node-red-contrib-chatbot/nodes/chatbot-message.js

REDBot a Chat bot for a full featured chat bot for Telegram, Facebook Messenger and Slack. Almost no coding skills required

const _ = require('underscore');
const emoji = require('node-emoji');
const { ChatExpress } = require('chat-platform');
const RegisterType = require('../lib/node-installer');
const {
  isValidMessage,
  getChatId,
  getMessageId,
  getTransport,
  extractValue,
  when,
  appendPayload
} = require('../lib/helpers/utils');
const MessageTemplate = require('../lib/message-template-async');
const GlobalContextHelper = require('../lib/helpers/global-context-helper');

module.exports = function(RED) {
  const registerType = RegisterType(RED);
  const globalContextHelper = GlobalContextHelper(RED);

  function ChatBotMessage(config) {
    RED.nodes.createNode(this, config);
    var node = this;
    globalContextHelper.init(this.context().global);
    this.message = config.message;
    this.parse_mode = config.parse_mode;
    this.language = config.language;

    this.pickOne = function(messages) {
      const luck = Math.floor(Math.random() * messages.length);
      return _.isString(messages[luck]) ? messages[luck] : messages[luck].message;
    };

    this.on('input', async function(msg, send, done) {
      // send/done compatibility for node-red < 1.0
      send = send || function() { node.send.apply(node, arguments) };
      done = done || function(error) { node.error.call(node, error, msg) };
      const sendPayload = appendPayload(send, msg);
      // check if valid message
      if (!isValidMessage(msg, node)) {
        return;
      }
      const chat = msg.chat();
      const chatId = getChatId(msg);
      const messageId = getMessageId(msg);
      const template = MessageTemplate(msg, node);
      const transport = getTransport(msg);
      // check transport compatibility
      if (!ChatExpress.isSupported(transport, 'message')) {
        done(`Node "message" is not supported by ${transport} transport`);
        return;
      }
      // try to get a plain string or number from config or payload or "message" variable
      // also try to get message from the "answer" key in payload, that to try to get the answer directly from nodes
      // like dialogflow/recast
      // also try to get an array of messages from config and pick one randomly
      const messages = extractValue(['string','messages', 'number'], 'message', node, msg, true, true)
        || extractValue('string', 'answer', node, msg, false);
      const fallback = extractValue('string', 'fallback', node, msg, false);
      const language = extractValue('string', 'language', node, msg, false);
      // extract a valid string
      let message;
      if (_.isArray(messages)) {
        message = node.pickOne(messages);
      } else {
        message = messages;
      }

      try {
        const parsedMessage = await template(message)
        const contextLanguage = await when(chat.get('language'));
        // if both context language and message language are defined and are different, then skip
        // message block was meant for a different language, skip if language is not defined in the node or
        // in the chat context (the platform don't provide it)
        // "none" means no filtering, so no language match is done, language = null in the config means that the
        // language value passed in the payload (from a mc_content for example) have to match the language in the
        // context (if present)
        if (!_.isEmpty(contextLanguage) && !_.isEmpty(language) && language !== 'none' && contextLanguage !== language) {
          send(msg);
          done();
          return;
        }
        // payload
        sendPayload({
          type: 'message',
          content: emoji.emojify(parsedMessage),
          chatId: chatId,
          messageId: messageId,
          inbound: false,
          fallback: fallback
        });
        done();
      } catch(e) {
        done(e);
      }
    });
  }

  registerType('chatbot-message', ChatBotMessage);
};