const rssUrl = window.__RSS_URL__;

const els = {
  feedTitle: document.getElementById('feedTitle'),
  headlineText: document.getElementById('headlineText'),
  headlineLink: document.getElementById('headlineLink'),
  clock: document.getElementById('clock'),
  articleTime: document.getElementById('articleTime'),
  progressFill: document.getElementById('progressFill'),
  bg: document.getElementById('bg'),
};

let items = [];
let idx = 0;
let timer = null;
let progressTimer = null;
let paused = false;

const SLIDE_MS = 6000;

function fmtClock(d) {
  const pad = (n) => String(n).padStart(2, '0');
  return `${pad(d.getDate())}-${pad(d.getMonth() + 1)}-${d.getFullYear()} ${pad(d.getHours())}:${pad(d.getMinutes())}`;
}

function tickClock() {
  els.clock.textContent = fmtClock(new Date());
}

function resetProgress() {
  if (progressTimer) {
    cancelAnimationFrame(progressTimer);
    progressTimer = null;
  }
  const start = performance.now();
  els.progressFill.style.width = '0%';

  const loop = (t) => {
    if (paused) return;
    const p = Math.min(1, (t - start) / SLIDE_MS);
    els.progressFill.style.width = `${(p * 100).toFixed(2)}%`;
    if (p < 1) progressTimer = requestAnimationFrame(loop);
  };
  progressTimer = requestAnimationFrame(loop);
}

function setBackground(item) {
  if (!els.bg) return;
  const url = item?.enclosure_url;
  if (url) {
    // Include the same gradient fallbacks as the CSS, but insert the image layer.
    // NOTE: No dark overlay on top of the image (requested).
    els.bg.style.backgroundImage = [
      `url("${url}")`,
      'radial-gradient(1200px 600px at 70% 20%, rgba(100, 150, 255, 0.35), transparent 55%)',
      'radial-gradient(900px 500px at 20% 70%, rgba(20, 255, 190, 0.16), transparent 55%)',
      'linear-gradient(130deg, var(--bg1), var(--bg2))',
    ].join(', ');
  } else {
    // Reset to stylesheet default.
    els.bg.style.backgroundImage = '';
  }
}

function setHeadline(i, animate = true) {
  if (!items.length) return;
  const item = items[i];

  setBackground(item);

  const node = els.headlineText;

  if (animate) {
    node.classList.remove('slide-in');
    node.classList.add('slide-out');
    setTimeout(() => {
      node.textContent = item.title || '(untitled)';
      els.headlineLink.href = item.link || '#';
      if (els.articleTime) els.articleTime.textContent = item.published || '—';
      node.classList.remove('slide-out');
      node.classList.add('slide-in');
    }, 280);
  } else {
    node.textContent = item.title || '(untitled)';
    els.headlineLink.href = item.link || '#';
    node.classList.add('slide-in');
  }

  resetProgress();
}

function next() {
  if (!items.length) return;
  idx = (idx + 1) % items.length;
  setHeadline(idx);
}

function prev() {
  if (!items.length) return;
  idx = (idx - 1 + items.length) % items.length;
  setHeadline(idx);
}

function startAuto() {
  stopAuto();
  timer = setInterval(() => {
    if (!paused) next();
  }, SLIDE_MS);
}

function stopAuto() {
  if (timer) clearInterval(timer);
  timer = null;
}

function togglePause() {
  paused = !paused;
  if (!paused) resetProgress();
}

async function loadFeed() {
  els.feedTitle.textContent = 'Loading…';
  els.headlineText.textContent = 'Loading headlines…';

  const apiUrl = `/api/feed?url=${encodeURIComponent(rssUrl)}`;
  const r = await fetch(apiUrl, { cache: 'no-store' });
  const data = await r.json();
  if (!r.ok) throw new Error(data?.error || 'Failed to load feed');

  els.feedTitle.textContent = data.title || 'News';
  items = (data.items || []).filter((x) => (x.title || '').trim().length > 0).slice(0, 5);
  if (!items.length) {
    els.headlineText.textContent = 'No items found.';
    return;
  }
  idx = 0;
  setHeadline(idx, false);
  startAuto();
}

function wireControls() {
  // Removed manual navigation controls. This is now a passive slideshow.
}

(async function init() {
  tickClock();
  setInterval(tickClock, 1000);
  wireControls();
  try {
    await loadFeed();
  } catch (e) {
    els.feedTitle.textContent = 'Error';
    els.headlineText.textContent = e?.message || 'Failed to load.';
  }
})();