'use strict';

var utils = require('./../utils');

module.exports = (
  utils.isStandardBrowserEnv() ?

  // Standard browser envs have full support of the APIs needed to test
  // whether the request URL is of the same origin as current location.
  (function standardBrowserEnv() {
    var msie = /(msie|trident)/i.test(navigator.userAgent);
    var urlParsingNode = document.createElement('a');
    var originURL;

    /**
    * Parse a URL to discover it's components
    *
    * @param {String} url The URL to be parsed
    * @returns {Object}
    */
    function resolveURL(url) {
      var href = url;

      if (msie) {
        // IE needs attribute set twice to normalize properties
        urlParsingNode.setAttribute('href', href);
        href = urlParsingNode.href;
      }

      urlParsingNode.setAttribute('href', href);

      // urlParsingNode provides the UrlUtils interface - http://url.spec.whatwg.org/#urlutils
      return {
        href: urlParsingNode.href,
        protocol: urlParsingNode.protocol ? urlParsingNode.protocol.replace(/:$/, '') : '',
        host: urlParsingNode.host,
        search: urlParsingNode.search ? urlParsingNode.search.replace(/^\?/, '') : '',
        hash: urlParsingNode.hash ? urlParsingNode.hash.replace(/^#/, '') : '',
        hostname: urlParsingNode.hostname,
        port: urlParsingNode.port,
        pathname: (urlParsingNode.pathname.charAt(0) === '/') ?
                  urlParsingNode.pathname :
                  '/' + urlParsingNode.pathname
      };
    }

    originURL = resolveURL(window.location.href);

    /**
    * Determine if a URL shares the same origin as the current location
    *
    * @param {String} requestURL The URL to test
    * @returns {boolean} True if URL shares the same origin, otherwise false
    */
    return function isURLSameOrigin(requestURL) {
      var parsed = (utils.isString(requestURL)) ? resolveURL(requestURL) : requestURL;
      return (parsed.protocol === originURL.protocol &&
            parsed.host === originURL.host);
    };
  })() :

  // Non standard browser envs (web workers, react-native) lack needed support.
  (function nonStandardBrowserEnv() {
    return function isURLSameOrigin() {
      return true;
    };
  })()
);