From f264923cad9b867771c793cc10af36689c1c657e Mon Sep 17 00:00:00 2001
From: Michael <heluecht@pirati.ca>
Date: Fri, 11 Mar 2022 14:00:05 +0000
Subject: [PATCH] Issue 11309: Check if a post is wanted

---
 src/Protocol/ActivityPub/Processor.php | 52 ++++++++++++++++++++++++++
 src/Protocol/DFRN.php                  |  5 +--
 src/Protocol/Diaspora.php              |  5 +--
 3 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index 79d24d1602..2e2d18b391 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -572,6 +572,53 @@ class Processor
 		return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 	}
 
+	/**
+	 * Checks if an incoming message is wanted
+	 *
+	 * @param array $activity
+	 * @param array $item
+	 * @return boolean Is the message wanted?
+	 */
+	private static function isSolicitedMessage(array $activity, array $item)
+	{
+		// The checks are split to improve the support when searching why a message was accepted.
+		if (count($activity['receiver']) != 1) {
+			// The message has more than one receiver, so it is wanted.
+			Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
+			return true;
+		}
+
+		if ($item['private'] == Item::PRIVATE) {
+			// We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
+			Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
+			return true;
+		}
+		
+		if (!empty($activity['from-relay'])) {
+			// We check relay posts at another place. When it arrived here, the message is already checked.
+			Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
+			return true;
+		}
+
+		if (!empty($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' => $item['uri']]);
+			return true;
+		}
+
+		if ($item['gravity'] != GRAVITY_PARENT) {
+			// We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
+			// This can possibly be improved in the future.
+			Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
+			return true;
+		}
+
+		$tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
+		return Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB);
+	}
+
 	/**
 	 * Creates an item post
 	 *
@@ -589,6 +636,11 @@ class Processor
 		$stored = false;
 		ksort($activity['receiver']);
 
+		if (!self::isSolicitedMessage($activity, $item)) {
+			DBA::delete('item-uri', ['id' => $item['uri-id']]);
+			return;
+		}
+
 		foreach ($activity['receiver'] as $receiver) {
 			if ($receiver == -1) {
 				continue;
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index 2be55b8a55..a20d54fb64 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -1775,12 +1775,11 @@ class DFRN
 	{
 		if (DBA::exists('contact', ["`nurl` = ? AND `uid` != ? AND `rel` IN (?, ?)",
 			Strings::normaliseLink($item["author-link"]), 0, Contact::FRIEND, Contact::SHARING])) {
-			Logger::info('Author has got followers - accepted', ['uri' => $item['uri'], 'author' => $item["author-link"]]);
+			Logger::debug('Author has got followers - accepted', ['uri' => $item['uri'], 'author' => $item["author-link"]]);
 			return true;
 		}
 
-		$taglist = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]);
-		$tags = array_column($taglist, 'name');
+		$tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 		return Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::DFRN);
 	}
 
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index ad8e2bbef8..331a3bd9fe 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -2620,12 +2620,11 @@ class Diaspora
 		$contact = Contact::getByURL($author);
 		if (DBA::exists('contact', ["`nurl` = ? AND `uid` != ? AND `rel` IN (?, ?)",
 			$contact['nurl'], 0, Contact::FRIEND, Contact::SHARING])) {
-			Logger::info('Author has got followers - accepted', ['url' => $url, 'author' => $author]);
+			Logger::debug('Author has got followers - accepted', ['url' => $url, 'author' => $author]);
 			return true;
 		}
 
-		$taglist = Tag::getByURIId($uriid, [Tag::HASHTAG]);
-		$tags = array_column($taglist, 'name');
+		$tags = array_column(Tag::getByURIId($uriid, [Tag::HASHTAG]), 'name');
 		return Relay::isSolicitedPost($tags, $body, $contact['id'], $url, Protocol::DIASPORA);
 	}