implement deletion/tombstones?

7 files changed, 158 insertions, 16 deletions

diff --git a/Digitigrade/Job/ProcessIncomingPush.php b/Digitigrade/Job/ProcessIncomingPush.php
index fefa122..4f6d955 100644
--- a/Digitigrade/Job/ProcessIncomingPush.php
+++ b/Digitigrade/Job/ProcessIncomingPush.php
@@ -18,6 +18,14 @@ class ProcessIncomingPush extends Job {
     public function run() {
         assert(isset($this->object->type));
         $log = Logger::getInstance();
+        $type = $this->object->type;
+        if ($type == 'tombstone') {
+            if (!isset($this->object->previousType)) {
+                throw new \RuntimeException('tombstone object does not have a previousType');
+            }
+            $log->info('the following object import is actually a tombstone ...');
+            $type = $this->object->previousType;
+        }
         switch ($this->object->type) {
             case 'actor':
                 $log->info('importing actor with uri ' . $this->object->self);
@@ -32,7 +40,6 @@ class ProcessIncomingPush extends Job {
                 Interaction::importFromReceivedObject($this->object);
                 break;
             case 'extension':
-            case 'tombstone':
                 throw new \RuntimeException('object type ' . $this->object->type . ' not yet implemented :(');
             default:
                 throw new \RuntimeException('invalid object type: ' . $this->object->type);
diff --git a/Digitigrade/Model/Actor.php b/Digitigrade/Model/Actor.php
index 07f24ec..8059409 100644
--- a/Digitigrade/Model/Actor.php
+++ b/Digitigrade/Model/Actor.php
@@ -196,7 +196,22 @@ class Actor extends PushableModel implements RpcReceiver {
         return Instance::findByHostname(hostname_from_uri($this->uri));
     }
 
+    protected function getRelevantServers(): array {
+        $actors = array_unique(array_merge($this->findFollowers(), $this->findFollowees()));
+        $instances = array_unique(array_map(function (Actor $actor) {
+            return Instance::findByHostname(hostname_from_uri($actor->uri));
+        }, $actors));
+        return $instances;
+    }
+
     public function jsonSerialize(): array {
+        if ($this->deleted) {
+            return [
+                'type' => 'tombstone',
+                'self' => path_to_uri("/user/$this->handle"),
+                'previousType' => 'actor'
+            ];
+        }
         return [
             'type' => 'actor',
             'self' => path_to_uri("/user/$this->handle"),
diff --git a/Digitigrade/Model/FetchableModel.php b/Digitigrade/Model/FetchableModel.php
index 5e4d1e8..e14cc2e 100644
--- a/Digitigrade/Model/FetchableModel.php
+++ b/Digitigrade/Model/FetchableModel.php
@@ -62,6 +62,16 @@ abstract class FetchableModel extends Model implements RemoteFetchable {
         if ($data === null)
             return null;
 
+        if (($data->type ?? null) == 'tombstone') {
+            // handle deletes
+            $obj = static::findWhere('uri = ?', [$data->self]);
+            if ($obj == null)
+                return null;
+            $obj->deleted = true;
+            $obj->save();
+            return null;
+        }
+
         $obj = static::createFromJson($data, $autoSave, $uri);
 
         $obj->finaliseAfterFetch($uri);
diff --git a/Digitigrade/Model/Interaction.php b/Digitigrade/Model/Interaction.php
index bf0745e..38065c1 100644
--- a/Digitigrade/Model/Interaction.php
+++ b/Digitigrade/Model/Interaction.php
@@ -47,7 +47,22 @@ class Interaction extends PushableModel {
         return self::findAllWhere('target = ?', [$target->id]);
     }
 
+    protected function getRelevantServers(): array {
+        $instances = array_map(function (Actor $actor) {
+            return Instance::findByHostname(hostname_from_uri($actor->uri));
+        }, $this->author->findFollowers());
+        $instances[] = Instance::findByHostname(hostname_from_uri($this->target->uri));
+        return $instances;
+    }
+
     public function jsonSerialize(): array {
+        if ($this->deleted) {
+            return [
+                'type' => 'tombstone',
+                'self' => path_to_uri("/interaction/$this->id"),
+                'previousType' => 'interaction'
+            ];
+        }
         return [
             'type' => 'interaction',
             'self' => path_to_uri("/interaction/$this->id"),
diff --git a/Digitigrade/Model/Note.php b/Digitigrade/Model/Note.php
index 7ffb67e..9d73a89 100644
--- a/Digitigrade/Model/Note.php
+++ b/Digitigrade/Model/Note.php
@@ -110,15 +110,7 @@ class Note extends PushableModel {
         return Interaction::findAllWithTarget($this);
     }
 
-    /**
-     * Sends this note to all instances it's relevant to.
-     * 
-     * For example, this may include the servers of any followers if the scope is at
-     * least 'followers', anyone mentioned, and anyone in the alsoVisibleTo field.
-     * If the scope is 'public' it may also send it to other servers? i'm not sure
-     * @return void
-     */
-    public function publish() {
+    protected function getRelevantServers(): array {
         $recipientActors = match ($this->privacy->scope) {
             NotePrivacyScope::NONE => [],
             NotePrivacyScope::MUTUALS => $this->author->findMutualFollows(),
@@ -129,14 +121,17 @@ class Note extends PushableModel {
         $instances = array_map(function (Actor $a) {
             return $a->findHomeInstance();
         }, $recipientActors);
-        $instances = array_unique($instances);
-
-        foreach ($instances as $instance) {
-            (new PushObject($this, $instance))->submit();
-        }
+        return array_unique($instances);
     }
 
     public function jsonSerialize(): array {
+        if ($this->deleted) {
+            return [
+                'type' => 'tombstone',
+                'self' => path_to_uri("/post/$this->id"),
+                'previousType' => 'note'
+            ];
+        }
         return [
             'type' => 'note',
             'self' => path_to_uri("/post/$this->id"),
diff --git a/Digitigrade/Model/PushableModel.php b/Digitigrade/Model/PushableModel.php
index c008320..9de3507 100644
--- a/Digitigrade/Model/PushableModel.php
+++ b/Digitigrade/Model/PushableModel.php
@@ -1,11 +1,24 @@
 <?php
 namespace Digitigrade\Model;
 
+use Digitigrade\Job\PushObject;
+
 abstract class PushableModel extends FetchableModel implements \JsonSerializable {
     public ?int $id;
     public string $uri;
+    public bool $deleted = false;
+
+    public static function importFromReceivedObject(\stdClass $data, bool $autoSave = true): ?static {
+        if ($data->type == 'tombstone') {
+            // actually just delete the object if we know it and do nothing if not
+            $obj = static::findWhere('uri = ?', [$data->self]);
+            if ($obj == null)
+                return null;
+            $obj->deleted = true;
+            $obj->save();
+            return null;
+        }
 
-    public static function importFromReceivedObject(\stdClass $data, bool $autoSave = true): static {
         $obj = static::createFromJson($data, $autoSave);
         if ($autoSave) {
             $obj->save();
@@ -13,4 +26,31 @@ abstract class PushableModel extends FetchableModel implements \JsonSerializable
         }
         return $obj;
     }
+
+    /**
+     * @return Instance[] a list of instances who this object should be pushed to
+     */
+    protected abstract function getRelevantServers(): array;
+
+    /**
+     * Sends this object to all instances it's relevant to.
+     * 
+     * Please don't call this on non-local objects :3
+     * @return void
+     */
+    public function publish() {
+        foreach ($this->getRelevantServers() as $instance) {
+            (new PushObject($this, $instance))->submit();
+        }
+    }
+
+    /**
+     * Marks this object as deleted and publishes a tombstone in its place.
+     * @return void
+     */
+    public function markDeleted() {
+        $this->deleted = true;
+        $this->save();
+        $this->publish();
+    }
 }
\ No newline at end of file
diff --git a/migrations/20241220_152023_deletion.php b/migrations/20241220_152023_deletion.php
new file mode 100644
index 0000000..3b5dd9b
--- /dev/null
+++ b/migrations/20241220_152023_deletion.php
@@ -0,0 +1,60 @@
+<?php
+
+use \Digitigrade\Db\Migrator;
+
+Migrator::getInstance()->register(20241220_152023, function (PDO $db) {
+    // all fetchable/pushable objects can be marked as deleted, which will hide them, and make them get swept up later
+    // when they're actually deleted i also need any referents to be cascade-deleted
+    // also i noticed the column type for note.in_reply_to is wrong lol
+    $db->beginTransaction();
+    $db->exec(<<<END
+    ALTER TABLE actor ADD COLUMN deleted boolean not null default false;
+    ALTER TABLE note ADD COLUMN deleted boolean not null default false;
+    ALTER TABLE interaction ADD COLUMN deleted boolean not null default false;
+
+    ALTER TABLE actor_endpoints
+        DROP CONSTRAINT actor_endpoints_actor_id_fkey,
+        ADD foreign key (actor_id) references actor on delete cascade;
+    ALTER TABLE actor_extension
+        DROP CONSTRAINT actor_extension_actor_id_fkey,
+        ADD foreign key (actor_id) references actor on delete cascade;
+    ALTER TABLE actor_webfinger
+        DROP CONSTRAINT actor_webfinger_actor_fkey,
+        ADD foreign key (actor) references actor on delete cascade;
+    ALTER TABLE follow_relation
+        DROP CONSTRAINT follow_relation_object_fkey,
+        DROP CONSTRAINT follow_relation_subject_fkey,
+        ADD foreign key (object) references actor on delete cascade,
+        ADD foreign key (subject) references actor on delete cascade;
+    ALTER TABLE interaction
+        DROP CONSTRAINT interaction_author_fkey,
+        DROP CONSTRAINT interaction_target_fkey,
+        ADD foreign key (author) references actor on delete cascade,
+        ADD foreign key (target) references note on delete cascade;
+    ALTER TABLE note
+        DROP CONSTRAINT note_author_fkey,
+        DROP CONSTRAINT note_thread_apex_fkey,
+        DROP COLUMN in_reply_to,
+        ADD COLUMN in_reply_to bigint references note on delete set null,
+        ADD foreign key (author) references actor on delete cascade,
+        ADD foreign key (thread_apex) references note on delete set null;
+    ALTER TABLE note_attachment
+        DROP CONSTRAINT note_attachment_note_id_fkey,
+        ADD foreign key (note_id) references note on delete cascade;
+    ALTER TABLE note_extension
+        DROP CONSTRAINT note_extension_note_id_fkey,
+        ADD foreign key (note_id) references note on delete cascade;
+    ALTER TABLE note_formatted_content
+        DROP CONSTRAINT note_formatted_content_note_id_fkey,
+        ADD foreign key (note_id) references note on delete cascade;
+    ALTER TABLE note_mention
+        DROP CONSTRAINT note_mention_actor_id_fkey,
+        DROP CONSTRAINT note_mention_note_id_fkey,
+        ADD foreign key (actor_id) references actor on delete cascade,
+        ADD foreign key (note_id) references note on delete cascade;
+    ALTER TABLE note_privacy
+        DROP CONSTRAINT note_privacy_note_id_fkey,
+        ADD foreign key (note_id) references note on delete cascade;
+    END);
+    $db->commit();
+});