Add logic to send visits to a matomo instance

module/Core/src/Matomo/MatomoOptions.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Matomo;
+
+class MatomoOptions
+{
+    public function __construct(
+        public readonly bool $enabled,
+        public readonly ?string $baseUrl,
+        /** @var numeric-string|int|null */
+        private readonly string|int|null $siteId,
+        public readonly ?string $apiToken,
+    ) {
+    }
+
+    public function siteId(): ?int
+    {
+        if ($this->siteId === null) {
+            return null;
+        }
+
+        // We enforce site ID to be hydrated as a numeric string or int, so it's safe to cast to int here
+        return (int) $this->siteId;
+    }
+}

module/Core/src/Matomo/MatomoTrackerBuilder.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Matomo;
+
+use MatomoTracker;
+use Shlinkio\Shlink\Core\Exception\RuntimeException;
+
+class MatomoTrackerBuilder implements MatomoTrackerBuilderInterface
+{
+    public function __construct(private readonly MatomoOptions $options)
+    {
+    }
+
+    /**
+     * @throws RuntimeException If there's any missing matomo parameter
+     */
+    public function buildMatomoTracker(): MatomoTracker
+    {
+        $siteId = $this->options->siteId();
+        if ($siteId === null || $this->options->baseUrl === null || $this->options->apiToken === null) {
+            throw new RuntimeException(
+                'Cannot create MatomoTracker. Either site ID, base URL or api token are not defined',
+            );
+        }
+
+        // Create a new MatomoTracker on every request, because it infers request info during construction
+        $tracker = new MatomoTracker($siteId, $this->options->baseUrl);
+        // Token required to set the IP and location
+        $tracker->setTokenAuth($this->options->apiToken);
+        // We don't want to bulk send, as every request to Shlink will create a new tracker
+        $tracker->disableBulkTracking();
+        // Ensure params are not sent in the URL, for security reasons
+        $tracker->setRequestMethodNonBulk('POST');
+
+        return $tracker;
+    }
+}

module/Core/src/Matomo/MatomoTrackerBuilderInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Matomo;
+
+use MatomoTracker;
+use Shlinkio\Shlink\Core\Exception\RuntimeException;
+
+interface MatomoTrackerBuilderInterface
+{
+    /**
+     * @throws RuntimeException If there's any missing matomo parameter
+     */
+    public function buildMatomoTracker(): MatomoTracker;
+}