Added event dispatcher to track when a short URL is visited

module/Core/src/EventDispatcher/LocateShortUrlVisit.php

@@ -0,0 +1,52 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\EventDispatcher;
+
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Shlinkio\Shlink\Common\IpGeolocation\IpLocationResolverInterface;
+use Shlinkio\Shlink\Common\IpGeolocation\Model\Location;
+use Shlinkio\Shlink\Core\Entity\Visit;
+use Shlinkio\Shlink\Core\Entity\VisitLocation;
+
+use function sprintf;
+
+class LocateShortUrlVisit
+{
+    /** @var IpLocationResolverInterface */
+    private $ipLocationResolver;
+    /** @var EntityManagerInterface */
+    private $em;
+    /** @var LoggerInterface */
+    private $logger;
+
+    public function __construct(
+        IpLocationResolverInterface $ipLocationResolver,
+        EntityManagerInterface $em,
+        LoggerInterface $logger
+    ) {
+        $this->ipLocationResolver = $ipLocationResolver;
+        $this->em = $em;
+        $this->logger = $logger;
+    }
+
+    public function __invoke(ShortUrlVisited $shortUrlVisited): void
+    {
+        $visitId = $shortUrlVisited->visitId();
+
+        /** @var Visit|null $visit */
+        $visit = $this->em->find(Visit::class, $visitId);
+        if ($visit === null) {
+            $this->logger->warning(sprintf('Tried to locate visit with id "%s", but it does not exist.', $visitId));
+            return;
+        }
+
+        $location = $visit->isLocatable()
+            ? $this->ipLocationResolver->resolveIpLocation($visit->getRemoteAddr())
+            : Location::emptyInstance();
+
+        $visit->locate(new VisitLocation($location));
+        $this->em->flush($visit);
+    }
+}