From 8c778ca02e4daa3936842f0e9eccc055fec80221 Mon Sep 17 00:00:00 2001
From: Michael <heluecht@pirati.ca>
Date: Sat, 12 Mar 2022 11:17:33 +0000
Subject: [PATCH] Improved completion check for AP

---
 src/Module/Debug/ActivityPubConversion.php |  4 ++++
 src/Protocol/ActivityPub/Processor.php     | 15 ++++++++-------
 src/Protocol/ActivityPub/Receiver.php      | 14 +++++++++++++-
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/Module/Debug/ActivityPubConversion.php b/src/Module/Debug/ActivityPubConversion.php
index 5de4b93b74..ec7fee3f46 100644
--- a/src/Module/Debug/ActivityPubConversion.php
+++ b/src/Module/Debug/ActivityPubConversion.php
@@ -114,6 +114,10 @@ class ActivityPubConversion extends BaseModule
 					$object_data['thread-completion'] = $activity['thread-completion'];
 				}
 
+				if (!empty($activity['completion-mode'])) {
+					$object_data['completion-mode'] = $activity['completion-mode'];
+				}
+
 				$results[] = [
 					'title'   => DI::l10n()->t('Object data'),
 					'content' => visible_whitespace(var_export($object_data, true))
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index 3778a0aa89..ae9dd4c790 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -235,7 +235,7 @@ class Processor
 
 		if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 			Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
-			self::fetchMissingActivity($activity['reply-to-id'], $activity);
+			self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 		}
 
 		$item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
@@ -600,11 +600,9 @@ class Processor
 			return true;
 		}
 
-		if (!empty($activity['thread-completion'])) {
-			// The thread completion mode means that the post is fetched intentionally.
-			// This can have several causes, in doubt we keep the message.
-			// This can possibly be improved in the future.
-			Logger::debug('Message is in completion mode - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
+		if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
+			// Manual completions and completions caused by reshares are allowed without any further checks.
+			Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 			return true;
 		}
 
@@ -903,7 +901,7 @@ class Processor
 	 * @return string fetched message URL
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
+	public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
 	{
 		if (!empty($child['receiver'])) {
 			$uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
@@ -967,10 +965,13 @@ class Processor
 
 		if (!empty($relay_actor)) {
 			$ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
+			$ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
 		} elseif (!empty($child['thread-completion'])) {
 			$ldactivity['thread-completion'] = $child['thread-completion'];
+			$ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
 		} else {
 			$ldactivity['thread-completion'] = Contact::getIdForURL($actor);
+			$ldactivity['completion-mode']   = $completion;
 		}
 
 		if (!empty($child['type'])) {
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 32994a9d5d..98d40137a9 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -68,6 +68,12 @@ class Receiver
 	const TARGET_ANSWER = 6;
 	const TARGET_GLOBAL = 7;
 
+	const COMPLETION_NONE    = 0;
+	const COMPLETION_ANNOUCE = 1;
+	const COMPLETION_RELAY   = 2;
+	const COMPLETION_MANUAL  = 3;
+	const COMPLETION_AUTO    = 4;
+
 	/**
 	 * Checks incoming message from the inbox
 	 *
@@ -190,7 +196,7 @@ class Receiver
 			return;
 		}
 
-		$id = Processor::fetchMissingActivity($object_id, [], $actor);
+		$id = Processor::fetchMissingActivity($object_id, [], $actor, self::COMPLETION_RELAY);
 		if (empty($id)) {
 			Logger::notice('Relayed message had not been fetched', ['id' => $object_id]);
 			return;
@@ -529,6 +535,11 @@ class Receiver
 		if (!empty($activity['thread-completion'])) {
 			$object_data['thread-completion'] = $activity['thread-completion'];
 		}
+
+		if (!empty($activity['completion-mode'])) {
+			$object_data['completion-mode'] = $activity['completion-mode'];
+		}
+
 		if (!empty($activity['thread-children-type'])) {
 			$object_data['thread-children-type'] = $activity['thread-children-type'];
 		}
@@ -555,6 +566,7 @@ class Receiver
 			case 'as:Announce':
 				if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 					$object_data['thread-completion'] = Contact::getIdForURL($actor);
+					$object_data['completion-mode']   = self::COMPLETION_ANNOUCE;
 
 					$item = ActivityPub\Processor::createItem($object_data);
 					if (empty($item)) {