(function() {
  'use strict';

  var root = this;

  var Countdown = function(duration, onTick, onComplete) {
    var secondsLeft = Math.round(duration)
        , tick = function() {
          if (secondsLeft > 0) {
              onTick(secondsLeft);
              secondsLeft -= 1;
          } else {
              clearInterval(interval);
              onComplete();
          }
        }
        // Setting the interval, by call tick and passing through this via a self-calling function wrap.
        , interval = setInterval(
          (function(self){
            return function() { tick.call(self); };
          })(this), 1000
        );

    // First tick.
    tick.call(this);

    return {
      abort: function() {
        clearInterval(interval);
      }

      , getRemainingTime: function() {
        return secondsLeft;
      }
    };
  };

  if (typeof exports !== 'undefined') module.exports = exports = Countdown;
  else root.Countdown = Countdown;

}).call(this);