API Builder Facebook Chat Bot (Echo)

fbwebhook.js

var Arrow = require('arrow');

var fbwebhook = Arrow.API.extend({
    group: 'webhooks',
    path: '/api/fbwebhook',
    method: 'GET',
    description: 'this is an api that shows how to handle requests from the FB chatbot',
    parameters: {
        'hub.mode': {
            description: 'hub.mode',
            optional: true
        },
        'hub.challenge': {
            description: 'hub.challenge',
            optional: true
        },
        'hub.verify_token': {
            description: 'hub.verify_token',
            optional: true
        }
    },
    action: function(req, resp, next) {
        console.log('fbwebhook - fbwebhook API called (GET)');

        if (req.query['hub.mode'] === 'subscribe' &&
            req.query['hub.verify_token'] === '<MY VERIFY TOKEN>') {
          console.log("Validating webhook");
          resp.response.status(200);
          resp.send(req.query['hub.challenge']);
        } else {
          console.error("Failed validation. Make sure the validation tokens match.");
          resp.response.status(403);
        }
        next();

    }
});
module.exports = fbwebhook;

fbwebhookp.js

var Arrow = require('arrow');
var request = require('request');

function sendGenericMessage(recipientId, messageText) {
  // To be expanded in later sections
}

function sendTextMessage(recipientId, messageText) {
  var messageData = {
    recipient: {
      id: recipientId
    },
    message: {
      text: messageText
    }
  };

  callSendAPI(messageData);
}

function callSendAPI(messageData) {
  request({
    uri: 'https://graph.facebook.com/v2.6/me/messages',
    qs: { access_token: '<MY ACCESS TOKEN>' },
    method: 'POST',
    json: messageData

  }, function (error, response, body) {
    if (!error && response.statusCode == 200) {
      var recipientId = body.recipient_id;
      var messageId = body.message_id;

      console.log("Successfully sent generic message with id %s to recipient %s",
        messageId, recipientId);
    } else {
      console.error("Unable to send message.");
      console.error(response);
      console.error(error);
    }
  });
}

function receivedMessage(event) {
  var senderID = event.sender.id;
  var recipientID = event.recipient.id;
  var timeOfMessage = event.timestamp;
  var message = event.message;

  console.log("Received message for user %d and page %d at %d with message:",
    senderID, recipientID, timeOfMessage);
  console.log(JSON.stringify(message));

  var messageId = message.mid;

  var messageText = message.text;
  var messageAttachments = message.attachments;

  if (messageText) {

    // If we receive a text message, check to see if it matches a keyword
    // and send back the example. Otherwise, just echo the text we received.
    switch (messageText) {
      case 'generic':
        sendGenericMessage(senderID);
        break;

      default:
        sendTextMessage(senderID, "The Chatbot detected that you wrote: "+messageText);
    }
  } else if (messageAttachments) {
    sendTextMessage(senderID, "Message with attachment received");
  }
}

var fbwebhookp = Arrow.API.extend({
    group: 'webhooks',
    path: '/api/fbwebhook',
    method: 'POST',
    description: 'this is an api that shows how to handle requests from the FB chatbot',
    parameters: {
        'object': {
            description: 'object',
            optional: true
        },
        'entry': {
            description: 'entry',
            optional: true
        }
    },
    action: function(req, resp, next) {
      console.log('fbwebhook - fbwebhook API called (POST)');


      var data = req.body;

      // Make sure this is a page subscription
      if (data.object === 'page') {

        // Iterate over each entry - there may be multiple if batched
        data.entry.forEach(function(entry) {
          var pageID = entry.id;
          var timeOfEvent = entry.time;

          // Iterate over each messaging event
          entry.messaging.forEach(function(event) {
            if (event.message) {
              receivedMessage(event);
            } else {
              console.log("Webhook received unknown event: ", event);
            }
          });
        });

        // Assume all went well.
        //
        // You must send back a 200, within 20 seconds, to let us know
        // you've successfully received the callback. Otherwise, the request
        // will time out and we will keep trying to resend.
        resp.response.status(200);
        next();
      } else {
        resp.response.status(200);
        next();
      }

    }
});
module.exports = fbwebhookp;