LS PayPal IPN

gistfile1.php

public function process_paypal_ipn($params)
{
	try
	{
		$order = null;
		
		/*
		 * Find order and load paypal settings
		 */
		
		sleep(5);

		$order_hash = array_key_exists(0, $params) ? $params[0] : null;
		if (!$order_hash)
			throw new Phpr_ApplicationException('Order not found');
		
		$order = Shop_Order::create()->find_by_order_hash($order_hash);
		if (!$order)
			throw new Phpr_ApplicationException('Order not found.');
		
		if (!$order->payment_method)
			throw new Phpr_ApplicationException('Payment method not found.');
		
		$order->payment_method->define_form_fields();
		$payment_method_obj = $order->payment_method->get_paymenttype_object();
		
		if (!($payment_method_obj instanceof Shop_PayPal_Standard_Payment))
			throw new Phpr_ApplicationException('Invalid payment method.');
		
		$endpoint = $order->payment_method->test_mode ? 
			"www.sandbox.paypal.com/cgi-bin/webscr" : 
			"www.paypal.com/cgi-bin/webscr";
		
		$fields = $_POST;
		
		foreach($fields as $key => $value)
		{
			//replace every \n that isn't part of \r\n with \r\n to prevent an invalid response from PayPal
			$fields[$key] = preg_replace("~(?<!\r)\n~","\r\n",$value);
		}
		$fields['cmd'] = '_notify-validate';
		if(array_key_exists('txn_id', $fields))
			$transaction_id = $fields['txn_id'];

		$response = Core_Http::post_data($endpoint, $fields);

		if (!$order->payment_processed(false))
		{
			if (post('mc_gross') != strval($this->get_paypal_total($order, $order->payment_method)))
				$this->log_payment_attempt($order, 'Invalid order total received in IPN: '.format_currency(post('mc_gross')), 0, array(), $_POST, $response);
			else
			{
				if (strpos($response, 'VERIFIED') !== false)
				{
					if ($order->set_payment_processed())
					{
						Shop_OrderStatusLog::create_record($order->payment_method->order_status, $order);
						$this->log_payment_attempt($order, 'Successful payment', 1, array(), $_POST, $response);
						if(isset($transaction_id) && strlen($transaction_id))
							$this->update_transaction_status($order->payment_method, $order, $transaction_id, 'Processed', 'processed');
					}
				} else
					$this->log_payment_attempt($order, 'Invalid payment notification', 0, array(), $_POST, $response);
			}
		}
	}
	catch (Exception $ex)
	{
		if ($order)
			$this->log_payment_attempt($order, $ex->getMessage(), 0, array(), $_POST, null);

		throw new Phpr_ApplicationException($ex->getMessage());
	}
}