/************************************************************************
 * This file is part of EspoCRM.
 *
 * EspoCRM - Open Source CRM application.
 * Copyright (C) 2014-2023 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
 * Website: https://www.espocrm.com
 *
 * EspoCRM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * EspoCRM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
 ************************************************************************/

/** @module broadcast-channel */

class BroadcastChannel {

    constructor() {
        this.object = null;

        if (window.BroadcastChannel) {
            this.object = new window.BroadcastChannel('app');
        }
    }

    /**
     * Post a message.
     *
     * @param {string} message A message.
     */
    postMessage(message) {
        if (!this.object) {
            return;
        }

        this.object.postMessage(message);
    }

    /**
     * @callback module:broadcast-channel~callback
     *
     * @param {MessageEvent} event An event. A message can be obtained from the `data` property.
     */

    /**
     * Subscribe to a message.
     *
     * @param {module:broadcast-channel~callback} callback A callback.
     */
    subscribe(callback) {
        if (!this.object) {
            return;
        }

        this.object.addEventListener('message', callback);
    }
}

export default BroadcastChannel;
