MailOnline/VPAIDHTML5Client

'use strict';

function Subscriber() {
    this._subscribers = {};
}

Subscriber.prototype.subscribe = function subscribe(handler, eventName, context) {
    if (!this.isHandlerAttached(handler, eventName)) {
        this.get(eventName).push({handler: handler, context: context, eventName: eventName});
    }
};

Subscriber.prototype.unsubscribe = function unsubscribe(handler, eventName) {
    this._subscribers[eventName] = this.get(eventName).filter(function (subscriber) {
        return handler !== subscriber.handler;
    });
};

Subscriber.prototype.unsubscribeAll = function unsubscribeAll() {
    this._subscribers = {};
};

Subscriber.prototype.trigger = function(eventName, data) {
    var that = this;
    var subscribers = this.get(eventName)
        .concat(this.get('*'));

    subscribers.forEach(function (subscriber) {
        setTimeout(function () {
            if (that.isHandlerAttached(subscriber.handler, subscriber.eventName)) {
                subscriber.handler.call(subscriber.context, data);
            }
        }, 0);
    });
};

Subscriber.prototype.triggerSync = function(eventName, data) {
    var subscribers = this.get(eventName)
        .concat(this.get('*'));

    subscribers.forEach(function (subscriber) {
        subscriber.handler.call(subscriber.context, data);
    });
};

Subscriber.prototype.get = function get(eventName) {
    if (!this._subscribers[eventName]) {
        this._subscribers[eventName] = [];
    }
    return this._subscribers[eventName];
};

Subscriber.prototype.isHandlerAttached = function isHandlerAttached(handler, eventName) {
    return this.get(eventName).some(function(subscriber) {
        return handler === subscriber.handler;
    })
};

module.exports = Subscriber;