// Shared client-side news search over /search.json (no dependencies, no modules).
// Used by the header search (field + mobile reveal) and /search (full results).
// Focused-empty state per Baymard autocomplete guidance: recent searches (local
// only — localStorage, no network) plus the newest articles, never a void.
(function () {
  const RKEY = 'ctao-recent-searches';
  function recents() {
    try { return JSON.parse(localStorage.getItem(RKEY) || '[]'); } catch { return []; }
  }
  function remember(q) {
    q = (q || '').trim();
    if (q.length < 2) return;
    try {
      const r = [q, ...recents().filter((x) => x.toLowerCase() !== q.toLowerCase())].slice(0, 4);
      localStorage.setItem(RKEY, JSON.stringify(r));
    } catch { /* private mode — recents are a nicety */ }
  }

  window.newsSearch = function (opts) {
    const input = document.getElementById(opts.input);
    const list = document.getElementById(opts.list);
    const status = document.getElementById(opts.status);
    // Null-safe: a page may render only some search surfaces — bail silently
    // (returning a no-op) so one missing input can't kill later inits.
    if (!input || !list || !status) return function () {};
    let index = null;
    let timer;
    async function ensureIndex() {
      if (index) return index;
      try {
        index = await (await fetch('/search.json')).json();
      } catch {
        // Network hiccup: say so instead of failing silently; index stays
        // null so the next keystroke retries.
        status.textContent = 'Search is unavailable right now.';
        return null;
      }
      return index;
    }
    // First title match wrapped in <mark> (Starlight search pattern) — built
    // from text nodes, never innerHTML.
    function highlight(text, q) {
      const i = text.toLowerCase().indexOf(q);
      if (i < 0) return [text];
      const mark = document.createElement('mark');
      mark.textContent = text.slice(i, i + q.length);
      return [text.slice(0, i), mark, text.slice(i + q.length)];
    }
    function label(text) {
      const li = document.createElement('li');
      li.className = 'suggest-label';
      li.setAttribute('aria-hidden', 'true'); // the status line announces it
      li.textContent = text;
      return li;
    }
    function row(children, href, q) {
      const li = document.createElement('li');
      const a = document.createElement('a');
      a.href = href;
      if (q) a.dataset.q = q;
      a.append(...children);
      li.append(a);
      return li;
    }
    // Dropdowns close with a "Press Enter for all results" row — a real list
    // element (was a CSS ::after), aria-hidden like the group labels so
    // screen-reader exposure stays consistent (the status line announces).
    function hint() {
      if (!opts.dismiss || !list.firstChild) return;
      const li = document.createElement('li');
      li.className = 'suggest-hint';
      li.setAttribute('aria-hidden', 'true');
      li.textContent = 'Press Enter for all results';
      list.append(li);
    }
    // Focused-empty state: up to 4 recent queries, topped up to 5 rows with
    // the newest articles from the same index.
    async function idle() {
      if (input.value.trim().length >= 2) return;
      // Build off-DOM, swap atomically — clearing before the await shrinks the
      // page mid-flight and the browser clamps the scroll position ("jumps up").
      const frag = document.createDocumentFragment();
      const r = recents();
      if (r.length) {
        frag.append(label('Recent'));
        for (const term of r) frag.append(row([term], '/search?q=' + encodeURIComponent(term), term));
      }
      const idx = await ensureIndex();
      if (!idx) return;
      const fresh = idx.slice(0, Math.max(1, 5 - r.length));
      if (input.value.trim().length >= 2) return; // typed meanwhile — run() owns the list
      frag.append(label('Latest news'));
      for (const p of fresh) {
        const li = row([p.title], '/news/' + encodeURIComponent(p.slug));
        const small = document.createElement('small');
        small.textContent = p.date;
        li.append(small);
        frag.append(li);
      }
      list.replaceChildren(frag);
      hint();
      status.textContent = opts.hint || (r.length ? 'Showing recent searches and latest news' : 'Showing latest news');
    }
    async function run() {
      const q = input.value.trim().toLowerCase();
      if (q.length < 2) { list.replaceChildren(); idle(); return; }
      const idx = await ensureIndex();
      if (!idx) { list.replaceChildren(); return; }
      const hits = idx
        .filter((p) => (p.title + ' ' + p.description + ' ' + p.category).toLowerCase().includes(q))
        .slice(0, opts.limit);
      const unit = opts.unit || 'result';
      status.textContent = hits.length
        ? hits.length + ' ' + unit + (hits.length === 1 ? '' : 's') + ' for “' + input.value.trim() + '”'
        : 'No results for “' + input.value.trim() + '” — try a shorter or different term.';
      // Off-DOM build + atomic swap (no transient page-height collapse)
      const frag = document.createDocumentFragment();
      for (const p of hits) {
        const li = row(highlight(p.title, q), '/news/' + encodeURIComponent(p.slug));
        const small = document.createElement('small');
        small.textContent = p.date;
        li.append(small);
        frag.append(li);
      }
      // Dropdown only: an empty list would collapse (.suggest:empty) and the
      // panel would just vanish — show the no-results line sighted users too
      // (the status line above is sr-only in the header; /search shows a
      // visible notice instead).
      if (!hits.length && opts.dismiss) {
        const li = document.createElement('li');
        li.className = 'suggest-hint';
        li.setAttribute('aria-hidden', 'true'); // the status line announces it
        li.textContent = 'No results for “' + input.value.trim() + '”';
        frag.append(li);
      }
      list.replaceChildren(frag);
      hint();
    }
    input.addEventListener('input', () => { clearTimeout(timer); timer = setTimeout(run, 150); });
    input.addEventListener('focus', () => { if (input.value.trim().length < 2) idle(); });
    // Remember successful queries: Enter (form submit) and suggestion clicks
    if (input.form) input.form.addEventListener('submit', () => remember(input.value));
    list.addEventListener('click', (e) => {
      const a = e.target.closest && e.target.closest('a');
      remember((a && a.dataset.q) || input.value);
    });
    // Dropdown dismiss (opt-in — /search keeps its results list). The
    // suggestion list is a NON-MODAL popup (combobox-style; plain
    // Tab-reachable links, no roving arrow-key focus): interacting outside
    // the field+list closes it but the interaction is NOT swallowed —
    // unlike the modal header panels, which scrim-dismiss in Base.astro.
    if (opts.dismiss) {
      const box = input.closest('form') || input.parentElement;
      const hide = () => { clearTimeout(timer); list.replaceChildren(); status.textContent = ''; };
      document.addEventListener('pointerdown', (e) => { if (list.firstChild && !box.contains(e.target)) hide(); });
      // relatedTarget may be null mid-click on our own links — pointerdown covers that path
      box.addEventListener('focusout', (e) => { if (e.relatedTarget && !box.contains(e.relatedTarget)) hide(); });
      input.addEventListener('keydown', (e) => {
        if (e.key === 'Escape' && list.firstChild) { hide(); e.stopPropagation(); } // panel Escape stays a second step
      });
    }
    return run; // callers may run() immediately (e.g. /search?q=…)
  };
})();