/**
 * Copyright (c) 2016 The xterm.js authors. All rights reserved.
 * @license MIT
 */

interface INavigator {
  userAgent: string;
  language: string;
  platform: string;
}

// We're declaring a navigator global here as we expect it in all runtimes (node and browser), but
// we want this module to live in common.
declare const navigator: INavigator;

const isNode = (typeof navigator === 'undefined') ? true : false;
const userAgent = (isNode) ? 'node' : navigator.userAgent;
const platform = (isNode) ? 'node' : navigator.platform;

export const isFirefox = !!~userAgent.indexOf('Firefox');
export const isSafari = /^((?!chrome|android).)*safari/i.test(userAgent);
export const isMSIE = !!~userAgent.indexOf('MSIE') || !!~userAgent.indexOf('Trident');

// Find the users platform. We use this to interpret the meta key
// and ISO third level shifts.
// http://stackoverflow.com/q/19877924/577598
export const isMac = contains(['Macintosh', 'MacIntel', 'MacPPC', 'Mac68K'], platform);
export const isIpad = platform === 'iPad';
export const isIphone = platform === 'iPhone';
export const isMSWindows = contains(['Windows', 'Win16', 'Win32', 'WinCE'], platform);
export const isLinux = platform.indexOf('Linux') >= 0;

/**
 * Return if the given array contains the given element
 * @param arr The array to search for the given element.
 * @param el The element to look for into the array
 */
function contains(arr: any[], el: any): boolean {
  return arr.indexOf(el) >= 0;
}