claudia-bot-builder-fb/lib/facebook/reply.js

Create chat-bots for various platforms and deploy to AWS Lambda quickly

'use strict';

const rp = require('minimal-request-promise'),
  breakText = require('../breaktext');

module.exports = function fbReply(recipient, message, fbAccessToken) {
  var sendSingle = function sendSingle (message) {
      if (typeof message === 'object' && typeof message.claudiaPause === 'number') {
        return new Promise(resolve => setTimeout(resolve, parseInt(message.claudiaPause, 10)));
      }
      const messageBody = {
        recipient: {
          id: recipient
        }
      };
      
      // Append special parameters to body of outbound POST
      if (message.hasOwnProperty('messaging_type')) {
        messageBody.messaging_type = message.messaging_type;
        delete message.messaging_type;
      }
      if (message.hasOwnProperty('message_tag')) {
        messageBody.tag = message.message_tag;
        delete message.message_tag;
      }
      if (message.hasOwnProperty('notification_type')) {
        messageBody.notification_type = message.notification_type;
        delete message.notification_type;
      }
      if (message.hasOwnProperty('sender_action')) {
        messageBody.sender_action = message.sender_action;
      } else {
        messageBody.message = message;
      }

      const options = {
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(messageBody)
      };

      return rp.post(`https://graph.facebook.com/v2.6/me/messages?access_token=${fbAccessToken}`, options);
    },
    sendAll = function () {
      if (!messages.length) {
        return Promise.resolve();
      } else {
        return sendSingle(messages.shift()).then(sendAll);
      }
    },
    messages = [];

  function breakTextAndReturnFormatted(message) {
    return breakText(message, 640).map(m => ({ text: m }));
  }

  if (typeof message === 'string') {
    messages = breakTextAndReturnFormatted(message);
  } else if (Array.isArray(message)) {
    message.forEach(msg => {
      if (typeof msg === 'string') {
        messages = messages.concat(breakTextAndReturnFormatted(msg));
      } else {
        messages.push(msg);
      }
    });
  } else if (!message) {
    return Promise.resolve();
  } else {
    messages = [message];
  }
  return sendAll();
};