// your
if (isset($data['invert'])) {
    $id = $data['invert'];
    $tmp = $this->getProduct($id);
    $flag = $tmp['status'];
    $flag =($flag + 1) % 2;
    $this->db->query("UPDATE " . DB_PREFIX . "product SET status='" . $flag . "' WHERE product_id = '" . (int)$id . "'");
}


// new one
if (isset($data['invert'])) {
    $id = (int) $data['invert'];
    $tmp = $this->getProduct($id);
    $flag = ! (int) $tmp['status'];
    $this->db->query("UPDATE " . DB_PREFIX . "product SET status = {$flag} WHERE product_id = {$id}");
}