(() => {
  const badges=document.querySelectorAll('[data-share-unread-count]');
  if(!badges.length)return;
  const countUrl=badges[0].dataset.countUrl;
  let running=false;
  const refresh=async()=>{
    if(running || document.visibilityState!=='visible')return;
    running=true;
    try{
      const response=await fetch(countUrl,{cache:'no-store',credentials:'same-origin'});
      if(!response.ok || response.redirected)return;
      const data=await response.json();
      badges.forEach(badge=>{badge.textContent=String(data.unread_shares);badge.hidden=!data.unread_shares});
    }catch(_){
      // Retain the last count until the next successful refresh.
    }finally{running=false}
  };
  document.addEventListener('visibilitychange',refresh);
  window.addEventListener('pageshow',refresh);
  window.addEventListener('focus',refresh);
  setInterval(refresh,15000);
  refresh();
})();