// Shared state
const st = { tailLoading: false, atBottom: true, current: '#', earliest: null, sse: null, channels: [] };

function measureBars(){
  const hdr = document.querySelector('header.nav');
  const ftr = document.querySelector('footer');
  if(hdr){ document.documentElement.style.setProperty('--headerH', hdr.getBoundingClientRect().height+'px'); }
  if(ftr){ document.documentElement.style.setProperty('--footerH', ftr.getBoundingClientRect().height+'px'); }
}

function colorFor(nick){ let h=0; for(let i=0;i<nick.length;i++){ h=(h*31+nick.charCodeAt(i))>>>0 } return 'hsl('+(h%360)+',60%,'+(window.matchMedia('(prefers-color-scheme: dark)').matches? '70%':'35%')+')'; }
function escapeHtml(s){ return s.replace(/[&<>"]/g, c=>({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;'}[c])); }
function linkify(t){ return t.replace(/https?:\/\/\S+/g, function(u){ return '<a href="' + u + '" target="_blank" rel="noopener">' + u + '</a>'; }); }
function lineHTML(m){ const ts = '<span class=ts>[' + m.time + ']</span>'; const nick = '<b style="color:' + colorFor(m.author) + '">' + m.author + '</b>'; const body = escapeHtml(m.body); return ts + ' ' + nick + ': ' + linkify(body); }

function snapBottom(){ window.scrollTo(0, document.documentElement.scrollHeight); }
function pinBottomMulti(){ if(!st.atBottom) return; [0,16,64,200].forEach(d=> setTimeout(()=>requestAnimationFrame(snapBottom), d)); }

async function api(path, params){
  const url = new URL(path, window.location.origin);
  if(params && params.query){ Object.entries(params.query).forEach(([k,v])=>url.searchParams.set(k,v)); }
  const res = await fetch(url);
  if(!res.ok) throw new Error('HTTP '+res.status);
  const ct = res.headers.get('content-type')||'';
  if(ct.includes('application/json')) return res.json();
  return res.text();
}

function appendBatch(arr){ const el=document.getElementById('tail'); const frag=document.createDocumentFragment(); arr.forEach(m=>{ const div=document.createElement('div'); div.className='msg'; div.innerHTML=lineHTML(m); frag.appendChild(div); processLinks(div); }); el.appendChild(frag); pinBottomMulti(); }
function prependBatch(arr){ const el=document.getElementById('tail'); const oldTop=el.firstChild; const beforeTop = oldTop ? oldTop.getBoundingClientRect().top : 0; const frag=document.createDocumentFragment(); arr.forEach(m=>{ const div=document.createElement('div'); div.className='msg'; div.innerHTML=lineHTML(m); frag.appendChild(div); processLinks(div); }); el.insertBefore(frag, el.firstChild); if(oldTop){ const afterTop = oldTop.getBoundingClientRect().top; const delta = afterTop - beforeTop; window.scrollBy(0, delta); } }

function processLinks(scope){ const links = scope.querySelectorAll('a[href]:not([data-card])'); links.forEach(a=>{ a.setAttribute('data-card','1');
  // Fetch and render card
  fetch('/api/linkcard?url='+encodeURIComponent(a.href)).then(r=>r.json()).then(card=>{
    if(!card) return;
    if(card.title||card.description||card.image){
      const c=document.createElement('div'); c.className='card'; var html='';
      if(card.image){ html += '<div><img src="'+card.image+'" alt="" style="max-width:160px;max-height:120px;object-fit:cover;border-radius:.25rem"></div>'; }
      html += '<div style="flex:1;margin-left:.5rem">';
      if(card.title){ html += '<div style="font-weight:600">'+escapeHtml(card.title)+'</div>'; }
      if(card.description){ html += '<div style="opacity:.8">'+escapeHtml(card.description)+'</div>'; }
      html += '</div>';
      const row = document.createElement('div'); row.style.display='flex'; row.style.alignItems='flex-start'; row.style.gap='.5rem'; row.innerHTML = html;
      c.appendChild(row);
      c.querySelectorAll('img').forEach(img=> img.addEventListener('load', ()=> pinBottomMulti()));
      // Summary control row
      const ctrl = document.createElement('div'); ctrl.style.marginTop='.25rem';
      const btn = document.createElement('button'); btn.type='button'; btn.title='Summarize this link'; btn.textContent='\u25B6'; btn.style.padding='0 .4rem'; btn.style.fontSize='.9rem';
      const spinner = document.createElement('span'); spinner.textContent=''; spinner.style.marginLeft='.5rem';
      const sum = document.createElement('div'); sum.className='link-summary'; sum.style.whiteSpace='pre-wrap'; sum.style.marginTop='.25rem';
      btn.onclick = async ()=>{
        btn.disabled=true; spinner.textContent='…'; sum.textContent='';
        try{ const data = await api('/api/linksummary',{query:{url:a.href}}); sum.textContent = (data && data.summary) ? data.summary : '(no summary)'; }
        catch(e){ sum.textContent = 'error: '+e; }
        spinner.textContent=''; btn.disabled=false;
      };
      ctrl.appendChild(btn); ctrl.appendChild(spinner);
      c.appendChild(ctrl);
      c.appendChild(sum);
      a.parentNode.insertBefore(c, a.nextSibling);
    }
  }).catch(()=>{});
}); }

async function loadChannels(){ try{ const data = await api('/api/channels'); st.channels = data; renderChannels(); if(data.length>0){ selectChannel(data[0]); } } catch(e){} }
function renderChannels(){ const list=document.getElementById('nav-chans') || document.getElementById('brand-chans')?.querySelector('ul'); if(!list) return; list.innerHTML=''; st.channels.forEach(c=>{ const li=document.createElement('li'); const a=document.createElement('a'); a.href='#'; a.textContent=c + (c===st.current? ' ✓':''); a.onclick=(ev)=>{ev.preventDefault(); selectChannel(c);}; li.appendChild(a); list.appendChild(li); }); }

async function selectChannel(ch){ if(st.sse){ st.sse.close(); st.sse=null; } st.current=ch; renderChannels(); const el=document.getElementById('tail'); if(!el) return; el.textContent=''; const data = await api('/api/tail',{query:{channel:ch,limit:50}}); appendBatch(data); requestAnimationFrame(()=>{ snapBottom(); st.atBottom=true; }); st.earliest = data.length? data[0].time : null; startStream(); initScrollHandlers(); }
function initScrollHandlers(){ const el=document.getElementById('tail'); if(!el) return; const onScroll = async ()=>{ const nearBottom = (window.innerHeight + window.pageYOffset + 16) >= document.documentElement.scrollHeight; st.atBottom = nearBottom; const nearTop = window.pageYOffset <= 4; if(nearTop && st.earliest){ try{ const older = await api('/api/history',{query:{channel:st.current,before:st.earliest,limit:50}}); if(older.length){ prependBatch(older); st.earliest = older[0].time; } } catch(e){} } }; window.removeEventListener('scroll', st._scrollHandler || (()=>{})); st._scrollHandler = onScroll; window.addEventListener('scroll', onScroll, {passive:true}); }

function startStream(){ const el=document.getElementById('tail'); if(!el) return; const url=new URL('/api/stream', window.location.origin); url.searchParams.set('channel', st.current); const es=new EventSource(url); st.sse=es; es.onmessage=(ev)=>{ try{ const m=JSON.parse(ev.data); appendBatch([m]); }catch(e){} }; es.onerror=()=>{ es.close(); st.sse=null; setTimeout(startStream, 3000); } }

async function summarize(){ const ch=document.getElementById('channel'); const win=document.getElementById('window'); const push=document.getElementById('push'); const btn=document.getElementById('btn'); const out=document.getElementById('out'); if(!ch||!win||!btn||!out) return; btn.disabled=true; out.textContent=''; try{ const data = await api('/api/trigger',{query:{channel:ch.value,window:win.value||'6h',push:push && push.checked? '1':'0'}}); if(typeof data === 'string'){ out.textContent = data; } else { out.textContent = (data.summary||''); } } catch(e){ out.textContent = 'error: '+e; } btn.disabled=false; }

window.addEventListener('DOMContentLoaded', ()=>{
  if('scrollRestoration' in history){ history.scrollRestoration = 'manual'; }
  measureBars();
  loadChannels();
  if(document.getElementById('channel')){
    fetch('/api/channels').then(r=>r.json()).then(arr=>{ const sel=document.getElementById('channel'); arr.forEach(c=>{ const o=document.createElement('option'); o.value=c; o.textContent=c; sel.appendChild(o); }); }).catch(()=>{});
  }
});
window.addEventListener('load', measureBars);
window.addEventListener('resize', ()=>{ measureBars(); if(st.atBottom) pinBottomMulti(); });