Payment Provider Integration

interface iBxBaseModPaymentProvider
{
    public function initializeCheckout($iPendingId, $aCartInfo);
    public function finalizeCheckout(&$aData);
    public function finalizedCheckout();
}

INSERT INTO `bx_payment_providers`(
  `name`, `caption`, `description`, `option_prefix`,
  `for_visitor`, `for_single`, `for_recurring`, `single_seller`, `time_tracker`,
  `active`, `order`, `class_name`, `class_file`
) VALUES (
  'mygate', '_bx_payment_mygate_cpt', '_bx_payment_mygate_dsc', 'mygate_',
  1, 1, 0, 0, 0,
  1, 80, 'BxPaymentProviderMygate', ''
);
SET @iProviderId = LAST_INSERT_ID();

INSERT INTO `bx_payment_providers_options`(
  `provider_id`, `name`, `type`, `caption`, `description`,
  `extra`, `check_type`, `check_params`, `check_error`, `order`
) VALUES
(@iProviderId, 'mygate_active', 'checkbox', '_bx_payment_mygate_active_cpt', '_bx_payment_mygate_active_dsc', '', '', '', '', 1),
(@iProviderId, 'mygate_api_key', 'secret', '_bx_payment_mygate_api_key_cpt', '_bx_payment_mygate_api_key_dsc', '', '', '', '', 2),
(@iProviderId, 'mygate_return_data_url', 'value', '_bx_payment_mygate_return_data_url_cpt', '', '', '', '', '', 3),
(@iProviderId, 'mygate_notify_url', 'value', '_bx_payment_mygate_notify_url_cpt', '', '', '', '', '', 4);

class BxPaymentProviderOffline extends BxBaseModPaymentProvider implements iBxBaseModPaymentProvider
{
    function __construct($aConfig)
    {
        $this->MODULE = 'bx_payment';
        parent::__construct($aConfig);
    }

    public function initializeCheckout($iPendingId, $aCartInfo, $sRedirect = '')
    {
        $aPending = $this->_oModule->_oDb->getOrderPending(array('type' => 'id', 'id' => $iPendingId));
        if(!empty($aPending['order']) || (int)$aPending['processed'] != 0)
            return $this->_sLangsPrefix . 'err_already_processed';

        // Build form / redirect for BX_PAYMENT_TYPE_SINGLE; reject recurring.
        $this->_oModule->_oTemplate->displayPageCodeRedirect($this->getCheckoutUrl(), $aFormData);
        exit;
    }

    public function finalizeCheckout(&$aData)
    {
        return array('code' => 1, 'message' => $this->_sLangsPrefix . 'cdt_err_not_available');
    }

    public function finalizedCheckout()
    {
        return array('code' => 1, 'message' => $this->_sLangsPrefix . 'cdt_err_not_available');
    }
}