Implemented subscription logic

src/Broker/TopicManager.php

@@ -9,6 +9,12 @@ class TopicManager
     /** @var array<string,Topic> */
     private array $topics = [];
 
+    private SplObjectStorage $subscribers;
+
+    public function __construct()
+    {
+        $this->subscribers = new SplObjectStorage();
+    }
 
     public function getTopic(string $topic): Topic
     {
@@ -25,6 +31,26 @@ class TopicManager
         }
     }
 
+    public function subscribe(SubscriberInterface $subscriber, array $topics): void
+    {
+        foreach ($topics as $topic) {
+            $this->getTopic($topic)->addSubscriber($subscriber);
+        }
+    }
+
+    public function unsubscribe(SubscriberInterface $subscriber, ?array $topics=null): void
+    {
+        if (!$topics) {
+            foreach ($this->topics as $topic) {
+                $topic->removeSubscriber($subscriber);
+            }
+            return;
+        }
+        foreach ($topics as $topic) {
+            $this->getTopic($topic)->removeSubscriber($subscriber);
+        }
+    }
+
     public function getTopicCount(): int
     {
         return count($this->topics);
@@ -32,7 +58,7 @@ class TopicManager
 
     public function getSubscriberCount(): int
     {
-        return array_sum(array_map(fn($t) => $t->getSubscriberCount(), $this->topics));
+        return count($this->subscribers);
     }
 
     public function garbageCollect(): void