messenger_botkit_public_profile.js

/*
  Example Facebook Messenger app that pulls the user's public profile and echoes back any messages sent
  with the user's first and last name. This one uses BotKit.
  
  So if I sent the bot "Good morning!" it will reply to me with "Echoing message from Jeff Israel: Good morning!"
*/

const reqPromise = require('request-promise');
const graphApiUrl = 'https://graph.facebook.com/v2.6';

if (!process.env.MESSENGER_PAGE_ACCESS_TOKEN) {
  console.log('Error: Specify page_token in environment');
  process.exit(1);
}

if (!process.env.MESSENGER_VALIDATION_TOKEN) {
  console.log('Error: Specify verify_token in environment');
  process.exit(1);
}

const Botkit = require('botkit');

const crypto = require("crypto");
const os = require('os');

const controller = Botkit.facebookbot({
  debug: false,
  access_token: process.env.MESSENGER_PAGE_ACCESS_TOKEN,
  verify_token: process.env.MESSENGER_VALIDATION_TOKEN,
});

const bot = controller.spawn({});

controller.setupWebserver(process.env.PORT || 3000, (err, webserver) => {
  controller.createWebhookEndpoints(webserver, bot, () => {
  console.log('ONLINE!');
  });
});

// webserver is an express instance, why not use it!
controller.webserver.get('/', (req, res) => {
  res.send('Hello!');
});

// to supress the debug messages
controller.on('tick', (bot, event) => {});

controller.on('message_received', (bot, message) => {

  if (message.text.startsWith('Echoing message from ')) {
    // hack to ignore our echoed messages
    return false;
  }

  // setup options for call to Graph API for public profile
  const options = {
    qs: {
      access_token: process.env.MESSENGER_PAGE_ACCESS_TOKEN,
      fields: 'first_name,last_name,profile_pic,locale,timezone,gender'
    },
    url: `${graphApiUrl}/${message.user}`
  };

  // call the Graph API!
  reqPromise(options)
    .then((jsonString) => {
      const jsonObj = JSON.parse(jsonString);
      const reply = `Echoing message from ${jsonObj.first_name} ${jsonObj.last_name}: ${message.text}`;
      bot.reply(message, reply);
    })
    .catch((err) => {
      // this will throw a 400 when called on echo messages
      // it will try to lookup the FB profile for the page, which is not a valid action
    });

});