() => {
  let PAPERS = [];
  let cur = null;
  let pile = [];        // indices into items, top of pile first
  let held = [];        // indices, newest first
  let items = [];       // [{text, kind}]
  let busy = false;
  let jid = null;
  let epoch = 0;
  let animLock = false;

  const $ = (id) => document.getElementById(id);
  function esc(t) { const d = document.createElement('div'); d.textContent = t; return d.innerHTML; }

  function shuffle(a) {
    for (let i = a.length - 1; i > 0; i--) {
      const j = Math.floor(Math.random() * (i + 1));
      [a[i], a[j]] = [a[j], a[i]];
    }
    return a;
  }

  function counter() {
    $('ivx-counter').textContent = pile.length + ' in the pile \u00b7 ' + held.length + ' held';
    $('ivx-gen').disabled = busy || held.length === 0;
    $('ivx-heldhead').hidden = held.length === 0;
  }

  function showTop() {
    const card = $('ivx-card');
    card.classList.remove('fly-left', 'fly-right');
    if (!pile.length) {
      card.querySelector('.kind').textContent = '';
      card.querySelector('.txt').textContent = held.length
        ? 'Pile empty. Write, or remove a held card to reconsider it.'
        : 'Pile empty.';
      counter();
      return;
    }
    const it = items[pile[0]];
    card.querySelector('.kind').textContent = it.kind;
    card.querySelector('.txt').textContent = it.text;
    counter();
  }

  function renderHeld() {
    const box = $('ivx-held');
    box.innerHTML = '';
    held.forEach((idx) => {
      const el = document.createElement('div');
      el.className = 'hcard';
      el.innerHTML = '<div class="txt">' + esc(items[idx].text) +
        '</div><button class="rm" title="remove, back into the pile">&#10005;</button>';
      el.querySelector('.rm').addEventListener('click', () => {
        held = held.filter(h => h !== idx);
        pile.push(idx);
        renderHeld(); showTop();
      });
      box.appendChild(el);
    });
    counter();
  }

  function verdict(dir) {
    if (animLock || !pile.length) return;
    animLock = true;
    const card = $('ivx-card');
    card.classList.add(dir === 'hold' ? 'fly-right' : 'fly-left');
    setTimeout(() => {
      const idx = pile.shift();
      if (dir === 'hold') { held.unshift(idx); renderHeld(); }
      else { pile.push(idx); }
      showTop();
      animLock = false;
    }, 240);
  }

  function pickPaper(pid) {
    cur = PAPERS.find(p => p.id === pid);
    epoch += 1;
    items = cur.rhetorical.map(t => ({ text: t, kind: 'rhetorical' }))
      .concat(cur.content.map(t => ({ text: t, kind: 'content' })));
    pile = shuffle(items.map((_, i) => i));
    held = [];
    document.querySelectorAll('#ivx-tabs button').forEach(b =>
      b.classList.toggle('on', b.dataset.pid === pid));
    $('ivx-ptitle').textContent = cur.title;
    $('ivx-out').hidden = true;
    $('ivx-empty').hidden = false;
    $('ivx-think').textContent = '';
    $('ivx-abs').textContent = '';
    $('ivx-bars').innerHTML = '';
    renderHeld(); showTop();
  }

  function setStatus(t) {
    const s = $('ivx-status');
    if (!t) { s.hidden = true; s.textContent = ''; return; }
    s.hidden = false; s.textContent = t;
  }

  function bars(sel, scores) {
    return sel.map((t, i) => {
      const s = scores[String(i + 1)] || scores[i + 1];
      const pct = s ? s / 5 * 100 : 0;
      const color = (s || 0) >= 4 ? 'var(--hold)' : (s || 0) === 3 ? '#d9a514' : '#cc4b4b';
      return '<div class="barrow"><div class="bartext" title="' + esc(t) + '">' + esc(t) +
        '</div><div class="bartrack"><div class="barfill" style="width:' + pct +
        '%;background:' + color + '"></div></div><div class="barnum">' + (s ? s + '/5' : '?') +
        '</div></div>';
    }).join('');
  }

  function bridgeCall(inputId, btnId, value) {
    const inp = document.querySelector('#' + inputId + ' textarea, #' + inputId + ' input');
    const setter = Object.getOwnPropertyDescriptor(window.HTMLTextAreaElement.prototype, 'value') ||
      Object.getOwnPropertyDescriptor(window.HTMLInputElement.prototype, 'value');
    setter.set.call(inp, value);
    inp.dispatchEvent(new Event('input', { bubbles: true }));
    setTimeout(() => document.querySelector('#' + btnId + ' button, button#' + btnId).click(), 30);
  }

  function outValue() {
    const el = document.querySelector('#ivx-bridge-out textarea, #ivx-bridge-out input');
    return el ? el.value : '';
  }

  async function restCall(name, args) {
    const r = await fetch('gradio_api/call/' + name, {
      method: 'POST', headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ data: args }) });
    const j = await r.json();
    const r2 = await fetch('gradio_api/call/' + name + '/' + j.event_id);
    const t = await r2.text();
    const lines = t.split('\n').filter(x => x.startsWith('data:'));
    if (!lines.length) throw new Error('no data from ' + name);
    return JSON.parse(lines[lines.length - 1].slice(5))[0];
  }

  function run() {
    if (busy || !cur || !held.length) return;
    busy = true;
    const myEpoch = epoch;
    const sel = held.map(i => items[i].text);
    jid = 'j' + Math.random().toString(36).slice(2);
    $('ivx-empty').hidden = true;
    $('ivx-out').hidden = false;
    $('ivx-thinkbox').open = true;
    $('ivx-think').textContent = '';
    $('ivx-abs').textContent = '';
    $('ivx-bars').innerHTML = '';
    setStatus('waking the model\u2026');
    counter();
    const lastRaw = outValue();
    bridgeCall('ivx-bridge-in', 'ivx-bridge-btn',
      JSON.stringify({ jid: jid, paper_id: cur.id, intuitions: sel }));
    const poll = setInterval(async () => {
      if (epoch !== myEpoch) { clearInterval(poll); finish(); return; }
      let raw = outValue();
      if (!raw || raw === lastRaw) {
        try { raw = await restCall('peek', [jid]); } catch (e) { /* keep polling */ }
      }
      if (!raw || raw === lastRaw) return;
      let ob;
      try { ob = JSON.parse(raw); } catch (e) { return; }
      if (ob.jid !== jid) return;
      if (ob.phase === 'error') { setStatus(ob.msg); clearInterval(poll); finish(); return; }
      if (ob.thinking) $('ivx-think').textContent = ob.thinking;
      if (ob.abstract) $('ivx-abs').textContent = ob.abstract;
      setStatus(ob.abstract ? 'writing the abstract\u2026' : 'thinking\u2026');
      const tb = $('ivx-think');
      tb.scrollTop = tb.scrollHeight;
      if (ob.phase === 'done') {
        $('ivx-bars').innerHTML = bars(sel, ob.scores || {});
        $('ivx-thinkbox').open = false;
        setStatus('done');
        clearInterval(poll); finish();
      }
    }, 800);
    function finish() { busy = false; counter(); }
  }

  async function init() {
    try {
      PAPERS = JSON.parse(await restCall('papers', []));
      const tabs = $('ivx-tabs');
      PAPERS.forEach(p => {
        const b = document.createElement('button');
        b.textContent = p.title.length > 42 ? p.title.slice(0, 40) + '\u2026' : p.title;
        b.dataset.pid = p.id;
        b.addEventListener('click', () => pickPaper(p.id));
        tabs.appendChild(b);
      });
      $('ivx-gen').addEventListener('click', run);
      $('ivx-pass').addEventListener('click', () => verdict('pass'));
      $('ivx-hold').addEventListener('click', () => verdict('hold'));
      document.addEventListener('keydown', (e) => {
        if (e.key === 'ArrowLeft') verdict('pass');
        if (e.key === 'ArrowRight') verdict('hold');
      });
      $('ivx-ver').textContent = 'VERSION';
      pickPaper(PAPERS[0].id);
    } catch (e) {
      const pt = $('ivx-ptitle');
      if (pt) pt.textContent = 'The page failed to load its data. Refresh to retry. (' + e.message + ')';
    }
  }

  const waiter = setInterval(() => {
    if (document.getElementById('ivx-app')) { clearInterval(waiter); init(); }
  }, 200);
}