counter.js

const Firebase = require('firebase');

const firebase = new Firebase("https://fiery-inferno-7517.firebaseio.com/");
const users = [];

const stats = {
    totalNumberOfEvents: -4,
    totalNumberOfSpheroEvents: -1,
    totalNumberOfGameEvents: -1,
    totalNumberOfLampEvents: -1,
    totalNumberOfUserEvents: -1
};


if (require.main === module) {

    console.log("Start");

    firebase.child("gadgets/sphero").on("value", function (snapshot) {
        if (snapshot.val()) {
            stats.totalNumberOfSpheroEvents++;
            stats.totalNumberOfEvents++;
            firebase.child("stats").set(stats);
        }
    });

    firebase.child("gadgets/game").on("value", function (snapshot) {
        if (snapshot.val()) {
            stats.totalNumberOfGameEvents++;
            stats.totalNumberOfEvents++;
            firebase.child("stats").set(stats);
        }
    });

    firebase.child("gadgets/lamp").on("value", function (snapshot) {
        if (snapshot.val()) {
            stats.totalNumberOfLampEvents++;
            stats.totalNumberOfEvents++;
            firebase.child("stats").set(stats);
        }
    });

    firebase.child("users").on("value", function (snapshot) {
        if (snapshot.val()) {
            stats.totalNumberOfEvents++;
            stats.totalNumberOfUserEvents++;
            firebase.child("stats").set(stats);
        }
    });
}