AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  shoppingcart-service

  SAM Template for shoppingcart-service

Parameters:
  UserPoolArn:
    Type: 'AWS::SSM::Parameter::Value<String>'
    Default: '/serverless-shopping-cart-demo/auth/user-pool-arn'
  UserPoolId:
    Type: 'AWS::SSM::Parameter::Value<String>'
    Default: '/serverless-shopping-cart-demo/auth/user-pool-id'
  ProductServiceUrl:
    Type: 'AWS::SSM::Parameter::Value<String>'
    Default: '/serverless-shopping-cart-demo/products/products-api-url'
  AllowedOrigin:
    Type: 'String'

Globals:
  Function:
    Timeout: 5
    MemorySize: 512
    Tracing: Active
    AutoPublishAlias: live
    Runtime: python3.8
    Layers:
      - !Sub arn:aws:lambda:${AWS::Region}:017000801446:layer:AWSLambdaPowertoolsPython:3
    Environment:
      Variables:
        TABLE_NAME: !Ref DynamoDBShoppingCartTable
        LOG_LEVEL: "INFO"
        ALLOWED_ORIGIN: !Ref AllowedOrigin
        POWERTOOLS_SERVICE_NAME: shopping-cart
        POWERTOOLS_METRICS_NAMESPACE: ecommerce-app
  Api:
    EndpointConfiguration: REGIONAL
    TracingEnabled: true
    OpenApiVersion: '2.0'
    Cors:
      AllowMethods: "'OPTIONS,POST,GET,PUT'"
      AllowHeaders: "'Content-Type,Authorization'"
      AllowCredentials: true
      AllowOrigin: !Sub "'${AllowedOrigin}'"

Resources:
  UtilsLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      ContentUri: ./layers/
      CompatibleRuntimes:
        - python3.8
    Metadata:
      BuildMethod: python3.8

  CartApi:
    Type: AWS::Serverless::Api
    DependsOn:
      - ApiGWAccount
    Properties:
      StageName: Prod
      MethodSettings:
        - DataTraceEnabled: True
          MetricsEnabled: True
          ResourcePath: "/*"
          HttpMethod: "*"
          LoggingLevel: INFO
      Auth:
        Authorizers:
          CognitoAuthorizer:
            UserPoolArn: !Ref UserPoolArn
            Identity: # OPTIONAL
              Header: Authorization # OPTIONAL; Default: 'Authorization'

  ListCartRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Action:
            - "sts:AssumeRole"
            Effect: "Allow"
            Principal:
              Service:
                - "lambda.amazonaws.com"

  AddToCartRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Action:
            - "sts:AssumeRole"
            Effect: "Allow"
            Principal:
              Service:
                - "lambda.amazonaws.com"

  LambdaLoggingPolicy:
    Type: "AWS::IAM::Policy"
    Properties:
      PolicyName: LambdaXRayPolicy
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Effect: "Allow"
            Action: [
              "xray:PutTraceSegments",
              "xray:PutTelemetryRecords",
              "logs:CreateLogGroup",
              "logs:CreateLogStream",
              "logs:PutLogEvents"
              ]
            Resource: "*"
      Roles:
        - !Ref ListCartRole
        - !Ref AddToCartRole

  DynamoDBReadPolicy:
    Type: "AWS::IAM::Policy"
    Properties:
      PolicyName: DynamoDBReadPolicy
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Effect: "Allow"
            Action: [
              "dynamodb:GetItem",
              "dynamodb:Scan",
              "dynamodb:Query",
              "dynamodb:BatchGetItem",
              "dynamodb:DescribeTable"
              ]
            Resource:
              - !GetAtt DynamoDBShoppingCartTable.Arn
      Roles:
        - !Ref ListCartRole
        - !Ref AddToCartRole

  DynamoDBWritePolicy:
    Type: "AWS::IAM::Policy"
    Properties:
      PolicyName: DynamoDBWritePolicy
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Effect: "Allow"
            Action: [
              "dynamodb:PutItem",
              "dynamodb:UpdateItem",
              "dynamodb:ConditionCheckItem",
              "dynamodb:DeleteItem",
              "dynamodb:BatchWriteItem"
            ]
            Resource: !GetAtt DynamoDBShoppingCartTable.Arn
      Roles:
        - !Ref AddToCartRole

  SQSSendMessagePolicy:
    Type: "AWS::IAM::Policy"
    Properties:
      PolicyName: SQSSendMessagePolicy
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          -
            Effect: "Allow"
            Action: [
              "sqs:SendMessage*"
            ]
            Resource: !GetAtt CartDeleteSQSQueue.Arn
      Roles:
        - !Ref AddToCartRole

  ListCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: list_cart.lambda_handler
      Role: !GetAtt ListCartRole.Arn
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          USERPOOL_ID: !Ref UserPoolId
      Events:
        ListCart:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart
            Method: get

  AddToCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: add_to_cart.lambda_handler
      Role: !GetAtt AddToCartRole.Arn
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          PRODUCT_SERVICE_URL: !Ref ProductServiceUrl
          USERPOOL_ID: !Ref UserPoolId
      Events:
        AddToCart:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart
            Method: post

  UpdateCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: update_cart.lambda_handler
      Role: !GetAtt AddToCartRole.Arn
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          PRODUCT_SERVICE_URL: !Ref ProductServiceUrl
          USERPOOL_ID: !Ref UserPoolId
      Events:
        AddToCart:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart/{product_id}
            Method: put

  MigrateCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: migrate_cart.lambda_handler
      Timeout: 30
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          PRODUCT_SERVICE_URL: !Ref ProductServiceUrl
          USERPOOL_ID: !Ref UserPoolId
          DELETE_FROM_CART_SQS_QUEUE: !Ref CartDeleteSQSQueue
      Role: !GetAtt AddToCartRole.Arn
      Events:
        AddToCart:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart/migrate
            Method: post
            Auth:
              Authorizer: CognitoAuthorizer

  CheckoutCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: checkout_cart.lambda_handler
      Timeout: 10
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          PRODUCT_SERVICE_URL: !Ref ProductServiceUrl
          USERPOOL_ID: !Ref UserPoolId
      Role: !GetAtt AddToCartRole.Arn
      Events:
        AddToCart:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart/checkout
            Method: post
            Auth:
              Authorizer: CognitoAuthorizer

  GetCartTotalFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: get_cart_total.lambda_handler
      Timeout: 10
      Layers:
        - !Ref UtilsLayer
      Role: !GetAtt ListCartRole.Arn
      Events:
        GetCartTotal:
          Type: Api
          Properties:
            RestApiId: !Ref CartApi
            Path: /cart/{product_id}/total
            Method: get

  DeleteFromCartFunction:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: delete_from_cart.lambda_handler
      ReservedConcurrentExecutions: 25  # Keep the ddb spikes down in case of many deletes at once
      Policies:
        - SQSPollerPolicy:
            QueueName:
              !GetAtt CartDeleteSQSQueue.QueueName
        - Statement:
            - Effect: Allow
              Action:
                - "dynamodb:DeleteItem"
                - "dynamodb:BatchWriteItem"
              Resource:
                - !GetAtt DynamoDBShoppingCartTable.Arn
      Layers:
        - !Ref UtilsLayer
      Environment:
        Variables:
          USERPOOL_ID: !Ref UserPoolId
      Events:
        RetrieveFromSQS:
          Type: SQS
          Properties:
            Queue: !GetAtt CartDeleteSQSQueue.Arn
            BatchSize: 5

  CartDBStreamHandler:
    Type: AWS::Serverless::Function
    DependsOn:
      - LambdaLoggingPolicy
    Properties:
      CodeUri: shopping-cart-service/
      Handler: db_stream_handler.lambda_handler
      Layers:
        - !Ref UtilsLayer
      Policies:
        - AWSLambdaDynamoDBExecutionRole
        - Statement:
            - Effect: Allow
              Action:
                - "dynamodb:UpdateItem"
              Resource:
                - !GetAtt DynamoDBShoppingCartTable.Arn
      Events:
        Stream:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt DynamoDBShoppingCartTable.StreamArn
            BatchSize: 100
            MaximumBatchingWindowInSeconds: 60
            StartingPosition: LATEST

  DynamoDBShoppingCartTable:
    Type: AWS::DynamoDB::Table
    Properties:
      AttributeDefinitions:
        - AttributeName: pk
          AttributeType: S
        - AttributeName: sk
          AttributeType: S
      KeySchema:
        - AttributeName: pk
          KeyType: HASH
        - AttributeName: sk
          KeyType: RANGE
      BillingMode: PAY_PER_REQUEST
      StreamSpecification:
        StreamViewType: 'NEW_AND_OLD_IMAGES'
      TimeToLiveSpecification:
        AttributeName: expirationTime
        Enabled: True

  APIGWCloudWatchRole:
    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
  ApiGWAccount:
    Type: 'AWS::ApiGateway::Account'
    Properties:
      CloudWatchRoleArn: !GetAtt APIGWCloudWatchRole.Arn

  CartDeleteSQSQueue:
    Type: AWS::SQS::Queue
    Properties:
      VisibilityTimeout: 20
      RedrivePolicy:
        deadLetterTargetArn:
          !GetAtt CartDeleteSQSDLQ.Arn
        maxReceiveCount: 5
  CartDeleteSQSDLQ:
    Type: AWS::SQS::Queue

  CartApiUrl:
    Type: AWS::SSM::Parameter
    Properties:
      Type: String
      Name: /serverless-shopping-cart-demo/shopping-cart/cart-api-url
      Value: !Sub "https://${CartApi}.execute-api.${AWS::Region}.amazonaws.com/Prod"

Outputs:
  CartApi:
    Description: "API Gateway endpoint URL for Prod stage for Cart Service"
    Value: !Sub "https://${CartApi}.execute-api.${AWS::Region}.amazonaws.com/Prod"