/**
 * Generic modal helpers for the dashboard.
 * Handles open/close animations, error display, backdrop click, and Escape key.
 * Depends on: core/utils.js ($), core/navigation.js (navigateTo)
 */

let _modalPreviousFocus = null;

/**
 * Open a modal by adding the `open` class and focusing the first focusable element.
 * Stores the previously focused element for restore on close. Sets ARIA attributes.
 * @param {string} id - The modal backdrop element ID.
 */
function openModal(id) {
  const el = $(id);
  if (!el) return;
  _modalPreviousFocus = document.activeElement;
  el.classList.add('open');
  el.setAttribute('aria-hidden', 'false');
  el.setAttribute('aria-modal', 'true');
  el.setAttribute('role', 'dialog');
  const modalTitle = el.querySelector('.modal-title');
  if (modalTitle && modalTitle.id) el.setAttribute('aria-labelledby', modalTitle.id);
  else if (modalTitle && !modalTitle.id) {
    const tid = 'modal-title-' + id;
    modalTitle.id = tid;
    el.setAttribute('aria-labelledby', tid);
  }
  setTimeout(() => {
    const focusable = el.querySelector('input:not([type="checkbox"]):not([disabled]), button:not([disabled]), [tabindex="0"]');
    if (focusable) focusable.focus();
  }, 50);
}

/**
 * Close a modal by removing the `open` class and clearing any error messages.
 * Restores focus to the element that had focus before the modal opened.
 * @param {string} id - The modal backdrop element ID.
 */
function closeModal(id) {
  const el = $(id);
  if (!el) return;
  el.classList.remove('open');
  el.setAttribute('aria-hidden', 'true');
  el.removeAttribute('aria-modal');
  el.removeAttribute('role');
  el.removeAttribute('aria-labelledby');
  el.querySelectorAll('.modal-error').forEach(e => { e.style.display = 'none'; e.textContent = ''; });
  if (_modalPreviousFocus && typeof _modalPreviousFocus.focus === 'function') {
    _modalPreviousFocus.focus();
    _modalPreviousFocus = null;
  }
}

/**
 * Display an error message inside a modal's error element.
 * @param {string} modalId - Unused; kept for API symmetry.
 * @param {string} errorId - ID of the error display element.
 * @param {string} msg - Error message text.
 */
function showModalError(modalId, errorId, msg) {
  const el = $(errorId);
  if (!el) return;
  el.textContent = msg;
  el.style.display = 'block';
  el.setAttribute('role', 'alert');
}

// Close modals on backdrop click or close button
document.addEventListener('click', (e) => {
  const closeBtn = e.target.closest('[data-close-modal]');
  if (closeBtn) {
    closeModal(closeBtn.dataset.closeModal);
    return;
  }
  if (e.target.classList.contains('modal-backdrop')) {
    closeModal(e.target.id);
  }
  const pageLink = e.target.closest('[data-page-link]');
  if (pageLink) {
    navigateTo(pageLink.dataset.pageLink);
  }
});

// Escape key closes topmost open modal; Tab trap focus inside modal
document.addEventListener('keydown', (e) => {
  if (e.key === 'Escape') {
    const open = document.querySelector('.modal-backdrop.open');
    if (open) closeModal(open.id);
    return;
  }
  if (e.key !== 'Tab') return;
  const open = document.querySelector('.modal-backdrop.open');
  if (!open) return;
  const focusable = open.querySelectorAll('input:not([disabled]), button:not([disabled]), select:not([disabled]), [tabindex="0"]');
  const first = focusable[0];
  const last = focusable[focusable.length - 1];
  if (!first || !last) return;
  if (e.shiftKey) {
    if (document.activeElement === first) { e.preventDefault(); last.focus(); }
  } else {
    if (document.activeElement === last) { e.preventDefault(); first.focus(); }
  }
});