(function(){
  function getSource(){
    try{
      let s=sessionStorage.getItem('ctb.src');
      if(s)return s;
      const p=new URLSearchParams(location.search);
      s=p.get('utm_source')||p.get('src')||'';
      if(!s&&document.referrer){try{const h=new URL(document.referrer).hostname;if(h&&h!==location.hostname)s=h}catch(e){}}
      s=s||'(direct)';
      sessionStorage.setItem('ctb.src',s);
      return s;
    }catch(e){return '(direct)'}
  }
  window.ctbGetSource=getSource;
  try{
    const p2=new URLSearchParams(location.search);
    const cid=p2.get('clickid')||p2.get('cid');
    if(cid&&!sessionStorage.getItem('ctb.clickid'))sessionStorage.setItem('ctb.clickid',cid.slice(0,80));
  }catch(e){}
  window.ctbGetClickId=function(){try{return sessionStorage.getItem('ctb.clickid')||''}catch(e){return ''}};
  const path=location.pathname.replace(/\/$/,'')||'/';
  const page=path==='/'?'bridge':(path==='/start'?'start':(path==='/training'?'training':(/^\/join\/\d+$/.test(path)?'join':null)));
  if(page)fetch('/api/public/track',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({event:page,source:getSource()})}).catch(()=>{});
})();