fetch( "SELECT id FROM admin_users WHERE username = ? AND id != ?", [$username, $userId] ); if ($existing) { throw new Exception('El nombre de usuario ya está en uso'); } // Actualizar usuario $db->execute( "UPDATE admin_users SET username = ?, full_name = ?, email = ? WHERE id = ?", [$username, $fullName, $email, $userId] ); echo json_encode([ 'success' => true, 'message' => 'Usuario actualizado correctamente' ]); } catch (Exception $e) { error_log('Error updating admin user: ' . $e->getMessage()); http_response_code(500); echo json_encode([ 'success' => false, 'error' => $e->getMessage() ]); }