Method calculatedRewardDiscountProduct

public function calculatedRewardDiscountProduct(&$rewards)
{
    $rewards['percentage'] = 0;
    $rewards['usedproduct'] = 0;
    if ($rewards['needed'] == $rewards['used']) {
        $rewards['usedproduct'] = $rewards['used'];
        $rewards['percentage'] = 100;
        $rewards['used'] = 0;
        // Rest
    } else {
        if ($rewards['needed'] > $rewards['used']) {
            $rewards['usedproduct'] = $rewards['used'];
            $rewards['percentage'] = 100 * $rewards['usedproduct'] / $rewards['needed'];
            $rewards['used'] = $rewards['used'] - $rewards['usedproduct'];
            // Rest
        } else {
            if ($rewards['used'] > $rewards['needed']) {
                $rewards['usedproduct'] = $rewards['needed'];
                $rewards['percentage'] = 100;
                $rewards['used'] = $rewards['used'] - $rewards['needed'];
                // Rest
            }
        }
    }
    $rewards['usedtotal'] += $rewards['usedproduct'];
}