// Same origin as the page (works for LAN IP / hostname). Avoid relative issues
// when the app is served with a non-root base path later.
const API_BASE = window.location.origin;
let queuePoll = null;

async function apiFetch(path, opts) {
  const res = await fetch(`${API_BASE}${path}`, {
    ...opts,
    headers: {
      Accept: 'application/json',
      ...(opts && opts.headers),
    },
  });
  if (!res.ok) {
    const text = await res.text().catch(() => '');
    throw new Error(text || `HTTP ${res.status}`);
  }
  const ct = res.headers.get('content-type') || '';
  if (ct.includes('application/json')) return res.json();
  return res.text();
}

// ── Tabs ────────────────────────────────────────────────────────────────────

function startQueuePoll() {
  stopQueuePoll();
  queuePoll = setInterval(renderQueue, 2000);
}

function stopQueuePoll() {
  if (queuePoll) { clearInterval(queuePoll); queuePoll = null; }
}

function switchTab(name) {
  document.querySelectorAll('.tab').forEach(t => {
    const on = t.dataset.tab === name;
    t.classList.toggle('active', on);
    t.setAttribute('aria-selected', on ? 'true' : 'false');
  });
  document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
  document.getElementById('tab-' + name).classList.add('active');
  if (name === 'queue') { renderQueue(); startQueuePoll(); }
  else stopQueuePoll();
}

// TUI-ish keys: 1/2 switch tabs, / focuses search
document.addEventListener('keydown', (e) => {
  if (e.target.matches('input, textarea')) return;
  if (e.key === '1') switchTab('search');
  else if (e.key === '2') switchTab('queue');
  else if (e.key === '/') {
    e.preventDefault();
    switchTab('search');
    searchInput.focus();
  }
});

document.querySelectorAll('.tab').forEach(tab => {
  tab.addEventListener('click', () => switchTab(tab.dataset.tab));
});

// ── Search ──────────────────────────────────────────────────────────────────

const searchInput = document.getElementById('searchInput');
const searchBtn = document.getElementById('searchBtn');
const searchResults = document.getElementById('searchResults');

async function doSearch() {
  const q = searchInput.value.trim();
  if (!q) return;
  searchResults.innerHTML = '<div class="spinner">Searching...</div>';
  try {
    const data = await apiFetch(`/api/search?q=${encodeURIComponent(q)}&limit=30`);
    renderSearchResults(data);
  } catch (err) {
    searchResults.innerHTML = `<div class="empty">Search failed: ${err.message}</div>`;
  }
}

searchBtn.addEventListener('click', doSearch);
searchInput.addEventListener('keydown', e => { if (e.key === 'Enter') doSearch(); });

function formatSize(bytes) {
  if (!bytes) return '0 B';
  const units = ['B', 'KB', 'MB', 'GB', 'TB'];
  let i = 0;
  let size = bytes;
  while (size >= 1024 && i < units.length - 1) { size /= 1024; i++; }
  return size.toFixed(i > 0 ? 1 : 0) + ' ' + units[i];
}

function renderSearchResults(files) {
  if (!files || files.length === 0) {
    searchResults.innerHTML = '<div class="empty">No results found.</div>';
    return;
  }
  searchResults.innerHTML = files.map(f => {
    const added = Boolean(addedIdents[f.ident]);
    return `
      <div class="result-item">
        <div class="result-info">
          <div class="result-name">${escapeHtml(f.name)}</div>
          <div class="result-meta">${formatSize(f.size)} · votes: ${f.votes}</div>
        </div>
        <button class="${added ? 'added' : ''}" data-ident="${f.ident}" data-name="${escapeAttr(f.name)}" data-size="${f.size}">
          ${added ? '[+]' : '[add]'}
        </button>
      </div>
    `;
  }).join('');

  searchResults.querySelectorAll('button:not(.added)').forEach(btn => {
    btn.addEventListener('click', async () => {
      const ident = btn.dataset.ident;
      const name = btn.dataset.name;
      const size = parseInt(btn.dataset.size);
      btn.disabled = true;
      btn.textContent = '[…]';
      try {
        await addDownload(ident, name, size);
        btn.classList.add('added');
        btn.textContent = '[+]';
      } catch (err) {
        btn.textContent = '[err]';
        setTimeout(() => { btn.disabled = false; btn.textContent = '[add]'; }, 2000);
      }
    });
  });
}

// ── Add download via new API route ──────────────────────────────────────────

const addedIdents = {};

async function addDownload(ident, name, size) {
  await apiFetch('/api/queue/add', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ ident, name, size }),
  });
  addedIdents[ident] = true;
}

// ── Queue ───────────────────────────────────────────────────────────────────

const queueList = document.getElementById('queueList');

async function fetchQueue() {
  return apiFetch('/api/queue');
}

function renderQueue() {
  fetchQueue().then(entries => {
    if (!entries || entries.length === 0) {
      queueList.innerHTML = '<div class="empty">Queue is empty.</div>';
      return;
    }
    queueList.innerHTML = entries.map(e => {
      const pct = Math.round((e.progress || 0) * 100);
      const downloaded = formatSize(e.progress * e.size);
      const total = formatSize(e.size);
      let fillClass = '';
      if (e.state === 'uploading') fillClass = 'done';
      else if (e.state === 'error') fillClass = 'error';
      else if (e.state === 'queuedDL') fillClass = 'queued';
      return `
        <div class="queue-item">
          <div class="queue-name">
            <span class="badge ${e.state}">${e.state}</span>
            <span>${escapeHtml(e.name)}</span>
            <button class="cancel-btn" data-hash="${e.hash}">[x]</button>
          </div>
          <div class="queue-stats">
            <span>${downloaded} / ${total}</span>
            <span>${pct}%</span>
          </div>
          <div class="queue-speed">${e.speed || ''}</div>
          <div class="progress-bar">
            <div class="progress-fill ${fillClass}" style="width:${pct}%"></div>
          </div>
        </div>
      `;
    }).join('');

    // Attach cancel handlers
    queueList.querySelectorAll('.cancel-btn').forEach(btn => {
      btn.addEventListener('click', async () => {
        const hash = btn.dataset.hash;
        btn.disabled = true;
        btn.textContent = '[…]';
        try {
          await apiFetch('/api/queue/cancel', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ hash }),
          });
        } catch {}
        renderQueue();
      });
    });
  }).catch(err => {
    queueList.innerHTML = `<div class="empty">Failed to load queue: ${err.message}</div>`;
  });
}

// On load, switch to queue tab if there are active downloads
fetchQueue().then(entries => {
  if (entries && entries.length > 0) switchTab('queue');
});

// Stop polling when tab hidden
document.addEventListener('visibilitychange', () => {
  if (document.hidden) stopQueuePoll();
  else {
    const active = document.querySelector('.tab.active');
    if (active && active.dataset.tab === 'queue') startQueuePoll();
  }
});

// ── Helpers ─────────────────────────────────────────────────────────────────

function escapeHtml(str) {
  const d = document.createElement('div');
  d.textContent = str;
  return d.innerHTML;
}

function escapeAttr(str) {
  return str.replace(/"/g, '&quot;').replace(/'/g, '&#39;');
}