[ActivityPub][INBOX][Delete] Fix misconceptions

References:
- https://socialhub.activitypub.rocks/t/the-delete-activity-and-its-misconceptions/137
- https://socialhub.activitypub.rocks/t/the-update-activity-more-than-caching/260

plugins/ActivityPub/classes/Activitypub_profile.php

@@ -189,11 +189,11 @@ class Activitypub_profile extends Managed_DataObject
     /**
      * Fetch the locally stored profile for this Activitypub_profile
      *
-     * @return get_called_class
+     * @return Profile
      * @throws NoProfileException if it was not found
      * @author Diogo Cordeiro <diogo@fc.up.pt>
      */
-    public function local_profile()
+    public function local_profile(): Profile
     {
         $profile = Profile::getKV('id', $this->profile_id);
         if (!$profile instanceof Profile) {
@@ -481,16 +481,22 @@ class Activitypub_profile extends Managed_DataObject
 
     /**
      * Update remote user profile in local instance
-     * Depends on do_update
      *
      * @param Activitypub_profile $aprofile
-     * @param array $res remote response
+     * @param array|false $res remote response, if array it updates, if false it deletes
      * @return Profile remote Profile object
      * @throws NoProfileException
      * @author Diogo Cordeiro <diogo@fc.up.pt>
      */
     public static function update_profile($aprofile, $res)
     {
+        if ($res === false) {
+            $profile = $aprofile->local_profile();
+            $id = $profile->getID();
+            $profile->delete();
+            throw new NoProfileException($id, "410 Gone");
+        }
+
         // ActivityPub Profile
         $aprofile->uri = $res['id'];
         $aprofile->nickname = $res['preferredUsername'];

plugins/ActivityPub/lib/explorer.php

@@ -431,14 +431,18 @@ class Activitypub_explorer
      * profile updating and shall not be used for anything else)
      *
      * @param string $url User's url
-     * @return array
+     * @return array|false If it is able to fetch, false if it's gone
      * @throws Exception Either network issues or unsupported Activity format
      * @author Diogo Cordeiro <diogo@fc.up.pt>
      */
-    public static function get_remote_user_activity($url)
+    public static function get_remote_user_activity(string $url)
     {
         $client = new HTTPClient();
         $response = $client->get($url, ACTIVITYPUB_HTTP_CLIENT_HEADERS);
+        // If it was deleted
+        if ($response->getStatus() == 410) {
+            return false;
+        }
         $res = json_decode($response->getBody(), true);
         if (Activitypub_explorer::validate_remote_response($res)) {
             common_debug('ActivityPub Explorer: Found a valid remote actor for ' . $url);

plugins/ActivityPub/lib/inbox_handler.php

@@ -232,64 +232,77 @@ class Activitypub_inbox_handler
      * @throws NoProfileException
      * @throws Exception
      * @author Bruno Casteleiro <brunoccast@fc.up.pt>
+     * @author Diogo Cordeiro <diogo@fc.up.pt>
      */
     private function handle_delete()
     {
         $object = $this->object;
-        if (is_array($object)) {
+        if (is_string($object)) {
-            $object = $object['id'];
+            $client = new HTTPClient();
-        }
+            $response = $client->get($object, ACTIVITYPUB_HTTP_CLIENT_HEADERS);
-
+            $gone = !$response->isOk();
-        // profile deletion ?
+            if (!$gone) { // It's not gone, we're updating it.
-        if ($this->activity['actor'] == $object) {
+                $object = json_decode($response->getBody(), true);
-            $aprofile = Activitypub_profile::from_profile($this->actor);
+                switch ($object['type']) {
-            $this->handle_delete_profile($aprofile);
+                    case 'Person':
-            return;
+                        try {
-        }
+                            // Update profile if we already have a copy of it
-
+                            $aprofile = Activitypub_profile::fromUri($object['id'], false);
-        // note deletion ?
+                            Activitypub_profile::update_profile($aprofile, $object);
-        try {
+                        } catch (Exception $e) {
-            $notice = ActivityPubPlugin::grab_notice_from_url($object, false);
+                            // Import profile if we don't
-            if ($notice instanceof Notice) {
+                            Activitypub_explorer::get_profile_from_url($object['id']);
-                $this->handle_delete_note($notice);
+                        }
+                        break;
+                    case 'Tombstone':
+                        try {
+                            $notice = ActivityPubPlugin::grab_notice_from_url($object, false);
+                            if ($notice instanceof Notice) {
+                                $notice->delete();
+                            }
+                            return;
+                        } catch (Exception $e) {
+                            // either already deleted or not an object at all
+                            // nothing to do..
+                        }
+                        break;
+                    case 'Note':
+                        // XXX: We do not support updating a note's contents so, we'll ignore it for now...
+                    default:
+                        common_log(LOG_INFO, "Ignoring Delete activity, we do not understand for {$object['type']}.");
+                }
             }
+        } else {
+            // We don't know the type of the deleted object :(
+            // Nor if it's gone or not.
+            try {
+                $aprofile = Activitypub_profile::fromUri($object, false);
+                $res = Activitypub_explorer::get_remote_user_activity($object);
+                Activitypub_profile::update_profile($aprofile, $res);
+                return;
+            } catch (Exception $e) {
+                // Means this wasn't a profile
+            }
+
+            try {
+                $client = new HTTPClient();
+                $response = $client->get($object, ACTIVITYPUB_HTTP_CLIENT_HEADERS);
+                // If it was deleted
+                if ($response->getStatus() == 410) {
+                    $notice = ActivityPubPlugin::grab_notice_from_url($object, false);
+                    if ($notice instanceof Notice) {
+                        $notice->delete();
+                    }
+                } else {
+                    // We can't update a note's contents so, we'll ignore it for now...
+                }
+                return;
+            } catch (Exception $e) {
+                // Means we didn't have this note already
+            }
+
             return;
-        } catch (Exception $e) {
-            // either already deleted or not an object at all
-            // nothing to do..
         }
-
-        common_log(LOG_INFO, "Ignoring Delete activity, nothing that we can/need to handle.");
-    }
-
-    /**
-     * Handles a Delete-Profile Activity.
-     *
-     * Note that the actual ap_profile is deleted during the ProfileDeleteRelated event,
-     * subscribed by ActivityPubPlugin.
-     *
-     * @param Activitypub_profile $aprofile remote user being deleted
-     * @return void
-     * @throws NoProfileException
-     * @author Bruno Casteleiro <brunoccast@fc.up.pt>
-     */
-    private function handle_delete_profile(Activitypub_profile $aprofile): void
-    {
-        $profile = $aprofile->local_profile();
-        $profile->delete();
-    }
-
-    /**
-     * Handles a Delete-Note Activity.
-     *
-     * @param Notice $note remote note being deleted
-     * @return void
-     * @throws AuthorizationException
-     * @author Bruno Casteleiro <brunoccast@fc.up.pt>
-     */
-    private function handle_delete_note(Notice $note): void
-    {
-        $note->deleteAs($this->actor);
     }
 
     /**

plugins/ActivityPub/scripts/update_activitypub_profiles.php

@@ -97,7 +97,11 @@ while ($user->fetch()) {
         $res = Activitypub_explorer::get_remote_user_activity($user->uri);
         $updated_profile = Activitypub_profile::update_profile($user, $res);
         if (!$quiet) {
-            echo "Updated ".$updated_profile->getBestName()."\n";
+            echo 'Updated '.$updated_profile->getBestName()."\n";
+        }
+    } catch (NoProfileException $e) {
+        if (!$quiet) {
+            echo 'Deleted '.$user->uri."\n";
         }
     } catch (Exception $e) {
         // let it go