exports.handler = function()

in apps/televisit-demo/backend/messagemoderator/index.js [17:125]
71 lines of code
7 McCabe index (conditional complexity)

exports.handler = function (event, context) {
  try {
    event.Records.forEach(async (record) => {
      // If event.Records has many items, e.g. 100 times, this Lambda will make 100 sendChannelMessage API calls simultaneously, so please consider throttling exceptions.
      // Kinesis data is base64 encoded so decode here
      const payload = Buffer.from(record.kinesis.data, 'base64').toString();
      console.log('Decoded payload:', payload);
      //Parsing payload as a JSON message payload
      const jsonMessage = JSON.parse(payload);
      const senderId = jsonMessage.Payload.Sender.Arn.substring(
        jsonMessage.Payload.Sender.Arn.lastIndexOf('/') + 1
      );
      const channelArn = jsonMessage.Payload.ChannelArn;
      const messageId = jsonMessage.Payload.MessageId;
      console.log('Message content:', jsonMessage.Payload.Content);
      // chatbot
      const userinput = jsonMessage.Payload.Content;
      if (
        jsonMessage.Payload.Redacted === true ||
        jsonMessage.EventType === 'UPDATE_CHANNEL_MESSAGE' ||
        jsonMessage.Payload.Sender.Name === 'ModeratorBot'
      ) {
        return;
      }
      const comprehendParams = {
        Text: userinput,
      };
      const detectedLang = await comprehend
        .detectDominantLanguage(comprehendParams)
        .promise();
      console.log('detectedLang: ' + detectedLang.Languages[0].LanguageCode);

      let translatedText;
      if (detectedLang.Languages[0].LanguageCode !== 'en') {
        const translateParams = {
          SourceLanguageCode: detectedLang.Languages[0].LanguageCode,
          TargetLanguageCode: 'en',
          Text: userinput,
        };
        translatedText = await translate
          .translateText(translateParams)
          .promise();
        console.log('TranslatedText: ' + translatedText.TranslatedText);
        await updateChannelMessage(
          channelArn,
          messageId,
          userinput + ' ' + translatedText.TranslatedText,
          jsonMessage.Payload.Metadata,
          senderId
        );
      }

      if (
        senderId !== 'ModeratorBot' &&
        (userinput.toLowerCase() === 'yes' || userinput.toLowerCase() === 'no')
      ) {
        const messages = await listChannelMessages(channelArn, senderId);
        await updateChannelMessage(
          channelArn,
          messageId,
          messages.Messages.slice(-2)[0].Content + ': ' + userinput,
          jsonMessage.Payload.Metadata,
          senderId
        );
      }

      const botinput = translatedText
        ? translatedText.TranslatedText
        : jsonMessage.Payload.Content;
      const params = {
        botName: LEX_BOT_NAME,
        botAlias: LEX_BOT_ALIAS,
        inputText: botinput,
        userId: senderId,
        sessionAttributes: {
          userPreferredLocale: 'en',
        },
      };
      const lexResponse = await lex.postText(params).promise();
      console.log('Lex response: ' + JSON.stringify(lexResponse));

      if (detectedLang.Languages[0].LanguageCode !== 'en') {
        const translateParams = {
          SourceLanguageCode: 'en',
          TargetLanguageCode: detectedLang.Languages[0].LanguageCode,
          Text: lexResponse.message,
        };
        translatedText = await translate
          .translateText(translateParams)
          .promise();
        console.log('TranslatedText: ' + translatedText.TranslatedText);
        await sendChannelMessage(
          channelArn,
          lexResponse.message + ' ' + translatedText.TranslatedText,
          'ModeratorBot'
        );
      } else {
        await sendChannelMessage(
          channelArn,
          lexResponse.message,
          'ModeratorBot'
        );
      }
    });
  } catch (e) {
    console.log(JSON.stringify(e));
    return;
  }
};