    /**
     * @file browser.js
     * @module browser
     */
    import * as Dom from './dom';
    import window from 'global/window';

    const USER_AGENT = window.navigator && window.navigator.userAgent || '';
    const webkitVersionMap = (/AppleWebKit\/([\d.]+)/i).exec(USER_AGENT);
    const appleWebkitVersion = webkitVersionMap ? parseFloat(webkitVersionMap.pop()) : null;

    /*
     * Device is an iPhone
     *
     * @type {Boolean}
     * @constant
     * @private
     */
    export const IS_IPAD = (/iPad/i).test(USER_AGENT);

    // The Facebook app's UIWebView identifies as both an iPhone and iPad, so
    // to identify iPhones, we need to exclude iPads.
    // http://artsy.github.io/blog/2012/10/18/the-perils-of-ios-user-agent-sniffing/
    export const IS_IPHONE = (/iPhone/i).test(USER_AGENT) && !IS_IPAD;
    export const IS_IPOD = (/iPod/i).test(USER_AGENT);
    export const IS_IOS = IS_IPHONE || IS_IPAD || IS_IPOD;

    export const IOS_VERSION = (function() {
      const match = USER_AGENT.match(/OS (\d+)_/i);

      if (match && match[1]) {
        return match[1];
      }
      return null;
    }());

    export const IS_ANDROID = (/Android/i).test(USER_AGENT);
    export const ANDROID_VERSION = (function() {
      // This matches Android Major.Minor.Patch versions
      // ANDROID_VERSION is Major.Minor as a Number, if Minor isn't available, then only Major is returned
      const match = USER_AGENT.match(/Android (\d+)(?:\.(\d+))?(?:\.(\d+))*/i);

      if (!match) {
        return null;
      }

      const major = match[1] && parseFloat(match[1]);
      const minor = match[2] && parseFloat(match[2]);

      if (major && minor) {
        return parseFloat(match[1] + '.' + match[2]);
      } else if (major) {
        return major;
      }
      return null;
    }());

    // Old Android is defined as Version older than 2.3, and requiring a webkit version of the android browser
    export const IS_OLD_ANDROID = IS_ANDROID && (/webkit/i).test(USER_AGENT) && ANDROID_VERSION < 2.3;
    export const IS_NATIVE_ANDROID = IS_ANDROID && ANDROID_VERSION < 5 && appleWebkitVersion < 537;

    export const IS_FIREFOX = (/Firefox/i).test(USER_AGENT);
    export const IS_EDGE = (/Edge/i).test(USER_AGENT);
    export const IS_CHROME = !IS_EDGE && (/Chrome/i).test(USER_AGENT);
    export const CHROME_VERSION = (function() {
      const match = USER_AGENT.match(/Chrome\/(\d+)/);

      if (match && match[1]) {
        return parseFloat(match[1]);
      }
      return null;
    }());
    export const IS_IE8 = (/MSIE\s8\.0/).test(USER_AGENT);
    export const IE_VERSION = (function() {
      const result = (/MSIE\s(\d+)\.\d/).exec(USER_AGENT);
      let version = result && parseFloat(result[1]);

      if (!version && (/Trident\/7.0/i).test(USER_AGENT) && (/rv:11.0/).test(USER_AGENT)) {
        // IE 11 has a different user agent string than other IE versions
        version = 11.0;
      }

      return version;
    }());

    export const IS_SAFARI = (/Safari/i).test(USER_AGENT) && !IS_CHROME && !IS_ANDROID && !IS_EDGE;
    export const IS_ANY_SAFARI = IS_SAFARI || IS_IOS;

    export const TOUCH_ENABLED = Dom.isReal() && (
      'ontouchstart' in window ||
      window.DocumentTouch &&
      window.document instanceof window.DocumentTouch);

    export const BACKGROUND_SIZE_SUPPORTED = (
      Dom.isReal() &&
      'backgroundSize' in window.document.createElement('video').style);