AWSTemplateFormatVersion: 2010-09-09
Description: >
    This template creates a Lex bot and associated resources.
    It uses a custom resource to read the bot definition from a file.

Parameters:
    NamePrefix:
        Type: String
        Description: Prefix to add to Lex resource names
        Default: WebUi
        MinLength: 3
        MaxLength: 32
        AllowedPattern: '^[a-zA-Z\._]+$'
        ConstraintDescription: >
            Must conform with the permitted Lex Bot name pattern.

    CustomResourceCodeBucket:
        Description: S3 bucket where the Lambda bundle is located
        Type: String
        Default: aws-bigdata-blog

    CustomResourceCodeObject:
        Type: String
        Description: >
            S3 object zip file containing Lambda custom resource functions
        Default: artifacts/aws-lex-web-ui/artifacts/custom-resources.zip

    ShouldDeleteBot:
        Type: String
        Default: true
        AllowedValues:
          - true
          - false
        Description: >
            If set to True, the Lex bot and associated resources will
            be deleted when the stack is deleted. Otherwise, the bot
            will be preserved.

Resources:
    # custom resource to start code build project
    LexBot:
        Type: Custom::LexBot
        Properties:
            ServiceToken: !GetAtt LexBotLambda.Arn
            NamePrefix: !Ref NamePrefix
            ShouldDelete: !Ref ShouldDeleteBot

    # Lambda function for custom resource
    LexBotLambda:
        Type: AWS::Lambda::Function
        Properties:
            Code:
                S3Bucket: !Ref CustomResourceCodeBucket
                S3Key: !Ref CustomResourceCodeObject
            Handler: lex-manager.handler
            Role: !GetAtt LexBotLambdaRole.Arn
            Runtime: python2.7
            Timeout: 300

    LexBotLambdaRole:
        Type: AWS::IAM::Role
        Properties:
            Path: /
            AssumeRolePolicyDocument:
                Version: 2012-10-17
                Statement:
                    - Principal:
                          Service:
                              - lambda.amazonaws.com
                      Effect: Allow
                      Action:
                          - sts:AssumeRole
            Policies:
                - PolicyName: LogsForLambda
                  PolicyDocument:
                      Version: 2012-10-17
                      Statement:
                          - Effect: Allow
                            Action:
                                - logs:CreateLogGroup
                                - logs:CreateLogStream
                                - logs:PutLogEvents
                            Resource:
                                - !Sub "arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/*"
                                - !Sub "arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/*:*"
                - PolicyName: LexGet
                  PolicyDocument:
                      Version: 2012-10-17
                      Statement:
                          - Effect: Allow
                            Action:
                                - lex:Get*
                            Resource: '*'
                - PolicyName: LexMutating
                  PolicyDocument:
                      Version: 2012-10-17
                      Statement:
                          - Effect: Allow
                            Action:
                                - lex:Put*
                                - lex:Delete*
                            Resource:
                                - !Sub "arn:aws:lex:${AWS::Region}:${AWS::AccountId}:bot:${NamePrefix}*:*"
                                - !Sub "arn:aws:lex:${AWS::Region}:${AWS::AccountId}:intent:${NamePrefix}*:*"
                                - !Sub "arn:aws:lex:${AWS::Region}:${AWS::AccountId}:slottype:${NamePrefix}*:*"

Outputs:
    BotName:
        Description: Lex Bot Name
        Value: !Sub "${LexBot.BotName}"