export default function throttle(fn, onThrottle, opts) {
  var context = this;
  var limit = opts.limit;
  var interval = opts.interval;
  var counter = 0;
  var timeoutId;
  var throttleZone = typeof Zone !== 'undefined' && Zone.root.fork({name: 'apm-throttle-zone'});

  return function () {
    counter++;

    if (typeof timeoutId === 'undefined') {
        var timeoutFn = function () {
          timeoutId = setTimeout(function () {
            counter = 0;
            timeoutId = undefined;
          }, interval);
        };

        if (throttleZone) {
          throttleZone.run(timeoutFn)
        } else {
          timeoutFn();
        }
    }

    if (counter > limit && typeof onThrottle === 'function') {
      return onThrottle.apply(context, arguments);
    } else {
      return fn.apply(context, arguments);
    }
  };
}