/* example :
table = point
coloum = total, user. */

/* this is just example */

/* count on giver total point */
$pointgiver = $db->query("SELECT `total` FROM `point` WHERE `user` = ''.$systemUser->id.''")->fetchColumn();
/* count on receiver total point */
$pointreceive = $db->query("SELECT `total` FROM `point` WHERE `user` = ''.$user['id'].''")->fetchColumn();

/* executor */
if (isset($_POST['submit'])) {
	$error = [];
	$point = isset($_POST['point']) ? trim($_POST['point']) : false;
	if (empty($_POST['text'])) {
		$error['point'][] = _t('You cant send empty point!','system');
	}
	if ($point >= $pointgiver) {
		$error['point'][] = _t('You cant send more than your point!','system');
	}
	if ($user['id'] == $systemUser->id) {
		$error['point'][] = _t('You cant send to your self!','system');
	}
	$flood = $tools->antiflood();
	if ($flood) {
		$error['flood'][] = sprintf(_t('You cannot add point so often. Please, wait %d seconds.','system'), $flood);
	}
	/* update data for receiver */
	if (!$error) {
		$receive = $pointreceive + $point;
		$db->prepare('
		UPDATE `point` SET
			`total` = ?
			WHERE `user` = ?
		')->execute([
			$receive,
			$user['id'],
		]);
	}
	
	/* update data for giver */
	if (!$error) {
		$given = $pointgiver - $point;
		$db->prepare('
		UPDATE `point` SET
			`total` = ?
			WHERE `user` = ?
		')->execute([
			$given,
			$user['id'],
		]);
	}
	$db->query("OPTIMIZE TABLE `point`");
}

/* form (edit form action) */
echo '<form action="?" method="post" name="form">'.
	(isset($error['flood']) ? '<p class="red">'.implode($error['flood']).'</p>' : '').
	(isset($error['point']) ? '<p class="red">'.implode($error['point']).'</p>' : '');
echo '<p>Point giver</p>';
echo '<p><input type="number" name="point" value="'.$point.'"/></p>';
echo '<input type="submit" name="submit" value="'._t('Send','system').'"/></form>';