// search.js — minimal client-side search.
// Loads /search.json?lang=<locale>, builds an in-memory index, renders results
// as the user types in the header search box.
//
// Deliberately tiny — no FlexSearch dependency yet (the page set is small,
// linear scan with case-insensitive substring is plenty). Swap in FlexSearch
// or Lunr if the corpus grows past a few hundred pages.
(function () {
  const input = document.getElementById('search-input');
  const results = document.getElementById('search-results');
  if (!input || !results) return;

  const lang = document.documentElement.lang || 'en';
  let pages = [];
  let loaded = false;

  function loadIndex() {
    if (loaded) return Promise.resolve();
    return fetch('/search.json?lang=' + encodeURIComponent(lang))
      .then(r => r.json())
      .then(data => { pages = data || []; loaded = true; })
      .catch(() => { /* silent — search just stays empty */ });
  }

  function escapeHtml(s) {
    return String(s).replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c]));
  }

  function search(q) {
    if (!q || q.length < 2) return [];
    const needle = q.toLowerCase();
    const out = [];
    for (const p of pages) {
      const titleHit = p.title && p.title.toLowerCase().includes(needle);
      const summaryHit = p.summary && p.summary.toLowerCase().includes(needle);
      const bodyHit = p.body && p.body.toLowerCase().includes(needle);
      if (titleHit || summaryHit || bodyHit) {
        // crude scoring: title > summary > body
        const score = (titleHit ? 100 : 0) + (summaryHit ? 10 : 0) + (bodyHit ? 1 : 0);
        out.push({ ...p, score });
      }
      if (out.length >= 50) break;
    }
    out.sort((a, b) => b.score - a.score);
    return out.slice(0, 8);
  }

  function render(matches) {
    if (!matches.length) { results.hidden = true; results.innerHTML = ''; return; }
    results.innerHTML = matches.map(m =>
      `<li><a href="${escapeHtml(m.path)}">
        <span class="title">${escapeHtml(m.title)}</span>
        ${m.summary ? `<span class="summary">${escapeHtml(m.summary)}</span>` : ''}
      </a></li>`
    ).join('');
    results.hidden = false;
  }

  let timer = null;
  input.addEventListener('focus', loadIndex);
  input.addEventListener('input', () => {
    clearTimeout(timer);
    timer = setTimeout(() => {
      loadIndex().then(() => render(search(input.value.trim())));
    }, 80);
  });
  input.addEventListener('blur', () => {
    // Delay so click on a result registers before hiding.
    setTimeout(() => { results.hidden = true; }, 150);
  });
})();