<?php declare(strict_types=1);
namespace Shopware\Storefront\Framework\Cache;
use Shopware\Core\Checkout\Cart\Cart;
use Shopware\Core\Checkout\Cart\SalesChannel\CartService;
use Shopware\Core\PlatformRequest;
use Shopware\Core\System\SalesChannel\Context\SalesChannelContextService;
use Shopware\Core\System\SalesChannel\SalesChannelContext;
use Shopware\Storefront\Framework\Cache\Annotation\HttpCache;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\Cookie;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Event\ResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
class CacheResponseSubscriber implements EventSubscriberInterface
{
public const STATE_LOGGED_IN = 'logged-in';
public const STATE_CART_FILLED = 'cart-filled';
public const CURRENCY_COOKIE = 'sw-currency';
public const CONTEXT_CACHE_COOKIE = 'sw-cache-hash';
public const SYSTEM_STATE_COOKIE = 'sw-states';
public const INVALIDATION_STATES_HEADER = 'sw-invalidation-states';
/**
* @var CartService
*/
private $cartService;
/**
* @var int
*/
private $defaultTtl;
/**
* @var bool
*/
private $httpCacheEnabled;
public function __construct(CartService $cartService, int $defaultTtl, bool $httpCacheEnabled)
{
$this->cartService = $cartService;
$this->defaultTtl = $defaultTtl;
$this->httpCacheEnabled = $httpCacheEnabled;
}
public static function getSubscribedEvents()
{
return [
KernelEvents::RESPONSE => [
['setResponseCache', -1500],
],
];
}
public function setResponseCache(ResponseEvent $event): void
{
if (!$this->httpCacheEnabled) {
return;
}
$response = $event->getResponse();
$request = $event->getRequest();
$context = $request->attributes->get(PlatformRequest::ATTRIBUTE_SALES_CHANNEL_CONTEXT_OBJECT);
if (!$context instanceof SalesChannelContext) {
return;
}
$route = $request->attributes->get('_route');
if ($route === 'frontend.checkout.configure') {
$this->setCurrencyCookie($request, $response);
}
$cart = $this->cartService->getCart($context->getToken(), $context);
/* @var SalesChannelContext $context */
$states = $this->updateSystemState($cart, $context, $request, $response);
if ($request->getMethod() !== Request::METHOD_GET) {
return;
}
if ($context->getCustomer() || $cart->getLineItems()->count() > 0) {
$cookie = Cookie::create(self::CONTEXT_CACHE_COOKIE, $this->buildCacheHash($context));
$cookie->setSecureDefault($request->isSecure());
$response->headers->setCookie($cookie);
} else {
$response->headers->removeCookie(self::CONTEXT_CACHE_COOKIE);
$response->headers->clearCookie(self::CONTEXT_CACHE_COOKIE);
}
$config = $request->attributes->get('_' . HttpCache::ALIAS);
if (empty($config)) {
return;
}
/** @var HttpCache $cache */
$cache = array_shift($config);
if ($this->hasInvalidationState($cache, $states)) {
return;
}
$maxAge = $cache->getMaxAge() ?? $this->defaultTtl;
$maxAge = $maxAge ?? 3600;
$response->setSharedMaxAge($maxAge);
$response->headers->addCacheControlDirective('must-revalidate');
$response->headers->set(
self::INVALIDATION_STATES_HEADER,
implode(',', $cache->getStates())
);
}
private function hasInvalidationState(HttpCache $cache, array $states): bool
{
foreach ($states as $state) {
if (\in_array($state, $cache->getStates(), true)) {
return true;
}
}
return false;
}
private function buildCacheHash(SalesChannelContext $context): string
{
return md5(json_encode([
$context->getRuleIds(),
$context->getContext()->getVersionId(),
$context->getCurrency()->getId(),
]));
}
/**
* System states can be used to stop caching routes at certain states. For example,
* the checkout routes are no longer cached if the customer has products in the cart or is logged in.
*/
private function updateSystemState(Cart $cart, SalesChannelContext $context, Request $request, Response $response): array
{
$states = $this->getSystemStates($request, $context, $cart);
if (empty($states)) {
$response->headers->removeCookie(self::SYSTEM_STATE_COOKIE);
$response->headers->clearCookie(self::SYSTEM_STATE_COOKIE);
return [];
}
$cookie = Cookie::create(self::SYSTEM_STATE_COOKIE, implode(',', $states));
$cookie->setSecureDefault($request->isSecure());
$response->headers->setCookie($cookie);
return $states;
}
private function getSystemStates(Request $request, SalesChannelContext $context, Cart $cart): array
{
$states = [];
if ($request->cookies->has(self::SYSTEM_STATE_COOKIE)) {
$states = explode(',', $request->cookies->get(self::SYSTEM_STATE_COOKIE));
$states = array_flip($states);
}
$states = $this->switchState($states, self::STATE_LOGGED_IN, $context->getCustomer() !== null);
$states = $this->switchState($states, self::STATE_CART_FILLED, $cart->getLineItems()->count() > 0);
return array_keys($states);
}
private function switchState(array $states, string $key, bool $match): array
{
if ($match) {
$states[$key] = true;
return $states;
}
unset($states[$key]);
return $states;
}
private function setCurrencyCookie(Request $request, Response $response): void
{
$currencyId = $request->get(SalesChannelContextService::CURRENCY_ID);
if (!$currencyId) {
return;
}
$cookie = Cookie::create(self::CURRENCY_COOKIE, $currencyId);
$cookie->setSecureDefault($request->isSecure());
$response->headers->setCookie($cookie);
}
}