/* ════════════════════════════════════════════════════════════════════════
   Minimal interactions. MOTION_INTENSITY 3: hover + a single subtle reveal.
   No custom cursor, no particle canvas, no typewriter, no scroll listeners.
   ════════════════════════════════════════════════════════════════════════ */

/* ─── Navbar border on scroll (IntersectionObserver, not a scroll listener) */
(function () {
  const nav = document.getElementById('navbar');
  const sentinel = document.getElementById('nav-sentinel');
  if (!nav || !sentinel) return;
  const io = new IntersectionObserver(
    ([entry]) => nav.classList.toggle('scrolled', !entry.isIntersecting),
    { threshold: 0 }
  );
  io.observe(sentinel);
})();

/* ─── Scrollspy: highlight the nav link for the section in view ───────── */
(function () {
  const links = Array.from(document.querySelectorAll('#navbar a[href*="#"]'));
  if (!links.length || !('IntersectionObserver' in window)) return;
  const map = {};
  links.forEach((a) => {
    const id = (a.getAttribute('href') || '').split('#')[1];
    if (id) (map[id] = map[id] || []).push(a);
  });
  const sections = Object.keys(map)
    .map((id) => document.getElementById(id))
    .filter(Boolean);
  if (!sections.length) return;

  const io = new IntersectionObserver((entries) => {
    entries.forEach((e) => {
      if (!e.isIntersecting) return;
      links.forEach((a) => a.classList.remove('active'));
      (map[e.target.id] || []).forEach((a) => a.classList.add('active'));
    });
  }, { rootMargin: '-45% 0px -50% 0px', threshold: 0 });
  sections.forEach((s) => io.observe(s));
})();

/* ─── Mobile menu toggle ─────────────────────────────────────────────── */
(function () {
  const btn  = document.getElementById('menu-btn');
  const menu = document.getElementById('mobile-menu');
  if (!btn || !menu) return;
  btn.addEventListener('click', () => {
    const hidden = menu.classList.toggle('hidden');
    btn.setAttribute('aria-expanded', String(!hidden));
  });
  menu.querySelectorAll('a').forEach(a => a.addEventListener('click', () => menu.classList.add('hidden')));
})();

/* ─── Scroll reveal (one subtle entry per element, then unobserve) ────── */
(function () {
  const els = document.querySelectorAll('.reveal');
  if (!els.length) return;
  if (!('IntersectionObserver' in window)) {
    els.forEach(el => el.classList.add('visible'));
    return;
  }
  const io = new IntersectionObserver((entries) => {
    entries.forEach(e => {
      if (e.isIntersecting) { e.target.classList.add('visible'); io.unobserve(e.target); }
    });
  }, { threshold: 0.12, rootMargin: '0px 0px -8% 0px' });
  els.forEach(el => io.observe(el));
})();

/* ─── Contact form (AJAX, JSON → /contact) ───────────────────────────── */
(function () {
  const form = document.getElementById('contact-form');
  if (!form) return;
  const status = document.getElementById('contact-status');

  form.addEventListener('submit', async (e) => {
    e.preventDefault();
    const data = Object.fromEntries(new FormData(form));
    const btn  = form.querySelector('[type="submit"]');
    if (btn) btn.disabled = true;

    const setStatus = (msg, cls) => { if (status) { status.textContent = msg; status.className = 'mt-1 text-sm ' + cls; } };

    try {
      const res = await fetch('/contact', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(data),
      });
      if (res.ok) {
        setStatus(form.dataset.successMsg || 'Sent.', 'text-emerald-600');
        form.reset();
      } else {
        setStatus(form.dataset.errorMsg || 'Something went wrong.', 'text-red-600');
      }
    } catch {
      setStatus(form.dataset.errorMsg || 'Network error.', 'text-red-600');
    } finally {
      if (btn) btn.disabled = false;
    }
  });
})();