// Stackless — contact form behaviour: step nav, validation, submit state
(function () {
  var form = document.getElementById('contactForm');
  if (!form) return;

  var steps = Array.prototype.slice.call(form.querySelectorAll('.step'));
  var dots = Array.prototype.slice.call(document.querySelectorAll('.progress .dot'));
  var prevBtn = document.getElementById('prevBtn');
  var nextBtn = document.getElementById('nextBtn');
  var submitBtn = document.getElementById('submitBtn');
  var successEl = document.getElementById('formSuccess');
  var errBanner = document.getElementById('errBanner');

  var current = 0;

  function paint() {
    steps.forEach(function (s, i) { s.classList.toggle('is-active', i === current); });
    dots.forEach(function (d, i) {
      d.classList.toggle('is-on', i === current);
      d.classList.toggle('is-done', i < current);
    });
    prevBtn.disabled = current === 0;
    if (current === steps.length - 1) {
      nextBtn.style.display = 'none';
      submitBtn.style.display = 'inline-flex';
    } else {
      nextBtn.style.display = 'inline-flex';
      submitBtn.style.display = 'none';
    }
  }

  function validateStep(idx) {
    var step = steps[idx];
    var fields = step.querySelectorAll('input[required], select[required], textarea[required]');
    var ok = true;
    fields.forEach(function (el) {
      var bad = !el.checkValidity();
      el.classList.toggle('is-invalid', bad);
      el.parentElement.classList.toggle('is-invalid', bad);
      if (bad) ok = false;
    });
    // Custom: at least one service checkbox picked if on step 1
    if (idx === 0) {
      var any = step.querySelectorAll('input[name="services"]:checked').length;
      var servicesErr = document.getElementById('servicesErr');
      if (any === 0) {
        ok = false;
        servicesErr.style.display = 'block';
      } else {
        servicesErr.style.display = 'none';
      }
    }
    return ok;
  }

  function goto(i) {
    if (i > current && !validateStep(current)) {
      errBanner.style.display = 'flex';
      return;
    }
    errBanner.style.display = 'none';
    current = Math.max(0, Math.min(steps.length - 1, i));
    paint();
    // scroll the active step into view (only on mobile-ish where steps stack)
    var active = steps[current];
    if (active && window.innerWidth < 720) {
      active.scrollIntoView({ behavior: 'smooth', block: 'start' });
    }
  }

  // live-clear invalid state as the user fixes it
  form.addEventListener('input', function (e) {
    var t = e.target;
    if (t.classList && t.classList.contains('is-invalid') && t.checkValidity()) {
      t.classList.remove('is-invalid');
      if (t.parentElement) t.parentElement.classList.remove('is-invalid');
    }
    if (t.name === 'services') {
      var any = form.querySelectorAll('input[name="services"]:checked').length;
      var servicesErr = document.getElementById('servicesErr');
      if (any > 0 && servicesErr) servicesErr.style.display = 'none';
    }
  });

  prevBtn.addEventListener('click', function () { goto(current - 1); });
  nextBtn.addEventListener('click', function () { goto(current + 1); });

  // Submit (no real backend — show the success state, log the payload)
  form.addEventListener('submit', function (e) {
    e.preventDefault();
    if (!validateStep(current)) { errBanner.style.display = 'flex'; return; }
    var data = {};
    new FormData(form).forEach(function (v, k) { data[k] = v; });
    console.log('[Stackless] contact submission:', data);

    submitBtn.disabled = true;
    submitBtn.textContent = 'Sending…';
    setTimeout(function () {
      form.style.display = 'none';
      successEl.style.display = 'block';
      successEl.scrollIntoView({ behavior: 'smooth', block: 'start' });
    }, 700);
  });

  paint();
})();