/**
 * Dynamic domain select for handover wizard step 1.
 *
 * Reads config from data-* attributes on #wizard-domain-group:
 *   data-domains-url, data-text-initial, data-text-loading,
 *   data-text-select, data-text-empty, data-text-error,
 *   data-initial-debitor, data-initial-domain
 */

const group = document.getElementById('wizard-domain-group');
const lookupContainer = document.querySelector('[data-app-lookup]');
const domainSelect = document.getElementById('wizard-domain');
const domainUrlInput = document.getElementById('wizard-domain-url');
const feedback = document.getElementById('wizard-domain-feedback');

if (group && lookupContainer && domainSelect) {
  const domainsUrl = group.dataset.domainsUrl || '';
  const textInitial = group.dataset.textInitial || '';
  const textLoading = group.dataset.textLoading || '';
  const textSelect = group.dataset.textSelect || '';
  const textEmpty = group.dataset.textEmpty || '';
  const textError = group.dataset.textError || '';

  function clearOptions() {
    while (domainSelect.options.length > 0) {
      domainSelect.remove(0);
    }
  }

  function addPlaceholder(text) {
    const opt = document.createElement('option');
    opt.value = '';
    opt.textContent = text;
    domainSelect.appendChild(opt);
  }

  function setFeedback(text, variant) {
    if (!feedback) return;
    feedback.textContent = text;
    feedback.hidden = !text;
    feedback.dataset.variant = variant || '';
  }

  function resetDomain() {
    clearOptions();
    addPlaceholder(textInitial);
    domainSelect.disabled = true;
    if (domainUrlInput) domainUrlInput.value = '';
    setFeedback('', '');
  }

  async function loadDomains(debitorNo) {
    clearOptions();
    addPlaceholder(textLoading);
    domainSelect.disabled = true;
    group.setAttribute('aria-busy', 'true');
    setFeedback('', '');

    try {
      const res = await fetch(domainsUrl + '?debitor_no=' + encodeURIComponent(debitorNo), {
        headers: { 'Accept': 'application/json' },
      });
      const data = await res.json();
      const items = Array.isArray(data) ? data : [];

      clearOptions();
      addPlaceholder(textSelect);

      if (items.length === 0) {
        domainSelect.disabled = true;
        setFeedback(textEmpty, 'warning');
        return;
      }

      items.forEach(function (item) {
        const opt = document.createElement('option');
        opt.value = item.value || '';
        opt.textContent = item.label || item.value || '';
        opt.dataset.url = item.url || '';
        domainSelect.appendChild(opt);
      });
      domainSelect.disabled = false;
    } catch {
      clearOptions();
      addPlaceholder(textSelect);
      domainSelect.disabled = true;
      setFeedback(textError, 'error');
    } finally {
      group.removeAttribute('aria-busy');
    }
  }

  domainSelect.addEventListener('change', function () {
    const selected = domainSelect.options[domainSelect.selectedIndex];
    if (domainUrlInput) {
      domainUrlInput.value = selected?.dataset.url || '';
    }
  });

  lookupContainer.addEventListener('lookup:select', function (e) {
    const debitorNo = e.detail?.value || '';
    if (debitorNo) {
      loadDomains(debitorNo);
    } else {
      resetDomain();
    }
  });

  lookupContainer.addEventListener('lookup:clear', function () {
    resetDomain();
  });

  // Restore selection if returning to step 1 with session data
  const initialDebitor = group.dataset.initialDebitor || '';
  const initialDomain = group.dataset.initialDomain || '';
  if (initialDebitor) {
    loadDomains(initialDebitor).then(function () {
      if (initialDomain && !domainSelect.disabled) {
        domainSelect.value = initialDomain;
        domainSelect.dispatchEvent(new Event('change'));
      }
    });
  }
}