template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A chat without negative content.
Resources:

  PositiveChatWebSocket:
    Type: AWS::ApiGatewayV2::Api
    Properties:
      Name: PositiveChatWebSocket
      ProtocolType: WEBSOCKET
      RouteSelectionExpression: "$request.body.action"

  ConnectRoute:
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      RouteKey: $connect
      AuthorizationType: NONE
      OperationName: ConnectRoute
      Target: !Join
        - '/'
        - - 'integrations'
          - !Ref ConnectInteg

  ConnectInteg:
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      Description: Connect Integration
      IntegrationType: AWS_PROXY
      IntegrationUri: 
        Fn::Sub:
            arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PositiveChatFunction.Arn}/invocations

  DisconnectRoute:
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      RouteKey: $disconnect
      AuthorizationType: NONE
      OperationName: DisconnectRoute
      Target: !Join
        - '/'
        - - 'integrations'
          - !Ref DisconnectInteg

  DisconnectInteg:
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      Description: Disconnect Integration
      IntegrationType: AWS_PROXY
      IntegrationUri: 
        Fn::Sub:
            arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PositiveChatFunction.Arn}/invocations

  DefaultRoute:
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      RouteKey: "$default"
      AuthorizationType: NONE
      OperationName: DefaultRoute
      Target: !Join
        - '/'
        - - 'integrations'
          - !Ref DefaultInteg

  DefaultInteg:
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId: !Ref PositiveChatWebSocket
      Description: Default Integration
      IntegrationType: AWS_PROXY
      IntegrationUri: 
        Fn::Sub:
            arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PositiveChatFunction.Arn}/invocations

  Deployment:
    Type: AWS::ApiGatewayV2::Deployment
    DependsOn:
    - ConnectRoute
    - DefaultRoute
    - DisconnectRoute
    Properties:
      ApiId: !Ref PositiveChatWebSocket

  Stage:
    Type: AWS::ApiGatewayV2::Stage
    Properties:
      StageName: Prod
      Description: Prod Stage
      DeploymentId: !Ref Deployment
      ApiId: !Ref PositiveChatWebSocket

  PositiveChatPermission:
    Type: AWS::Lambda::Permission
    DependsOn:
      - PositiveChatWebSocket
      - PositiveChatFunction
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !Ref PositiveChatFunction
      Principal: apigateway.amazonaws.com

  ConnectionsTable:
    Type: AWS::DynamoDB::Table
    Properties:
      BillingMode: 'PAY_PER_REQUEST'
      AttributeDefinitions:
        - AttributeName: 'connectionId'
          AttributeType: 'S'
        - AttributeName: 'room'
          AttributeType: 'S'
      KeySchema:
        - AttributeName: 'connectionId'
          KeyType: 'HASH'
      GlobalSecondaryIndexes:
        - IndexName: 'roomIndex'
          KeySchema:
            - AttributeName: 'room'
              KeyType: 'HASH'
          Projection:
            ProjectionType: ALL

  ConversationsTable:
    Type: AWS::DynamoDB::Table
    Properties:
      BillingMode: 'PAY_PER_REQUEST'
      AttributeDefinitions:
        - AttributeName: 'room'
          AttributeType: 'S'
        - AttributeName: 'timestamp'
          AttributeType: 'N'
      KeySchema:
        - AttributeName: 'room'
          KeyType: 'HASH'
        - AttributeName: 'timestamp'
          KeyType: 'RANGE'

  TopicsTable:
    Type: AWS::DynamoDB::Table
    Properties:
      BillingMode: 'PAY_PER_REQUEST'
      AttributeDefinitions:
        - AttributeName: 'room'
          AttributeType: 'S'
        - AttributeName: 'topic'
          AttributeType: 'S'
        - AttributeName: 'num'
          AttributeType: 'N'
      KeySchema:
        - AttributeName: 'room'
          KeyType: 'HASH'
        - AttributeName: 'topic'
          KeyType: 'RANGE'
      GlobalSecondaryIndexes:
        - IndexName: 'numIndex'
          KeySchema:
            - AttributeName: 'room'
              KeyType: 'HASH'
            - AttributeName: 'num'
              KeyType: 'RANGE'
          Projection:
            ProjectionType: ALL

  PositiveChatFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: positive-chat/
      Handler: app.lambdaHandler
      Runtime: nodejs8.10
      Timeout: 30
      Policies:
        - Statement:
          - Effect: Allow
            Action:
              - 'execute-api:ManageConnections'
            Resource:
              - 'arn:aws:execute-api:*:*:*/@connections/*'
          - Effect: Allow
            Action:
              - 'dynamoDb:PutItem'
              - 'dynamoDb:GetItem'
              - 'dynamoDb:DeleteItem'
            Resource:
              - !GetAtt ConnectionsTable.Arn
          - Effect: Allow
            Action:
              - 'dynamoDb:Query'
            Resource:
              - !Sub "${ConnectionsTable.Arn}/index/roomIndex"
          - Effect: Allow
            Action:
              - 'dynamoDb:PutItem'
              - 'dynamoDb:Query'
            Resource:
              - !GetAtt ConversationsTable.Arn
          - Effect: Allow
            Action:
              - 'dynamoDb:UpdateItem'
            Resource:
              - !GetAtt TopicsTable.Arn
          - Effect: Allow
            Action:
              - 'dynamoDb:Query'
            Resource:
              - !Sub "${TopicsTable.Arn}/index/numIndex"
          - Effect: Allow
            Action:
              - 'comprehend:DetectDominantLanguage'
              - 'comprehend:DetectSentiment'
              - 'comprehend:DetectEntities'
              - 'translate:TranslateText'
            Resource: '*'
      Environment:
        Variables:
          CONNECTIONS_TABLE: !Ref ConnectionsTable
          CONVERSATIONS_TABLE: !Ref ConversationsTable
          TOPICS_TABLE: !Ref TopicsTable

Outputs:
  PositiveChatFunction:
    Description: "Positive Chat Lambda Function ARN"
    Value: !GetAtt PositiveChatFunction.Arn
  PositiveChatFunctionIamRole:
    Description: "Implicit IAM Role created for Positive Chat function"
    Value: !GetAtt PositiveChatFunctionRole.Arn
  WebSocketURI:
    Description: "The WSS Protocol URI to connect to"
    Value: !Sub "wss://${PositiveChatWebSocket}.execute-api.${AWS::Region}.amazonaws.com/${Stage}"