(function ($) {

function extlinkAttach(context) {
  // Strip the host name down, removing ports, subdomains, or www.
  var pattern = /^(([^\/:]+?\.)*)([^\.:]{4,})((\.[a-z]{1,4})*)(:[0-9]{1,5})?$/;
  var host = window.location.host.replace(pattern, '$3$4');
  var subdomain = window.location.host.replace(pattern, '$1');

  // Determine what subdomains are considered internal.
  if (Drupal.settings.extlink.extSubdomains) {
    var subdomains = "([^/]*\\.)?";
  }
  else if (subdomain == 'www.' || subdomain == '') {
    var subdomains = "(www\\.)?";
  }
  else {
    var subdomains = subdomain.replace(".", "\\.");
  }

  // Build regular expressions that define an internal link.
  var internal_link = new RegExp("^https?://" + subdomains + host, "i");

  // Extra internal link matching.
  var extInclude = false;
  if (Drupal.settings.extlink.extInclude) {
    extInclude = new RegExp(Drupal.settings.extlink.extInclude.replace(/\\/, '\\'), "i");
  }

  // Extra external link matching.
  var extExclude = false;
  if (Drupal.settings.extlink.extExclude) {
    extExclude = new RegExp(Drupal.settings.extlink.extExclude.replace(/\\/, '\\'), "i");
  }

  // Extra external link CSS selector exclusion.
  var extCssExclude = false;
  if (Drupal.settings.extlink.extCssExclude) {
    extCssExclude = Drupal.settings.extlink.extCssExclude;
  }

  // Extra external link CSS selector explicit.
  var extCssExplicit = false;
  if (Drupal.settings.extlink.extCssExplicit) {
    extCssExplicit = Drupal.settings.extlink.extCssExplicit;
  }

  // Find all links which are NOT internal and begin with http (as opposed
  // to ftp://, javascript:, etc. other kinds of links.
  // When operating on the 'this' variable, the host has been appended to
  // all links by the browser, even local ones.
  // In jQuery 1.1 and higher, we'd use a filter method here, but it is not
  // available in jQuery 1.0 (Drupal 5 default).
  var external_links = new Array();
  var mailto_links = new Array();
  $("a:not(." + Drupal.settings.extlink.extClass + ", ." + Drupal.settings.extlink.mailtoClass + "), area:not(." + Drupal.settings.extlink.extClass + ", ." + Drupal.settings.extlink.mailtoClass + ")", context).each(function(el) {
    try {
      var url = this.href.toLowerCase();
      if (url.indexOf('http') == 0 
        && ((!url.match(internal_link) && !(extExclude && url.match(extExclude))) || (extInclude && url.match(extInclude)))
        && !(extCssExclude && $(this).parents(extCssExclude).length > 0)
        && !(extCssExplicit && $(this).parents(extCssExplicit).length < 1)) {
        external_links.push(this);
      }
      // Do not include area tags with begin with mailto: (this prohibits
      // icons from being added to image-maps).
      else if (this.tagName != 'AREA' 
        && url.indexOf('mailto:') == 0 
        && !(extCssExclude && $(this).parents(extCssExclude).length > 0)
        && !(extCssExplicit && $(this).parents(extCssExplicit).length < 1)) {
        mailto_links.push(this);
      }
    }
    // IE7 throws errors often when dealing with irregular links, such as:
    // <a href="node/10"></a> Empty tags.
    // <a href="http://user:pass@example.com">example</a> User:pass syntax.
    catch(error) {
      return false;
    }
  });

  if (Drupal.settings.extlink.extClass) {
    // Apply the "ext" class to all links not containing images.
    if (parseFloat($().jquery) < 1.2) {
      $(external_links).not('[img]').addClass(Drupal.settings.extlink.extClass).each(function() { if ($(this).css('display') == 'inline') $(this).after('<span class=' + Drupal.settings.extlink.extClass + '></span>'); });
    }
    else {
      $(external_links).not($(external_links).find('img').parents('a')).addClass(Drupal.settings.extlink.extClass).each(function() { if ($(this).css('display') == 'inline') $(this).after('<span class=' + Drupal.settings.extlink.extClass + '></span>'); });
    }
  }

  if (Drupal.settings.extlink.mailtoClass) {
    // Apply the "mailto" class to all mailto links not containing images.
    if (parseFloat($().jquery) < 1.2) {
      $(mailto_links).not('[img]').addClass(Drupal.settings.extlink.mailtoClass).each(function() { if ($(this).css('display') == 'inline') $(this).after('<span class=' + Drupal.settings.extlink.mailtoClass + '></span>'); });
    }
    else {
      $(mailto_links).not($(mailto_links).find('img').parents('a')).addClass(Drupal.settings.extlink.mailtoClass).each(function() { if ($(this).css('display') == 'inline') $(this).after('<span class=' + Drupal.settings.extlink.mailtoClass + '></span>'); });
    }
  }

  if (Drupal.settings.extlink.extTarget) {
    // Apply the target attribute to all links.
    $(external_links).attr('target', Drupal.settings.extlink.extTarget);
  }

  Drupal.extlink = Drupal.extlink || {};

  // Set up default click function for the external links popup. This should be
  // overridden by modules wanting to alter the popup.
  Drupal.extlink.popupClickHandler = Drupal.extlink.popupClickHandler || function() {
    if (Drupal.settings.extlink.extAlert) {
      return confirm(Drupal.settings.extlink.extAlertText);
    }
   }
  
  $(external_links).click(function(e) {
    return Drupal.extlink.popupClickHandler(e);
  });
}

Drupal.behaviors.extlink = function(context) {
  extlinkAttach(context);
}

})(jQuery);