var ScriptUtil = require('../util/ScriptUtil');

// Load the integration of a third-party analytics API such as Google Analytics.
// Since we cannot guarantee the quality of the third-party service (e.g. their
// server may take noticeably long time to respond), it is in our best interest
// (in the sense that the intergration of the analytics API is important to us
// but not enough to allow it to prevent people from joining a conference) to
// download the API asynchronously. Additionally, Google Analytics will download
// its implementation asynchronously anyway so it makes sense to append the
// loading on our side rather than prepend it.
if (config.disableThirdPartyRequests !== true) {
    ScriptUtil.loadScript(
            'analytics.js?v=1',
            /* async */ true,
            /* prepend */ false);
}

// NoopAnalytics
function NoopAnalytics() {}

NoopAnalytics.prototype.sendEvent = function () {};

// AnalyticsAdapter
function AnalyticsAdapter() {
    // XXX Since we asynchronously load the integration of the analytics API and
    // the analytics API may asynchronously load its implementation (e.g. Google
    // Analytics), we cannot make the decision with respect to which analytics
    // implementation we will use here and we have to postpone it i.e. we will
    // make a lazy decision.
}

AnalyticsAdapter.prototype.sendEvent = function (action, data) {
  var a = this.analytics;

  if (a === null || typeof a === 'undefined') {
      this.analytics = a = new (window.Analytics || NoopAnalytics)();
  }
  try {
      a.sendEvent.apply(a, arguments);
  } catch (ignored) {}
};

module.exports = new AnalyticsAdapter();