// Toast notification system — shared across all pages.
// Usage: showToast('message', 'error' | 'info' | 'success');
// Auto-dismisses after 4 seconds. Multiple toasts stack vertically.

(function () {
  'use strict';

  const TOAST_DURATION = 4000;
  const MAX_VISIBLE = 3;
  const STACK_GAP = 8; // px between stacked toasts

  /**
   * Show a toast notification.
   * @param {string} message - Toast text content.
   * @param {'error'|'info'|'success'} [type='info'] - Visual style.
   */
  window.showToast = function showToast(message, type) {
    if (typeof message !== 'string') return;
    type = type || 'info';

    // Remove old toasts of the same type to avoid clutter
    document.querySelectorAll('.toast-' + type).forEach(function (t) {
      t.remove();
    });

    var toast = document.createElement('div');
    toast.className = 'toast toast-' + type;
    toast.setAttribute('role', 'alert');
    toast.textContent = message;

    // Position: stack from bottom
    var existing = document.querySelectorAll('.toast');
    var offset = existing.length * STACK_GAP;
    toast.style.bottom = (1.5 + offset / 16) + 'rem';

    document.body.appendChild(toast);

    setTimeout(function () {
      if (toast.parentNode) toast.remove();
    }, TOAST_DURATION);
  };
})();