{% comment %}
localStorage draft backup for long / multi-step forms — no backend needed.

Restores saved values into EMPTY fields on load (so server-rendered values and
prefills always win), persists on every input/change, and clears the draft on
submit. File, password, hidden, checkbox/radio and CSRF fields are never stored.

Args:
  form_id      — id of the <form> to back up (required)
  storage_key  — static slug for this form, e.g. "business-register" (required).
                 The partial scopes it per-user automatically.
{% endcomment %}
<script>
(function () {
  var form = document.getElementById("{{ form_id }}");
  if (!form || !window.localStorage) return;
  var KEY = "smehub-draft:{{ storage_key }}-{{ user.pk|default:'anon' }}";
  var SEL = "input, textarea, select";
  function skip(el) {
    return !el.name
      || el.type === "file" || el.type === "password" || el.type === "hidden"
      || el.type === "checkbox" || el.type === "radio"
      || el.name === "csrfmiddlewaretoken";
  }
  try {
    var saved = JSON.parse(localStorage.getItem(KEY) || "{}");
    form.querySelectorAll(SEL).forEach(function (el) {
      if (skip(el)) return;
      if (saved[el.name] != null && !el.value) {
        el.value = saved[el.name];
        el.dispatchEvent(new Event("change", { bubbles: true }));
      }
    });
  } catch (e) {}
  function save() {
    var data = {};
    form.querySelectorAll(SEL).forEach(function (el) {
      if (skip(el) || !el.value) return;
      data[el.name] = el.value;
    });
    try { localStorage.setItem(KEY, JSON.stringify(data)); } catch (e) {}
  }
  form.addEventListener("input", save);
  form.addEventListener("change", save);
  form.addEventListener("submit", function () {
    try { localStorage.removeItem(KEY); } catch (e) {}
  });
})();
</script>