if ($operation === "remove") {
$code = $_GET["code"];
$rewardMgr->removeRewardCode($code);
header("Location: admin.php");
} else {
if ($operation === "create") {
$number = $_POST['numberOfCode'];
$rewardMgr->createRewardCode($number);
header("Location: admin.php");
} else {
if ($operation === "check") {
$userid = null;
$userid = $_SESSION["userid"];
$code = addslashes(filter_input(INPUT_POST, 'code'));
$exist = $rewardMgr->checkCode($code);
$used = $rewardMgr->checkHistory($userid, $code);
if ($exist === false || $used === true) {
$arr = array();
$arr['code'] = $code;
$arr['status'] = $exist;
echo json_encode($arr);
exit;
}
$arr = array();
$arr['code'] = $code;
$arr['status'] = $exist;
echo json_encode($arr);
} else {
if ($operation === "reward") {
$code = addslashes(filter_input(INPUT_POST, 'code'));
$gift = $rewardMgr->getGiftByRewardCode($code);
