User:Acagastya/double.js

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$.when(mw.loader.using(['mediawiki.util']), $.ready).done(function() {
  if (
    mw.config.get('wgNamespaceNumber') == 0 ||
    mw.config.get('wgNamespaceNumber' == 2)
  ) {
    // only check links in mainspace and userspace (for userspace drafts)
    return;
  }
  const portletlink = mw.util.addPortletLink(
    'p-article-tools',
    '#',
    'Highlight duplicate links',
    'ca-findduplicatelinks',
    'Highlight duplicate links',
    'd'
  );
  $(portletlink).click(function(e) {
    e.preventDefault();
    // create a separate div surrounding the lead
    // first get the element immediately surrounding the article text. Unfortunately, MW doesn't seem to provide a non-fragile way for that.
    const content = '.mw-content-ltr';
    $(content).prepend(document.createElement('div'));
    const lead = $(content).children()[0];
    $(lead).attr('id', 'lead');
    $(content)
      .children()
      .each(function() {
        if (this.nodeName.toLowerCase() == 'h2') {
          return false;
        }
        if ($(this).attr('id') != 'lead') {
          $(lead).append(this);
        }
        return true;
      });

    // detect duplicate links
    mw.util.addCSS(
      '.duplicate-link { background: gold; color:#000; border: 1px solid red !important}'
    );
    const finddups = function() {
      const href = $(this).attr('href');
      if (href !== undefined && href.indexOf('#') !== 0) {
        if (seen[href]) {
          $(this).addClass('duplicate-link');
          count++;
          console.log(this.title);
        } else {
          seen[href] = true;
        }
      }
      return true;
    };
    // array to keep track of whether we've seen a link before
    const seen = [];
    let count = 0;
    mw.util.$content
      .find('p a')
      .not('#lead *, .infobox *, .navbox *, .mobile-only *')
      .each(finddups);
    seen.length = 0;
    mw.util.$content
      .find('#lead p a')
      .not('.infobox *, .navbox *, .sourceTemplate *, .mobile-only *')
      .each(finddups);
    if (count) alert(`${count} dublicate links found.`);
    count = 0;
  });
});