Created event listener that notifies mercure hub for new visits

module/Core/src/EventDispatcher/NotifyVisitToMercure.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\EventDispatcher;
+
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Shlinkio\Shlink\Core\Entity\Visit;
+use Shlinkio\Shlink\Core\Mercure\MercureUpdatesGeneratorInterface;
+use Symfony\Component\Mercure\PublisherInterface;
+use Throwable;
+
+class NotifyVisitToMercure
+{
+    private PublisherInterface $publisher;
+    private MercureUpdatesGeneratorInterface $updatesGenerator;
+    private EntityManagerInterface $em;
+    private LoggerInterface $logger;
+
+    public function __construct(
+        PublisherInterface $publisher,
+        MercureUpdatesGeneratorInterface $updatesGenerator,
+        EntityManagerInterface $em,
+        LoggerInterface $logger
+    ) {
+        $this->publisher = $publisher;
+        $this->em = $em;
+        $this->logger = $logger;
+        $this->updatesGenerator = $updatesGenerator;
+    }
+
+    public function __invoke(VisitLocated $shortUrlLocated): void
+    {
+        $visitId = $shortUrlLocated->visitId();
+
+        /** @var Visit|null $visit */
+        $visit = $this->em->find(Visit::class, $visitId);
+        if ($visit === null) {
+            $this->logger->warning('Tried to notify mercure for visit with id "{visitId}", but it does not exist.', [
+                'visitId' => $visitId,
+            ]);
+            return;
+        }
+
+        try {
+            ($this->publisher)($this->updatesGenerator->newVisitUpdate($visit));
+        } catch (Throwable $e) {
+            $this->logger->debug('Error while trying to notify mercure hub with new visit. {e}', [
+                'e' => $e,
+            ]);
+        }
+    }
+}