var RTCBrowserType = require("../RTC/RTCBrowserType");

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

function AnalyticsAdapter() {
    this.browserName = RTCBrowserType.getBrowserName();
}

// some events may happen before init or implementation script download
// in this case we accumulate them in this array and send them on init
AnalyticsAdapter.eventsQueue = [];

// 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, will wait for loaded or dispose methods to be called.
// in the meantime we accumulate any events received
AnalyticsAdapter.prototype.sendEvent = function (action, data, label) {
    if (this.analytics === null || typeof this.analytics === 'undefined') {
        // missing this.analytics but have window implementation, let's use it
        if (window.Analytics) {
            this.loaded();
        }
        else {
            AnalyticsAdapter.eventsQueue.push({
                action: action,
                data: data,
                label: label
            });
            // stored, lets break here
            return;
        }
    }
    try {
        this.analytics.sendEvent(action, data, label, this.browserName);
    } catch (ignored) { // eslint-disable-line no-empty
    }
};

/**
 * Dispose analytics. Clears any available queue element and sets
 * NoopAnalytics to be used.
 */
AnalyticsAdapter.prototype.dispose = function () {
    this.analytics = new NoopAnalytics();
    AnalyticsAdapter.eventsQueue.length = 0;
};

/**
 * Loaded analytics script. Sens queued events.
 */
AnalyticsAdapter.prototype.loaded = function () {
    var AnalyticsImpl = window.Analytics || NoopAnalytics;

    this.analytics = new AnalyticsImpl();

    // new analytics lets send all events if any
    if (AnalyticsAdapter.eventsQueue.length) {
        AnalyticsAdapter.eventsQueue.forEach(function (event) {
            this.sendEvent(event.action, event.data, event.label);
        }.bind(this));
        AnalyticsAdapter.eventsQueue.length = 0;
    }
};

module.exports = new AnalyticsAdapter();