X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FProtocol%2FActivityPub.php;h=7c0a2b706c8d7ef3d2afb4b622bd0e340af436ae;hb=cbfc3d0c28e0b55c3ccf1ddfd321798a8c2532e8;hp=df6b0342be0aa871ff53f22548d91e306f346f3f;hpb=f5104f3e46d27e6535bd8a07a98ead5b0c6755a8;p=friendica.git

diff --git a/src/Protocol/ActivityPub.php b/src/Protocol/ActivityPub.php
index df6b0342be..7c0a2b706c 100644
--- a/src/Protocol/ActivityPub.php
+++ b/src/Protocol/ActivityPub.php
@@ -12,13 +12,18 @@ use Friendica\Util\HTTPSignature;
 use Friendica\Core\Protocol;
 use Friendica\Model\Conversation;
 use Friendica\Model\Contact;
+use Friendica\Model\APContact;
 use Friendica\Model\Item;
+use Friendica\Model\Profile;
+use Friendica\Model\Term;
 use Friendica\Model\User;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Crypto;
 use Friendica\Content\Text\BBCode;
 use Friendica\Content\Text\HTML;
-use Friendica\Network\Probe;
+use Friendica\Util\JsonLD;
+use Friendica\Util\LDSignature;
+use Friendica\Core\Config;
 
 /**
  * @brief ActivityPub Protocol class
@@ -33,222 +38,33 @@ use Friendica\Network\Probe;
  * Digest: https://tools.ietf.org/html/rfc5843
  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  *
- * Part of the code for HTTP signing is taken from the Osada project.
- * 
+ * 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
- * - Object Types: Person, Tombstome
- *
- * Transmitter:
- * - Activities: Like, Dislike, Update, Delete
- * - Object Tyoes: Article, Announce, Person, Tombstone
- *
- * General:
- * - Message distribution
- * - Endpoints: Outbox, Object, Follower, Following
+ * - Polling the outboxes for missing content?
+ * - "about" needs HTML2BBCode parser
  */
 class ActivityPub
 {
-	const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
-
-	public static function transmit($data, $target, $uid)
-	{
-		$owner = User::getOwnerDataById($uid);
-
-		if (!$owner) {
-			return;
-		}
-
-		$content = json_encode($data);
-
-		$host = parse_url($target, PHP_URL_HOST);
-		$path = parse_url($target, PHP_URL_PATH);
-		$date = date('r');
-
-		$headers = ['Host: ' . $host, 'Date: ' . $date];
-
-		$signed_data = "(request-target): post " . $path . "\nhost: " . $host . "\ndate: " . $date;
-
-		$signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
-
-		$headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",headers="(request-target) host date",signature="' . $signature . '"';
-		$headers[] = 'Content-Type: application/activity+json';
-
-		Network::post($target, $content, $headers);
-		$return_code = BaseObject::getApp()->get_curl_code();
-
-		logger('Transmit to ' . $target . ' returned ' . $return_code);
-	}
-
+	const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
+	const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
+		['vcard' => 'http://www.w3.org/2006/vcard/ns#',
+		'diaspora' => 'https://diasporafoundation.org/ns/',
+		'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
+		'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
+	const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
+	const CONTENT_TYPES = ['Note', 'Article', 'Video', 'Image'];
+	const ACTIVITY_TYPES = ['Like', 'Dislike', 'Accept', 'Reject', 'TentativeAccept'];
 	/**
-	 * Return the ActivityPub profile of the given user
+	 * @brief Checks if the web request is done for the AP protocol
 	 *
-	 * @param integer $uid User ID
-	 * @return array
+	 * @return is it AP?
 	 */
-	public static function profile($uid)
+	public static function isRequest()
 	{
-		$accounttype = ['Person', 'Organization', 'Service', 'Group', 'Application'];
-
-		$condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
-			'account_removed' => false, 'verified' => true];
-		$fields = ['guid', 'nickname', 'pubkey', 'account-type'];
-		$user = DBA::selectFirst('user', $fields, $condition);
-		if (!DBA::isResult($user)) {
-			return [];
-		}
-
-		$fields = ['locality', 'region', 'country-name'];
-		$profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
-		if (!DBA::isResult($profile)) {
-			return [];
-		}
-
-		$fields = ['name', 'url', 'location', 'about', 'avatar'];
-		$contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
-		if (!DBA::isResult($contact)) {
-			return [];
-		}
-
-		$data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-			['uuid' => 'http://schema.org/identifier', 'sensitive' => 'as:sensitive',
-			'vcard' => 'http://www.w3.org/2006/vcard/ns#']]];
-
-		$data['id'] = $contact['url'];
-		$data['uuid'] = $user['guid'];
-		$data['type'] = $accounttype[$user['account-type']];
-		$data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
-		$data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
-		$data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
-		$data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
-		$data['preferredUsername'] = $user['nickname'];
-		$data['name'] = $contact['name'];
-		$data['vcard:hasAddress'] = ['@type' => 'Home', 'vcard:country-name' => $profile['country-name'],
-			'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
-		$data['summary'] = $contact['about'];
-		$data['url'] = $contact['url'];
-		$data['manuallyApprovesFollowers'] = false;
-		$data['publicKey'] = ['id' => $contact['url'] . '#main-key',
-			'owner' => $contact['url'],
-			'publicKeyPem' => $user['pubkey']];
-		$data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
-		$data['icon'] = ['type' => 'Image',
-			'url' => $contact['avatar']];
-
-		// tags: https://kitty.town/@inmysocks/100656097926961126.json
-		return $data;
-	}
-
-	public static function createActivityFromItem($item_id)
-	{
-		$item = Item::selectFirst([], ['id' => $item_id]);
-
-		$data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-			['Emoji' => 'toot:Emoji', 'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
-			'conversation' => 'ostatus:conversation', 'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri',
-			'ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
-			'toot' => 'http://joinmastodon.org/ns#']]];
-
-		$data['type'] = 'Create';
-		$data['id'] = $item['uri'];
-		$data['actor'] = $item['author-link'];
-		$data['to'] = 'https://www.w3.org/ns/activitystreams#Public';
-		$data['object'] = self::createNote($item);
-		return $data;
-	}
-
-	public static function createNote($item)
-	{
-		$data = [];
-		$data['type'] = 'Note';
-		$data['id'] = $item['uri'];
-
-		if ($item['uri'] != $item['thr-parent']) {
-			$data['inReplyTo'] = $item['thr-parent'];
-		}
-
-		$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['context'] = $data['conversation'] = $conversation_uri;
-		$data['actor'] = $item['author-link'];
-		$data['to'] = [];
-		if (!$item['private']) {
-			$data['to'][] = 'https://www.w3.org/ns/activitystreams#Public';
-		}
-		$data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
-		$data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
-		$data['attributedTo'] = $item['author-link'];
-		$data['name'] = BBCode::convert($item['title'], false, 7);
-		$data['content'] = BBCode::convert($item['body'], false, 7);
-		$data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
-		//$data['summary'] = ''; // Ignore by now
-		//$data['sensitive'] = false; // - Query NSFW
-		//$data['emoji'] = []; // Ignore by now
-		//$data['tag'] = []; /// @ToDo
-		//$data['attachment'] = []; // @ToDo
-		return $data;
-	}
-
-	public static function transmitActivity($activity, $target, $uid)
-	{
-		$profile = Probe::uri($target, Protocol::ACTIVITYPUB);
-
-		$owner = User::getOwnerDataById($uid);
-
-		$data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-			'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-			'type' => $activity,
-			'actor' => $owner['url'],
-			'object' => $profile['url']];
-
-		logger('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, LOGGER_DEBUG);
-		return self::transmit($data,  $profile['notify'], $uid);
-	}
-
-	public static function transmitContactAccept($target, $id, $uid)
-	{
-		$profile = Probe::uri($target, Protocol::ACTIVITYPUB);
-
-		$owner = User::getOwnerDataById($uid);
-		$data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-			'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-			'type' => 'Accept',
-			'actor' => $owner['url'],
-			'object' => ['id' => $id, 'type' => 'Follow',
-				'actor' => $profile['url'],
-				'object' => $owner['url']]];
-
-		logger('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
-		return self::transmit($data,  $profile['notify'], $uid);
-	}
-
-	public static function transmitContactUndo($target, $id, $uid)
-	{
-		$profile = Probe::uri($target, Protocol::ACTIVITYPUB);
-
-		if (empty($id)) {
-			$id = System::baseUrl() . '/activity/' . System::createGUID();
-		}
-
-		$owner = User::getOwnerDataById($uid);
-		$data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-			'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-			'type' => 'Undo',
-			'actor' => $owner['url'],
-			'object' => ['id' => $id, 'type' => 'Follow',
-				'actor' => $owner['url'],
-				'object' => $profile['url']]];
-
-		logger('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
-		return self::transmit($data,  $profile['notify'], $uid);
+		return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
+			stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
 	}
 
 	/**
@@ -259,256 +75,44 @@ class ActivityPub
 	 */
 	public static function fetchContent($url)
 	{
-		$ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json']);
-
-		if (!$ret['success'] || empty($ret['body'])) {
-			return;
-		}
-
-		return json_decode($ret['body'], true);
-	}
-
-	/**
-	 * Resolves the profile url from the address by using webfinger
-	 *
-	 * @param string $addr profile address (user@domain.tld)
-	 * @return string url
-	 */
-	private static function addrToUrl($addr)
-	{
-		$addr_parts = explode('@', $addr);
-		if (count($addr_parts) != 2) {
-			return false;
-		}
-
-		$webfinger = 'https://' . $addr_parts[1] . '/.well-known/webfinger?resource=acct:' . urlencode($addr);
-
-		$ret = Network::curl($webfinger, false, $redirects, ['accept_content' => 'application/jrd+json,application/json']);
+		$ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
 		if (!$ret['success'] || empty($ret['body'])) {
 			return false;
 		}
 
-		$data = json_decode($ret['body'], true);
-
-		if (empty($data['links'])) {
-			return false;
-		}
-
-		foreach ($data['links'] as $link) {
-			if (empty($link['href']) || empty($link['rel']) || empty($link['type'])) {
-				continue;
-			}
-
-			if (($link['rel'] == 'self') && ($link['type'] == 'application/activity+json')) {
-				return $link['href'];
-			}
-		}
-
-		return false;
-	}
-
-	public static function verifySignature($content, $http_headers)
-	{
-		$object = json_decode($content, true);
-
-		if (empty($object)) {
-			return false;
-		}
-
-		$actor = self::processElement($object, 'actor', 'id');
-
-		$headers = [];
-		$headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . $http_headers['REQUEST_URI'];
-
-		// First take every header
-		foreach ($http_headers as $k => $v) {
-			$field = str_replace('_', '-', strtolower($k));
-			$headers[$field] = $v;
-		}
-
-		// Now add every http header
-		foreach ($http_headers as $k => $v) {
-			if (strpos($k, 'HTTP_') === 0) {
-				$field = str_replace('_', '-', strtolower(substr($k, 5)));
-				$headers[$field] = $v;
-			}
-		}
-
-		$sig_block = ActivityPub::parseSigHeader($http_headers['HTTP_SIGNATURE']);
-
-		if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) {
-			return false;
-		}
-
-		$signed_data = '';
-		foreach ($sig_block['headers'] as $h) {
-			if (array_key_exists($h, $headers)) {
-				$signed_data .= $h . ': ' . $headers[$h] . "\n";
-			}
-		}
-		$signed_data = rtrim($signed_data, "\n");
-
-		if (empty($signed_data)) {
-			return false;
-		}
-
-		$algorithm = null;
-
-		if ($sig_block['algorithm'] === 'rsa-sha256') {
-			$algorithm = 'sha256';
-		}
-
-		if ($sig_block['algorithm'] === 'rsa-sha512') {
-			$algorithm = 'sha512';
-		}
-
-		if (empty($algorithm)) {
-			return false;
-		}
-
-		$key = self::fetchKey($sig_block['keyId'], $actor);
-
-		if (empty($key)) {
-			return false;
-		}
-
-		if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm)) {
-			return false;
-		}
-
-		// Check the digest if it was part of the signed data
-		if (in_array('digest', $sig_block['headers'])) {
-			$digest = explode('=', $headers['digest'], 2);
-			if ($digest[0] === 'SHA-256') {
-				$hashalg = 'sha256';
-			}
-			if ($digest[0] === 'SHA-512') {
-				$hashalg = 'sha512';
-			}
-
-			/// @todo add all hashes from the rfc
-
-			if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) {
-				return false;
-			}
-		}
-
-		// Check the content-length if it was part of the signed data
-		if (in_array('content-length', $sig_block['headers'])) {
-			if (strlen($content) != $headers['content-length']) {
-				return false;
-			}
-		}
-
-		return true;
-
-	}
-
-	private static function fetchKey($id, $actor)
-	{
-		$url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id);
-
-		$profile = Probe::uri($url, Protocol::ACTIVITYPUB);
-		if (!empty($profile)) {
-			return $profile['pubkey'];
-		} elseif ($url != $actor) {
-			$profile = Probe::uri($actor, Protocol::ACTIVITYPUB);
-			if (!empty($profile)) {
-				return $profile['pubkey'];
-			}
-		}
-
-		return false;
-	}
-
-	/**
-	 * @brief
-	 *
-	 * @param string $header
-	 * @return array associate array with
-	 *   - \e string \b keyID
-	 *   - \e string \b algorithm
-	 *   - \e array  \b headers
-	 *   - \e string \b signature
-	 */
-	private static function parseSigHeader($header)
-	{
-		$ret = [];
-		$matches = [];
-
-		if (preg_match('/keyId="(.*?)"/ism',$header,$matches)) {
-			$ret['keyId'] = $matches[1];
-		}
-
-		if (preg_match('/algorithm="(.*?)"/ism',$header,$matches)) {
-			$ret['algorithm'] = $matches[1];
-		}
-
-		if (preg_match('/headers="(.*?)"/ism',$header,$matches)) {
-			$ret['headers'] = explode(' ', $matches[1]);
-		}
-
-		if (preg_match('/signature="(.*?)"/ism',$header,$matches)) {
-			$ret['signature'] = base64_decode(preg_replace('/\s+/','',$matches[1]));
-		}
-
-		return $ret;
+		return json_decode($ret['body'], true);
 	}
 
 	/**
-	 * Fetches a profile from the given url
+	 * Fetches a profile from the given url into an array that is compatible to Probe::uri
 	 *
 	 * @param string $url profile url
 	 * @return array
 	 */
-	public static function fetchProfile($url)
+	public static function probeProfile($url)
 	{
-		if (empty(parse_url($url, PHP_URL_SCHEME))) {
-			$url = self::addrToUrl($url);
-			if (empty($url)) {
-				return false;
-			}
-		}
-
-		$data = self::fetchContent($url);
-
-		if (empty($data) || empty($data['id']) || empty($data['inbox'])) {
+		$apcontact = APContact::getByURL($url, true);
+		if (empty($apcontact)) {
 			return false;
 		}
 
 		$profile = ['network' => Protocol::ACTIVITYPUB];
-		$profile['nick'] = $data['preferredUsername'];
-		$profile['name'] = defaults($data, 'name', $profile['nick']);
-		$profile['guid'] = defaults($data, 'uuid', null);
-		$profile['url'] = $data['id'];
-
-		$parts = parse_url($profile['url']);
-		unset($parts['scheme']);
-		unset($parts['path']);
-		$profile['addr'] = $profile['nick'] . '@' . str_replace('//', '', Network::unparseURL($parts));
-		$profile['alias'] = self::processElement($data, 'url', 'href');
-		$profile['photo'] = self::processElement($data, 'icon', 'url');
+		$profile['nick'] = $apcontact['nick'];
+		$profile['name'] = $apcontact['name'];
+		$profile['guid'] = $apcontact['uuid'];
+		$profile['url'] = $apcontact['url'];
+		$profile['addr'] = $apcontact['addr'];
+		$profile['alias'] = $apcontact['alias'];
+		$profile['photo'] = $apcontact['photo'];
 		// $profile['community']
 		// $profile['keywords']
 		// $profile['location']
-		$profile['about'] = defaults($data, 'summary', '');
-		$profile['batch'] = self::processElement($data, 'endpoints', 'sharedInbox');
-		$profile['notify'] = $data['inbox'];
-		$profile['poll'] = $data['outbox'];
-		$profile['pubkey'] = self::processElement($data, 'publicKey', 'publicKeyPem');
-
-		// Check if the address is resolvable
-		if (self::addrToUrl($profile['addr']) == $profile['url']) {
-			$parts = parse_url($profile['url']);
-			unset($parts['path']);
-			$profile['baseurl'] = Network::unparseURL($parts);
-		} else {
-			unset($profile['addr']);
-		}
-
-		if ($profile['url'] == $profile['alias']) {
-			unset($profile['alias']);
-		}
+		$profile['about'] = $apcontact['about'];
+		$profile['batch'] = $apcontact['sharedinbox'];
+		$profile['notify'] = $apcontact['inbox'];
+		$profile['poll'] = $apcontact['outbox'];
+		$profile['pubkey'] = $apcontact['pubkey'];
+		$profile['baseurl'] = $apcontact['baseurl'];
 
 		// Remove all "null" fields
 		foreach ($profile as $field => $content) {
@@ -517,51 +121,16 @@ class ActivityPub
 			}
 		}
 
-/*
-		// To-Do
-		unset($data['type']);
-		unset($data['manuallyApprovesFollowers']);
-
-		// Unhandled
-		unset($data['@context']);
-		unset($data['tag']);
-		unset($data['attachment']);
-		unset($data['image']);
-		unset($data['nomadicLocations']);
-		unset($data['signature']);
-		unset($data['following']);
-		unset($data['followers']);
-		unset($data['featured']);
-		unset($data['movedTo']);
-		unset($data['liked']);
-		unset($data['sharedInbox']); // Misskey
-		unset($data['isCat']); // Misskey
-		unset($data['kroeg:blocks']); // Kroeg
-		unset($data['updated']); // Kroeg
-*/
 		return $profile;
 	}
 
-	public static function processInbox($body, $header, $uid)
-	{
-		logger('Incoming message for user ' . $uid, LOGGER_DEBUG);
-
-		if (!self::verifySignature($body, $header)) {
-			logger('Invalid signature, message will be discarded.', LOGGER_DEBUG);
-			return;
-		}
-
-		$activity = json_decode($body, true);
-
-		if (!is_array($activity)) {
-			logger('Invalid body.', LOGGER_DEBUG);
-			return;
-		}
-
-		self::processActivity($activity, $body, $uid);
-	}
-
-	public static function fetchOutbox($url)
+	/**
+	 * @brief 
+	 *
+	 * @param $url
+	 * @param integer $uid User ID
+	 */
+	public static function fetchOutbox($url, $uid)
 	{
 		$data = self::fetchContent($url);
 		if (empty($data)) {
@@ -573,609 +142,14 @@ class ActivityPub
 		} elseif (!empty($data['first']['orderedItems'])) {
 			$items = $data['first']['orderedItems'];
 		} elseif (!empty($data['first'])) {
-			self::fetchOutbox($data['first']);
+			self::fetchOutbox($data['first'], $uid);
 			return;
 		} else {
 			$items = [];
 		}
 
 		foreach ($items as $activity) {
-			self::processActivity($activity);
-		}
-	}
-
-	function processActivity($activity, $body = '', $uid = null)
-	{
-		if (empty($activity['type'])) {
-			logger('Empty type', LOGGER_DEBUG);
-			return;
-		}
-
-		if (empty($activity['object'])) {
-			logger('Empty object', LOGGER_DEBUG);
-			return;
-		}
-
-		if (empty($activity['actor'])) {
-			logger('Empty actor', LOGGER_DEBUG);
-			return;
-
-		}
-
-		$actor = self::processElement($activity, 'actor', 'id');
-		if (empty($actor)) {
-			logger('Empty actor - 2', LOGGER_DEBUG);
-			return;
+			ActivityPub\Receiver::processActivity($activity, '', $uid, true);
 		}
-
-		if (is_string($activity['object'])) {
-			$object_url = $activity['object'];
-		} elseif (!empty($activity['object']['id'])) {
-			$object_url = $activity['object']['id'];
-		} else {
-			logger('No object found', LOGGER_DEBUG);
-			return;
-		}
-
-		// ----------------------------------
-/*
-		// unhandled
-		unset($activity['@context']);
-		unset($activity['id']);
-
-		// Non standard
-		unset($activity['title']);
-		unset($activity['atomUri']);
-		unset($activity['context_id']);
-		unset($activity['statusnetConversationId']);
-
-		// To-Do?
-		unset($activity['context']);
-		unset($activity['location']);
-		unset($activity['signature']);
-*/
-		// Fetch all receivers from to, cc, bto and bcc
-		$receivers = self::getReceivers($activity);
-
-		// When it is a delivery to a personal inbox we add that user to the receivers
-		if (!empty($uid)) {
-			$owner = User::getOwnerDataById($uid);
-			$additional = [$owner['url'] => $uid];
-			$receivers = array_merge($receivers, $additional);
-		}
-
-		logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
-
-		logger('Processing activity: ' . $activity['type'], LOGGER_DEBUG);
-
-		// Fetch the content only on activities where this matters
-		if (in_array($activity['type'], ['Create', 'Update', 'Announce'])) {
-			$item = self::fetchObject($object_url, $activity['object']);
-			if (empty($item)) {
-				logger("Object data couldn't be processed", LOGGER_DEBUG);
-				return;
-			}
-		} else {
-			if (in_array($activity['type'], ['Accept'])) {
-				$item['object'] = self::processElement($activity, 'object', 'actor', 'type', 'Follow');
-			} elseif (in_array($activity['type'], ['Undo'])) {
-				$item['object'] = self::processElement($activity, 'object', 'object', 'type', 'Follow');
-			} else {
-				$item['object'] = $object_url;
-			}
-			$item['id'] = $activity['id'];
-			$item['receiver'] = [];
-			$item['type'] = $activity['type'];
-		}
-
-		$item = self::addActivityFields($item, $activity);
-
-		$item['owner'] = $actor;
-
-		$item['receiver'] = array_merge($item['receiver'], $receivers);
-
-		switch ($activity['type']) {
-			case 'Create':
-			case 'Update':
-			case 'Announce':
-				self::createItem($item, $body);
-				break;
-
-			case 'Like':
-				self::likeItem($item, $body);
-				break;
-
-			case 'Dislike':
-				break;
-
-			case 'Delete':
-				break;
-
-			case 'Follow':
-				self::followUser($item);
-				break;
-
-			case 'Accept':
-				self::acceptFollowUser($item);
-				break;
-
-			case 'Undo':
-				self::undoFollowUser($item);
-				break;
-
-			default:
-				logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
-				break;
-		}
-	}
-
-	private static function getReceivers($activity)
-	{
-		$receivers = [];
-
-		$elements = ['to', 'cc', 'bto', 'bcc'];
-		foreach ($elements as $element) {
-			if (empty($activity[$element])) {
-				continue;
-			}
-
-			// The receiver can be an arror or a string
-			if (is_string($activity[$element])) {
-				$activity[$element] = [$activity[$element]];
-			}
-
-			foreach ($activity[$element] as $receiver) {
-				if ($receiver == self::PUBLIC) {
-					$receivers[$receiver] = 0;
-				}
-
-				$condition = ['self' => true, 'nurl' => normalise_link($receiver)];
-				$contact = DBA::selectFirst('contact', ['uid'], $condition);
-				if (!DBA::isResult($contact)) {
-					continue;
-				}
-				$receivers[$receiver] = $contact['uid'];
-			}
-		}
-		return $receivers;
-	}
-
-	private static function addActivityFields($item, $activity)
-	{
-		if (!empty($activity['published']) && empty($item['published'])) {
-			$item['published'] = $activity['published'];
-		}
-
-		if (!empty($activity['updated']) && empty($item['updated'])) {
-			$item['updated'] = $activity['updated'];
-		}
-
-		if (!empty($activity['inReplyTo']) && empty($item['parent-uri'])) {
-			$item['parent-uri'] = self::processElement($activity, 'inReplyTo', 'id');
-		}
-
-		if (!empty($activity['instrument'])) {
-			$item['service'] = self::processElement($activity, 'instrument', 'name', 'type', 'Service');
-		}
-		return $item;
-	}
-
-	private static function fetchObject($object_url, $object = [])
-	{
-		$data = self::fetchContent($object_url);
-		if (empty($data)) {
-			$data = $object;
-			if (empty($data)) {
-				logger('Empty content', LOGGER_DEBUG);
-				return false;
-			} elseif (is_string($data)) {
-				logger('No object array provided.', LOGGER_DEBUG);
-				$item = Item::selectFirst([], ['uri' => $data]);
-				if (!DBA::isResult($item)) {
-					logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
-					return false;
-				}
-				logger('Using already stored item', LOGGER_DEBUG);
-				$data = self::createNote($item);
-			} else {
-				logger('Using provided object', LOGGER_DEBUG);
-			}
-		}
-
-		if (empty($data['type'])) {
-			logger('Empty type', LOGGER_DEBUG);
-			return false;
-		} else {
-			$type = $data['type'];
-			logger('Type ' . $type, LOGGER_DEBUG);
-		}
-
-		if (in_array($type, ['Note', 'Article', 'Video'])) {
-			$common = self::processCommonData($data);
-		}
-
-		switch ($type) {
-			case 'Note':
-				return array_merge($common, self::processNote($data));
-			case 'Article':
-				return array_merge($common, self::processArticle($data));
-			case 'Video':
-				return array_merge($common, self::processVideo($data));
-
-			case 'Announce':
-				if (empty($data['object'])) {
-					return false;
-				}
-				return self::fetchObject($data['object']);
-
-			case 'Person':
-			case 'Tombstone':
-				break;
-
-			default:
-				logger('Unknown object type: ' . $data['type'], LOGGER_DEBUG);
-				break;
-		}
-	}
-
-	private static function processCommonData(&$object)
-	{
-		if (empty($object['id']) || empty($object['attributedTo'])) {
-			return false;
-		}
-
-		$item = [];
-		$item['type'] = $object['type'];
-		$item['uri'] = $object['id'];
-
-		if (!empty($object['inReplyTo'])) {
-			$item['reply-to-uri'] = self::processElement($object, 'inReplyTo', 'id');
-		} else {
-			$item['reply-to-uri'] = $item['uri'];
-		}
-
-		$item['published'] = defaults($object, 'published', null);
-		$item['updated'] = defaults($object, 'updated', $item['published']);
-
-		if (empty($item['published']) && !empty($item['updated'])) {
-			$item['published'] = $item['updated'];
-		}
-
-		$item['uuid'] = defaults($object, 'uuid', null);
-		$item['owner'] = $item['author'] = self::processElement($object, 'attributedTo', 'id');
-		$item['context'] = defaults($object, 'context', null);
-		$item['conversation'] = defaults($object, 'conversation', null);
-		$item['sensitive'] = defaults($object, 'sensitive', null);
-		$item['name'] = defaults($object, 'title', null);
-		$item['name'] = defaults($object, 'name', $item['name']);
-		$item['summary'] = defaults($object, 'summary', null);
-		$item['content'] = defaults($object, 'content', null);
-		$item['source'] = defaults($object, 'source', null);
-		$item['location'] = self::processElement($object, 'location', 'name', 'type', 'Place');
-		$item['attachments'] = defaults($object, 'attachment', null);
-		$item['tags'] = defaults($object, 'tag', null);
-		$item['service'] = self::processElement($object, 'instrument', 'name', 'type', 'Service');
-		$item['alternate-url'] = self::processElement($object, 'url', 'href');
-		$item['receiver'] = self::getReceivers($object);
-
-/*
-		// To-Do
-		unset($object['source']);
-
-		// Unhandled
-		unset($object['@context']);
-		unset($object['type']);
-		unset($object['actor']);
-		unset($object['signature']);
-		unset($object['mediaType']);
-		unset($object['duration']);
-		unset($object['replies']);
-		unset($object['icon']);
-
-		// Also missing:
-		audience, preview, endTime, startTime, generator, image
-*/
-		return $item;
-	}
-
-	private static function processNote($object)
-	{
-		$item = [];
-
-/*
-		// To-Do?
-		unset($object['emoji']);
-		unset($object['atomUri']);
-		unset($object['inReplyToAtomUri']);
-
-		// Unhandled
-		unset($object['contentMap']);
-		unset($object['announcement_count']);
-		unset($object['announcements']);
-		unset($object['context_id']);
-		unset($object['likes']);
-		unset($object['like_count']);
-		unset($object['inReplyToStatusId']);
-		unset($object['shares']);
-		unset($object['quoteUrl']);
-		unset($object['statusnetConversationId']);
-*/
-		return $item;
-	}
-
-	private static function processArticle($object)
-	{
-		$item = [];
-
-		return $item;
-	}
-
-	private static function processVideo($object)
-	{
-		$item = [];
-/*
-		// To-Do?
-		unset($object['category']);
-		unset($object['licence']);
-		unset($object['language']);
-		unset($object['commentsEnabled']);
-
-		// Unhandled
-		unset($object['views']);
-		unset($object['waitTranscoding']);
-		unset($object['state']);
-		unset($object['support']);
-		unset($object['subtitleLanguage']);
-		unset($object['likes']);
-		unset($object['dislikes']);
-		unset($object['shares']);
-		unset($object['comments']);
-*/
-		return $item;
-	}
-
-	private static function processElement($array, $element, $key, $type = null, $type_value = null)
-	{
-		if (empty($array)) {
-			return false;
-		}
-
-		if (empty($array[$element])) {
-			return false;
-		}
-
-		if (is_string($array[$element])) {
-			return $array[$element];
-		}
-
-		if (is_null($type_value)) {
-			if (!empty($array[$element][$key])) {
-				return $array[$element][$key];
-			}
-
-			if (!empty($array[$element][0][$key])) {
-				return $array[$element][0][$key];
-			}
-
-			return false;
-		}
-
-		if (!empty($array[$element][$key]) && !empty($array[$element][$type]) && ($array[$element][$type] == $type_value)) {
-			return $array[$element][$key];
-		}
-
-		/// @todo Add array search
-
-		return false;
-	}
-
-	private static function convertMentions($body)
-	{
-		$URLSearchString = "^\[\]";
-		$body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
-
-		return $body;
-	}
-
-	private static function constructTagList($tags, $sensitive)
-	{
-		if (empty($tags)) {
-			return '';
-		}
-
-		$tag_text = '';
-		foreach ($tags as $tag) {
-			if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
-				if (!empty($tag_text)) {
-					$tag_text .= ',';
-				}
-
-				$tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
-			}
-		}
-
-		/// @todo add nsfw for $sensitive
-
-		return $tag_text;
-	}
-
-	private static function constructAttachList($attachments, $item)
-	{
-		if (empty($attachments)) {
-			return $item;
-		}
-
-		foreach ($attachments as $attach) {
-			$filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
-			if ($filetype == 'image') {
-				$item['body'] .= "\n[img]".$attach['url'].'[/img]';
-			} else {
-				if (!empty($item["attach"])) {
-					$item["attach"] .= ',';
-				} else {
-					$item["attach"] = '';
-				}
-				if (!isset($attach['length'])) {
-					$attach['length'] = "0";
-				}
-				$item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
-			}
-		}
-
-		return $item;
-	}
-
-	private static function createItem($activity, $body)
-	{
-		$item = [];
-		$item['verb'] = ACTIVITY_POST;
-		$item['parent-uri'] = $activity['reply-to-uri'];
-
-		if ($activity['reply-to-uri'] == $activity['uri']) {
-			$item['gravity'] = GRAVITY_PARENT;
-			$item['object-type'] = ACTIVITY_OBJ_NOTE;
-		} else {
-			$item['gravity'] = GRAVITY_COMMENT;
-			$item['object-type'] = ACTIVITY_OBJ_COMMENT;
-		}
-
-		self::postItem($activity, $item, $body);
-	}
-
-	private static function likeItem($activity, $body)
-	{
-		$item = [];
-		$item['verb'] = ACTIVITY_LIKE;
-		$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']?
-
-		$item['network'] = Protocol::ACTIVITYPUB;
-		$item['private'] = !in_array(0, $activity['receiver']);
-		$item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
-		$item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
-		$item['uri'] = $activity['uri'];
-		$item['created'] = $activity['published'];
-		$item['edited'] = $activity['updated'];
-		$item['guid'] = $activity['uuid'];
-		$item['title'] = HTML::toBBCode($activity['name']);
-		$item['content-warning'] = HTML::toBBCode($activity['summary']);
-		$item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
-		$item['location'] = $activity['location'];
-		$item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
-		$item['app'] = $activity['service'];
-		$item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
-
-		$item = self::constructAttachList($activity['attachments'], $item);
-
-		$source = self::processElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
-		if (!empty($source)) {
-			$item['body'] = $source;
-		}
-
-		$item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
-		$item['source'] = $body;
-		$item['conversation-uri'] = $activity['conversation'];
-
-		foreach ($activity['receiver'] as $receiver) {
-			$item['uid'] = $receiver;
-			$item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
-
-			if (($receiver != 0) && empty($item['contact-id'])) {
-				$item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
-			}
-
-			$item_id = Item::insert($item);
-			logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
-			if (!empty($item_id) && ($item['uid'] == 0)) {
-				Item::distribute($item_id);
-			}
-		}
-	}
-
-	private static function followUser($activity)
-	{
-		if (empty($activity['receiver'][$activity['object']])) {
-			return;
-		}
-
-		$uid = $activity['receiver'][$activity['object']];
-		$owner = User::getOwnerDataById($uid);
-
-		$cid = Contact::getIdForURL($activity['owner'], $uid);
-		if (!empty($cid)) {
-			$contact = DBA::selectFirst('contact', [], ['id' => $cid]);
-		} else {
-			$contact = false;
-		}
-
-		$item = ['author-id' => Contact::getIdForURL($activity['owner']),
-			'author-link' => $activity['owner']];
-
-		Contact::addRelationship($owner, $contact, $item);
-		$cid = Contact::getIdForURL($activity['owner'], $uid);
-		if (empty($cid)) {
-			return;
-		}
-
-		$contact = DBA::selectFirst('contact', ['network'], ['id' => $cid]);
-		if ($contact['network'] != Protocol::ACTIVITYPUB) {
-			Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
-		}
-
-		DBA::update('contact', ['hub-verify' => $activity['id']], ['id' => $cid]);
-		logger('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
-	}
-
-	private static function acceptFollowUser($activity)
-	{
-		if (empty($activity['receiver'][$activity['object']])) {
-			return;
-		}
-
-		$uid = $activity['receiver'][$activity['object']];
-		$owner = User::getOwnerDataById($uid);
-
-		$cid = Contact::getIdForURL($activity['owner'], $uid);
-		if (empty($cid)) {
-			logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
-			return;
-		}
-
-		$fields = ['pending' => false];
-		$condition = ['id' => $cid, 'pending' => true];
-		DBA::update('comtact', $fields, $condition);
-		logger('Accept contact request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
-	}
-
-	private static function undoFollowUser($activity)
-	{
-		if (empty($activity['receiver'][$activity['object']])) {
-			return;
-		}
-
-		$uid = $activity['receiver'][$activity['object']];
-		$owner = User::getOwnerDataById($uid);
-
-		$cid = Contact::getIdForURL($activity['owner'], $uid);
-		if (empty($cid)) {
-			logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
-			return;
-		}
-
-		$contact = DBA::selectFirst('contact', [], ['id' => $cid]);
-		if (!DBA::isResult($contact)) {
-			return;
-		}
-
-		Contact::removeFollower($owner, $contact);
-		logger('Undo following request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
 	}
 }