let selectedMediaType    = 'video';
let selectedOutputFormat = 'mp4';
let pollTimer            = null;
let debounceTimer        = null;
let currentFetchController = null;

let availableFormats = { audio: [], video: [] };

const TEXT_DOWNLOADING  = "Descargando...";
const TEXT_DOWNLOAD = "Descargar";
const TEXT_COMPLETED = "Completed";
// ---------------------------------------------------------------------------
// Only fire /info when the input looks like a real supported URL.
// ---------------------------------------------------------------------------
const URL_RE = /^https?:\/\/(www\.)?(youtube\.com\/(watch|shorts|live)|youtu\.be|vimeo\.com|dailymotion\.com|twitch\.tv|soundcloud\.com)/i;

function looksLikeVideoUrl(str) {
  try { new URL(str); } catch { return false; }
  return URL_RE.test(str);
}

// ---------------------------------------------------------------------------
// Format chips
// ---------------------------------------------------------------------------
async function loadFormats() {
  try {
    const res = await fetch('/formats');
    availableFormats = await res.json();
  } catch {
    availableFormats = {
      audio: ['mp3','aac','m4a','opus','flac','wav','vorbis','alac'],
      video: ['mp4','mkv','webm','mov','avi','flv'],
    };
  }
  renderFormatChips();
}

function setMediaType(type) {
  selectedMediaType = type;
  document.querySelectorAll('.fmt-btn').forEach(b => b.classList.toggle('active', b.dataset.fmt === type));
  renderFormatChips();
}

function renderFormatChips() {
  const list = selectedMediaType === 'audio' ? availableFormats.audio : availableFormats.video;
  const def  = list[0] || (selectedMediaType === 'audio' ? 'mp3' : 'mp4');
  selectedOutputFormat = def;
  document.getElementById('format-chips').innerHTML = list.map(f =>
    `<button class="chip${f === def ? ' selected' : ''}" onclick="selectFormat(this,'${f}')">${f}</button>`
  ).join('');
}

function selectFormat(el, f) {
  document.querySelectorAll('#format-chips .chip').forEach(c => c.classList.remove('selected'));
  el.classList.add('selected');
  selectedOutputFormat = f;
}

// ---------------------------------------------------------------------------
// UI helpers
// ---------------------------------------------------------------------------
function fmtDuration(s) {
  if (!s) return '';
  const h = Math.floor(s / 3600), m = Math.floor((s % 3600) / 60), sec = s % 60;
  return h
    ? `${h}:${String(m).padStart(2,'0')}:${String(sec).padStart(2,'0')}`
    : `${m}:${String(sec).padStart(2,'0')}`;
}

function showStatus(msg, type) {
  const el = document.getElementById('status-msg');
  el.textContent = msg; el.className = type;
}

function clearStatus() {
  const el = document.getElementById('status-msg');
  el.className = ''; el.textContent = '';
}

// ---------------------------------------------------------------------------
// Auto-fetch video info (debounced, abortable, URL-guarded)
// ---------------------------------------------------------------------------
async function fetchInfo() {
  const url = document.getElementById('url-input').value.trim();

  if (!looksLikeVideoUrl(url)) {
    document.getElementById('info-box').classList.remove('visible');
    clearStatus();
    return;
  }

  if (currentFetchController) currentFetchController.abort();
  currentFetchController = new AbortController();

  clearStatus();
  document.getElementById('info-box').classList.remove('visible');
  document.getElementById('url-spinner').classList.add('active');

  try {
    const res  = await fetch('/info', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ url }),
      signal: currentFetchController.signal,
    });
    const data = await res.json();

    if (data.error) { showStatus('⚠ ' + data.error, 'error'); return; }

    document.getElementById('thumb').src              = data.thumbnail || '';
    document.getElementById('vid-title').textContent  = data.title || 'Unknown';
    document.getElementById('vid-meta').textContent   =
      [data.uploader, fmtDuration(data.duration)].filter(Boolean).join(' · ');
    document.getElementById('info-box').classList.add('visible');

  } catch (e) {
    if (e.name !== 'AbortError') showStatus('⚠ Could not reach server.', 'error');
  } finally {
    document.getElementById('url-spinner').classList.remove('active');
  }
}

// ---------------------------------------------------------------------------
// Download
// ---------------------------------------------------------------------------
async function startDownload() {
  const url = document.getElementById('url-input').value.trim();
  if (!url) { showStatus('⚠ Please enter a URL.', 'error'); return; }
  clearStatus();

  if (currentFetchController) { currentFetchController.abort(); currentFetchController = null; }
  document.getElementById('url-spinner').classList.remove('active');

  const btn = document.getElementById('start-btn');
  btn.disabled  = true;
  btn.innerHTML = '<span class="spin"></span> Starting...';

  document.getElementById('download-btn-wrap').style.display = 'none';
  document.getElementById('progress-box').classList.add('visible');
  document.getElementById('progress-label').textContent = TEXT_DOWNLOADING;
  document.getElementById('progress-fill').style.width  = '0%';
  document.getElementById('prog-pct').textContent       = '0%';
  document.getElementById('prog-speed').textContent     = '';

  try {
    const res  = await fetch('/download', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ url, format: selectedMediaType, chosen_format: selectedOutputFormat }),
    });
    const data = await res.json();
    if (data.error) { showStatus('⚠ ' + data.error, 'error'); resetBtn(); return; }
    pollStatus(data.job_id);
  } catch {
    showStatus('⚠ Server error.', 'error');
    resetBtn();
  }
}

function pollStatus(jobId) {
  if (pollTimer) clearInterval(pollTimer);
  pollTimer = setInterval(async () => {
    try {
      const data = await (await fetch('/status/' + jobId)).json();

      if (data.progress !== undefined) {
        document.getElementById('progress-fill').style.width = data.progress + '%';
        document.getElementById('prog-pct').textContent      = data.progress + '%';
        if (data.speed) document.getElementById('prog-speed').textContent =
          data.speed + (data.eta ? ' · ETA ' + data.eta : '');
      }

      if (data.status === 'done') {
        clearInterval(pollTimer);
        document.getElementById('progress-label').textContent = TEXT_COMPLETED;
        document.getElementById('prog-speed').textContent     = '';
        showStatus('✓ Download ready: ' + (data.title || 'file'), 'success');
        document.getElementById('dl-link').href              = '/file/' + jobId;
        document.getElementById('dl-link').download          = true;
        document.getElementById('download-btn-wrap').style.display = 'flex';
        resetBtn();
      } else if (data.status === 'error') {
        clearInterval(pollTimer);
        showStatus('⚠ ' + (data.error || 'Unknown error'), 'error');
        document.getElementById('progress-box').classList.remove('visible');
        resetBtn();
      }
    } catch { /* ignore transient poll errors */ }
  }, 800);
}

function resetBtn() {
  const btn = document.getElementById('start-btn');
  btn.disabled = false; btn.innerHTML = TEXT_DOWNLOAD;
}

// ---------------------------------------------------------------------------
// Event listeners
// ---------------------------------------------------------------------------
document.getElementById('url-input').addEventListener('input', () => {
  clearTimeout(debounceTimer);
  debounceTimer = setTimeout(fetchInfo, 1200);
});

document.getElementById('url-input').addEventListener('paste', () => {
  clearTimeout(debounceTimer);
  debounceTimer = setTimeout(fetchInfo, 400);
});

loadFormats();