// Full-screen ad viewer: the advertiser URL fills the tab, a countdown runs in
// the top bar (paused whenever this tab loses focus), and once the dwell is
// done the server hands out a human check. Solve it and the view credits.
// The dwell floor is enforced on the SERVER clock; this UI cannot cheat it.
(() => {
  const $ = id => document.getElementById(id);
  const token = location.pathname.split('/').pop();
  let left = 5, timer = null, credited = false, asking = false;
  const setMsg = t => { $('vMsg').textContent = t; };
  async function j(url, body) {
    const r = await fetch(url, body
      ? { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body) }
      : undefined);
    return r.json();
  }
  function tick() {
    if (credited || asking) return;
    if (document.visibilityState !== 'visible' || !document.hasFocus()) {
      $('vTimer').classList.add('paused');
      $('vTimer').textContent = 'paused';
      setMsg('Come back to this tab to keep the countdown moving.');
      return;
    }
    $('vTimer').classList.remove('paused');
    left = Math.max(0, left - 0.25);
    $('vTimer').textContent = Math.ceil(left) + 's left';
    if (left <= 0) { clearInterval(timer); askChallenge(); }
  }
  async function askChallenge() {
    asking = true;
    $('vTimer').textContent = 'check';
    $('vTimer').classList.add('done');
    setMsg('One quick check to count the view:');
    let c = await j('/api/my/viewchallenge?token=' + token);
    if (c.early) { // server clock says not quite yet: wait it out and re-ask
      await new Promise(r => setTimeout(r, (c.wait || 1) * 1000 + 300));
      c = await j('/api/my/viewchallenge?token=' + token);
    }
    if (c.error) return fail(c.error);
    renderChallenge(c);
  }
  function renderChallenge(c) {
    $('vPrompt').textContent = 'Click the ' + c.prompt + ':';
    const w = $('vOpts');
    w.innerHTML = '';
    c.options.forEach((em, i) => {
      const b = document.createElement('button');
      b.type = 'button';
      b.textContent = em;
      b.addEventListener('click', () => answer(i));
      w.appendChild(b);
    });
    $('vCheck').classList.add('on');
  }
  async function answer(i) {
    const r = await j('/api/my/adview', { token, answer: i });
    if (r.error) {
      if (r.retry) {
        setMsg('Not that one — try again.');
        const c = await j('/api/my/viewchallenge?token=' + token);
        if (!c.error) return renderChallenge(c);
        return fail(c.error);
      }
      return fail(r.error);
    }
    credited = true;
    $('vCheck').classList.remove('on');
    $('vTimer').textContent = '✓ credited';
    const st = r.status || r;
    setMsg('View ' + st.views + ' of ' + st.target + ' counted for today.'
      + (st.views >= st.target && !st.claimed ? ' Head back and claim your credits.' : ''));
    $('vDone').classList.add('on');
    try { localStorage.setItem('iap-view-done', String(Date.now())); } catch (e) {}
  }
  function fail(msg) {
    credited = true; // stop the loop; this view is over either way
    if (timer) clearInterval(timer);
    $('vCheck').classList.remove('on');
    $('vTimer').textContent = '—';
    setMsg(msg);
    $('vDone').classList.add('on');
  }
  $('vClose').addEventListener('click', () => {
    window.close();
    setMsg('You can close this tab now.');
  });
  (async () => {
    const info = await j('/api/my/viewinfo?token=' + token);
    if (info.error) {
      $('vFrame').remove();
      const d = document.createElement('div');
      d.className = 'vfail';
      d.textContent = info.error;
      document.querySelector('.vw').appendChild(d);
      $('vDone').classList.add('on');
      $('vTimer').textContent = '—';
      setMsg('');
      return;
    }
    left = info.dwell || 5;
    $('vFrame').src = info.targetUrl;
    setMsg('Watching: ' + (info.adName || 'member ad') + ' — stay on this tab.');
    $('vTimer').textContent = left + 's left';
    timer = setInterval(tick, 250);
  })();
})();