// Purpose: include this in your module to avoids adding dependencies on
// micro modules like 'global'

/* global window, global, document, navigator */
export const userAgent =
  typeof navigator !== 'undefined' && navigator.userAgent ? navigator.userAgent.toLowerCase() : '';

const window_ = typeof window !== 'undefined' ? window : global;
const global_ = typeof global !== 'undefined' ? global : window;
const document_ = typeof document !== 'undefined' ? document : {};

export {window_ as window, global_ as global, document_ as document};

/*
 * Detect whether passive option is supported by the current browser.
 * https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener
   #Safely_detecting_option_support
 */
let passiveSupported = false;

/* eslint-disable accessor-pairs, no-empty */
try {
  const options = {
    // This function will be called when the browser
    // attempts to access the passive property.
    get passive() {
      passiveSupported = true;
      return true;
    }
  };

  window_.addEventListener('test', null, options);
  window_.removeEventListener('test', null);
} catch (err) {
  passiveSupported = false;
}

export {passiveSupported};