Help for payment plugin

I try to make a plugin Payment and i have this error
Subscriptions terms in the IPN does not match subscription terms in our Invoice

xception Am_Exception_Paysystem_TransactionInvalid
Am_Paysystem_Transaction_Incoming->validate [ library/Am/Paysystem/Transaction/Abstract.php : 46 ]
Am_Paysystem_Transaction_Abstract->process [ library/Am/Paysystem/Transaction/Incoming.php : 228 ]
Am_Paysystem_Transaction_Incoming->process [ library/Am/Paysystem/Abstract.php : 444 ]
Am_Paysystem_Abstract->directAction [ application/default/plugins/payment/swreg.php : 139 ]
Am_Paysystem_Swreg->directAction [ application/default/controllers/DirectController.php : 35 ]
DirectController->__call [ library/Am/Controller.php : 118 ]
Am_Controller->dispatch [ library/Zend/Controller/Dispatcher/Standard.php : 295 ]
Zend_Controller_Dispatcher_Standard->dispatch [ library/Zend/Controller/Front.php : 954 ]
Zend_Controller_Front->dispatch [ library/Am/App.php : 1374 ]
Am_App->run [ index.php : 41 ]

My validate term is empty :

public function validateTerms() {
// compare our invoice payment settings, and what payment system handled
// if there is difference, it is possible that redirect url was modified
// before payment
//$invoice->first_total=$invoice->first_total*100;
//return ($this->request->get('montant') == $this->invoice->first_total);
return true;
}

Ok this is

<?php
class Am_Paysystem_Swreg2 extends Am_Paysystem_Abstract
{
const PLUGIN_STATUS = self::STATUS_DEV;
const PLUGIN_REVISION = '0.2';
const URL = "xxxxxxxxxxxxxxx/cgi-bin/modulev2.cgi";
const TESTING_URL = "xxxxxxxxxxxxxxxxxxx/cgi-bin/modulev2.cgi";
const MODE_LIVE = 'live';
const MODE_SANDBOX = 'sandbox';
const MODE_TEST = 'test';

protected $defaultTitle = 'Paybox';
protected $defaultDescription = 'Carte bancaire sécurisée';
public function _initSetupForm(Am_Form_Setup $form) {
$s = $form->addSelect("testing")
->setLabel("test Mode Enabled");
$s->addOption("Live account", self::MODE_LIVE);
$s->addOption("Sandbox account", self::MODE_SANDBOX);
// $s->addOption("Account in test mode", self::MODE_TEST);
}
public function getSupportedCurrencies()
{
return array(
'EUR');
}
public function init()
{
parent::init();
$this->getDi()->billingPlanTable->customFields()
->add(new Am_CustomFieldText('plimus_contract_id', "Nombre de paiement 1 pour 1 fois, et 3 pour Fois",
"(les autres ne sont pas progammés, mais à voir pour mettre 2 fois par exemple"));
}
public function _process(Invoice $invoice, Am_Request $request, Am_Paysystem_Result $result)
{

$a = new Am_Paysystem_Action_Redirect((($this->getConfig('testing')==self::MODE_SANDBOX) ? self::TESTING_URL : self::URL));
$a->contract_id = $invoice->getItem(0)->getBillingPlanData("plimus_contract_id");
$a->custom1 = $invoice->public_id;
$a->member_id = $invoice->user_id;
$a->invoice_id = $invoice->invoice_id;

if ($a->contract_id > 1){
$prixpaybox = ($invoice->first_total*100);
$a->PBX_CMD = "custom1=$a->custom1&prix=$prixpaybox&r=$a->member_id&pr=$invoice->first_total&o=$a->invoice_id&ret=http://xxxxxxxx/amember&nom=$a->Nom";

$now = time();
$dans_1_mois = mktime(0,0,0,date("m" ) + 1 ,date("d" ) ,date("Y" ));
$dans_2_mois = mktime(0,0,0,date("m" ) + 2 ,date("d" ) ,date("Y" ));
$date1 = date("d/m/Y", $dans_1_mois);
$date2 = date("d/m/Y", $dans_2_mois);

$a->PBX_2MONT1 = $prixpaybox;
$a->PBX_DATE1 = $date1;
$a->PBX_2MONT2 = $prixpaybox ;
$a->PBX_DATE2 = $date2;

}else {
$prixpaybox=$invoice->first_total*100;
$a->PBX_CMD = "custom1=$a->custom1&prix=$prixpaybox&r=$a->member_id&pr=$prixpaybox&o=$a->invoice_id&ret=http://xxxxxxx/amember&nom=$a->Nom";
}
$o = $invoice->invoice_id;
$a->currency = $this->getCurrencyCode();
$a->Nom= $invoice->getFirstName();
$a->Prenom = $invoice->getLastName();
$a->PBX_PORTEUR = $invoice->getEmail();
$a->PBX_MODE = "1";
$a->PBX_SITE = "5864408";
$a->PBX_RANG = "01";
$a->PBX_IDENTIFIANT = "58644081";
$a->PBX_TOTAL = $prixpaybox;
$a->PBX_WAIT = "0";
$a->PBX_DEVISE = "978";
$a->PBX_RETOUR = "montant:M;ref:R;auto:A;trans:T;numabo:B,datefin";
$a->PBX_EFFECTUE = "http://xxxxxx/amember/payment/swreg2/ipn";
$a->PBX_REFUSE = "http://xxxxxxxx/amember/content/p/id/3/";
$a->PBX_ANNULE = "http://xxxxxxx/amember/signup";
$a->filterEmpty();
$result->setAction($a);
}

public function getRecurringType()
{
return self::REPORTS_NOT_RECURRING;
}
public function getReadme()
{
$ipn = $this->getPluginUrl('ipn');
$refund = $this->getPluginUrl('refund');
return <<<CUT
Swreg2 payment plugin installation
1. In Swreg2 control panel, create a bundle product and enable
variable pricing for it.
2. In Swreg2 control panel, set
Keygen routine URL to
$ipn
Refund reporting URL to
$refund
4. Configure Swreg2 plugin at aMember CP -> Setup -> Swreg2

CUT;
}
public function createTransaction(Am_Request $request, Zend_Controller_Response_Http $response, array $invokeArgs)
{
return new Am_Paysystem_Transaction_Swreg2_Order($this, $request, $response, $invokeArgs);
}

function getCurrencyCode()
{
return strtoupper($this->invoice->currency);
}
public function directAction(Am_Request $request, Zend_Controller_Response_Http $response, array $invokeArgs) {
echo "<softshop></softshop>"; ob_flush();
if ($request->getActionName() == 'refund')
return $this->refundAction($request, $response, $invokeArgs);
else
parent::directAction($request, $response, $invokeArgs);
}
public function refundAction(Am_Request $request, Zend_Controller_Response_Http $response, array $invokeArgs)
{
$log = $this->logRequest($request);
$transaction = new Am_Paysystem_Transaction_Swreg2_Refund($this, $request, $response, $invokeArgs);
$transaction->setInvoiceLog($log);
try {
$transaction->process();
} catch (Exception $e) {
throw $e;
$this->getDi()->errorLogTable->logException($e);
throw Am_Exception_InputError(___("Error happened during transaction handling. Please contact website administrator"));
}
$log->setInvoice($transaction->getInvoice())->update();
}
}
abstract class Am_Paysystem_Transaction_Swreg2 extends Am_Paysystem_Transaction_Incoming
{
public function validateSource()
{
$this->_checkIp($this->plugin->getConfig('ip'));
if ($this->plugin->getConfig('product_id') != $this->request->get('pc'))
throw new Am_Exception_Paysystem_TransactionInvalid("Wrong [pc] passed, this transaction is not related to aMember?");
return true;
}
public function validateStatus()
{
return true;
}
public function validateTerms()
{
return true;
}
}
class Am_Paysystem_Transaction_Swreg2_Order extends Am_Paysystem_Transaction_Swreg2
{
public function findInvoiceId(){
return $this->request->getFiltered('r');
}

public function getUniqId() {
return $this->request->get("o");
}

public function validateSource() {
// there must be some code to validate if IPN came from payment system, and not from a "hacker"
return true;
}
public function validateStatus() {
// there must be code to check post variables and confirm that the post indicates successful payment transaction
return true;
}

public function processValidated()
{
$this->invoice->addPayment($this);
}
public function validateTerms()
{
return $this->request->get('pp') == $this->invoice->first_total;
}
}
class Am_Paysystem_Transaction_Swreg2_Refund extends Am_Paysystem_Transaction_Swreg2
{
public function findInvoiceId()
{
$invoice = Am_Di::getInstance()->invoiceTable->findByReceiptIdAndPlugin($this->getReceiptId(), $this->plugin->getId());
if ($invoice) return $invoice->public_id;
}
public function getUniqId()
{
return $this->request->get('order_no');
}
public function processValidated()
{
$this->invoice->addRefund($this, $this->getReceiptId());
echo "<softshop></softshop>";
}
public function validateSource()
{
return true;
}
}