engagement.js

/**
 * sendEngagement - Sends an engagement message to all users.
 *
 * @param  {Object} req The request object.
 * @param  {Object} res The response object.
 */
export function sendEngagement(req, res) {
  let engagement = req.body.engagement;

  Bot.findOne({
    pageId: engagement.pageId
  }).exec().then(bot => {
    if (!bot) {
      return;
    }

    let engagementRef = new Engagement(engagement);

    engagementRef.save()
      .then(newEngagement  => {

        if(_.isEmpty(newEngagement.intents)) {
          return;
        }

        let initialResponse =
            newEngagement.intents.find(intent => intent.getStarted);

        Follower.find({
          pageId: engagementRef.pageId,
          subscriptionType: 'realtime'
        })
        .exec()
        .then(followers => {

          followers.forEach(follower => {
            // TODO: Needs to handle collection content
            let output = formatResponse(initialResponse.messages);

            const informationOject = {
              bot: bot,
              sender: follower.userId,
            };

            sendBotFacebookResponse(output, informationOject);
          });
        });

        return res.status(200).json(newEngagement);
      });
  });
}