X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FProtocol%2FActivityPub.php;h=fa88847f37892e50e203a7d78d375c7dcd952d56;hb=8c7e5bb776583ac97b31bc023fbc335b1a2b1251;hp=b27101aac8fb2f30a07f8b11ab93cce2310068d9;hpb=b44fc62708f111449f9ead95c09d4570465c94b7;p=friendica.git

diff --git a/src/Protocol/ActivityPub.php b/src/Protocol/ActivityPub.php
index b27101aac8..fa88847f37 100644
--- a/src/Protocol/ActivityPub.php
+++ b/src/Protocol/ActivityPub.php
@@ -13,6 +13,7 @@ use Friendica\Core\Protocol;
 use Friendica\Model\Conversation;
 use Friendica\Model\Contact;
 use Friendica\Model\Item;
+use Friendica\Model\Profile;
 use Friendica\Model\Term;
 use Friendica\Model\User;
 use Friendica\Util\DateTimeFormat;
@@ -21,6 +22,7 @@ use Friendica\Content\Text\BBCode;
 use Friendica\Content\Text\HTML;
 use Friendica\Util\JsonLD;
 use Friendica\Util\LDSignature;
+use Friendica\Core\Config;
 
 /**
  * @brief ActivityPub Protocol class
@@ -34,29 +36,33 @@ use Friendica\Util\LDSignature;
  *
  * Digest: https://tools.ietf.org/html/rfc5843
  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
- * https://github.com/digitalbazaar/php-json-ld
  *
- * Part of the code for HTTP signing is taken from the Osada project.
- * https://framagit.org/macgirvin/osada
+ * Mastodon implementation of supported activities:
+ * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  *
  * To-do:
  *
  * Receiver:
- * - Activities: Dislike, Update, Delete
+ * - Activities: Update (Notes, Person), Delete (Person, Activities, Notes)
  * - Object Types: Person, Tombstome
  *
  * Transmitter:
- * - Activities: Like, Dislike, Update, Delete, Announce
- * - Object Tyoes: Article, Person, Tombstone
+ * - Activities: Announce, Update (Person)
+ * - Object Tyoes: Person
  *
  * General:
- * - Endpoints: Outbox, Follower, Following
- * - General cleanup
  * - Queueing unsucessful deliveries
+ * - Event support
+ * - Polling the outboxes for missing content?
  */
 class ActivityPub
 {
 	const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
+	const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
+		['ostatus' => 'http://ostatus.org#', 'uuid' => 'http://schema.org/identifier',
+		'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
+		'atomUri' => 'ostatus:atomUri', 'conversation' => 'ostatus:conversation',
+		'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']];
 
 	public static function isRequest()
 	{
@@ -64,6 +70,124 @@ class ActivityPub
 			stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
 	}
 
+	public static function getFollowers($owner, $page = null)
+	{
+		$condition = ['rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::NATIVE_SUPPORT, 'uid' => $owner['uid'],
+			'self' => false, 'hidden' => false, 'archive' => false, 'pending' => false];
+		$count = DBA::count('contact', $condition);
+
+		$data = ['@context' => self::CONTEXT];
+		$data['id'] = System::baseUrl() . '/followers/' . $owner['nickname'];
+		$data['type'] = 'OrderedCollection';
+		$data['totalItems'] = $count;
+
+		// When we hide our friends we will only show the pure number but don't allow more.
+		$profile = Profile::getProfileForUser($owner['uid']);
+		if (!empty($profile['hide-friends'])) {
+			return $data;
+		}
+
+		if (empty($page)) {
+			$data['first'] = System::baseUrl() . '/followers/' . $owner['nickname'] . '?page=1';
+		} else {
+			$list = [];
+
+			$contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
+			while ($contact = DBA::fetch($contacts)) {
+				$list[] = $contact['url'];
+			}
+
+			if (!empty($list)) {
+				$data['next'] = System::baseUrl() . '/followers/' . $owner['nickname'] . '?page=' . ($page + 1);
+			}
+
+			$data['partOf'] = System::baseUrl() . '/followers/' . $owner['nickname'];
+
+			$data['orderedItems'] = $list;
+		}
+
+		return $data;
+	}
+
+	public static function getFollowing($owner, $page = null)
+	{
+		$condition = ['rel' => [Contact::SHARING, Contact::FRIEND], 'network' => Protocol::NATIVE_SUPPORT, 'uid' => $owner['uid'],
+			'self' => false, 'hidden' => false, 'archive' => false, 'pending' => false];
+		$count = DBA::count('contact', $condition);
+
+		$data = ['@context' => self::CONTEXT];
+		$data['id'] = System::baseUrl() . '/following/' . $owner['nickname'];
+		$data['type'] = 'OrderedCollection';
+		$data['totalItems'] = $count;
+
+		// When we hide our friends we will only show the pure number but don't allow more.
+		$profile = Profile::getProfileForUser($owner['uid']);
+		if (!empty($profile['hide-friends'])) {
+			return $data;
+		}
+
+		if (empty($page)) {
+			$data['first'] = System::baseUrl() . '/following/' . $owner['nickname'] . '?page=1';
+		} else {
+			$list = [];
+
+			$contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
+			while ($contact = DBA::fetch($contacts)) {
+				$list[] = $contact['url'];
+			}
+
+			if (!empty($list)) {
+				$data['next'] = System::baseUrl() . '/following/' . $owner['nickname'] . '?page=' . ($page + 1);
+			}
+
+			$data['partOf'] = System::baseUrl() . '/following/' . $owner['nickname'];
+
+			$data['orderedItems'] = $list;
+		}
+
+		return $data;
+	}
+
+	public static function getOutbox($owner, $page = null)
+	{
+		$public_contact = Contact::getIdForURL($owner['url'], 0, true);
+
+		$condition = ['uid' => $owner['uid'], 'contact-id' => $owner['id'], 'author-id' => $public_contact,
+			'wall' => true, 'private' => false, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
+			'deleted' => false, 'visible' => true];
+		$count = DBA::count('item', $condition);
+
+		$data = ['@context' => self::CONTEXT];
+		$data['id'] = System::baseUrl() . '/outbox/' . $owner['nickname'];
+		$data['type'] = 'OrderedCollection';
+		$data['totalItems'] = $count;
+
+		if (empty($page)) {
+			$data['first'] = System::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
+		} else {
+			$list = [];
+
+			$condition['parent-network'] = Protocol::NATIVE_SUPPORT;
+
+			$items = Item::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
+			while ($item = Item::fetch($items)) {
+				$object = self::createObjectFromItemID($item['id']);
+				unset($object['@context']);
+				$list[] = $object;
+			}
+
+			if (!empty($list)) {
+				$data['next'] = System::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
+			}
+
+			$data['partOf'] = System::baseUrl() . '/outbox/' . $owner['nickname'];
+
+			$data['orderedItems'] = $list;
+		}
+
+		return $data;
+	}
+
 	/**
 	 * Return the ActivityPub profile of the given user
 	 *
@@ -122,7 +246,7 @@ class ActivityPub
 		return $data;
 	}
 
-	public static function fetchPermissionBlockFromConversation($item)
+	private static function fetchPermissionBlockFromConversation($item)
 	{
 		if (empty($item['thr-parent'])) {
 			return [];
@@ -139,6 +263,13 @@ class ActivityPub
 		$actor = JsonLD::fetchElement($activity, 'actor', 'id');
 		$profile = ActivityPub::fetchprofile($actor);
 
+		$item_profile = ActivityPub::fetchprofile($item['author-link']);
+		$exclude[] = $item['author-link'];
+
+		if ($item['gravity'] == GRAVITY_PARENT) {
+			$exclude[] = $item['owner-link'];
+		}
+
 		$permissions = [];
 
 		$elements = ['to', 'cc', 'bto', 'bcc'];
@@ -150,10 +281,12 @@ class ActivityPub
 				$activity[$element] = [$activity[$element]];
 			}
 			foreach ($activity[$element] as $receiver) {
-				if ($receiver == $profile['followers']) {
-					$receiver = System::baseUrl() . '/followers/' . $item['author-nick'];
+				if ($receiver == $profile['followers'] && !empty($item_profile['followers'])) {
+					$receiver = $item_profile['followers'];
+				}
+				if (!in_array($receiver, $exclude)) {
+					$permissions[$element][] = $receiver;
 				}
-				$permissions[$element][] = $receiver;
 			}
 		}
 		return $permissions;
@@ -165,27 +298,32 @@ class ActivityPub
 
 		$data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 
+		$actor_profile = ActivityPub::fetchprofile($item['author-link']);
+
 		$terms = Term::tagArrayFromItemId($item['id']);
 
+		$contacts[$item['author-link']] = $item['author-link'];
+
 		if (!$item['private']) {
 			$data['to'][] = self::PUBLIC;
-			$data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
+			if (!empty($actor_profile['followers'])) {
+				$data['cc'][] = $actor_profile['followers'];
+			}
 
 			foreach ($terms as $term) {
 				if ($term['type'] != TERM_MENTION) {
 					continue;
 				}
-				$profile = self::fetchprofile($term['url']);
-				if (!empty($profile)) {
+				$profile = self::fetchprofile($term['url'], false);
+				if (!empty($profile) && empty($contacts[$profile['url']])) {
 					$data['cc'][] = $profile['url'];
+					$contacts[$profile['url']] = $profile['url'];
 				}
 			}
 		} else {
-			//$data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
 			$receiver_list = Item::enumeratePermissions($item);
 
 			$mentioned = [];
-			$contacts = [];
 
 			foreach ($terms as $term) {
 				if ($term['type'] != TERM_MENTION) {
@@ -206,97 +344,107 @@ class ActivityPub
 					$contacts[$contact['url']] = $contact['url'];
 				}
 			}
+		}
+
+// It is to decide whether we should include all profiles in a thread to the list of receivers
+/*
+		$parents = Item::select(['author-link', 'owner-link', 'gravity'], ['parent' => $item['parent']]);
+		while ($parent = Item::fetch($parents)) {
+			$profile = self::fetchprofile($parent['author-link'], false);
+			if (!empty($profile) && empty($contacts[$profile['url']])) {
+				$data['cc'][] = $profile['url'];
+				$contacts[$profile['url']] = $profile['url'];
+			}
+
+			if ($item['gravity'] != GRAVITY_PARENT) {
+				continue;
+			}
 
-			if (empty($data['to'])) {
-				$data['to'] = $data['cc'];
-				$data['cc'] = [];
+			$profile = self::fetchprofile($parent['owner-link'], false);
+			if (!empty($profile) && empty($contacts[$profile['url']])) {
+				$data['cc'][] = $profile['url'];
+				$contacts[$profile['url']] = $profile['url'];
 			}
 		}
+		DBA::close($parents);
+*/
+		if (empty($data['to'])) {
+			$data['to'] = $data['cc'];
+			$data['cc'] = [];
+		}
 
 		return $data;
 	}
 
 	public static function fetchTargetInboxes($item, $uid)
 	{
+		$permissions = self::createPermissionBlockForItem($item);
+		if (empty($permissions)) {
+			return [];
+		}
+
 		$inboxes = [];
 
-		$parents = Item::select(['author-link', 'owner-link'], ['parent' => $item['parent']]);
-		while ($parent = Item::fetch($parents)) {
-			$profile = self::fetchprofile($parent['author-link']);
-			if (!empty($profile)) {
-				$target = defaults($profile, 'sharedinbox', $profile['inbox']);
-				$inboxes[$target] = $target;
-			}
-			$profile = self::fetchprofile($parent['owner-link']);
-			if (!empty($profile)) {
-				$target = defaults($profile, 'sharedinbox', $profile['inbox']);
-				$inboxes[$target] = $target;
-			}
+		if ($item['gravity'] == GRAVITY_ACTIVITY) {
+			$item_profile = ActivityPub::fetchprofile($item['author-link']);
+		} else {
+			$item_profile = ActivityPub::fetchprofile($item['owner-link']);
 		}
-		DBA::close($parents);
-
-		$terms = Term::tagArrayFromItemId($item['id']);
-		if (!$item['private']) {
-			$contacts = DBA::select('contact', ['notify', 'batch'], ['uid' => $uid,
-					'rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB]);
-			while ($contact = DBA::fetch($contacts)) {
-				$contact = defaults($contact, 'batch', $contact['notify']);
-				$inboxes[$contact] = $contact;
-			}
-			DBA::close($contacts);
 
-			foreach ($terms as $term) {
-				if ($term['type'] != TERM_MENTION) {
-					continue;
-				}
-				$profile = self::fetchprofile($term['url']);
-				if (!empty($profile)) {
-					$target = defaults($profile, 'sharedinbox', $profile['inbox']);
-					$inboxes[$target] = $target;
-				}
+		$elements = ['to', 'cc', 'bto', 'bcc'];
+		foreach ($elements as $element) {
+			if (empty($permissions[$element])) {
+				continue;
 			}
-		} else {
-			$receiver_list = Item::enumeratePermissions($item);
-			$mentioned = [];
 
-			foreach ($terms as $term) {
-				if ($term['type'] != TERM_MENTION) {
-					continue;
-				}
-				$cid = Contact::getIdForURL($term['url'], $uid);
-				if (!empty($cid) && in_array($cid, $receiver_list)) {
-					$contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
-					$profile = self::fetchprofile($contact['url']);
+			foreach ($permissions[$element] as $receiver) {
+				if ($receiver == $item_profile['followers']) {
+					$contacts = DBA::select('contact', ['notify', 'batch'], ['uid' => $uid,
+						'rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB]);
+					while ($contact = DBA::fetch($contacts)) {
+						$contact = defaults($contact, 'batch', $contact['notify']);
+						$inboxes[$contact] = $contact;
+					}
+					DBA::close($contacts);
+				} else {
+					$profile = self::fetchprofile($receiver);
 					if (!empty($profile)) {
 						$target = defaults($profile, 'sharedinbox', $profile['inbox']);
 						$inboxes[$target] = $target;
 					}
 				}
 			}
-
-			foreach ($receiver_list as $receiver) {
-				$contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
-				$profile = self::fetchprofile($contact['url']);
-				if (!empty($profile)) {
-					$target = defaults($profile, 'sharedinbox', $profile['inbox']);
-					$inboxes[$target] = $target;
-				}
-			}
 		}
 
-		$profile = self::fetchprofile($item['author-link']);
-		if (!empty($profile['sharedinbox'])) {
-			unset($inboxes[$profile['sharedinbox']]);
-		}
+		return $inboxes;
+	}
 
-		if (!empty($profile['inbox'])) {
-			unset($inboxes[$profile['inbox']]);
+	public static function getTypeOfItem($item)
+	{
+		if ($item['verb'] == ACTIVITY_POST) {
+			if ($item['created'] == $item['edited']) {
+				$type = 'Create';
+			} else {
+				$type = 'Update';
+			}
+		} elseif ($item['verb'] == ACTIVITY_LIKE) {
+			$type = 'Like';
+		} elseif ($item['verb'] == ACTIVITY_DISLIKE) {
+			$type = 'Dislike';
+		} elseif ($item['verb'] == ACTIVITY_ATTEND) {
+			$type = 'Accept';
+		} elseif ($item['verb'] == ACTIVITY_ATTENDNO) {
+			$type = 'Reject';
+		} elseif ($item['verb'] == ACTIVITY_ATTENDMAYBE) {
+			$type = 'TentativeAccept';
+		} else {
+			$type = '';
 		}
 
-		return $inboxes;
+		return $type;
 	}
 
-	public static function createActivityFromItem($item_id)
+	public static function createActivityFromItem($item_id, $object_mode = false)
 	{
 		$item = Item::selectFirst([], ['id' => $item_id]);
 
@@ -313,14 +461,22 @@ class ActivityPub
 			}
 		}
 
-		$data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-			['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
-			'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
-			'conversation' => 'ostatus:conversation',
-			'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
+		$type = self::getTypeOfItem($item);
+
+		if (!$object_mode) {
+			$data = ['@context' => self::CONTEXT];
+
+			if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
+				$type = 'Undo';
+			} elseif ($item['deleted']) {
+				$type = 'Delete';
+			}
+		} else {
+			$data = [];
+		}
 
-		$data['id'] = $item['uri'] . '#activity';
-		$data['type'] = 'Create';
+		$data['id'] = $item['uri'] . '#' . $type;
+		$data['type'] = $type;
 		$data['actor'] = $item['author-link'];
 
 		$data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
@@ -329,13 +485,25 @@ class ActivityPub
 			$data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 		}
 
+		$data['context'] = self::createConversationURLFromItem($item);
+
 		$data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 
-		$data['object'] = self::createNote($item);
+		if (in_array($data['type'], ['Create', 'Update', 'Announce', 'Delete'])) {
+			$data['object'] = self::CreateNote($item);
+		} elseif ($data['type'] == 'Undo') {
+			$data['object'] = self::createActivityFromItem($item_id, true);
+		} else {
+			$data['object'] = $item['thr-parent'];
+		}
 
 		$owner = User::getOwnerDataById($item['uid']);
 
-		return LDSignature::sign($data, $owner);
+		if (!$object_mode) {
+			return LDSignature::sign($data, $owner);
+		} else {
+			return $data;
+		}
 	}
 
 	public static function createObjectFromItemID($item_id)
@@ -346,14 +514,8 @@ class ActivityPub
 			return false;
 		}
 
-		$data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-			['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
-			'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
-			'conversation' => 'ostatus:conversation',
-			'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
-
-		$data = array_merge($data, self::createNote($item));
-
+		$data = ['@context' => self::CONTEXT];
+		$data = array_merge($data, self::CreateNote($item));
 
 		return $data;
 	}
@@ -375,15 +537,40 @@ class ActivityPub
 				$tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
 			}
 		}
-
 		return $tags;
 	}
 
-	public static function createNote($item)
+	private static function createConversationURLFromItem($item)
+	{
+		$conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
+		if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
+			$conversation_uri = $conversation['conversation-uri'];
+		} else {
+			$conversation_uri = $item['parent-uri'];
+		}
+		return $conversation_uri;
+	}
+
+	private static function CreateNote($item)
 	{
+		if (!empty($item['title'])) {
+			$type = 'Article';
+		} else {
+			$type = 'Note';
+		}
+
+		if ($item['deleted']) {
+			$type = 'Tombstone';
+		}
+
 		$data = [];
 		$data['id'] = $item['uri'];
-		$data['type'] = 'Note';
+		$data['type'] = $type;
+
+		if ($item['deleted']) {
+			return $data;
+		}
+
 		$data['summary'] = null; // Ignore by now
 
 		if ($item['uri'] != $item['thr-parent']) {
@@ -392,25 +579,18 @@ class ActivityPub
 			$data['inReplyTo'] = null;
 		}
 
+		$data['uuid'] = $item['guid'];
 		$data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 
 		if ($item["created"] != $item["edited"]) {
 			$data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 		}
 
-		$data['url'] = $item['uri'];
+		$data['url'] = $item['plink'];
 		$data['attributedTo'] = $item['author-link'];
 		$data['actor'] = $item['author-link'];
 		$data['sensitive'] = false; // - Query NSFW
-
-		$conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
-		if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
-			$conversation_uri = $conversation['conversation-uri'];
-		} else {
-			$conversation_uri = $item['parent-uri'];
-		}
-
-		$data['conversation'] = $conversation_uri;
+		$data['conversation'] = $data['context'] = self::createConversationURLFromItem($item);
 
 		if (!empty($item['title'])) {
 			$data['name'] = BBCode::convert($item['title'], false, 7);
@@ -519,7 +699,6 @@ class ActivityPub
 		if (!$ret['success'] || empty($ret['body'])) {
 			return;
 		}
-
 		return json_decode($ret['body'], true);
 	}
 
@@ -562,13 +741,20 @@ class ActivityPub
 		return false;
 	}
 
-	public static function fetchprofile($url, $update = false)
+	/**
+	 * Fetches a profile form a given url
+	 *
+	 * @param string  $url    profile url
+	 * @param boolean $update true = always update, false = never update, null = update when not found
+	 * @return array profile array
+	 */
+	public static function fetchprofile($url, $update = null)
 	{
 		if (empty($url)) {
 			return false;
 		}
 
-		if (!$update) {
+		if (empty($update)) {
 			$apcontact = DBA::selectFirst('apcontact', [], ['url' => $url]);
 			if (DBA::isResult($apcontact)) {
 				return $apcontact;
@@ -583,6 +769,10 @@ class ActivityPub
 			if (DBA::isResult($apcontact)) {
 				return $apcontact;
 			}
+
+			if (!is_null($update)) {
+				return false;
+			}
 		}
 
 		if (empty(parse_url($url, PHP_URL_SCHEME))) {
@@ -715,14 +905,17 @@ class ActivityPub
 
 		if (LDSignature::isSigned($activity)) {
 			$ld_signer = LDSignature::getSigner($activity);
-			if (!empty($ld_signer)) {
+			if (!empty($ld_signer && ($actor == $http_signer))) {
+				logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
+				$trust_source = true;
+			} elseif (!empty($ld_signer)) {
 				logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
 				$trust_source = true;
 			} elseif ($actor == $http_signer) {
 				logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
 				$trust_source = true;
 			} else {
-				logger('Invalid JSON-LD signature.', LOGGER_DEBUG);
+				logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
 				$trust_source = false;
 			}
 		} elseif ($actor == $http_signer) {
@@ -869,6 +1062,7 @@ class ActivityPub
 				break;
 
 			case 'Dislike':
+				self::dislikeItem($object_data, $body);
 				break;
 
 			case 'Update':
@@ -1016,7 +1210,7 @@ class ActivityPub
 				return false;
 			}
 			logger('Using already stored item for url ' . $object_url, LOGGER_DEBUG);
-			$data = self::createNote($item);
+			$data = self::CreateNote($item);
 		}
 
 		if (empty($data['type'])) {
@@ -1233,6 +1427,17 @@ class ActivityPub
 		self::postItem($activity, $item, $body);
 	}
 
+	private static function dislikeItem($activity, $body)
+	{
+		$item = [];
+		$item['verb'] = ACTIVITY_DISLIKE;
+		$item['parent-uri'] = $activity['object'];
+		$item['gravity'] = GRAVITY_ACTIVITY;
+		$item['object-type'] = ACTIVITY_OBJ_NOTE;
+
+		self::postItem($activity, $item, $body);
+	}
+
 	private static function postItem($activity, $item, $body)
 	{
 		/// @todo What to do with $activity['context']?
@@ -1279,6 +1484,10 @@ class ActivityPub
 
 	private static function fetchMissingActivity($url, $child)
 	{
+		if (Config::get('system', 'ostatus_full_threads')) {
+			return;
+		}
+
 		$object = ActivityPub::fetchContent($url);
 		if (empty($object)) {
 			logger('Activity ' . $url . ' was not fetchable, aborting.');