text: /**
   * @license Copyright (c) 2003-2021, CKSource - Frederico Knabben. All rights reserved.
   * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
   */
  
  /* globals navigator:false */
  
  /**
   * @module utils/env
   */
  
  const userAgent = navigator.userAgent.toLowerCase();
  
  /**
   * A namespace containing environment and browser information.
   *
   * @namespace
   */
  const env = {
  	/**
  	 * Indicates that the application is running on Macintosh.
  	 *
  	 * @static
  	 * @type {Boolean}
  	 */
  	isMac: isMac( userAgent ),
  
  	/**
  	 * Indicates that the application is running in Firefox (Gecko).
  	 *
  	 * @static
  	 * @type {Boolean}
  	 */
  	isGecko: isGecko( userAgent ),
  
  	/**
  	 * Indicates that the application is running in Safari.
  	 *
  	 * @static
  	 * @type {Boolean}
  	 */
  	isSafari: isSafari( userAgent ),
  
  	/**
  	 * Indicates that the application is running on Android mobile device.
  	 *
  	 * @static
  	 * @type {Boolean}
  	 */
  	isAndroid: isAndroid( userAgent ),
  
  	/**
  	 * Indicates that the application is running in a browser using the Blink engine.
  	 *
  	 * @static
  	 * @type {Boolean}
  	 */
  	isBlink: isBlink( userAgent ),
  
  	/**
  	 * Environment features information.
  	 *
  	 * @memberOf module:utils/env~env
  	 * @namespace
  	 */
  	features: {
  		/**
  		 * Indicates that the environment supports ES2018 Unicode property escapes — like `\p{P}` or `\p{L}`.
  		 * More information about unicode properties might be found
  		 * [in Unicode Standard Annex #44](https://www.unicode.org/reports/tr44/#GC_Values_Table).
  		 *
  		 * @type {Boolean}
  		 */
  		isRegExpUnicodePropertySupported: isRegExpUnicodePropertySupported()
  	}
  };
  
  export default env;
  
  /**
   * Checks if User Agent represented by the string is running on Macintosh.
   *
   * @param {String} userAgent **Lowercase** `navigator.userAgent` string.
   * @returns {Boolean} Whether User Agent is running on Macintosh or not.
   */
  export function isMac( userAgent ) {
  	return userAgent.indexOf( 'macintosh' ) > -1;
  }
  
  /**
   * Checks if User Agent represented by the string is Firefox (Gecko).
   *
   * @param {String} userAgent **Lowercase** `navigator.userAgent` string.
   * @returns {Boolean} Whether User Agent is Firefox or not.
   */
  export function isGecko( userAgent ) {
  	return !!userAgent.match( /gecko\/\d+/ );
  }
  
  /**
   * Checks if User Agent represented by the string is Safari.
   *
   * @param {String} userAgent **Lowercase** `navigator.userAgent` string.
   * @returns {Boolean} Whether User Agent is Safari or not.
   */
  export function isSafari( userAgent ) {
  	return userAgent.indexOf( ' applewebkit/' ) > -1 && userAgent.indexOf( 'chrome' ) === -1;
  }
  
  /**
   * Checks if User Agent represented by the string is Android mobile device.
   *
   * @param {String} userAgent **Lowercase** `navigator.userAgent` string.
   * @returns {Boolean} Whether User Agent is Safari or not.
   */
  export function isAndroid( userAgent ) {
  	return userAgent.indexOf( 'android' ) > -1;
  }
  
  /**
   * Checks if User Agent represented by the string is Blink engine.
   *
   * @param {String} userAgent **Lowercase** `navigator.userAgent` string.
   * @returns {Boolean} Whether User Agent is Blink engine or not.
   */
  export function isBlink( userAgent ) {
  	// The Edge browser before switching to the Blink engine used to report itself as Chrome (and "Edge/")
  	// but after switching to the Blink it replaced "Edge/" with "Edg/".
  	return userAgent.indexOf( 'chrome/' ) > -1 && userAgent.indexOf( 'edge/' ) < 0;
  }
  
  /**
   * Checks if the current environment supports ES2018 Unicode properties like `\p{P}` or `\p{L}`.
   * More information about unicode properties might be found
   * [in Unicode Standard Annex #44](https://www.unicode.org/reports/tr44/#GC_Values_Table).
   *
   * @returns {Boolean}
   */
  export function isRegExpUnicodePropertySupported() {
  	let isSupported = false;
  
  	// Feature detection for Unicode properties. Added in ES2018. Currently Firefox does not support it.
  	// See https://github.com/ckeditor/ckeditor5-mention/issues/44#issuecomment-487002174.
  
  	try {
  		// Usage of regular expression literal cause error during build (ckeditor/ckeditor5-dev#534).
  		isSupported = 'ć'.search( new RegExp( '[\\p{L}]', 'u' ) ) === 0;
  	} catch ( error ) {
  		// Firefox throws a SyntaxError when the group is unsupported.
  	}
  
  	return isSupported;
  }
  