Implement LikeHandler

src/Activities/LikeHandler.php

@@ -0,0 +1,93 @@
+<?php
+
+namespace ActivityPub\Activities;
+
+use ActivityPub\Entities\ActivityPubObject;
+use ActivityPub\Objects\CollectionsService;
+use ActivityPub\Objects\ContextProvider;
+use ActivityPub\Objects\ObjectsService;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+
+class LikeHandler implements EventSubscriberInterface
+{
+    /**
+     * @var ObjectsService
+     */
+    private $objectsService;
+
+    /**
+     * @var CollectionsService
+     */
+    private $collectionsService;
+
+    /**
+     * @var ContextProvider
+     */
+    private $contextProvider;
+
+    public static function getSubscribedEvents()
+    {
+        return array(
+            InboxActivityEvent::NAME => 'handleInbox',
+            OutboxActivityEvent::NAME => 'handleOutbox',
+        );
+    }
+
+    public function __construct( ObjectsService $objectsService,
+                                 CollectionsService $collectionsService,
+                                 ContextProvider $contextProvider )
+    {
+        $this->objectsService = $objectsService;
+        $this->collectionsService = $collectionsService;
+        $this->contextProvider = $contextProvider;
+    }
+
+    public function handleInbox( InboxActivityEvent $event )
+    {
+        $activity = $event->getActivity();
+        if ( $activity['type'] !== 'Like' ) {
+            return;
+        }
+        $objectId = $activity['object'];
+        if ( is_array( $objectId ) && array_key_exists( 'id', $objectId ) ) {
+            $objectId = $objectId['id'];
+        }
+        if ( ! is_string( $objectId ) ) {
+            throw new BadRequestHttpException('Invalid object');
+        }
+        $object = $this->objectsService->dereference( $objectId );
+        if ( ! $object->hasField( 'likes' ) ) {
+            $object = $this->addCollectionToObject( $object, 'likes' );
+        }
+        $likes = $object['likes'];
+        $this->collectionsService->addItem( $likes, $activity );
+    }
+
+    public function handleOutbox( OutboxActivityEvent $event )
+    {
+        $activity = $event->getActivity();
+        if ( $activity['type'] !== 'Like' ) {
+            return;
+        }
+        $object = $activity['object'];
+        $actor = $event->getActor();
+        if ( ! $actor->hasField( 'liked' ) ) {
+            $actor = $this->addCollectionToObject( $actor, 'liked' );
+        }
+        $liked = $actor['liked'];
+        $this->collectionsService->addItem( $liked, $object );
+    }
+
+    private function addCollectionToObject( ActivityPubObject $object, $collectionName )
+    {
+        $updatedObject = $object->asArray();
+        $updatedObject[$collectionName] = array(
+            '@context' => $this->contextProvider->getContext(),
+            'id' => rtrim( $updatedObject['id'], '/' ) . '/' . $collectionName,
+            'type' => 'Collection',
+            'items' => array(),
+        );
+        return $this->objectsService->update( $object['id'], $updatedObject );
+    }
+}