Effect: Allow
          Principal:
            Service: lambda.amazonaws.com
          Action: sts:AssumeRole
      Path: /
      Policies:
        - PolicyName: KendraFaqRefresherLambdaPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - logs:CreateLogStream
                  - logs:PutLogEvents
                Resource:
                  - !GetAtt FAQRefresherLambdaLogGroup.Arn
              - Effect: Allow
                Action:
                  - kendra:CreateFaq
                  - kendra:DeleteFaq
                  - kendra:ListFaqs
                Resource:
                  - !Sub arn:${AWS::Partition}:kendra:${AWS::Region}:${AWS::AccountId}:index/*
              - Effect: Allow
                Action:
                  - kendra:DescribeFaq
                Resource:
                  - !Sub arn:${AWS::Partition}:kendra:${AWS::Region}:${AWS::AccountId}:index/*
                  - !Sub arn:${AWS::Partition}:kendra:${AWS::Region}:${AWS::AccountId}:index/*/faq/*"
              - Effect: Allow
                Action:
                  - iam:PassRole
                Resource:
                  - !GetAtt FAQCreationRole.Arn
              - Effect: Allow
                Action:
                  - sns:Publish
                Resource: !Ref NotificationTopic

  NotificationTopic:
    Type: AWS::SNS::Topic
    Properties:
      Subscription:
      - Endpoint: !Ref EmailAddress
        Protocol: email
      KmsMasterKeyId: alias/aws/sns

  FAQRefresherLambda:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: kendra-faq-refresher-lambda
      Description: Lambda function to create/Delete Kendra FAQ
      Role: !GetAtt FAQRefresherLambdaExecutionRole.Arn
      Runtime: python3.9
      Handler: index.lambda_handler
      Environment:
        Variables:
          FAQ_BUCKET: !Join ['-', [!Ref BucketNamePrefix, !Select [2, !Split ['/', !Ref AWS::StackId]]]]
          KENDRA_FAQ_ROLE: !GetAtt FAQCreationRole.Arn
          SNS_TOPIC_ARN: !Ref NotificationTopic
      Timeout: 300
      MemorySize: 128
      TracingConfig:
        Mode: Active
      Layers:
        - !Sub arn:aws:lambda:${AWS::Region}:017000801446:layer:AWSLambdaPowertoolsPython:7
      Code:
        ZipFile: |
          # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
          # SPDX-License-Identifier: MIT-0
          #
          # 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.
          #
          # 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.

          import boto3
          import os
          from datetime import datetime
          from botocore.config import Config
          import time

          from aws_lambda_powertools import Tracer  # type: ignore
          from aws_lambda_powertools import Logger  # type: ignore

          tracer = Tracer(service='kendra-faq-refresher-lambda')
          logger = Logger(service='kendra-faq-refresher-lambda')

          FAQ_BUCKET = os.environ.get('FAQ_BUCKET')
          KENDRA_FAQ_ROLE = os.environ.get('KENDRA_FAQ_ROLE')
          SNS_TOPIC_ARN = os.environ['SNS_TOPIC_ARN']

          config = Config(
              retries=dict(
                  max_attempts=10
              )
          )
          client = boto3.client('kendra', config=config)
          sns_client = boto3.client('sns')

          @tracer.capture_method
          def lambda_handler(event, context):
              """
              Lambda Function handler
              event: Lambda Event
              context: Lambda Context
              """
              description = None
              file_format = None
              faq_list_response = None
              faq_summary_list = list()

              for object_name in event.get('Records'):
                  try:
                      # S3 object_key replaces spaces with +, hence revert back
                      object_key = object_name.get('s3').get('object').get('key').replace('+', ' ')
                      index_id = object_key.split('/')[0].split('faq-')[1]
                      document_name = object_key.split('/')[-1]
                      # json or csv FAQ type files are named as <faq_name_prefix>-desc-<description>.<json|csv>
                      # csv with header FAQ type files are named as header_<faq_name_prefix>-desc-<description>.csv
                      if '-desc-' in document_name:
                          description = document_name.split('-desc-')[1].split('.')[0]
                          document_name = document_name.split('-desc-')[0]
                          document_extension = object_key.split('.')[-1]
                      else:
                          document_name = object_key.split('/')[-1].split('.')[0]
                          document_extension = object_key.split('.')[-1]
                      document_extension = object_key.split('.')[-1]
                      try:
                          faq_list_response = client.list_faqs(
                              IndexId=index_id,
                          )
                          for faq_summaries in faq_list_response.get("FaqSummaryItems"):
                              faq_summary_list.append(faq_summaries)
                          while faq_list_response.get("NextToken"):
                              faq_list_response = client.list_faqs(
                                  IndexId=index_id,
                                  NextToken=faq_list_response.get("NextToken")
                              )
                              for faq_summaries in faq_list_response.get("FaqSummaryItems"):
                                  faq_summary_list.append(faq_summaries)
                          logger.info(faq_summary_list)
                      except Exception as error:
                          logger.error(error)
                          raise RuntimeError(f"Failed to list FAQ for {index_id} Index")

                      try:
                          file_format = document_extension.upper()
                          if 'header_' in document_name:
                              file_format = 'CSV_WITH_HEADER'
                      except:
                          raise RuntimeError('Failed to format document extension')

                      if file_format is not None and file_format in {'JSON', 'CSV', 'CSV_WITH_HEADER'}:
                          now = datetime.now()
                          faq_name = f"{document_name}-{document_extension}-faq-{now.strftime('%d-%m-%Y-%H-%M-%S')}"

                          # Create New FAQ
                          try:
                              response = client.create_faq(
                                  IndexId=index_id,
                                  Name=faq_name,
                                  Description=description if description is not None else document_name,
                                  S3Path={
                                      'Bucket': FAQ_BUCKET,
                                      'Key': object_key
                                  },
                                  RoleArn=KENDRA_FAQ_ROLE,
                                  FileFormat=file_format,
                              )
                              logger.info(f'Successfully created FAQ: {faq_name}')
                          except Exception as error:
                              logger.error(error)
                              sns_client.publish(
                                  TargetArn = SNS_TOPIC_ARN,
                                  Subject = f'[Error] FAQ upload failed',
                                  Message = f"Kendra Index ID: {index_id}\n\nS3 bucket: {FAQ_BUCKET}\n\nFile: {object_key}\n\nSomething went wrong when uploading a new Kendra FAQ. Please investigate the Lambda Function's CloudWatch Log Group for more information.\n\nThank you."
                              )
                              logger.info('Publish to SNS Topic for FAQ failed uploads')
                              raise RuntimeError(f'Failed to create FAQ for Kendra Index: {index_id}')

                          while True:
                              # Get the details of the FAQ, such as the status
                              describe_response = client.describe_faq(
                                  Id=response.get('Id'),
                                  IndexId=index_id
                              )
                              # When status is Active quit.
                              status = describe_response['Status']
                              logger.info(f"FAQ {response.get('Id')} status is {status}...")
                              if status == 'ACTIVE':
                                  break
                              else:
                                  time.sleep(5)

                          # Delete Old FAQ
                          for faq in faq_summary_list:
                              if f"{document_name}-{document_extension}-faq" in faq.get('Name'):
                                  try:
                                      client.delete_faq(
                                          Id=faq.get('Id'),
                                          IndexId=index_id
                                      )
                                      logger.info(f"Successfully deleted FAQ ID {faq.get('Id')}")
                                  except Exception as error:
                                      sns_client.publish(
                                          TargetArn = SNS_TOPIC_ARN,
                                          Subject = f'[Error] FAQ delete failed',
                                          Message = f"Kendra Index ID: {index_id}\n\nFAQ ID: {faq.get('Id')}\n\nKendra FAQ failed to be deleted. Please investigate the Lambda Function's CloudWatch Log Group for more information.\n\nThank you."
                                      )
                                      logger.info('Publish to SNS Topic for FAQ failed deletes')
                                      logger.error(f"Failed to delete FAQ {faq.get('Id')} for {index_id} Index")
                                      logger.error(error)
                          sns_client.publish(
                            TargetArn = SNS_TOPIC_ARN,
                            Subject = f"New FAQ {response.get('Id')} has been successfully added",
                            Message = f"Kendra Index ID: {index_id}\n\nFAQ ID: {response.get('Id')}\n\nNew Kendra FAQ has been successfully added by the FAQ automation solution. Older versions (if any) have been deleted. You may now upload new versions if required.\n\nThank you."
                          )
                          logger.info('Publish to SNS Topic for FAQ Successful upload and old FAQ deletes')
                      else:
                          sns_client.publish(
                              TargetArn = SNS_TOPIC_ARN,
                              Subject = f'[Error] FAQ invalid file format',
                              Message = f"An invalid file format was uploaded to S3 for the Kendra FAQ automation solution to process. Please ensure that only 'JSON', 'CSV', or 'CSV_WITH_HEADER' file formats are uploaded.\n\nThank you."
                          )
                          logger.info('Publish to SNS Topic for invalid FAQ file formats')
                          logger.error(f'Invalid File Format found for FAQ Document: {document_name}')
                  except Exception as error:
                      sns_client.publish(
                          TargetArn = SNS_TOPIC_ARN,
                          Subject = f'[Error] S3 processing',
                          Message = f"Error encountered when reading the S3 event. Please investigate the Lambda Function's CloudWatch Log Group for more information.\n\nThank you."
                      )
                      logger.info('Publish to SNS Topic for S3 event processing failures')
                      logger.error(f'Error processing S3 event {object}')
                      logger.error(error)
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W58
            reason: CloudWatch Log Group is created by CloudFormation and Lambda Function does not require logs:CreateLogGroup action
          - id: W89
            reason: This lambda function does not require configuration with VPC
          - id: W92
            reason: This lambda function does not require ReservedConcurrentExecutions

  FAQCreationRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          Effect: Allow
          Principal:
            Service: kendra.amazonaws.com
          Action: sts:AssumeRole
      Path: /
      Policies:
        - PolicyName: S3GetObjectPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - s3:GetObject
                Resource:
                  - !Join ['/', [!Join ['-', [!Sub 'arn:${AWS::Partition}:s3:::${BucketNamePrefix}', !Select [2, !Split ['/', !Ref AWS::StackId]]]], '*']]

  SampleKendraIndex:
    Type: AWS::Kendra::Index
    Properties:
      Description: Sample Kendra Index
      Edition: DEVELOPER_EDITION
      Name: sample-kendra-index
      RoleArn: !GetAtt SampleKendraIndexServiceRole.Arn
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W80
            reason: Amazon Kendra will encrypt your data with Amazon Kendra owned key by default

  SampleKendraIndexServiceRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          Effect: Allow
          Principal:
            Service: kendra.amazonaws.com
          Action: sts:AssumeRole
      Path: /
      Policies:
        - PolicyName: KendraIndexPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - cloudwatch:PutMetricData
                Resource: "*"
                Condition:
                    StringEquals:
                      cloudwatch:namespace: AWS/Kendra
              - Effect: Allow
                Action:
                  - logs:DescribeLogGroups
                Resource: "*"
              - Effect: Allow
                Action:
                  - logs:CreateLogGroup
                Resource:
                  - !Sub arn:${AWS::Partition}:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/kendra/*
              - Effect: Allow
                Action:
                  - logs:DescribeLogStreams
                  - logs:CreateLogStream
                  - logs:PutLogEvents
                Resource:
                  - !Sub arn:${AWS::Partition}:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/kendra/*:log-stream:*
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W11
            reason: PutMetricData is limited to AWS/Kendra namespace

Outputs:
  KendraIndex:
    Description: Kendra Index
    Value: !GetAtt SampleKendraIndex.Id
  S3Bucket:
    Description: S3 Bucket that stores FAQ documents
    Value: !Ref FAQBucket