findSingleFieldTarget function

function findSingleFieldTarget(fields: FormField[]): FormField | undefined {
  if (lastContextMenuElement) {
    const byContextMenu = fields.find(
      (f) => f.element === lastContextMenuElement,
    );
    if (byContextMenu) return byContextMenu;
  }

  if (document.activeElement instanceof HTMLElement) {
    const activeField = document.activeElement.closest(
      "input, select, textarea",
    );
    if (
      activeField instanceof HTMLInputElement ||
      activeField instanceof HTMLSelectElement ||
      activeField instanceof HTMLTextAreaElement
    ) {
      const byFocus = fields.find((f) => f.element === activeField);
      if (byFocus) return byFocus;
    }
  }

  return fields.find((f) => !(f.element as HTMLInputElement).disabled);
}