<?php

namespace Zotlabs\Lib;

use App;
use Zotlabs\Access\PermissionLimits;
use Zotlabs\Access\PermissionRoles;
use Zotlabs\Access\Permissions;
use Zotlabs\Daemon\Master;
use Zotlabs\Web\HTTPSig;

require_once('include/event.php');
require_once('include/html2plain.php');

class Activity {

	static function encode_object($x) {

		if (($x) && (!is_array($x)) && (substr(trim($x), 0, 1)) === '{') {
			$x = json_decode($x, true);
		}

		if (is_array($x)) {

			if (array_key_exists('asld', $x)) {
				return $x['asld'];
			}

			if ($x['type'] === ACTIVITY_OBJ_PERSON) {
				return self::fetch_person($x);
			}
			if ($x['type'] === ACTIVITY_OBJ_PROFILE) {
				return self::fetch_profile($x);
			}
			if (in_array($x['type'], [ACTIVITY_OBJ_NOTE, ACTIVITY_OBJ_ARTICLE])) {
				return self::fetch_item($x);
			}
			if ($x['type'] === ACTIVITY_OBJ_THING) {
				return self::fetch_thing($x);
			}
			if ($x['type'] === ACTIVITY_OBJ_EVENT) {
				return self::fetch_event($x);
			}
			if ($x['type'] === ACTIVITY_OBJ_PHOTO) {
				return self::fetch_image($x);
			}

			call_hooks('encode_object', $x);
		}

		return $x;

	}

	static function fetch($url, $channel = null) {
		$redirects = 0;
		if (!check_siteallowed($url)) {
			logger('blacklisted: ' . $url);
			return null;
		}
		if (!$channel) {
			$channel = get_sys_channel();
		}

		logger('fetch: ' . $url, LOGGER_DEBUG);

		if (strpos($url, 'x-zot:') === 0) {
			$x = ZotURL::fetch($url, $channel);
		}
		else {
			$m = parse_url($url);

			// handle bearcaps
			if ($m['scheme'] === 'bear') {
				$params = explode('&', $m['query']);
				if ($params) {
					foreach ($params as $p) {
						if (substr($p, 0, 2) === 'u=') {
							$url = substr($p, 2);
						}
						if (substr($p, 0, 2) === 't=') {
							$token = substr($p, 2);
						}
					}
					$m = parse_url($url);
				}
			}

			$headers = [
				'Accept'           => 'application/activity+json, application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
				'Host'             => $m['host'],
				'Date'             => datetime_convert('UTC', 'UTC', 'now', 'D, d M Y H:i:s \\G\\M\\T'),
				'(request-target)' => 'get ' . get_request_string($url)
			];
			if (isset($token)) {
				$headers['Authorization'] = 'Bearer ' . $token;
			}
			$h = HTTPSig::create_sig($headers, $channel['channel_prvkey'], channel_url($channel), false);
			$x = z_fetch_url($url, true, $redirects, ['headers' => $h]);
		}

		if ($x['success']) {
			$y = json_decode($x['body'], true);
			logger('returned: ' . json_encode($y, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES), LOGGER_DEBUG);
			return json_decode($x['body'], true);
		}
		else {
			logger('fetch failed: ' . $url);
			logger($x['body']);
		}
		return null;
	}


	static function fetch_person($x) {
		return self::fetch_profile($x);
	}

	static function fetch_profile($x) {
		$r = q("select * from xchan where xchan_url like '%s' limit 1",
			dbesc($x['id'] . '/%')
		);
		if (!$r) {
			$r = q("select * from xchan where xchan_hash = '%s' limit 1",
				dbesc($x['id'])
			);

		}
		if (!$r)
			return [];

		return self::encode_person($r[0]);

	}

	static function fetch_thing($x) {

		$r = q("select * from obj where obj_type = %d and obj_obj = '%s' limit 1",
			intval(TERM_OBJ_THING),
			dbesc($x['id'])
		);

		if (!$r)
			return [];

		$x = [
			'type' => 'Object',
			'id'   => z_root() . '/thing/' . $r[0]['obj_obj'],
			'name' => $r[0]['obj_term']
		];

		if ($r[0]['obj_image'])
			$x['image'] = $r[0]['obj_image'];

		return $x;

	}

	static function fetch_item($x) {

		if (array_key_exists('source', $x)) {
			// This item is already processed and encoded
			return $x;
		}

		$r = q("select * from item where mid = '%s' limit 1",
			dbesc($x['id'])
		);
		if ($r) {
			xchan_query($r, true);
			$r = fetch_post_tags($r);
			if (in_array($r[0]['verb'], ['Create', 'Invite']) && $r[0]['obj_type'] === ACTIVITY_OBJ_EVENT) {
				$r[0]['verb'] = 'Invite';
				return self::encode_activity($r[0]);
			}
			return self::encode_item($r[0]);
		}
	}


	static function fetch_image($x) {
		$ret = [
			'type'      => 'Image',
			'id'        => $x['id'],
			'name'      => $x['title'],
			'content'   => bbcode($x['body'], ['cache' => true]),
			'source'    => ['mediaType' => 'text/bbcode', 'content' => $x['body']],
			'published' => datetime_convert('UTC', 'UTC', $x['created'], ATOM_TIME),
			'updated'   => datetime_convert('UTC', 'UTC', $x['edited'], ATOM_TIME),
			'url'       => [
				'type'      => 'Link',
				'mediaType' => $x['link'][0]['type'],
				'href'      => $x['link'][0]['href'],
				'width'     => $x['link'][0]['width'],
				'height'    => $x['link'][0]['height']
			]
		];
		return $ret;
	}

	static function fetch_event($x) {

		// convert old Zot event objects to ActivityStreams Event objects

		if (array_key_exists('content', $x) && array_key_exists('dtstart', $x)) {
			$ev = bbtoevent($x['content']);
			if ($ev) {


				if (!$ev['timezone']) {
					$ev['timezone'] = 'UTC';
				}

				$actor = null;
				if (array_key_exists('author', $x) && array_key_exists('link', $x['author'])) {
					$actor = $x['author']['link'][0]['href'];
				}
				$y = [
					'type'      => 'Event',
					'id'        => z_root() . '/event/' . $ev['event_hash'],
					'name'      => $ev['summary'],
					// 'summary'   => bbcode($ev['summary'], [ 'cache' => true ]),
					// RFC3339 Section 4.3
					'startTime' => (($ev['adjust']) ? datetime_convert($ev['timezone'], 'UTC', $ev['dtstart'], ATOM_TIME) : datetime_convert('UTC', 'UTC', $ev['dtstart'], 'Y-m-d\\TH:i:s-00:00')),
					'content'   => bbcode($ev['description'], ['cache' => true]),
					'location'  => ['type' => 'Place', 'content' => bbcode($ev['location'], ['cache' => true])],
					'source'    => ['content' => format_event_bbcode($ev, true), 'mediaType' => 'text/bbcode'],
					'actor'     => $actor,
				];
				if (!$ev['nofinish']) {
					$y['endTime'] = (($ev['adjust']) ? datetime_convert($ev['timezone'], 'UTC', $ev['dtend'], ATOM_TIME) : datetime_convert('UTC', 'UTC', $ev['dtend'], 'Y-m-d\\TH:i:s-00:00'));
				}

				// copy attachments from the passed object - these are already formatted for ActivityStreams

				if ($x['attachment']) {
					$y['attachment'] = $x['attachment'];
				}

				if ($actor) {
					return $y;
				}
			}
		}

		return $x;

	}

	static function paged_collection_init($total, $id, $type = 'OrderedCollection') {

		$ret = [
			'id'         => z_root() . '/' . $id,
			'type'       => $type,
			'totalItems' => $total,
		];

		$numpages = $total / App::$pager['itemspage'];
		$lastpage = (($numpages > intval($numpages)) ? intval($numpages) + 1 : $numpages);

		$ret['first'] = z_root() . '/' . App::$query_string . '?page=1';
		$ret['last']  = z_root() . '/' . App::$query_string . '?page=' . $lastpage;

		return $ret;

	}

	static function encode_item_collection($items, $id, $type, $total = 0) {

		if ($total > 100) {
			$ret = [
				'id'   => z_root() . '/' . $id,
				'type' => $type . 'Page',
			];

			$numpages = $total / App::$pager['itemspage'];
			$lastpage = (($numpages > intval($numpages)) ? intval($numpages) + 1 : $numpages);

			$stripped = preg_replace('/([&|\?]page=[0-9]*)/', '', $id);
			$stripped = rtrim($stripped, '/');

			$ret['partOf'] = z_root() . '/' . $stripped;

			if (App::$pager['page'] < $lastpage) {
				$ret['next'] = z_root() . '/' . $stripped . '?page=' . (intval(App::$pager['page']) + 1);
			}
			if (App::$pager['page'] > 1) {
				$ret['prev'] = z_root() . '/' . $stripped . '?page=' . (intval(App::$pager['page']) - 1);
			}
		}
		else {
			$ret = [
				'id'         => z_root() . '/' . $id,
				'type'       => $type,
				'totalItems' => $total,
			];
		}

		if ($items) {
			$x = [];
			foreach ($items as $i) {
				$t = ((get_iconfig($i['id'], 'activitypub', 'rawmsg')) ? get_iconfig($i['id'], 'activitypub', 'rawmsg') : self::encode_activity($i));
				if ($t) {
					$x[] = $t;
				}
			}
			if ($type === 'OrderedCollection') {
				$ret['orderedItems'] = $x;
			}
			else {
				$ret['items'] = $x;
			}
		}

		return $ret;
	}

	static function encode_follow_collection($items, $id, $type, $extra = null) {

		$ret = [
			'id'         => z_root() . '/' . $id,
			'type'       => $type,
			'totalItems' => count($items),
		];
		if ($extra)
			$ret = array_merge($ret, $extra);

		if ($items) {
			$x = [];
			foreach ($items as $i) {
				if ($i['xchan_url']) {
					$x[] = $i['xchan_url'];
				}
			}

			if ($type === 'OrderedCollection')
				$ret['orderedItems'] = $x;
			else
				$ret['items'] = $x;
		}

		return $ret;
	}


	static function encode_item($i) {

		$ret = [];

		if ($i['verb'] === ACTIVITY_FRIEND) {
			// Hubzilla 'make-friend' activity, no direct mapping from AS1 to AS2 - make it a note
			$objtype = 'Note';
		}
		else {
			$objtype = self::activity_obj_mapper($i['obj_type']);
		}

		if ($i['obj']) {
			$ret = Activity::encode_object($i['obj']);
		}

		if (intval($i['item_deleted'])) {
			$ret['type']       = 'Tombstone';
			$ret['formerType'] = $objtype;
			$ret['id']         = $i['mid'];
			if ($i['id'] != $i['parent'])
				$ret['inReplyTo'] = $i['thr_parent'];

			$ret['to'] = [ACTIVITY_PUBLIC_INBOX];
			return $ret;
		}

		if ($i['obj']) {
			if (is_array($i['obj'])) {
				$ret = $i['obj'];
			}
			else {
				$ret = json_decode($i['obj'], true);
			}
		}

		$ret['type'] = $objtype;

		if ($objtype === 'Question') {
			if ($i['obj']) {
				if (is_array($i['obj'])) {
					$ret = $i['obj'];
				}
				else {
					$ret = json_decode($i['obj'], true);
				}

				if (array_path_exists('actor/id', $ret)) {
					$ret['actor'] = $ret['actor']['id'];
				}
			}
		}

		$ret['id']            = ((strpos($i['mid'], 'http') === 0) ? $i['mid'] : z_root() . '/item/' . urlencode($i['mid']));
		$ret['diaspora:guid'] = $i['uuid'];

		if ($i['title'])
			$ret['name'] = $i['title'];

		$ret['published'] = datetime_convert('UTC', 'UTC', $i['created'], ATOM_TIME);
		if ($i['created'] !== $i['edited'])
			$ret['updated'] = datetime_convert('UTC', 'UTC', $i['edited'], ATOM_TIME);
		if ($i['expires'] <= NULL_DATE) {
			$ret['expires'] = datetime_convert('UTC', 'UTC', $i['expires'], ATOM_TIME);
		}

		if ($i['app']) {
			$ret['generator'] = ['type' => 'Application', 'name' => $i['app']];
		}
		if ($i['location'] || $i['coord']) {
			$ret['location'] = ['type' => 'Place'];
			if ($i['location']) {
				$ret['location']['name'] = $i['location'];
			}
			if ($i['coord']) {
				$l                            = explode(' ', $i['coord']);
				$ret['location']['latitude']  = $l[0];
				$ret['location']['longitude'] = $l[1];
			}
		}

		if (intval($i['item_wall']) && $i['mid'] === $i['parent_mid']) {
			$ret['commentPolicy'] = map_scope(PermissionLimits::Get($i['uid'], 'post_comments'));
		}

		if (intval($i['item_private']) === 2) {
			$ret['directMessage'] = true;
		}

		if (array_key_exists('comments_closed', $i) && $i['comments_closed'] !== EMPTY_STR && $i['comments_closed'] !== NULL_DATE) {
			if ($ret['commentPolicy']) {
				$ret['commentPolicy'] .= ' ';
			}
			$ret['commentPolicy'] .= 'until=' . datetime_convert('UTC', 'UTC', $i['comments_closed'], ATOM_TIME);
		}

		$ret['attributedTo'] = $i['author']['xchan_url'];

		if ($i['id'] != $i['parent']) {
			$ret['inReplyTo'] = ((strpos($i['thr_parent'], 'http') === 0) ? $i['thr_parent'] : z_root() . '/item/' . urlencode($i['thr_parent']));
		}

		if ($i['mimetype'] === 'text/bbcode') {
			if ($i['title'])
				$ret['name'] = bbcode($i['title'], ['cache' => true]);
			if ($i['summary'])
				$ret['summary'] = bbcode($i['summary'], ['cache' => true]);
			$ret['content'] = bbcode($i['body'], ['cache' => true]);
			$ret['source']  = ['content' => $i['body'], 'mediaType' => 'text/bbcode'];
		}

		$actor = self::encode_person($i['author'], false);
		if ($actor)
			$ret['actor'] = $actor;
		else
			return [];

		$t = self::encode_taxonomy($i);
		if ($t) {
			$ret['tag'] = $t;
		}

		$a = self::encode_attachment($i);
		if ($a) {
			$ret['attachment'] = $a;
		}

		$public    = (($i['item_private']) ? false : true);
		$top_level = (($i['mid'] === $i['parent_mid']) ? true : false);

		if ($public) {
			$ret['to'] = [ACTIVITY_PUBLIC_INBOX];
			$ret['cc'] = [z_root() . '/followers/' . substr($i['author']['xchan_addr'], 0, strpos($i['author']['xchan_addr'], '@'))];
		}
		else {

			// private activity

			if ($top_level) {
				$ret['to'] = self::map_acl($i);
			}
			else {
				$ret['to'] = [];
				if ($ret['tag']) {
					foreach ($ret['tag'] as $mention) {
						if (is_array($mention) && array_key_exists('href', $mention) && $mention['href']) {
							$h = q("select * from hubloc where hubloc_id_url = '%s' limit 1",
								dbesc($mention['href'])
							);
							if ($h) {
								if ($h[0]['hubloc_network'] === 'activitypub') {
									$addr = $h[0]['hubloc_hash'];
								}
								else {
									$addr = $h[0]['hubloc_id_url'];
								}
								if (!in_array($addr, $ret['to'])) {
									$ret['to'][] = $addr;
								}
							}
						}
					}
				}
				$d = q("select hubloc.*  from hubloc left join item on hubloc_hash = owner_xchan where item.id = %d limit 1",
					intval($i['parent'])
				);
				if ($d) {
					if ($d[0]['hubloc_network'] === 'activitypub') {
						$addr = $d[0]['hubloc_hash'];
					}
					else {
						$addr = $d[0]['hubloc_id_url'];
					}
					if (!in_array($addr, $ret['to'])) {
						$ret['cc'][] = $addr;
					}
				}
			}
		}

		$mentions = self::map_mentions($i);
		if (count($mentions) > 0) {
			if (!$ret['to']) {
				$ret['to'] = $mentions;
			}
			else {
				$ret['to'] = array_values(array_unique(array_merge($ret['to'], $mentions)));
			}
		}

		return $ret;

	}

	static function decode_taxonomy($item) {

		$ret = [];

		if ($item['tag'] && is_array($item['tag'])) {
			$ptr = $item['tag'];
			if (!array_key_exists(0, $ptr)) {
				$ptr = [$ptr];
			}
			foreach ($ptr as $t) {
				if (!array_key_exists('type', $t))
					$t['type'] = 'Hashtag';

				switch ($t['type']) {
					case 'Hashtag':
						$ret[] = ['ttype' => TERM_HASHTAG, 'url' => $t['href'], 'term' => escape_tags((substr($t['name'], 0, 1) === '#') ? substr($t['name'], 1) : $t['name'])];
						break;

					case 'Mention':
						$mention_type = substr($t['name'], 0, 1);
						if ($mention_type === '!') {
							$ret[] = ['ttype' => TERM_FORUM, 'url' => $t['href'], 'term' => escape_tags(substr($t['name'], 1))];
						}
						else {
							$ret[] = ['ttype' => TERM_MENTION, 'url' => $t['href'], 'term' => escape_tags((substr($t['name'], 0, 1) === '@') ? substr($t['name'], 1) : $t['name'])];
						}
						break;

					default:
						break;
				}
			}
		}

		return $ret;
	}


	static function encode_taxonomy($item) {

		$ret = [];

		if ($item['term']) {
			foreach ($item['term'] as $t) {
				switch ($t['ttype']) {
					case TERM_HASHTAG:
						// href is required so if we don't have a url in the taxonomy, ignore it and keep going.
						if ($t['url']) {
							$ret[] = ['type' => 'Hashtag', 'href' => $t['url'], 'name' => '#' . $t['term']];
						}
						break;

					case TERM_FORUM:
						$ret[] = ['type' => 'Mention', 'href' => $t['url'], 'name' => '!' . $t['term']];
						break;

					case TERM_MENTION:
						$ret[] = ['type' => 'Mention', 'href' => $t['url'], 'name' => '@' . $t['term']];
						break;

					default:
						break;
				}
			}
		}

		return $ret;
	}

	static function encode_attachment($item) {

		$ret = [];

		if ($item['attach']) {
			$atts = ((is_array($item['attach'])) ? $item['attach'] : json_decode($item['attach'], true));
			if ($atts) {
				foreach ($atts as $att) {
					if (strpos($att['type'], 'image')) {
						$ret[] = ['type' => 'Image', 'url' => $att['href']];
					}
					else {
						$ret[] = ['type' => 'Link', 'mediaType' => $att['type'], 'href' => $att['href']];
					}
				}
			}
		}
		if ($item['iconfig']) {
			foreach ($item['iconfig'] as $att) {
				if ($att['sharing']) {
					$value = ((is_string($att['v']) && preg_match('|^a:[0-9]+:{.*}$|s', $att['v'])) ? unserialize($att['v']) : $att['v']);
					$ret[] = ['type' => 'PropertyValue', 'name' => 'zot.' . $att['cat'] . '.' . $att['k'], 'value' => $value];
				}
			}
		}

		return $ret;
	}

	static function decode_iconfig($item) {

		$ret = [];

		if (is_array($item['attachment']) && $item['attachment']) {
			$ptr = $item['attachment'];
			if (!array_key_exists(0, $ptr)) {
				$ptr = [$ptr];
			}
			foreach ($ptr as $att) {
				$entry = [];
				if ($att['type'] === 'PropertyValue') {
					if (array_key_exists('name', $att) && $att['name']) {
						$key = explode('.', $att['name']);
						if (count($key) === 3 && $key[0] === 'zot') {
							$entry['cat']     = $key[1];
							$entry['k']       = $key[2];
							$entry['v']       = $att['value'];
							$entry['sharing'] = '1';
							$ret[]            = $entry;
						}
					}
				}
			}
		}
		return $ret;
	}


	static function decode_attachment($item) {

		$ret = [];

		if ($item['attachment']) {
			foreach ($item['attachment'] as $att) {
				$entry = [];
				if ($att['href'])
					$entry['href'] = $att['href'];
				elseif ($att['url'])
					$entry['href'] = $att['url'];
				if ($att['mediaType'])
					$entry['type'] = $att['mediaType'];
				elseif ($att['type'] === 'Image')
					$entry['type'] = 'image/jpeg';
				if ($entry)
					$ret[] = $entry;
			}
		}

		return $ret;
	}


	static function encode_activity($i, $recurse = false) {

		$ret   = [];
		$reply = false;


		if ($i['verb'] === ACTIVITY_FRIEND) {
			// Hubzilla 'make-friend' activity, no direct mapping from AS1 to AS2 - make it a note
			$ret['obj'] = [];
		}

		$ret['type'] = self::activity_mapper($i['verb']);

		if (intval($i['item_deleted']) && !$recurse) {
			$is_response = false;

			if (ActivityStreams::is_response_activity($ret['type'])) {
				$ret['type'] = 'Undo';
				$fragment    = 'undo';
				$is_response = true;
			}
			else {
				$ret['type'] = 'Delete';
				$fragment    = 'delete';
			}

			$ret['id'] = str_replace('/item/', '/activity/', $i['mid']) . '#' . $fragment;
			$actor     = self::encode_person($i['author'], false);
			if ($actor)
				$ret['actor'] = $actor;
			else
				return [];

			$obj = (($is_response) ? self::encode_activity($i, true) : self::encode_item($i));
			if ($obj) {
				if (array_path_exists('object/id', $obj)) {
					$obj['object'] = $obj['object']['id'];
				}
				unset($obj['cc']);
				$obj['to']     = [ACTIVITY_PUBLIC_INBOX];
				$ret['object'] = $obj;
			}
			else
				return [];

			$ret['to'] = [ACTIVITY_PUBLIC_INBOX];

			return $ret;

		}

		if ($ret['type'] === 'emojiReaction') {
			// There may not be an object for these items for legacy reasons - it should be the conversation parent.
			$p = q("select * from item where mid = '%s' and uid = %d",
				dbesc($i['parent_mid']),
				intval($i['uid'])
			);
			if ($p) {
				xchan_query($p, true);
				$p        = fetch_post_tags($p);
				$i['obj'] = self::encode_item($p[0]);

				// convert to zot6 emoji reaction encoding which uses the target object to indicate the
				// specific emoji instead of overloading the verb or type.

				$im = explode('#', $i['verb']);
				if ($im && count($im) > 1)
					$emoji = $im[1];
				if (preg_match("/\[img(.*?)\](.*?)\[\/img\]/ism", $i['body'], $match)) {
					$ln = $match[2];
				}

				$i['tgt_type'] = 'Image';

				$i['target'] = [
					'type' => 'Image',
					'name' => $emoji,
					'url'  => (($ln) ? $ln : z_root() . '/images/emoji/' . $emoji . '.png')
				];

			}
		}

		if (strpos($i['mid'], z_root() . '/item/') !== false) {
			$ret['id'] = str_replace('/item/', '/activity/', $i['mid']);
		}
		elseif (strpos($i['mid'], z_root() . '/event/') !== false) {
			$ret['id'] = str_replace('/event/', '/activity/', $i['mid']);
		}
		else {
			$ret['id'] = ((strpos($i['mid'], 'http') === 0) ? $i['mid'] : z_root() . '/activity/' . urlencode($i['mid']));
		}

		$ret['diaspora:guid'] = $i['uuid'];

		if ($i['title'])
			$ret['name'] = html2plain(bbcode($i['title'], ['cache' => true]));

		if ($i['summary'])
			$ret['summary'] = bbcode($i['summary'], ['cache' => true]);

		if ($ret['type'] === 'Announce') {
			$tmp            = preg_replace('/\[share(.*?)\[\/share\]/ism', EMPTY_STR, $i['body']);
			$ret['content'] = bbcode($tmp, ['cache' => true]);
			$ret['source']  = [
				'content'   => $i['body'],
				'mediaType' => 'text/bbcode'
			];
		}

		$ret['published'] = datetime_convert('UTC', 'UTC', $i['created'], ATOM_TIME);
		if ($i['created'] !== $i['edited'])
			$ret['updated'] = datetime_convert('UTC', 'UTC', $i['edited'], ATOM_TIME);
		if ($i['app']) {
			$ret['generator'] = ['type' => 'Application', 'name' => $i['app']];
		}
		if ($i['location'] || $i['coord']) {
			$ret['location'] = ['type' => 'Place'];
			if ($i['location']) {
				$ret['location']['name'] = $i['location'];
			}
			if ($i['coord']) {
				$l                            = explode(' ', $i['coord']);
				$ret['location']['latitude']  = $l[0];
				$ret['location']['longitude'] = $l[1];
			}
		}

		if ($i['id'] != $i['parent']) {
			$reply = true;

			// inReplyTo needs to be set in the activity for followup actions (Like, Dislike, Announce, etc.),
			// but *not* for comments and RSVPs, where it should only be present in the object

			if (!in_array($ret['type'], ['Create', 'Update', 'Accept', 'Reject', 'TentativeAccept', 'TentativeReject'])) {
				$ret['inReplyTo'] = ((strpos($i['thr_parent'], 'http') === 0) ? $i['thr_parent'] : z_root() . '/item/' . urlencode($i['thr_parent']));
			}
		}

		$actor = self::encode_person($i['author'], false);
		if ($actor)
			$ret['actor'] = $actor;
		else
			return [];

		if (strpos($i['body'], '[/share]') !== false) {
			$i['obj'] = null;
		}

		if ($i['obj']) {
			if (!is_array($i['obj'])) {
				$i['obj'] = json_decode($i['obj'], true);
			}
			if ($i['obj']['type'] === ACTIVITY_OBJ_PHOTO) {
				$i['obj']['id'] = $i['mid'];
			}

			$obj = self::encode_object($i['obj']);
			if ($obj)
				$ret['object'] = $obj;
			else
				return [];
		}
		else {
			$obj = self::encode_item($i);
			if ($obj)
				$ret['object'] = $obj;
			else
				return [];
		}

		if (array_path_exists('object/type', $ret) && $ret['object']['type'] === 'Event' && $ret['type'] === 'Create') {
			$ret['type'] = 'Invite';
		}

		if ($i['target']) {
			if (!is_array($i['target'])) {
				$i['target'] = json_decode($i['target'], true);
			}
			$tgt = self::encode_object($i['target']);
			if ($tgt)
				$ret['target'] = $tgt;
			else
				return [];
		}

		$t = self::encode_taxonomy($i);
		if ($t) {
			$ret['tag'] = $t;
		}

		// addressing madness

		$public    = (($i['item_private']) ? false : true);
		$top_level = (($reply) ? false : true);

		if ($public) {
			$ret['to'] = [ACTIVITY_PUBLIC_INBOX];
			$ret['cc'] = [z_root() . '/followers/' . substr($i['author']['xchan_addr'], 0, strpos($i['author']['xchan_addr'], '@'))];
		}
		else {

			// private activity

			if ($top_level) {
				$ret['to'] = self::map_acl($i);
			}
			else {
				$ret['to'] = [];
				if ($ret['tag']) {
					foreach ($ret['tag'] as $mention) {
						if (is_array($mention) && array_key_exists('href', $mention) && $mention['href']) {
							$h = q("select * from hubloc where hubloc_id_url = '%s' limit 1",
								dbesc($mention['href'])
							);
							if ($h) {
								if ($h[0]['hubloc_network'] === 'activitypub') {
									$addr = $h[0]['hubloc_hash'];
								}
								else {
									$addr = $h[0]['hubloc_id_url'];
								}
								if (!in_array($addr, $ret['to'])) {
									$ret['to'][] = $addr;
								}
							}
						}
					}
				}

				$d = q("select hubloc.*  from hubloc left join item on hubloc_hash = owner_xchan where item.id = %d limit 1",
					intval($i['parent'])
				);
				if ($d) {
					if ($d[0]['hubloc_network'] === 'activitypub') {
						$addr = $d[0]['hubloc_hash'];
					}
					else {
						$addr = $d[0]['hubloc_id_url'];
					}
					if (!in_array($addr, $ret['to'])) {
						$ret['cc'][] = $addr;
					}
				}
			}
		}

		$mentions = self::map_mentions($i);
		if (count($mentions) > 0) {
			if (!$ret['to']) {
				$ret['to'] = $mentions;
			}
			else {
				$ret['to'] = array_values(array_unique(array_merge($ret['to'], $mentions)));
			}
		}

		return $ret;
	}

	// Returns an array of URLS for any mention tags found in the item array $i.

	static function map_mentions($i) {

		if (!$i['term']) {
			return [];
		}

		$list = [];

		foreach ($i['term'] as $t) {
			if (!$t['url']) {
				continue;
			}
			if ($t['ttype'] == TERM_MENTION) {
				$url    = self::lookup_term_url($t['url']);
				$list[] = (($url) ? $url : $t['url']);
			}
		}

		return $list;
	}

	// Returns an array of all recipients targeted by private item array $i.

	static function map_acl($i) {
		$ret = [];

		if (!$i['item_private']) {
			return $ret;
		}

		if ($i['allow_gid']) {
			$tmp = expand_acl($i['allow_gid']);
			if ($tmp) {
				foreach ($tmp as $t) {
					$ret[] = z_root() . '/lists/' . $t;
				}
			}
		}

		if ($i['allow_cid']) {
			$tmp  = expand_acl($i['allow_cid']);
			$list = stringify_array($tmp, true);
			if ($list) {
				$details = q("select hubloc_id_url from hubloc where hubloc_hash in (" . $list . ") and hubloc_id_url != ''");
				if ($details) {
					foreach ($details as $d) {
						$ret[] = $d['hubloc_id_url'];
					}
				}
			}
		}

		return $ret;
	}

	static function lookup_term_url($url) {

		// The xchan_url for mastodon is a text/html rendering. This is called from map_mentions where we need
		// to convert the mention url to an ActivityPub id. If this fails for any reason, return the url we have

		$r = q("select hubloc_network, hubloc_hash, hubloc_id_url from hubloc where hubloc_id_url = '%s' limit 1",
			dbesc($url)
		);

		if ($r) {
			if ($r[0]['hubloc_network'] === 'activitypub') {
				return $r[0]['hubloc_hash'];
			}
			return $r[0]['hubloc_id_url'];
		}

		return $url;
	}

	static function encode_person($p, $extended = true) {

		if (!$p['xchan_url'])
			return [];

		if (!$extended) {
			return $p['xchan_url'];
		}

		$ret = [];

		$c = ((array_key_exists('channel_id', $p)) ? $p : channelx_by_hash($p['xchan_hash']));

		$ret['type'] = 'Person';

		if ($c) {
			$role = get_pconfig($c['channel_id'], 'system', 'permissions_role');
			if (strpos($role, 'forum') !== false) {
				$ret['type'] = 'Group';
			}
		}

		if ($c) {
			$ret['id'] = channel_url($c);
		}
		else {
			$ret['id'] = ((strpos($p['xchan_hash'], 'http') === 0) ? $p['xchan_hash'] : $p['xchan_url']);
		}

		if ($p['xchan_addr'] && strpos($p['xchan_addr'], '@'))
			$ret['preferredUsername'] = substr($p['xchan_addr'], 0, strpos($p['xchan_addr'], '@'));
		$ret['name']    = $p['xchan_name'];
		$ret['updated'] = datetime_convert('UTC', 'UTC', $p['xchan_name_date'], ATOM_TIME);
		$ret['icon']    = [
			'type'      => 'Image',
			'mediaType' => (($p['xchan_photo_mimetype']) ? $p['xchan_photo_mimetype'] : 'image/png'),
			'updated'   => datetime_convert('UTC', 'UTC', $p['xchan_photo_date'], ATOM_TIME),
			'url'       => $p['xchan_photo_l'],
			'height'    => 300,
			'width'     => 300,
		];
		$ret['url']     = [
			[
				'type'      => 'Link',
				'mediaType' => 'text/html',
				'href'      => $p['xchan_url']
			],
			[
				'type'      => 'Link',
				'mediaType' => 'text/x-zot+json',
				'href'      => $p['xchan_url']
			]
		];

		$ret['publicKey'] = [
			'id'           => $p['xchan_url'],
			'owner'        => $p['xchan_url'],
			'publicKeyPem' => $p['xchan_pubkey']
		];

		$arr = ['xchan' => $p, 'encoded' => $ret];
		call_hooks('encode_person', $arr);

		$ret = $arr['encoded'];

		return $ret;
	}


	static function activity_mapper($verb) {

		if (strpos($verb, '/') === false) {
			return $verb;
		}

		$acts = [
			'http://activitystrea.ms/schema/1.0/post'     => 'Create',
			'http://activitystrea.ms/schema/1.0/share'    => 'Announce',
			'http://activitystrea.ms/schema/1.0/update'   => 'Update',
			'http://activitystrea.ms/schema/1.0/like'     => 'Like',
			'http://activitystrea.ms/schema/1.0/favorite' => 'Like',
			'http://purl.org/zot/activity/dislike'        => 'Dislike',
			'http://activitystrea.ms/schema/1.0/tag'      => 'Add',
			'http://activitystrea.ms/schema/1.0/follow'   => 'Follow',
			'http://activitystrea.ms/schema/1.0/unfollow' => 'Unfollow',
			'http://purl.org/zot/activity/attendyes'      => 'Accept',
			'http://purl.org/zot/activity/attendno'       => 'Reject',
			'http://purl.org/zot/activity/attendmaybe'    => 'TentativeAccept',
			'Invite'                                      => 'Invite',
			'Delete'                                      => 'Delete',
			'Undo'                                        => 'Undo'
		];

		call_hooks('activity_mapper', $acts);

		if (array_key_exists($verb, $acts) && $acts[$verb]) {
			return $acts[$verb];
		}

		// Reactions will just map to normal activities

		if (strpos($verb, ACTIVITY_REACT) !== false)
			return 'emojiReaction';
		if (strpos($verb, ACTIVITY_MOOD) !== false)
			return 'Create';

		if (strpos($verb, ACTIVITY_FRIEND) !== false)
			return 'Create';

		if (strpos($verb, ACTIVITY_POKE) !== false)
			return 'Activity';

		// We should return false, however this will trigger an uncaught execption  and crash 
		// the delivery system if encountered by the JSON-LDSignature library

		logger('Unmapped activity: ' . $verb);
		return 'Create';
		//	return false;
	}


	static function activity_decode_mapper($verb) {

		$acts = [
			'http://activitystrea.ms/schema/1.0/post'     => 'Create',
			'http://activitystrea.ms/schema/1.0/share'    => 'Announce',
			'http://activitystrea.ms/schema/1.0/update'   => 'Update',
			'http://activitystrea.ms/schema/1.0/like'     => 'Like',
			'http://activitystrea.ms/schema/1.0/favorite' => 'Like',
			'http://purl.org/zot/activity/dislike'        => 'Dislike',
			'http://activitystrea.ms/schema/1.0/tag'      => 'Add',
			'http://activitystrea.ms/schema/1.0/follow'   => 'Follow',
			'http://activitystrea.ms/schema/1.0/unfollow' => 'Unfollow',
			'http://purl.org/zot/activity/attendyes'      => 'Accept',
			'http://purl.org/zot/activity/attendno'       => 'Reject',
			'http://purl.org/zot/activity/attendmaybe'    => 'TentativeAccept',
			'Invite'                                      => 'Invite',
			'Delete'                                      => 'Delete',
			'Undo'                                        => 'Undo'
		];

		call_hooks('activity_decode_mapper', $acts);

		foreach ($acts as $k => $v) {
			if ($verb === $v) {
				return $k;
			}
		}

		logger('Unmapped activity: ' . $verb);
		return 'Create';

	}

	static function activity_obj_decode_mapper($obj) {

		$objs = [
			'http://activitystrea.ms/schema/1.0/note'          => 'Note',
			'http://activitystrea.ms/schema/1.0/note'          => 'Article',
			'http://activitystrea.ms/schema/1.0/comment'       => 'Note',
			'http://activitystrea.ms/schema/1.0/person'        => 'Person',
			'http://purl.org/zot/activity/profile'             => 'Profile',
			'http://activitystrea.ms/schema/1.0/photo'         => 'Image',
			'http://activitystrea.ms/schema/1.0/profile-photo' => 'Icon',
			'http://activitystrea.ms/schema/1.0/event'         => 'Event',
			'http://purl.org/zot/activity/location'            => 'Place',
			'http://purl.org/zot/activity/chessgame'           => 'Game',
			'http://purl.org/zot/activity/tagterm'             => 'zot:Tag',
			'http://purl.org/zot/activity/thing'               => 'Object',
			'http://purl.org/zot/activity/file'                => 'zot:File',
			'http://purl.org/zot/activity/mood'                => 'zot:Mood',
			'Invite'                                           => 'Invite',
			'Question'                                         => 'Question',
			'Document'                                         => 'Document',
			'Audio'                                            => 'Audio',
			'Video'                                            => 'Video',
			'Delete'                                           => 'Delete',
			'Undo'                                             => 'Undo'
		];

		call_hooks('activity_obj_decode_mapper', $objs);

		foreach ($objs as $k => $v) {
			if ($obj === $v) {
				return $k;
			}
		}

		logger('Unmapped activity object: ' . $obj);
		return 'Note';
	}


	static function activity_obj_mapper($obj) {

		$objs = [
			'http://activitystrea.ms/schema/1.0/note'          => 'Note',
			'http://activitystrea.ms/schema/1.0/comment'       => 'Note',
			'http://activitystrea.ms/schema/1.0/person'        => 'Person',
			'http://purl.org/zot/activity/profile'             => 'Profile',
			'http://activitystrea.ms/schema/1.0/photo'         => 'Image',
			'http://activitystrea.ms/schema/1.0/profile-photo' => 'Icon',
			'http://activitystrea.ms/schema/1.0/event'         => 'Event',
			'http://purl.org/zot/activity/location'            => 'Place',
			'http://purl.org/zot/activity/chessgame'           => 'Game',
			'http://purl.org/zot/activity/tagterm'             => 'zot:Tag',
			'http://purl.org/zot/activity/thing'               => 'Object',
			'http://purl.org/zot/activity/file'                => 'zot:File',
			'http://purl.org/zot/activity/mood'                => 'zot:Mood',
			'Invite'                                           => 'Invite',
			'Question'                                         => 'Question',
			'Audio'                                            => 'Audio',
			'Video'                                            => 'Video',
			'Delete'                                           => 'Delete',
			'Undo'                                             => 'Undo'
		];

		call_hooks('activity_obj_mapper', $objs);

		if ($obj === 'Answer') {
			return 'Note';
		}

		if (strpos($obj, '/') === false) {
			return $obj;
		}


		if (array_key_exists($obj, $objs)) {
			return $objs[$obj];
		}

		logger('Unmapped activity object: ' . $obj);
		return 'Note';

		//	return false;

	}


	static function follow($channel, $act) {

		$contact         = null;
		$their_follow_id = null;

		/*
		 * 
		 * if $act->type === 'Follow', actor is now following $channel 
		 * if $act->type === 'Accept', actor has approved a follow request from $channel 
		 *	 
		 */

		$person_obj = $act->actor;

		if ($act->type === 'Follow') {
			$their_follow_id = $act->id;
		}

		if (is_array($person_obj)) {

			// store their xchan and hubloc

			self::actor_store($person_obj['id'], $person_obj);

			// Find any existing abook record 

			$r = q("select * from abook left join xchan on abook_xchan = xchan_hash where abook_xchan = '%s' and abook_channel = %d limit 1",
				dbesc($person_obj['id']),
				intval($channel['channel_id'])
			);
			if ($r) {
				$contact = $r[0];
			}
		}

		$x           = PermissionRoles::role_perms('social');
		$p           = Permissions::FilledPerms($x['perms_connect']);
		$their_perms = Permissions::serialise($p);

		if ($contact && $contact['abook_id']) {

			// A relationship of some form already exists on this site. 

			switch ($act->type) {

				case 'Follow':

					// A second Follow request, but we haven't approved the first one

					if ($contact['abook_pending']) {
						return;
					}

					// We've already approved them or followed them first
					// Send an Accept back to them

					set_abconfig($channel['channel_id'], $person_obj['id'], 'pubcrawl', 'their_follow_id', $their_follow_id);
					Master::Summon(['Notifier', 'permissions_accept', $contact['abook_id']]);
					return;

				case 'Accept':

					// They accepted our Follow request - set default permissions

					set_abconfig($channel['channel_id'], $contact['abook_xchan'], 'system', 'their_perms', $their_perms);

					$abook_instance = $contact['abook_instance'];

					if (strpos($abook_instance, z_root()) === false) {
						if ($abook_instance)
							$abook_instance .= ',';
						$abook_instance .= z_root();

						q("update abook set abook_instance = '%s', abook_not_here = 0 
							where abook_id = %d and abook_channel = %d",
							dbesc($abook_instance),
							intval($contact['abook_id']),
							intval($channel['channel_id'])
						);
					}

					return;
				default:
					return;

			}
		}

		// No previous relationship exists.

		if ($act->type === 'Accept') {
			// This should not happen unless we deleted the connection before it was accepted.
			return;
		}

		// From here on out we assume a Follow activity to somebody we have no existing relationship with

		set_abconfig($channel['channel_id'], $person_obj['id'], 'pubcrawl', 'their_follow_id', $their_follow_id);

		// The xchan should have been created by actor_store() above

		$r = q("select * from xchan where xchan_hash = '%s' and xchan_network = 'activitypub' limit 1",
			dbesc($person_obj['id'])
		);

		if (!$r) {
			logger('xchan not found for ' . $person_obj['id']);
			return;
		}
		$ret = $r[0];

		$p         = Permissions::connect_perms($channel['channel_id']);
		$my_perms  = Permissions::serialise($p['perms']);
		$automatic = $p['automatic'];

		$closeness = get_pconfig($channel['channel_id'], 'system', 'new_abook_closeness', 80);

		$r = abook_store_lowlevel(
			[
				'abook_account'   => intval($channel['channel_account_id']),
				'abook_channel'   => intval($channel['channel_id']),
				'abook_xchan'     => $ret['xchan_hash'],
				'abook_closeness' => intval($closeness),
				'abook_created'   => datetime_convert(),
				'abook_updated'   => datetime_convert(),
				'abook_connected' => datetime_convert(),
				'abook_dob'       => NULL_DATE,
				'abook_pending'   => intval(($automatic) ? 0 : 1),
				'abook_instance'  => z_root()
			]
		);

		if ($my_perms)
			set_abconfig($channel['channel_id'], $ret['xchan_hash'], 'system', 'my_perms', $my_perms);

		if ($their_perms)
			set_abconfig($channel['channel_id'], $ret['xchan_hash'], 'system', 'their_perms', $their_perms);


		if ($r) {
			logger("New ActivityPub follower for {$channel['channel_name']}");

			$new_connection = q("select * from abook left join xchan on abook_xchan = xchan_hash left join hubloc on hubloc_hash = xchan_hash where abook_channel = %d and abook_xchan = '%s' order by abook_created desc limit 1",
				intval($channel['channel_id']),
				dbesc($ret['xchan_hash'])
			);
			if ($new_connection) {
				Enotify::submit(
					[
						'type'       => NOTIFY_INTRO,
						'from_xchan' => $ret['xchan_hash'],
						'to_xchan'   => $channel['channel_hash'],
						'link'       => z_root() . '/connedit/' . $new_connection[0]['abook_id'],
					]
				);

				if ($my_perms && $automatic) {
					// send an Accept for this Follow activity
					Master::Summon(['Notifier', 'permissions_accept', $new_connection[0]['abook_id']]);
					// Send back a Follow notification to them
					Master::Summon(['Notifier', 'permissions_create', $new_connection[0]['abook_id']]);
				}

				$clone = [];
				foreach ($new_connection[0] as $k => $v) {
					if (strpos($k, 'abook_') === 0) {
						$clone[$k] = $v;
					}
				}
				unset($clone['abook_id']);
				unset($clone['abook_account']);
				unset($clone['abook_channel']);

				$abconfig = load_abconfig($channel['channel_id'], $clone['abook_xchan']);

				if ($abconfig)
					$clone['abconfig'] = $abconfig;

				Libsync::build_sync_packet($channel['channel_id'], ['abook' => [$clone]]);
			}
		}


		/* If there is a default group for this channel and permissions are automatic, add this member to it */

		if ($channel['channel_default_group'] && $automatic) {
			$g = Group::rec_byhash($channel['channel_id'], $channel['channel_default_group']);
			if ($g)
				Group::member_add($channel['channel_id'], '', $ret['xchan_hash'], $g['id']);
		}


		return;

	}


	static function unfollow($channel, $act) {

		$contact = null;

		/* @FIXME This really needs to be a signed request. */

		/* actor is unfollowing $channel */

		$person_obj = $act->actor;

		if (is_array($person_obj)) {

			$r = q("select * from abook left join xchan on abook_xchan = xchan_hash where abook_xchan = '%s' and abook_channel = %d limit 1",
				dbesc($person_obj['id']),
				intval($channel['channel_id'])
			);
			if ($r) {
				// remove all permissions they provided
				del_abconfig($channel['channel_id'], $r[0]['xchan_hash'], 'system', 'their_perms');
			}
		}

		return;
	}


	static function actor_store($url, $person_obj) {

		if (!is_array($person_obj))
			return;

		$inbox = $person_obj['inbox'];

		// invalid identity

		if (!$inbox || strpos($inbox, z_root()) !== false) {
			return;
		}

		$name = $person_obj['name'];
		if (!$name)
			$name = $person_obj['preferredUsername'];
		if (!$name)
			$name = t('Unknown');

		if ($person_obj['icon']) {
			if (is_array($person_obj['icon'])) {
				if (array_key_exists('url', $person_obj['icon']))
					$icon = $person_obj['icon']['url'];
				else
					$icon = $person_obj['icon'][0]['url'];
			}
			else
				$icon = $person_obj['icon'];
		}

		$links   = false;
		$profile = false;

		if (is_array($person_obj['url'])) {
			if (!array_key_exists(0, $person_obj['url'])) {
				$links = [$person_obj['url']];
			}
			else {
				$links = $person_obj['url'];
			}
		}

		if ($links) {
			foreach ($links as $link) {
				if (array_key_exists('mediaType', $link) && $link['mediaType'] === 'text/html') {
					$profile = $link['href'];
				}
			}
			if (!$profile) {
				$profile = $links[0]['href'];
			}
		}
		elseif (isset($person_obj['url']) && is_string($person_obj['url'])) {
			$profile = $person_obj['url'];
		}

		if (!$profile) {
			$profile = $url;
		}

		$collections = [];

		if ($inbox) {
			$collections['inbox'] = $inbox;
			if ($person_obj['outbox'])
				$collections['outbox'] = $person_obj['outbox'];
			if ($person_obj['followers'])
				$collections['followers'] = $person_obj['followers'];
			if ($person_obj['following'])
				$collections['following'] = $person_obj['following'];
			if ($person_obj['endpoints'] && $person_obj['endpoints']['sharedInbox'])
				$collections['sharedInbox'] = $person_obj['endpoints']['sharedInbox'];
		}

		if (array_key_exists('publicKey', $person_obj) && array_key_exists('publicKeyPem', $person_obj['publicKey'])) {
			if ($person_obj['id'] === $person_obj['publicKey']['owner']) {
				$pubkey = $person_obj['publicKey']['publicKeyPem'];
				if (strstr($pubkey, 'RSA ')) {
					$pubkey = rsatopem($pubkey);
				}
			}
		}

		$r = q("select * from xchan where xchan_hash = '%s' limit 1",
			dbesc($url)
		);
		if (!$r) {
			// create a new record

			xchan_store_lowlevel(
				[
					'xchan_hash'      => $url,
					'xchan_guid'      => $url,
					'xchan_pubkey'    => $pubkey,
					'xchan_addr'      => '',
					'xchan_url'       => $profile,
					'xchan_name'      => $name,
					'xchan_name_date' => datetime_convert(),
					'xchan_network'   => 'activitypub'
				]
			);
		}
		else {

			// Record exists. Cache existing records for one week at most
			// then refetch to catch updated profile photos, names, etc. 

			$d = datetime_convert('UTC', 'UTC', 'now - 1 week');
			if ($r[0]['xchan_name_date'] > $d)
				return;

			// update existing record
			q("update xchan set xchan_name = '%s', xchan_pubkey = '%s', xchan_network = '%s', xchan_name_date = '%s' where xchan_hash = '%s'",
				dbesc($name),
				dbesc($pubkey),
				dbesc('activitypub'),
				dbesc(datetime_convert()),
				dbesc($url)
			);
		}

		if ($collections) {
			set_xconfig($url, 'activitypub', 'collections', $collections);
		}

		$r = q("select * from hubloc where hubloc_hash = '%s' limit 1",
			dbesc($url)
		);

		$m = parse_url($url);
		if ($m) {
			$hostname = $m['host'];
			$baseurl  = $m['scheme'] . '://' . $m['host'] . (($m['port']) ? ':' . $m['port'] : '');
		}

		if (!$r) {
			hubloc_store_lowlevel(
				[
					'hubloc_guid'     => $url,
					'hubloc_hash'     => $url,
					'hubloc_addr'     => '',
					'hubloc_network'  => 'activitypub',
					'hubloc_url'      => $baseurl,
					'hubloc_host'     => $hostname,
					'hubloc_callback' => $inbox,
					'hubloc_updated'  => datetime_convert(),
					'hubloc_primary'  => 1,
					'hubloc_id_url'   => $profile
				]
			);
		}

		if (!$icon)
			$icon = z_root() . '/' . get_default_profile_photo(300);

		$photos = import_xchan_photo($icon, $url);
		q("update xchan set xchan_photo_date = '%s', xchan_photo_l = '%s', xchan_photo_m = '%s', xchan_photo_s = '%s', xchan_photo_mimetype = '%s' where xchan_hash = '%s'",
			dbescdate(datetime_convert('UTC', 'UTC', $photos[5])),
			dbesc($photos[0]),
			dbesc($photos[1]),
			dbesc($photos[2]),
			dbesc($photos[3]),
			dbesc($url)
		);

	}


	static function create_action($channel, $observer_hash, $act) {

		if (in_array($act->obj['type'], ['Note', 'Article', 'Video'])) {
			self::create_note($channel, $observer_hash, $act);
		}


	}

	static function announce_action($channel, $observer_hash, $act) {

		if (in_array($act->type, ['Announce'])) {
			self::announce_note($channel, $observer_hash, $act);
		}

	}


	static function like_action($channel, $observer_hash, $act) {

		if (in_array($act->obj['type'], ['Note', 'Article', 'Video'])) {
			self::like_note($channel, $observer_hash, $act);
		}


	}

	// sort function width decreasing

	static function vid_sort($a, $b) {
		if ($a['width'] === $b['width'])
			return 0;
		return (($a['width'] > $b['width']) ? -1 : 1);
	}

	static function create_note($channel, $observer_hash, $act) {

		$s = [];

		// Mastodon only allows visibility in public timelines if the public inbox is listed in the 'to' field.
		// They are hidden in the public timeline if the public inbox is listed in the 'cc' field.
		// This is not part of the activitypub protocol - we might change this to show all public posts in pubstream at some point.
		$pubstream      = ((is_array($act->obj) && array_key_exists('to', $act->obj) && in_array(ACTIVITY_PUBLIC_INBOX, $act->obj['to'])) ? true : false);
		$is_sys_channel = is_sys_channel($channel['channel_id']);

		$parent = ((array_key_exists('inReplyTo', $act->obj)) ? urldecode($act->obj['inReplyTo']) : '');
		if ($parent) {

			$r = q("select * from item where uid = %d and ( mid = '%s' or  mid = '%s' ) limit 1",
				intval($channel['channel_id']),
				dbesc($parent),
				dbesc(basename($parent))
			);

			if (!$r) {
				logger('parent not found.');
				return;
			}

			if ($r[0]['owner_xchan'] === $channel['channel_hash']) {
				if (!perm_is_allowed($channel['channel_id'], $observer_hash, 'send_stream') && !($is_sys_channel && $pubstream)) {
					logger('no comment permission.');
					return;
				}
			}

			$s['parent_mid']   = $r[0]['mid'];
			$s['owner_xchan']  = $r[0]['owner_xchan'];
			$s['author_xchan'] = $observer_hash;

		}
		else {
			if (!perm_is_allowed($channel['channel_id'], $observer_hash, 'send_stream') && !($is_sys_channel && $pubstream)) {
				logger('no permission');
				return;
			}
			$s['owner_xchan'] = $s['author_xchan'] = $observer_hash;
		}

		$abook = q("select * from abook where abook_xchan = '%s' and abook_channel = %d limit 1",
			dbesc($observer_hash),
			intval($channel['channel_id'])
		);

		$content = self::get_content($act->obj);

		if (!$content) {
			logger('no content');
			return;
		}

		$s['aid'] = $channel['channel_account_id'];
		$s['uid'] = $channel['channel_id'];

		// Make sure we use the zot6 identity where applicable

		$s['author_xchan'] = self::find_best_identity($s['author_xchan']);
		$s['owner_xchan']  = self::find_best_identity($s['owner_xchan']);

		if (!$s['author_xchan']) {
			logger('No author: ' . print_r($act, true));
		}

		if (!$s['owner_xchan']) {
			logger('No owner: ' . print_r($act, true));
		}

		if (!$s['author_xchan'] || !$s['owner_xchan'])
			return;

		$s['mid']   = urldecode($act->obj['id']);
		$s['uuid']  = $act->obj['diaspora:guid'];
		$s['plink'] = urldecode($act->obj['id']);


		if ($act->data['published']) {
			$s['created'] = datetime_convert('UTC', 'UTC', $act->data['published']);
		}
		elseif ($act->obj['published']) {
			$s['created'] = datetime_convert('UTC', 'UTC', $act->obj['published']);
		}
		if ($act->data['updated']) {
			$s['edited'] = datetime_convert('UTC', 'UTC', $act->data['updated']);
		}
		elseif ($act->obj['updated']) {
			$s['edited'] = datetime_convert('UTC', 'UTC', $act->obj['updated']);
		}
		if ($act->data['expires']) {
			$s['expires'] = datetime_convert('UTC', 'UTC', $act->data['expires']);
		}
		elseif ($act->obj['expires']) {
			$s['expires'] = datetime_convert('UTC', 'UTC', $act->obj['expires']);
		}

		if (!$s['created'])
			$s['created'] = datetime_convert();

		if (!$s['edited'])
			$s['edited'] = $s['created'];


		if (!$s['parent_mid'])
			$s['parent_mid'] = $s['mid'];


		$s['title']    = self::bb_content($content, 'name');
		$s['summary']  = self::bb_content($content, 'summary');
		$s['body']     = self::bb_content($content, 'content');
		$s['verb']     = ACTIVITY_POST;
		$s['obj_type'] = ACTIVITY_OBJ_NOTE;

		$generator = $act->get_property_obj('generator');
		if (!$generator)
			$generator = $act->get_property_obj('generator', $act->obj);

		if ($generator && array_key_exists('type', $generator)
			&& in_array($generator['type'], ['Application', 'Service']) && array_key_exists('name', $generator)) {
			$s['app'] = escape_tags($generator['name']);
		}

		if ($channel['channel_system']) {
			if (!MessageFilter::evaluate($s, get_config('system', 'pubstream_incl'), get_config('system', 'pubstream_excl'))) {
				logger('post is filtered');
				return;
			}
		}


		if ($abook) {
			if (!post_is_importable($s, $abook[0])) {
				logger('post is filtered');
				return;
			}
		}

		if ($act->obj['conversation']) {
			set_iconfig($s, 'ostatus', 'conversation', $act->obj['conversation'], 1);
		}

		$a = self::decode_taxonomy($act->obj);
		if ($a) {
			$s['term'] = $a;
		}

		$a = self::decode_attachment($act->obj);
		if ($a) {
			$s['attach'] = $a;
		}

		if ($act->obj['type'] === 'Note' && $s['attach']) {
			$s['body'] .= self::bb_attach($s['attach'], $s['body']);
		}

		// we will need a hook here to extract magnet links e.g. peertube
		// right now just link to the largest mp4 we find that will fit in our
		// standard content region

		if ($act->obj['type'] === 'Video') {

			$vtypes = [
				'video/mp4',
				'video/ogg',
				'video/webm'
			];

			$mps = [];
			if (array_key_exists('url', $act->obj) && is_array($act->obj['url'])) {
				foreach ($act->obj['url'] as $vurl) {
					if (in_array($vurl['mimeType'], $vtypes)) {
						if (!array_key_exists('width', $vurl)) {
							$vurl['width'] = 0;
						}
						$mps[] = $vurl;
					}
				}
			}
			if ($mps) {
				usort($mps, [__CLASS__, 'vid_sort']);
				foreach ($mps as $m) {
					if (intval($m['width']) < 500) {
						$s['body'] .= "\n\n" . '[video]' . $m['href'] . '[/video]';
						break;
					}
				}
			}
		}

		if ($act->recips && (!in_array(ACTIVITY_PUBLIC_INBOX, $act->recips)))
			$s['item_private'] = 1;


		if (array_key_exists('directMessage', $act->obj) && intval($act->obj['directMessage'])) {
			$s['item_private'] = 2;
		}

		set_iconfig($s, 'activitypub', 'recips', $act->raw_recips);
		if ($parent) {
			set_iconfig($s, 'activitypub', 'rawmsg', $act->raw, 1);
		}

		$x = null;

		$r = q("select created, edited from item where mid = '%s' and uid = %d limit 1",
			dbesc($s['mid']),
			intval($s['uid'])
		);
		if ($r) {
			if ($s['edited'] > $r[0]['edited']) {
				$x = item_store_update($s);
			}
			else {
				return;
			}
		}
		else {
			$x = item_store($s);
		}

		if (is_array($x) && $x['item_id']) {
			if ($parent) {
				if ($s['owner_xchan'] === $channel['channel_hash']) {
					// We are the owner of this conversation, so send all received comments back downstream
					Master::Summon(['Notifier', 'comment-import', $x['item_id']]);
				}
				$r = q("select * from item where id = %d limit 1",
					intval($x['item_id'])
				);
				if ($r) {
					send_status_notifications($x['item_id'], $r[0]);
				}
			}
			sync_an_item($channel['channel_id'], $x['item_id']);
		}

	}

	static function get_actor_bbmention($id) {

		$x = q("select * from hubloc left join xchan on hubloc_hash = xchan_hash where hubloc_hash = '%s' or hubloc_id_url = '%s' limit 1",
			dbesc($id),
			dbesc($id)
		);

		if ($x) {
			return sprintf('@[zrl=%s]%s[/zrl]', $x[0]['xchan_url'], $x[0]['xchan_name']);
		}
		return '@{' . $id . '}';

	}


	static function update_poll($item, $post) {
		$multi   = false;
		$mid     = $post['mid'];
		$content = $post['title'];

		if (!$item) {
			return false;
		}

		$o = json_decode($item['obj'], true);
		if ($o && array_key_exists('anyOf', $o)) {
			$multi = true;
		}

		$r = q("select mid, title from item where parent_mid = '%s' and author_xchan = '%s'",
			dbesc($item['mid']),
			dbesc($post['author_xchan'])
		);

		// prevent any duplicate votes by same author for oneOf and duplicate votes with same author and same answer for anyOf

		if ($r) {
			if ($multi) {
				foreach ($r as $rv) {
					if ($rv['title'] === $content && $rv['mid'] !== $mid) {
						return false;
					}
				}
			}
			else {
				foreach ($r as $rv) {
					if ($rv['mid'] !== $mid) {
						return false;
					}
				}
			}
		}

		$answer_found = false;
		$found        = false;
		if ($multi) {
			for ($c = 0; $c < count($o['anyOf']); $c++) {
				if ($o['anyOf'][$c]['name'] === $content) {
					$answer_found = true;
					if (is_array($o['anyOf'][$c]['replies'])) {
						foreach ($o['anyOf'][$c]['replies'] as $reply) {
							if (is_array($reply) && array_key_exists('id', $reply) && $reply['id'] === $mid) {
								$found = true;
							}
						}
					}

					if (!$found) {
						$o['anyOf'][$c]['replies']['totalItems']++;
						$o['anyOf'][$c]['replies']['items'][] = ['id' => $mid, 'type' => 'Note'];
					}
				}
			}
		}
		else {
			for ($c = 0; $c < count($o['oneOf']); $c++) {
				if ($o['oneOf'][$c]['name'] === $content) {
					$answer_found = true;
					if (is_array($o['oneOf'][$c]['replies'])) {
						foreach ($o['oneOf'][$c]['replies'] as $reply) {
							if (is_array($reply) && array_key_exists('id', $reply) && $reply['id'] === $mid) {
								$found = true;
							}
						}
					}

					if (!$found) {
						$o['oneOf'][$c]['replies']['totalItems']++;
						$o['oneOf'][$c]['replies']['items'][] = ['id' => $mid, 'type' => 'Note'];
					}
				}
			}
		}
		logger('updated_poll: ' . print_r($o, true), LOGGER_DATA);
		if ($answer_found && !$found) {
			q("update item set obj = '%s', edited = '%s' where id = %d",
				dbesc(json_encode($o)),
				dbesc(datetime_convert()),
				intval($item['id'])
			);
			Master::Summon(['Notifier', 'wall-new', $item['id']]);
			return true;
		}

		return false;
	}


	static function decode_note($act) {

		$response_activity = false;

		$s = [];

		if (is_array($act->obj)) {
			$content = self::get_content($act->obj);
		}

		$s['owner_xchan']  = $act->actor['id'];
		$s['author_xchan'] = $act->actor['id'];

		// ensure we store the original actor
		self::actor_store($act->actor['id'], $act->actor);

		$s['mid']        = $act->obj['id'];
		$s['uuid']       = $act->obj['diaspora:guid'];
		$s['parent_mid'] = $act->parent_id;

		if ($act->data['published']) {
			$s['created'] = datetime_convert('UTC', 'UTC', $act->data['published']);
		}
		elseif ($act->obj['published']) {
			$s['created'] = datetime_convert('UTC', 'UTC', $act->obj['published']);
		}
		if ($act->data['updated']) {
			$s['edited'] = datetime_convert('UTC', 'UTC', $act->data['updated']);
		}
		elseif ($act->obj['updated']) {
			$s['edited'] = datetime_convert('UTC', 'UTC', $act->obj['updated']);
		}
		if ($act->data['expires']) {
			$s['expires'] = datetime_convert('UTC', 'UTC', $act->data['expires']);
		}
		elseif ($act->obj['expires']) {
			$s['expires'] = datetime_convert('UTC', 'UTC', $act->obj['expires']);
		}

		if (ActivityStreams::is_response_activity($act->type)) {

			$response_activity = true;

			$s['mid'] = $act->id;
			// $s['parent_mid'] = $act->obj['id'];
			$s['uuid'] = $act->data['diaspora:guid'];

			// over-ride the object timestamp with the activity

			if ($act->data['published']) {
				$s['created'] = datetime_convert('UTC', 'UTC', $act->data['published']);
			}

			if ($act->data['updated']) {
				$s['edited'] = datetime_convert('UTC', 'UTC', $act->data['updated']);
			}

			$obj_actor = ((isset($act->obj['actor'])) ? $act->obj['actor'] : $act->get_actor('attributedTo', $act->obj));
			// ensure we store the original actor
			self::actor_store($obj_actor['id'], $obj_actor);

			$mention = self::get_actor_bbmention($obj_actor['id']);

			if ($act->type === 'Like') {
				$content['content'] = sprintf(t('Likes %1$s\'s %2$s'), $mention, $act->obj['type']) . "\n\n" . $content['content'];
			}
			if ($act->type === 'Dislike') {
				$content['content'] = sprintf(t('Doesn\'t like %1$s\'s %2$s'), $mention, $act->obj['type']) . "\n\n" . $content['content'];
			}

			// handle event RSVPs
			if (($act->obj['type'] === 'Event') || ($act->obj['type'] === 'Invite' && array_path_exists('object/type', $act->obj) && $act->obj['object']['type'] === 'Event')) {
				if ($act->type === 'Accept') {
					$content['content'] = sprintf(t('Will attend %s\'s event'), $mention) . EOL . EOL . $content['content'];
				}
				if ($act->type === 'Reject') {
					$content['content'] = sprintf(t('Will not attend %s\'s event'), $mention) . EOL . EOL . $content['content'];
				}
				if ($act->type === 'TentativeAccept') {
					$content['content'] = sprintf(t('May attend %s\'s event'), $mention) . EOL . EOL . $content['content'];
				}
				if ($act->type === 'TentativeReject') {
					$content['content'] = sprintf(t('May not attend %s\'s event'), $mention) . EOL . EOL . $content['content'];
				}
			}

			if ($act->type === 'Announce') {
				$content['content'] = sprintf(t('&#x1f501; Repeated %1$s\'s %2$s'), $mention, $act->obj['type']);
			}
			if ($act->type === 'emojiReaction') {
				$content['content'] = (($act->tgt && $act->tgt['type'] === 'Image') ? '[img=32x32]' . $act->tgt['url'] . '[/img]' : '&#x' . $act->tgt['name'] . ';');
			}
		}

		if (!$s['created'])
			$s['created'] = datetime_convert();

		if (!$s['edited'])
			$s['edited'] = $s['created'];

		$s['title']   = (($response_activity) ? EMPTY_STR : self::bb_content($content, 'name'));
		$s['summary'] = self::bb_content($content, 'summary');
		$s['body']    = ((self::bb_content($content, 'bbcode') && (!$response_activity)) ? self::bb_content($content, 'bbcode') : self::bb_content($content, 'content'));

		$s['verb'] = self::activity_decode_mapper($act->type);

		// Mastodon does not provide update timestamps when updating poll tallies which means race conditions may occur here.
		if ($act->type === 'Update' && $act->obj['type'] === 'Question' && $s['edited'] === $s['created']) {
			$s['edited'] = datetime_convert();
		}

		if (in_array($act->type, ['Delete', 'Undo', 'Tombstone']) || ($act->type === 'Create' && $act->obj['type'] === 'Tombstone')) {
			$s['item_deleted'] = 1;
		}

		$s['obj_type'] = self::activity_obj_decode_mapper($act->obj['type']);
		if ($s['obj_type'] === ACTIVITY_OBJ_NOTE && $s['mid'] !== $s['parent_mid']) {
			$s['obj_type'] = ACTIVITY_OBJ_COMMENT;
		}

		$eventptr = null;

		if ($act->obj['type'] === 'Invite' && array_path_exists('object/type', $act->obj) && $act->obj['object']['type'] === 'Event') {
			$eventptr = $act->obj['object'];
			$s['mid'] = $s['parent_mid'] = $act->obj['id'];
		}

		if ($act->obj['type'] === 'Event') {
			if ($act->type === 'Invite') {
				$s['mid'] = $s['parent_mid'] = $act->id;
			}
			$eventptr = $act->obj;
		}

		if ($eventptr) {

			$s['obj']          = [];
			$s['obj']['asld']  = $eventptr;
			$s['obj']['type']  = ACTIVITY_OBJ_EVENT;
			$s['obj']['id']    = $eventptr['id'];
			$s['obj']['title'] = $eventptr['name'];

			if (strpos($act->obj['startTime'], 'Z'))
				$s['obj']['adjust'] = true;
			else
				$s['obj']['adjust'] = false;

			$s['obj']['dtstart'] = datetime_convert('UTC', 'UTC', $eventptr['startTime']);
			if ($act->obj['endTime'])
				$s['obj']['dtend'] = datetime_convert('UTC', 'UTC', $eventptr['endTime']);
			else
				$s['obj']['nofinish'] = true;
			$s['obj']['description'] = $eventptr['content'];

			if (array_path_exists('location/content', $eventptr))
				$s['obj']['location'] = $eventptr['location']['content'];

		}
		else {
			$s['obj'] = $act->obj;
		}

		$generator = $act->get_property_obj('generator');
		if ((!$generator) && (!$response_activity)) {
			$generator = $act->get_property_obj('generator', $act->obj);
		}

		if ($generator && array_key_exists('type', $generator)
			&& in_array($generator['type'], ['Application', 'Service']) && array_key_exists('name', $generator)) {
			$s['app'] = escape_tags($generator['name']);
		}


		if (!$response_activity) {
			$a = self::decode_taxonomy($act->obj);
			if ($a) {
				$s['term'] = $a;
				foreach ($a as $b) {
					if ($b['ttype'] === TERM_EMOJI) {
						$s['title']   = str_replace($b['term'], '[img=16x16]' . $b['url'] . '[/img]', $s['title']);
						$s['summary'] = str_replace($b['term'], '[img=16x16]' . $b['url'] . '[/img]', $s['summary']);
						$s['body']    = str_replace($b['term'], '[img=16x16]' . $b['url'] . '[/img]', $s['body']);
					}
				}
			}

		}

		$a = self::decode_attachment($act->obj);
		if ($a) {
			$s['attach'] = $a;
		}

		$a = self::decode_iconfig($act->obj);
		if ($a) {
			$s['iconfig'] = $a;
		}

		if ($act->obj['type'] === 'Note' && $s['attach']) {
			$s['body'] .= self::bb_attach($s['attach'], $s['body']);
		}

		if ($act->obj['type'] === 'Question' && in_array($act->type, ['Create', 'Update'])) {
			if ($act->obj['endTime']) {
				$s['comments_closed'] = datetime_convert('UTC', 'UTC', $act->obj['endTime']);
			}
		}

		if ($act->obj['closed']) {
			$s['comments_closed'] = datetime_convert('UTC', 'UTC', $act->obj['closed']);
		}


		// we will need a hook here to extract magnet links e.g. peertube
		// right now just link to the largest mp4 we find that will fit in our
		// standard content region

		if (!$response_activity) {
			if ($act->obj['type'] === 'Video') {

				$vtypes = [
					'video/mp4',
					'video/ogg',
					'video/webm'
				];

				$mps = [];
				$ptr = null;

				if (array_key_exists('url', $act->obj)) {
					if (is_array($act->obj['url'])) {
						if (array_key_exists(0, $act->obj['url'])) {
							$ptr = $act->obj['url'];
						}
						else {
							$ptr = [$act->obj['url']];
						}
						foreach ($ptr as $vurl) {
							// peertube uses the non-standard element name 'mimeType' here
							if (array_key_exists('mimeType', $vurl)) {
								if (in_array($vurl['mimeType'], $vtypes)) {
									if (!array_key_exists('width', $vurl)) {
										$vurl['width'] = 0;
									}
									$mps[] = $vurl;
								}
							}
							elseif (array_key_exists('mediaType', $vurl)) {
								if (in_array($vurl['mediaType'], $vtypes)) {
									if (!array_key_exists('width', $vurl)) {
										$vurl['width'] = 0;
									}
									$mps[] = $vurl;
								}
							}
						}
					}
					if ($mps) {
						usort($mps, [__CLASS__, 'vid_sort']);
						foreach ($mps as $m) {
							if (intval($m['width']) < 500 && self::media_not_in_body($m['href'], $s['body'])) {
								$s['body'] .= "\n\n" . '[video]' . $m['href'] . '[/video]';
								break;
							}
						}
					}
					elseif (is_string($act->obj['url']) && self::media_not_in_body($act->obj['url'], $s['body'])) {
						$s['body'] .= "\n\n" . '[video]' . $act->obj['url'] . '[/video]';
					}
				}
			}

			if ($act->obj['type'] === 'Audio') {

				$atypes = [
					'audio/mpeg',
					'audio/ogg',
					'audio/wav'
				];

				$ptr = null;

				if (array_key_exists('url', $act->obj)) {
					if (is_array($act->obj['url'])) {
						if (array_key_exists(0, $act->obj['url'])) {
							$ptr = $act->obj['url'];
						}
						else {
							$ptr = [$act->obj['url']];
						}
						foreach ($ptr as $vurl) {
							if (in_array($vurl['mediaType'], $atypes) && self::media_not_in_body($vurl['href'], $s['body'])) {
								$s['body'] .= "\n\n" . '[audio]' . $vurl['href'] . '[/audio]';
								break;
							}
						}
					}
					elseif (is_string($act->obj['url']) && self::media_not_in_body($act->obj['url'], $s['body'])) {
						$s['body'] .= "\n\n" . '[audio]' . $act->obj['url'] . '[/audio]';
					}
				}

			}

			if ($act->obj['type'] === 'Image') {

				$ptr = null;

				if (array_key_exists('url', $act->obj)) {
					if (is_array($act->obj['url'])) {
						if (array_key_exists(0, $act->obj['url'])) {
							$ptr = $act->obj['url'];
						}
						else {
							$ptr = [$act->obj['url']];
						}
						foreach ($ptr as $vurl) {
							if (strpos($s['body'], $vurl['href']) === false) {
								$bb_imgs = '[zmg]' . $vurl['href'] . '[/zmg]' . "\n\n";
								break;
							}
						}
						$s['body'] = $bb_imgs . $s['body'];
					}
					elseif (is_string($act->obj['url'])) {
						if (strpos($s['body'], $act->obj['url']) === false) {
							$s['body'] .= '[zmg]' . $act->obj['url'] . '[/zmg]' . "\n\n" . $s['body'];
						}
					}
				}
			}


			if ($act->obj['type'] === 'Page' && !$s['body']) {

				$ptr  = null;
				$purl = EMPTY_STR;

				if (array_key_exists('url', $act->obj)) {
					if (is_array($act->obj['url'])) {
						if (array_key_exists(0, $act->obj['url'])) {
							$ptr = $act->obj['url'];
						}
						else {
							$ptr = [$act->obj['url']];
						}
						foreach ($ptr as $vurl) {
							if (array_key_exists('mediaType', $vurl) && $vurl['mediaType'] === 'text/html') {
								$purl = $vurl['href'];
								break;
							}
							elseif (array_key_exists('mimeType', $vurl) && $vurl['mimeType'] === 'text/html') {
								$purl = $vurl['href'];
								break;
							}
						}
					}
					elseif (is_string($act->obj['url'])) {
						$purl = $act->obj['url'];
					}
					if ($purl) {
						$li = z_fetch_url(z_root() . '/linkinfo?binurl=' . bin2hex($purl));
						if ($li['success'] && $li['body']) {
							$s['body'] .= "\n" . $li['body'];
						}
						else {
							$s['body'] .= "\n\n" . $purl;
						}
					}
				}
			}
		}


		if (in_array($act->obj['type'], ['Note', 'Article', 'Page'])) {
			$ptr = null;

			if (array_key_exists('url', $act->obj)) {
				if (is_array($act->obj['url'])) {
					if (array_key_exists(0, $act->obj['url'])) {
						$ptr = $act->obj['url'];
					}
					else {
						$ptr = [$act->obj['url']];
					}
					foreach ($ptr as $vurl) {
						if (array_key_exists('mediaType', $vurl) && $vurl['mediaType'] === 'text/html') {
							$s['plink'] = $vurl['href'];
							break;
						}
					}
				}
				elseif (is_string($act->obj['url'])) {
					$s['plink'] = $act->obj['url'];
				}
			}
		}

		if (!$s['plink']) {
			$s['plink'] = $s['mid'];
		}

		// assume this is private unless specifically told otherwise.

		$s['item_private'] = 1;

		if ($act->recips && in_array(ACTIVITY_PUBLIC_INBOX, $act->recips)) {
			$s['item_private'] = 0;
		}

		if (is_array($act->obj)) {
			if (array_key_exists('directMessage', $act->obj) && intval($act->obj['directMessage'])) {
				$s['item_private'] = 2;
			}
		}

		set_iconfig($s, 'activitypub', 'recips', $act->raw_recips);

		$parent = (($s['parent_mid'] && $s['parent_mid'] === $s['mid']) ? true : false);
		if ($parent) {
			set_iconfig($s, 'activitypub', 'rawmsg', $act->raw, 1);
		}

		$hookinfo = [
			'act' => $act,
			's'   => $s
		];

		call_hooks('decode_note', $hookinfo);

		$s = $hookinfo['s'];

		return $s;

	}

	static function store($channel, $observer_hash, $act, $item, $fetch_parents = true) {

		$is_sys_channel = is_sys_channel($channel['channel_id']);

		// Mastodon only allows visibility in public timelines if the public inbox is listed in the 'to' field.
		// They are hidden in the public timeline if the public inbox is listed in the 'cc' field.
		// This is not part of the activitypub protocol - we might change this to show all public posts in pubstream at some point.

		$pubstream = ((is_array($act->obj) && array_key_exists('to', $act->obj) && in_array(ACTIVITY_PUBLIC_INBOX, $act->obj['to'])) ? true : false);
		$is_parent = (($item['parent_mid'] && $item['parent_mid'] === $item['mid']) ? true : false);

		if ($is_parent && (!perm_is_allowed($channel['channel_id'], $observer_hash, 'send_stream') && !($is_sys_channel && $pubstream))) {
			logger('no permission');
			return;
		}

		if (is_array($act->obj)) {
			$content = self::get_content($act->obj);
		}
		if (!$content) {
			logger('no content');
			return;
		}

		$item['aid'] = $channel['channel_account_id'];
		$item['uid'] = $channel['channel_id'];

		// Make sure we use the zot6 identity where applicable

		$item['author_xchan'] = self::find_best_identity($item['author_xchan']);
		$item['owner_xchan']  = self::find_best_identity($item['owner_xchan']);

		if (!$item['author_xchan']) {
			logger('No author: ' . print_r($act, true));
		}

		if (!$item['owner_xchan']) {
			logger('No owner: ' . print_r($act, true));
		}

		if (!$item['author_xchan'] || !$item['owner_xchan'])
			return;

		if ($channel['channel_system']) {
			if (!MessageFilter::evaluate($item, get_config('system', 'pubstream_incl'), get_config('system', 'pubstream_excl'))) {
				logger('post is filtered');
				return;
			}
		}

		$abook = q("select * from abook where abook_xchan = '%s' and abook_channel = %d limit 1",
			dbesc($observer_hash),
			intval($channel['channel_id'])
		);

		if ($abook) {
			if (!post_is_importable($item, $abook[0])) {
				logger('post is filtered');
				return;
			}
		}


		if ($act->obj['conversation']) {
			set_iconfig($item, 'ostatus', 'conversation', $act->obj['conversation'], 1);
		}

		// This isn't perfect but the best we can do for now.

		$item['comment_policy'] = 'authenticated';

		set_iconfig($item, 'activitypub', 'recips', $act->raw_recips);

		if (!$is_parent) {
			$p = q("select parent_mid, id, obj_type from item where mid = '%s' and uid = %d limit 1",
				dbesc($item['parent_mid']),
				intval($item['uid'])
			);
			if (!$p) {
				$a = (($fetch_parents) ? self::fetch_and_store_parents($channel, $item) : false);
				if ($a) {
					$p = q("select parent_mid from item where mid = '%s' and uid = %d limit 1",
						dbesc($item['parent_mid']),
						intval($item['uid'])
					);
				}
				else {
					logger('could not fetch parents');
					return;

					// @TODO we maybe could accept these is we formatted the body correctly with share_bb()
					// or at least provided a link to the object
					// if(in_array($act->type,[ 'Like','Dislike' ])) {
					//	return;
					// }

					// @TODO do we actually want that?
					// if no parent was fetched, turn into a top-level post

					// turn into a top level post
					// $s['parent_mid'] = $s['mid'];
					// $s['thr_parent'] = $s['mid'];
				}
			}


			if ($p[0]['obj_type'] === 'Question') {
				if ($item['obj_type'] === ACTIVITY_OBJ_NOTE && $item['title'] && (!$item['content'])) {
					$item['obj_type'] = 'Answer';
				}
			}


			if ($p[0]['parent_mid'] !== $item['parent_mid']) {
				$item['thr_parent'] = $item['parent_mid'];
			}
			else {
				$item['thr_parent'] = $p[0]['parent_mid'];
			}
			$item['parent_mid'] = $p[0]['parent_mid'];
		}

		$r = q("select id, created, edited from item where mid = '%s' and uid = %d limit 1",
			dbesc($item['mid']),
			intval($item['uid'])
		);
		if ($r) {
			if ($item['edited'] > $r[0]['edited']) {
				$item['id'] = $r[0]['id'];
				$x          = item_store_update($item);
			}
			else {
				return;
			}
		}
		else {
			$x = item_store($item);
		}

		if (is_array($x) && $x['item_id']) {
			if ($is_parent) {
				if ($item['owner_xchan'] === $channel['channel_hash']) {
					// We are the owner of this conversation, so send all received comments back downstream
					Master::Summon(['Notifier', 'comment-import', $x['item_id']]);
				}
				$r = q("select * from item where id = %d limit 1",
					intval($x['item_id'])
				);
				if ($r) {
					send_status_notifications($x['item_id'], $r[0]);
				}
			}
			sync_an_item($channel['channel_id'], $x['item_id']);
		}

	}

	static public function fetch_and_store_parents($channel, $item) {

		logger('fetching parents');

		$p = [];

		$current_item = $item;

		while ($current_item['parent_mid'] !== $current_item['mid']) {
			$n = self::fetch($current_item['parent_mid'], $channel);
			if (!$n) {
				break;
			}
			$a = new ActivityStreams($n);

			//logger($a->debug());

			if (!$a->is_valid()) {
				break;
			}

			if (is_array($a->actor) && array_key_exists('id', $a->actor)) {
				self::actor_store($a->actor['id'], $a->actor);
			}

			$replies = null;
			if (isset($a->obj['replies']['first']['items'])) {
				$replies = $a->obj['replies']['first']['items'];
				// we already have this one
				array_diff($replies, [$current_item['mid']]);
			}

			$item = null;

			switch ($a->type) {
				case 'Create':
				case 'Update':
					//case 'Like':
					//case 'Dislike':
				case 'Announce':
					$item = self::decode_note($a);
					break;
				default:
					break;

			}

			$hookinfo = [
				'a'    => $a,
				'item' => $item
			];

			call_hooks('fetch_and_store', $hookinfo);

			$item = $hookinfo['item'];

			if ($item) {

				array_unshift($p, [$a, $item, $replies]);

				if ($item['parent_mid'] === $item['mid'] || count($p) > 20) {
					break;
				}

			}
			$current_item = $item;
		}

		if ($p) {
			foreach ($p as $pv) {
				self::store($channel, $pv[0]->actor['id'], $pv[0], $pv[1], false);
				if ($pv[2])
					self::fetch_and_store_replies($channel, $pv[2]);
			}
			return true;
		}

		return false;
	}

	static public function fetch_and_store_replies($channel, $arr) {

		logger('fetching replies');
		logger(print_r($arr, true));

		$p = [];

		foreach ($arr as $url) {

			$n = self::fetch($url, $channel);
			if (!$n) {
				break;
			}

			$a = new ActivityStreams($n);

			if (!$a->is_valid()) {
				break;
			}

			$item = null;

			switch ($a->type) {
				case 'Create':
				case 'Update':
				case 'Like':
				case 'Dislike':
				case 'Announce':
					$item = self::decode_note($a);
					break;
				default:
					break;
			}

			$hookinfo = [
				'a'    => $a,
				'item' => $item
			];

			call_hooks('fetch_and_store', $hookinfo);

			$item = $hookinfo['item'];

			if ($item) {
				array_unshift($p, [$a, $item]);
			}

		}

		if ($p) {
			foreach ($p as $pv) {
				self::store($channel, $pv[0]->actor['id'], $pv[0], $pv[1], false);
			}
		}

	}

	static function announce_note($channel, $observer_hash, $act) {

		$s = [];

		$is_sys_channel = is_sys_channel($channel['channel_id']);

		// Mastodon only allows visibility in public timelines if the public inbox is listed in the 'to' field.
		// They are hidden in the public timeline if the public inbox is listed in the 'cc' field.
		// This is not part of the activitypub protocol - we might change this to show all public posts in pubstream at some point.
		$pubstream = ((is_array($act->obj) && array_key_exists('to', $act->obj) && in_array(ACTIVITY_PUBLIC_INBOX, $act->obj['to'])) ? true : false);

		if (!perm_is_allowed($channel['channel_id'], $observer_hash, 'send_stream') && !($is_sys_channel && $pubstream)) {
			logger('no permission');
			return;
		}

		$content = self::get_content($act->obj);

		if (!$content) {
			logger('no content');
			return;
		}

		$s['owner_xchan'] = $s['author_xchan'] = $observer_hash;

		$s['aid']   = $channel['channel_account_id'];
		$s['uid']   = $channel['channel_id'];
		$s['mid']   = urldecode($act->obj['id']);
		$s['plink'] = urldecode($act->obj['id']);

		if (!$s['created'])
			$s['created'] = datetime_convert();

		if (!$s['edited'])
			$s['edited'] = $s['created'];


		$s['parent_mid'] = $s['mid'];

		$s['verb']     = ACTIVITY_POST;
		$s['obj_type'] = ACTIVITY_OBJ_NOTE;
		$s['app']      = t('ActivityPub');

		if ($channel['channel_system']) {
			if (!MessageFilter::evaluate($s, get_config('system', 'pubstream_incl'), get_config('system', 'pubstream_excl'))) {
				logger('post is filtered');
				return;
			}
		}

		$abook = q("select * from abook where abook_xchan = '%s' and abook_channel = %d limit 1",
			dbesc($observer_hash),
			intval($channel['channel_id'])
		);

		if ($abook) {
			if (!post_is_importable($s, $abook[0])) {
				logger('post is filtered');
				return;
			}
		}

		if ($act->obj['conversation']) {
			set_iconfig($s, 'ostatus', 'conversation', $act->obj['conversation'], 1);
		}

		$a = self::decode_taxonomy($act->obj);
		if ($a) {
			$s['term'] = $a;
		}

		$a = self::decode_attachment($act->obj);
		if ($a) {
			$s['attach'] = $a;
		}

		$body = "[share author='" . urlencode($act->sharee['name']) .
			"' profile='" . $act->sharee['url'] .
			"' avatar='" . $act->sharee['photo_s'] .
			"' link='" . ((is_array($act->obj['url'])) ? $act->obj['url']['href'] : $act->obj['url']) .
			"' auth='" . ((is_matrix_url($act->obj['url'])) ? 'true' : 'false') .
			"' posted='" . $act->obj['published'] .
			"' message_id='" . $act->obj['id'] .
			"']";

		if ($content['name'])
			$body .= self::bb_content($content, 'name') . "\r\n";

		$body .= self::bb_content($content, 'content');

		if ($act->obj['type'] === 'Note' && $s['attach']) {
			$body .= self::bb_attach($s['attach'], $body);
		}

		$body .= "[/share]";

		$s['title'] = self::bb_content($content, 'name');
		$s['body']  = $body;

		if ($act->recips && (!in_array(ACTIVITY_PUBLIC_INBOX, $act->recips)))
			$s['item_private'] = 1;

		set_iconfig($s, 'activitypub', 'recips', $act->raw_recips);

		$r = q("select created, edited from item where mid = '%s' and uid = %d limit 1",
			dbesc($s['mid']),
			intval($s['uid'])
		);
		if ($r) {
			if ($s['edited'] > $r[0]['edited']) {
				$x = item_store_update($s);
			}
			else {
				return;
			}
		}
		else {
			$x = item_store($s);
		}

		if (is_array($x) && $x['item_id']) {
			if ($s['owner_xchan'] === $channel['channel_hash']) {
				// We are the owner of this conversation, so send all received comments back downstream
				Master::Summon(['Notifier', 'comment-import', $x['item_id']]);
			}
			$r = q("select * from item where id = %d limit 1",
				intval($x['item_id'])
			);
			if ($r) {
				send_status_notifications($x['item_id'], $r[0]);
			}

			sync_an_item($channel['channel_id'], $x['item_id']);
		}

	}

	static function like_note($channel, $observer_hash, $act) {

		$s = [];

		$parent = $act->obj['id'];

		if ($act->type === 'Like')
			$s['verb'] = ACTIVITY_LIKE;
		if ($act->type === 'Dislike')
			$s['verb'] = ACTIVITY_DISLIKE;

		if (!$parent)
			return;

		$r = q("select * from item where uid = %d and ( mid = '%s' or  mid = '%s' ) limit 1",
			intval($channel['channel_id']),
			dbesc($parent),
			dbesc(urldecode(basename($parent)))
		);

		if (!$r) {
			logger('parent not found.');
			return;
		}

		xchan_query($r);
		$parent_item = $r[0];

		if ($parent_item['owner_xchan'] === $channel['channel_hash']) {
			if (!perm_is_allowed($channel['channel_id'], $observer_hash, 'post_comments')) {
				logger('no comment permission.');
				return;
			}
		}

		if ($parent_item['mid'] === $parent_item['parent_mid']) {
			$s['parent_mid'] = $parent_item['mid'];
		}
		else {
			$s['thr_parent'] = $parent_item['mid'];
			$s['parent_mid'] = $parent_item['parent_mid'];
		}

		$s['owner_xchan']  = $parent_item['owner_xchan'];
		$s['author_xchan'] = $observer_hash;

		$s['aid'] = $channel['channel_account_id'];
		$s['uid'] = $channel['channel_id'];
		$s['mid'] = $act->id;

		if (!$s['parent_mid'])
			$s['parent_mid'] = $s['mid'];


		$post_type = (($parent_item['resource_type'] === 'photo') ? t('photo') : t('post'));

		$links   = [['rel' => 'alternate', 'type' => 'text/html', 'href' => $parent_item['plink']]];
		$objtype = (($parent_item['resource_type'] === 'photo') ? ACTIVITY_OBJ_PHOTO : ACTIVITY_OBJ_NOTE);

		$z = q("select * from xchan where xchan_hash = '%s' limit 1",
			dbesc($parent_item['author_xchan'])
		);
		if ($z)
			$item_author = $z[0];

		$object = json_encode([
			'type'    => $post_type,
			'id'      => $parent_item['mid'],
			'parent'  => (($parent_item['thr_parent']) ? $parent_item['thr_parent'] : $parent_item['parent_mid']),
			'link'    => $links,
			'title'   => $parent_item['title'],
			'content' => $parent_item['body'],
			'created' => $parent_item['created'],
			'edited'  => $parent_item['edited'],
			'author'  => [
				'name'     => $item_author['xchan_name'],
				'address'  => $item_author['xchan_addr'],
				'guid'     => $item_author['xchan_guid'],
				'guid_sig' => $item_author['xchan_guid_sig'],
				'link'     => [
					['rel' => 'alternate', 'type' => 'text/html', 'href' => $item_author['xchan_url']],
					['rel' => 'photo', 'type' => $item_author['xchan_photo_mimetype'], 'href' => $item_author['xchan_photo_m']]],
			],
		], JSON_UNESCAPED_SLASHES
		);

		if ($act->type === 'Like')
			$bodyverb = t('%1$s likes %2$s\'s %3$s');
		if ($act->type === 'Dislike')
			$bodyverb = t('%1$s doesn\'t like %2$s\'s %3$s');

		$ulink     = '[url=' . $item_author['xchan_url'] . ']' . $item_author['xchan_name'] . '[/url]';
		$alink     = '[url=' . $parent_item['author']['xchan_url'] . ']' . $parent_item['author']['xchan_name'] . '[/url]';
		$plink     = '[url=' . z_root() . '/display/' . urlencode($act->id) . ']' . $post_type . '[/url]';
		$s['body'] = sprintf($bodyverb, $ulink, $alink, $plink);

		$s['app'] = t('ActivityPub');

		// set the route to that of the parent so downstream hubs won't reject it.

		$s['route']        = $parent_item['route'];
		$s['item_private'] = $parent_item['item_private'];
		$s['obj_type']     = $objtype;
		$s['obj']          = $object;

		if ($act->obj['conversation']) {
			set_iconfig($s, 'ostatus', 'conversation', $act->obj['conversation'], 1);
		}

		if ($act->recips && (!in_array(ACTIVITY_PUBLIC_INBOX, $act->recips)))
			$s['item_private'] = 1;

		set_iconfig($s, 'activitypub', 'recips', $act->raw_recips);

		$result = item_store($s);

		if ($result['success']) {
			// if the message isn't already being relayed, notify others
			if (intval($parent_item['item_origin']))
				Master::Summon(['Notifier', 'comment-import', $result['item_id']]);
			sync_an_item($channel['channel_id'], $result['item_id']);
		}

		return;
	}


	static function bb_attach($attach, $body) {

		$ret = false;

		foreach ($attach as $a) {
			if (strpos($a['type'], 'image') !== false) {
				if (self::media_not_in_body($a['href'], $body)) {
					$ret .= "\n\n" . '[img]' . $a['href'] . '[/img]';
				}
			}
			if (array_key_exists('type', $a) && strpos($a['type'], 'video') === 0) {
				if (self::media_not_in_body($a['href'], $body)) {
					$ret .= "\n\n" . '[video]' . $a['href'] . '[/video]';
				}
			}
			if (array_key_exists('type', $a) && strpos($a['type'], 'audio') === 0) {
				if (self::media_not_in_body($a['href'], $body)) {
					$ret .= "\n\n" . '[audio]' . $a['href'] . '[/audio]';
				}
			}
		}

		return $ret;
	}


	// check for the existence of existing media link in body

	static function media_not_in_body($s, $body) {

		if ((strpos($body, ']' . $s . '[/img]') === false) &&
			(strpos($body, ']' . $s . '[/zmg]') === false) &&
			(strpos($body, ']' . $s . '[/video]') === false) &&
			(strpos($body, ']' . $s . '[/audio]') === false)) {
			return true;
		}
		return false;
	}


	static function bb_content($content, $field) {

		require_once('include/html2bbcode.php');
		require_once('include/event.php');
		$ret = false;

		if (is_array($content[$field])) {
			foreach ($content[$field] as $k => $v) {
				$ret .= html2bbcode($v);
				// save this for auto-translate or dynamic filtering
				// $ret .= '[language=' . $k . ']' . html2bbcode($v) . '[/language]';
			}
		}
		else {
			if ($field === 'bbcode' && array_key_exists('bbcode', $content)) {
				$ret = $content[$field];
			}
			else {
				$ret = html2bbcode($content[$field]);
			}
		}
		if ($field === 'content' && $content['event'] && (!strpos($ret, '[event'))) {
			$ret .= format_event_bbcode($content['event']);
		}

		return $ret;
	}


	static function get_content($act) {

		$content = [];
		$event   = null;

		if ((!$act) || (!is_array($act))) {
			return $content;
		}

		if ($act['type'] === 'Event') {
			$adjust              = false;
			$event               = [];
			$event['event_hash'] = $act['id'];
			if (array_key_exists('startTime', $act) && strpos($act['startTime'], -1, 1) === 'Z') {
				$adjust           = true;
				$event['adjust']  = 1;
				$event['dtstart'] = datetime_convert('UTC', 'UTC', $event['startTime'] . (($adjust) ? '' : 'Z'));
			}
			if (array_key_exists('endTime', $act)) {
				$event['dtend'] = datetime_convert('UTC', 'UTC', $event['endTime'] . (($adjust) ? '' : 'Z'));
			}
			else {
				$event['nofinish'] = true;
			}
		}

		foreach (['name', 'summary', 'content'] as $a) {
			if (($x = self::get_textfield($act, $a)) !== false) {
				$content[$a] = $x;
			}
		}

		if ($event) {
			$event['summary'] = $content['name'];
			if (!$event['summary']) {
				if ($content['summary']) {
					$event['summary'] = html2plain($content['summary']);
				}
			}
			$event['description'] = html2bbcode($content['content']);
			if ($event['summary'] && $event['dtstart']) {
				$content['event'] = $event;
			}
		}

		if (array_path_exists('source/mediaType', $act) && array_path_exists('source/content', $act)) {
			if ($act['source']['mediaType'] === 'text/bbcode') {
				$content['bbcode'] = purify_html($act['source']['content']);
			}
		}


		return $content;
	}


	static function get_textfield($act, $field) {

		$content = false;

		if (array_key_exists($field, $act) && $act[$field])
			$content = purify_html($act[$field]);
		elseif (array_key_exists($field . 'Map', $act) && $act[$field . 'Map']) {
			foreach ($act[$field . 'Map'] as $k => $v) {
				$content[escape_tags($k)] = purify_html($v);
			}
		}
		return $content;
	}

	// Find either an Authorization: Bearer token or 'token' request variable
	// in the current web request and return it

	static function token_from_request() {

		foreach (['REDIRECT_REMOTE_USER', 'HTTP_AUTHORIZATION'] as $s) {
			$auth = ((array_key_exists($s, $_SERVER) && strpos($_SERVER[$s], 'Bearer ') === 0)
				? str_replace('Bearer ', EMPTY_STR, $_SERVER[$s])
				: EMPTY_STR
			);
			if ($auth) {
				break;
			}
		}

		if (!$auth) {
			if (array_key_exists('token', $_REQUEST) && $_REQUEST['token']) {
				$auth = $_REQUEST['token'];
			}
		}

		return $auth;
	}

	static function find_best_identity($xchan) {

		if (filter_var($xchan, FILTER_VALIDATE_URL)) {
			$r = q("select hubloc_hash, hubloc_network from hubloc where hubloc_id_url = '%s' and hubloc_network in ('zot6', 'zot') and hubloc_deleted = 0",
				dbesc($xchan)
			);
			if ($r) {
				$r = Libzot::zot_record_preferred($r);
				logger('find_best_identity: ' . $xchan . ' > ' . $r['hubloc_hash']);
				return $r['hubloc_hash'];
			}
		}

		return $xchan;

	}

}