Paysbuy integration for php

index.php

<?
include 'paysbuy.php';
//config the gateway
//by default is FALSE, put this to true to test
paysbuy::$sandbox = TRUE; 
//set your emails here if none written demo email will be used
//paysbuy::$email   = 'your mail account here';


if ($_POST)
{
    if ( paysbuy::result() === TRUE )
        echo 'Paid do something';
    else
        echo 'NOT paid';
}
else
{
    //TODO!!
    //sample fill it dynamically
    $invoice     = "INV-".($inv=time());
    $description ="Product Description ".$inv;
    $price       = "10";
    $postURL     = "index.php";//change this where you check the result of the payment
    ?>
    <form name="paysbuy" id="paysbuy" method="post" action="<?=paysbuy::url_gateway()?>">
    <input type="Hidden" Name="psb" value="psb"/>
    <input Type="Hidden" Name="biz" value="<?=paysbuy::$email?>"/>
    <input Type="Hidden" Name="inv" value="<?=$invoice?>"/>
    <input Type="Hidden" Name="itm" value="<?=$description?>"/>
    <input Type="Hidden" Name="amt" value="<?=$price?>"/>
    <input Type="Hidden" Name="postURL" value="<?=$postURL?>"/>
    <input type="image" src="https://www.paysbuy.com/imgs/S_click2buy.gif" border="0" name="submit" alt="Make it easier,PaySbuy - it's fast,free and secure!"/>
    </form >
<?
}
?>

paysbuy.php

<?php
/**
 * paysbuy helper class
 *
 * @category   Payment
 * @author     Chema <[email protected]>
 * @copyright  (c) 2015 garridodiaz.com
 * @license    GPL v3
 */

class paysbuy
{
    public static $email    = '[email protected]';
    public static $sandbox  = FALSE;

    const url_gateway            = 'https://www.paysbuy.com/paynow.aspx';
    const url_recheck            = 'https://www.paysbuy.com/getinvoice/getinvoicestatus.asmx/GetInvoice';

    const url_sandbox_gateway    = 'https://demo.paysbuy.com/paynow.aspx';
    const url_sandbox_recheck    = 'https://demo.paysbuy.com/getinvoice/getinvoicestatus.asmx/GetInvoice';

    public static function result()
    {
        // Security Checking : The results from Paysbuy should be completed and not corrupted.
        if (empty($_POST['result']) OR empty($_POST['apCode']) OR empty($_REQUEST['amt'])) 
            return FALSE;

        // Value from untrusts identity which Act as Paysbuy Co. Ltd.
        $payment_status	 = substr($_POST["result"], 0, 2);
        $cartnumber      = trim(substr($_POST["result"],2));
        $amount          = $_POST['amt'];
        $psbRef          = $_POST['apCode'];

        //correct payment?
        if($payment_status == '00' AND paysbuy::recheck(self::email, $cartnumber, $psbRef,$amount) ) 
        	return TRUE;
        else
            return FALSE;
    }

    // Original Source by : Siambox.com http://www.thaihosttalk.com/index.php?topic=19899.0
    public static function recheck($psbmail, $cart, $psbRef, $amount)
    {
    	$query = "invoiceNo=$cart&merchantEmail=$psbmail&strApCode=$psbRef";

    	// Request URI (Secure)
    	$ch = curl_init((self::$sandbox)?self::url_sandbox_recheck:self::url_recheck);

    	curl_setopt($ch, CURLOPT_HEADER, 0);
    	curl_setopt($ch, CURLOPT_POST, 1);
    	curl_setopt($ch, CURLOPT_POSTFIELDS, "$query");
    	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    	$xmlResponse  = curl_exec($ch);
    	curl_close($ch);

    	$StatusResult   = XMLGetValue($xmlResponse, 'StatusResult');
    	$AmountResult	= XMLGetValue($xmlResponse, 'AmountResult');

        if ($StatusResult == 'Accept' AND $AmountResult == $amount)
            return TRUE;
        else
    		return FALSE; // Reject the payment.
    	
    }

    private static function XMLGetValue($msg, $str)
    {
    	$str1 = "<$str>";
    	$str2 = "</$str>";
    	$start_pos = strpos($msg, $str1);
    	$stop_post = strpos($msg, $str2);
    	$start_pos += strlen($str1);
    	return substr($msg, $start_pos, $stop_post - $start_pos);
    }

    /**
     * get the url of the gateway
     * @return string 
     */
    public static function url_gateway()
    {
        return ((self::$sandbox)?self::url_sandbox_gateway:self::url_gateway).'?c=true&m=true&j=true&a=true&p=true&psb=true';
    }
}