Title

<?php
use \Bitrix\Main\Application;
use \Bitrix\Sale\PaySystem;

$logDir  = $_SERVER["DOCUMENT_ROOT"] . "/bitrix/logs/";
$logFile = $logDir . "payment_requests.log";
SECRET_KEY = 's0m3r@nd0m$tring';

if ($request->get('token') !== SECRET_KEY) {
    header('HTTP/1.1 403 Forbidden');
    die('Bad token');
}

if (!is_dir($logDir)) {
    mkdir($logDir, 0755, true);
}

if (!function_exists('getallheaders')) {
    function getallheaders(): array {
        $headers = [];
        foreach ($_SERVER as $name => $value) {
            if (substr($name, 0, 5) === 'HTTP_') {
                $key = str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))));
                $headers[$key] = $value;
            }
        }
        return $headers;
    }
}

$timestamp = date('Y-m-d H:i:s');
$method    = $_SERVER['REQUEST_METHOD'];
$uri       = $_SERVER['REQUEST_URI'];
$headers   = json_encode(getallheaders(), JSON_UNESCAPED_UNICODE);
$getParams = json_encode($_GET, JSON_UNESCAPED_UNICODE);
$postParams= json_encode($_POST, JSON_UNESCAPED_UNICODE);
$rawBody   = file_get_contents('php://input');

$logEntry  = "=== [$timestamp] New request ===\n";
$logEntry .= "Method: $method\n";
$logEntry .= "URI:    $uri\n";
$logEntry .= "Headers:  $headers\n";
$logEntry .= "GET:      $getParams\n";
$logEntry .= "POST:     $postParams\n";
$logEntry .= "RawBody:  " . ($rawBody ?: '(empty)') . "\n\n";

file_put_contents($logFile, $logEntry, FILE_APPEND | LOCK_EX);

define("STOP_STATISTICS",    true);
define('NO_AGENT_CHECK',     true);
define('NOT_CHECK_PERMISSIONS', true);
define("DisableEventsCheck", true);
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/modules/main/include/prolog_before.php");

global $APPLICATION;

if (CModule::IncludeModule("sale"))
{
    $context = Application::getInstance()->getContext();
    $request = $context->getRequest();

    $item = PaySystem\Manager::searchByRequest($request);
    if ($item !== false)
    {
        $service = new PaySystem\Service($item);
        if ($service instanceof PaySystem\Service)
        {
            $result = $service->processRequest($request);
        }
    }
    else
    {
        $debugInfo = http_build_query($request->toArray(), "", "\n");
        if (empty($debugInfo))
        {
            $debugInfo = $rawBody;
        }
        PaySystem\Logger::addDebugInfo('Pay system not found. Request: '.($debugInfo ?: "empty"));
    }
}

$APPLICATION->FinalActions();
die();