path: root/Zotlabs/Daemon/Notifier.php

<?php /** @file */

namespace Zotlabs\Daemon;

use Zotlabs\Lib\Libzot;
use Zotlabs\Lib\Activity;
use Zotlabs\Lib\Queue;

require_once('include/queue_fn.php');
require_once('include/html2plain.php');
require_once('include/conversation.php');
require_once('include/zot.php');
require_once('include/items.php');
require_once('include/bbcode.php');



/*
 * This file was at one time responsible for doing all deliveries, but this caused
 * big problems on shared hosting systems, where the process might get killed by the
 * hosting provider and nothing would get delivered.
 * It now only delivers one message under certain cases, and invokes a queued
 * delivery mechanism (include/deliver.php) to deliver individual contacts at
 * controlled intervals.
 * This has a much better chance of surviving random processes getting killed
 * by the hosting provider.
 *
 * The basic flow is:
 *   Identify the type of message
 *   Collect any information that needs to be sent
 *   Convert it into a suitable generic format for sending
 *   Figure out who the recipients are and if we need to relay
 *       through a conversation owner
 *   Once we know what recipients are involved, collect a list of
 *       destination sites
 *   Build and store a queue item for each unique site and invoke
 *       a delivery process for each site or a small number of sites (1-3)
 *       and add a slight delay between each delivery invocation if desired (usually)
 *
 */

/*
 * The notifier is typically called with:
 *
 *		Zotlabs\Daemon\Master::Summon(array('Notifier', COMMAND, ITEM_ID));
 *
 * where COMMAND is one of the following:
 *
 *	activity		(in diaspora.php, dfrn_confirm.php, profiles.php)
 *	comment-import		(in diaspora.php, items.php)
 *	comment-new		(in item.php)
 *	drop			(in diaspora.php, items.php, photos.php)
 *	edit_post		(in item.php)
 *	event			(in events.php)
 *	expire			(in items.php)
 *	like			(in like.php, poke.php)
 *	mail			(in message.php)
 *	tag			(in photos.php, poke.php, tagger.php)
 *	tgroup			(in items.php)
 *	wall-new		(in photos.php, item.php)
 *
 * and ITEM_ID is the id of the item in the database that needs to be sent to others.
 *
 * ZOT
 *       permission_create      abook_id
 *       permission_accept      abook_id
 *       permission_reject      abook_id
 *       permission_update      abook_id
 *       refresh_all            channel_id
 *       purge                  channel_id            xchan_hash
 *       purge_all              channel_id
 *       expire                 channel_id
 *       relay			item_id (item was relayed to owner, we will deliver it as owner)
 *       single_activity        item_id (deliver to a singleton network from the appropriate clone)
 *       single_mail            mail_id (deliver to a singleton network from the appropriate clone)
 *       location               channel_id
 *       request                channel_id            xchan_hash             message_id
 *       rating                 xlink_id
 *       keychange              channel_id
 *
 */



class Notifier {

	static public function run($argc,$argv){

		if($argc < 3)
			return;

		logger('notifier: invoked: ' . print_r($argv,true), LOGGER_DEBUG);

		$cmd = $argv[1];

		$item_id = $argv[2];

		if(! $item_id)
			return;

		$sys = get_sys_channel();

		$deliveries = array();

		$request = false;
		$mail = false;
		$top_level = false;
		$location  = false;
		$recipients = array();
		$url_recipients = array();
		$normal_mode = true;
		$packet_type = 'undefined';

		if($cmd === 'mail' || $cmd === 'single_mail') {
			$normal_mode = false;
			$mail = true;
			$private = true;
			$message = q("SELECT * FROM mail WHERE id = %d LIMIT 1",
					intval($item_id)
			);
			if(! $message) {
				return;
			}
			xchan_mail_query($message[0]);
			$uid = $message[0]['channel_id'];
			$recipients[] = $message[0]['from_xchan']; // include clones
			$recipients[] = $message[0]['to_xchan'];
			$item = $message[0];

			$encoded_item = encode_mail($item);

			$s = q("select * from channel where channel_id = %d limit 1",
				intval($item['channel_id'])
			);
			if($s)
				$channel = $s[0];

		}
		elseif($cmd === 'request') {
			$channel_id = $item_id;
			$xchan = $argv[3];
			$request_message_id = $argv[4];

			$s = q("select * from channel where channel_id = %d limit 1",
				intval($channel_id)
			);
			if($s)
				$channel = $s[0];

			$private = true;
			$recipients[] = $xchan;
			$packet_type = 'request';
			$normal_mode = false;
		}
		elseif($cmd === 'keychange') {
			$channel = channelx_by_n($item_id);
			$r = q("select abook_xchan from abook where abook_channel = %d",
				intval($item_id)
			);
			if($r) {
				foreach($r as $rr) {
					$recipients[] = $rr['abook_xchan'];
				}
			}
			$private = false;
			$packet_type = 'keychange';
			$normal_mode = false;
		}
		elseif(in_array($cmd, [ 'permission_update', 'permission_reject', 'permission_accept', 'permission_create' ])) {
			// Get the (single) recipient
			$r = q("select * from abook left join xchan on abook_xchan = xchan_hash where abook_id = %d and abook_self = 0",
				intval($item_id)
			);
			if($r) {
				$uid = $r[0]['abook_channel'];
				// Get the sender
				$channel = channelx_by_n($uid);
				if($channel) {
					$perm_update = array('sender' => $channel, 'recipient' => $r[0], 'success' => false, 'deliveries' => '');

					if($cmd === 'permission_create')
						call_hooks('permissions_create',$perm_update);
					elseif($cmd === 'permission_accept')
						call_hooks('permissions_accept',$perm_update);
					elseif($cmd === 'permission_reject')
						call_hooks('permissions_reject',$perm_update);
					else
						call_hooks('permissions_update',$perm_update);

					if($perm_update['success']) {
						if($perm_update['deliveries']) {
							$deliveries[] = $perm_update['deliveries'];
							do_delivery($deliveries);
						}
						return;
					}
					else {
						$recipients[] = $r[0]['abook_xchan'];
						$private = false;
						$packet_type = 'refresh';
						$packet_recips = array(array('guid' => $r[0]['xchan_guid'],'guid_sig' => $r[0]['xchan_guid_sig'],'hash' => $r[0]['xchan_hash']));
					}
				}
			}
		}
		elseif($cmd === 'refresh_all') {
			logger('notifier: refresh_all: ' . $item_id);
			$uid = $item_id;
			$channel = channelx_by_n($item_id);
			$r = q("select abook_xchan from abook where abook_channel = %d",
				intval($item_id)
			);
			if($r) {
				foreach($r as $rr) {
					$recipients[] = $rr['abook_xchan'];
				}
			}
			$private = false;
			$packet_type = 'refresh';
		}
		elseif($cmd === 'location') {
			logger('notifier: location: ' . $item_id);
			$s = q("select * from channel where channel_id = %d limit 1",
				intval($item_id)
			);
			if($s)
				$channel = $s[0];
			$uid = $item_id;
			$recipients = array();
			$r = q("select abook_xchan from abook where abook_channel = %d",
				intval($item_id)
			);
			if($r) {
				foreach($r as $rr) {
					$recipients[] = $rr['abook_xchan'];
				}
			}

			$encoded_item = array('locations' => Libzot::encode_locations($channel),'type' => 'location', 'encoding' => 'zot');
			$target_item = array('aid' => $channel['channel_account_id'],'uid' => $channel['channel_id']);
			$private = false;
			$packet_type = 'location';
			$location = true;
		}
		elseif($cmd === 'purge') {
			$xchan = $argv[3];
			logger('notifier: purge: ' . $item_id . ' => ' . $xchan);
			if (! $xchan) {
				return;
			}

			$channel     = channelx_by_n($item_id);
			$recipients[]  = $xchan;
			$private     = true;
			$packet_type = 'purge';
			$packet_recips[] = ['hash' => $xchan];
		}
		elseif($cmd === 'purge_all') {

			logger('notifier: purge_all: ' . $item_id);
			$channel = channelx_by_n($item_id);

			$recipients = [];
			$r = q("select abook_xchan from abook where abook_channel = %d and abook_self = 0",
				intval($item_id)
			);
			if (! $r) {
				return;
			}
			foreach ($r as $rr) {
				$recipients[] = $rr['abook_xchan'];
				$packet_recips[] = ['hash' => $rr['abook_xchan']];
			}

			$private = false;
			$packet_type = 'purge';


		}
		else {

			// Normal items

			// Fetch the target item

			$r = q("SELECT * FROM item WHERE id = %d and parent != 0 LIMIT 1",
				intval($item_id)
			);

			if(! $r)
				return;

			xchan_query($r);

			$r = fetch_post_tags($r);

			$target_item = $r[0];

			if(in_array($target_item['author']['xchan_network'], ['rss', 'anon'])) {
				logger('notifier: target item author is not a fetchable actor', LOGGER_DEBUG);
				return;
			}

			$deleted_item = false;

			if(intval($target_item['item_deleted'])) {
				logger('notifier: target item ITEM_DELETED', LOGGER_DEBUG);
				$deleted_item = true;
			}

			if(! in_array(intval($target_item['item_type']), [ ITEM_TYPE_POST ] )) {
				$hookinfo=[
					'targetitem'=>$target_item,
					'deliver'=>false
				];
				if (intval($target_item['item_type'] == ITEM_TYPE_CUSTOM)) {
					call_hooks('customitem_deliver',$hookinfo);
				}

				if (!$hookinfo['deliver']) {
					logger('notifier: target item not forwardable: type ' . $target_item['item_type'], LOGGER_DEBUG);
					return;
				}

				$target_item = $hookinfo['targetitem'];

			}

			// Check for non published items, but allow an exclusion for transmitting hidden file activities

			if(intval($target_item['item_unpublished']) || intval($target_item['item_delayed']) ||
				intval($target_item['item_blocked']) ||
				( intval($target_item['item_hidden']) && ($target_item['obj_type'] !== ACTIVITY_OBJ_FILE))) {
				logger('notifier: target item not published, so not forwardable', LOGGER_DEBUG);
				return;
			}

			if(strpos($target_item['postopts'],'nodeliver') !== false) {
				logger('notifier: target item is undeliverable', LOGGER_DEBUG);
				return;
			}

			$s = q("select * from channel left join xchan on channel_hash = xchan_hash where channel_id = %d limit 1",
				intval($target_item['uid'])
			);
			if($s)
				$channel = $s[0];

			if($channel['channel_hash'] !== $target_item['author_xchan'] && $channel['channel_hash'] !== $target_item['owner_xchan']) {
				logger("notifier: Sending channel {$channel['channel_hash']} is not owner {$target_item['owner_xchan']} or author {$target_item['author_xchan']}", LOGGER_NORMAL, LOG_WARNING);
				return;
			}


			if($target_item['mid'] === $target_item['parent_mid']) {
				$parent_item = $target_item;
				$top_level_post = true;
			}
			else {
				// fetch the parent item
				$r = q("SELECT * from item where id = %d order by id asc",
					intval($target_item['parent'])
				);

				if(! $r)
					return;

				if(strpos($r[0]['postopts'],'nodeliver') !== false) {
					logger('notifier: target item is undeliverable', LOGGER_DEBUG, LOG_NOTICE);
					return;
				}

				xchan_query($r);
				$r = fetch_post_tags($r);

				$parent_item = $r[0];
				$top_level_post = false;
			}

			// avoid looping of discover items 12/4/2014

			if($sys && $parent_item['uid'] == $sys['channel_id'])
				return;

			$encoded_item = encode_item($target_item);

			// Re-use existing signature unless the activity type changed to a Tombstone, which won't verify.
			$m = ((intval($target_item['item_deleted'])) ? '' : get_iconfig($target_item,'activitystreams','signed_data'));

			if($m) {
				$activity = json_decode($m,true);
			}
			else {
				$activity = array_merge(['@context' => [
					ACTIVITYSTREAMS_JSONLD_REV,
					'https://w3id.org/security/v1',
					z_root() . ZOT_APSCHEMA_REV
					]], Activity::encode_activity($target_item)
				);
			}

			logger('target_item: ' . print_r($target_item,true), LOGGER_DEBUG);
			logger('encoded: ' . print_r($activity,true), LOGGER_DEBUG);

			// Send comments to the owner to re-deliver to everybody in the conversation
			// We only do this if the item in question originated on this site. This prevents looping.
			// To clarify, a site accepting a new comment is responsible for sending it to the owner for relay.
			// Relaying should never be initiated on a post that arrived from elsewhere.

			// We should normally be able to rely on ITEM_ORIGIN, but start_delivery_chain() incorrectly set this
			// flag on comments for an extended period. So we'll also call comment_local_origin() which looks at
			// the hostname in the message_id and provides a second (fallback) opinion.

			$relay_to_owner = (((! $top_level_post) && (intval($target_item['item_origin'])) && comment_local_origin($target_item)) ? true : false);



			$uplink = false;

			// $cmd === 'relay' indicates the owner is sending it to the original recipients
			// don't allow the item in the relay command to relay to owner under any circumstances, it will loop

			logger('notifier: relay_to_owner: ' . (($relay_to_owner) ? 'true' : 'false'), LOGGER_DATA, LOG_DEBUG);
			logger('notifier: top_level_post: ' . (($top_level_post) ? 'true' : 'false'), LOGGER_DATA, LOG_DEBUG);

			// tag_deliver'd post which needs to be sent back to the original author

			if(($cmd === 'uplink') && intval($parent_item['item_uplink']) && (! $top_level_post)) {
				logger('notifier: uplink');
				$uplink = true;
			}

			if(($relay_to_owner || $uplink) && ($cmd !== 'relay')) {
				logger('notifier: followup relay', LOGGER_DEBUG);
				$recipients = array(($uplink) ? $parent_item['source_xchan'] : $parent_item['owner_xchan']);
				$private = true;
				if(! $encoded_item['flags'])
					$encoded_item['flags'] = array();
				$encoded_item['flags'][] = 'relay';
				$upstream = true;
			}
			else {
				logger('notifier: normal distribution', LOGGER_DEBUG);
				if($cmd === 'relay')
					logger('notifier: owner relay');
				$upstream = false;
				// if our parent is a tag_delivery recipient, uplink to the original author causing
				// a delivery fork.

				if(($parent_item) && intval($parent_item['item_uplink']) && (! $top_level_post) && ($cmd !== 'uplink')) {
					// don't uplink a relayed post to the relay owner
					if($parent_item['source_xchan'] !== $parent_item['owner_xchan']) {
						logger('notifier: uplinking this item');
						Master::Summon(array('Notifier','uplink',$item_id));
					}
				}

				$private = false;
				$recipients = collect_recipients($parent_item,$private);


				if ($top_level_post) {
					// remove clones who will receive the post via sync
					$recipients = array_diff($recipients, [ $target_item['owner_xchan'] ]);
				}

				// FIXME add any additional recipients such as mentions, etc.

				// don't send deletions onward for other people's stuff
				// TODO verify this is needed - copied logic from same place in old code

				if(intval($target_item['item_deleted']) && (! intval($target_item['item_wall']))) {
					logger('notifier: ignoring delete notification for non-wall item', LOGGER_NORMAL, LOG_NOTICE);
					return;
				}
			}
		}

		$walltowall = (($top_level_post && $channel['xchan_hash'] === $target_item['author_xchan']) ? true : false);

		// Generic delivery section, we have an encoded item and recipients
		// Now start the delivery process

		$x = $encoded_item;
		$x['title'] = 'private';
		$x['body'] = 'private';
		logger('notifier: encoded item: ' . print_r($x,true), LOGGER_DATA, LOG_DEBUG);

		//logger('notifier: encoded activity: ' . print_r($activity,true), LOGGER_DATA, LOG_DEBUG);

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

		//	logger('notifier: recipients: ' . print_r($recipients,true), LOGGER_NORMAL, LOG_DEBUG);

		$env_recips = (($private) ? array() : null);

		$details = q("select xchan_hash, xchan_network, xchan_addr, xchan_guid, xchan_guid_sig from xchan where xchan_hash in (" . protect_sprintf(implode(',',$recipients)) . ")");

		$recip_list = array();

		if($details) {
			foreach($details as $d) {

				$recip_list[] = $d['xchan_addr'] . ' (' . $d['xchan_hash'] . ')';
				if($private) {
					$env_recips[] = [
						'guid'     => $d['xchan_guid'],
						'guid_sig' => $d['xchan_guid_sig'],
						'hash'     => $d['xchan_hash']
					];
				}
			}
		}


		$narr = [
			'channel'        => $channel,
			'upstream'       => $upstream,
			'env_recips'     => $env_recips,
			'packet_recips'  => $packet_recips,
			'recipients'     => $recipients,
			'item'           => $item,
			'target_item'    => $target_item,
			'parent_item'    => $parent_item,
			'top_level_post' => $top_level_post,
			'private'        => $private,
			'relay_to_owner' => $relay_to_owner,
			'uplink'         => $uplink,
			'cmd'            => $cmd,
			'mail'           => $mail,
			'single'         => (($cmd === 'single_mail' || $cmd === 'single_activity') ? true : false),
			'location'       => $location,
			'request'        => $request,
			'normal_mode'    => $normal_mode,
			'packet_type'    => $packet_type,
			'walltowall'     => $walltowall,
			'queued'         => []
		];

		call_hooks('notifier_process', $narr);
		if($narr['queued']) {
			foreach($narr['queued'] as $pq)
				$deliveries[] = $pq;
		}

		// notifier_process can alter the recipient list

		$recipients    = $narr['recipients'];
		$env_recips    = $narr['env_recips'];
		$packet_recips = $narr['packet_recips'];

		if(($private) && (! $env_recips)) {
			// shouldn't happen
			logger('notifier: private message with no envelope recipients.' . print_r($argv,true), LOGGER_NORMAL, LOG_NOTICE);
		}

		logger('notifier: recipients (may be delivered to more if public): ' . print_r($recip_list,true), LOGGER_DEBUG);


		// Now we have collected recipients (except for external mentions, FIXME)
		// Let's reduce this to a set of hubs; checking that the site is not dead.

		$hubs = q("select hubloc.*, site.site_crypto, site.site_flags, site.site_version, site.site_project, site.site_dead from hubloc left join site on site_url = hubloc_url
			where hubloc_hash in (" . protect_sprintf(implode(',',$recipients)) . ")
			and hubloc_error = 0 and hubloc_deleted = 0"
		);

		// public posts won't make it to the local public stream unless there's a recipient on this site.
		// This code block sees if it's a public post and localhost is missing, and if so adds an entry for the local sys channel to the $hubs list

		if (! $private) {
			$found_localhost = false;
			if ($hubs) {
				foreach ($hubs as $h) {
					if ($h['hubloc_url'] === z_root()) {
						$found_localhost = true;
						break;
					}
				}
			}
			if (! $found_localhost) {
				$localhub = q("select hubloc.*, site.site_crypto, site.site_flags, site.site_version, site.site_project, site.site_dead from hubloc
					left join site on site_url = hubloc_url where hubloc_id_url = '%s' and hubloc_error = 0 and hubloc_deleted = 0",
					dbesc(z_root() . '/channel/sys')
				);
				if ($localhub) {
					$hubs = array_merge($hubs, $localhub);
				}
			}
		}

		if(! $hubs) {
			logger('notifier: no hubs', LOGGER_NORMAL, LOG_NOTICE);
			return;
		}

		/**
		 * Reduce the hubs to those that are unique. For zot hubs, we need to verify uniqueness by the sitekey,
		 * since it may have been a re-install which has not yet been detected and pruned.
		 * For other networks which don't have or require sitekeys, we'll have to use the URL
		 */


		$hublist = []; // this provides an easily printable list for the logs
		$dhubs   = []; // delivery hubs where we store our resulting unique array
		$keys    = []; // array of keys to check uniquness for zot hubs
		$urls    = []; // array of urls to check uniqueness of hubs from other networks
		$hub_env = []; // per-hub envelope so we don't broadcast the entire envelope to all
		$dead    = []; // known dead hubs - report them as undeliverable

		foreach($hubs as $hub) {

			if (intval($hub['site_dead'])) {
				$dead[] = $hub;
				continue;
			}

			if($env_recips) {
				foreach($env_recips as $er) {
					if($hub['hubloc_hash'] === $er['hash']) {
						if(! array_key_exists($hub['hubloc_host'] . $hub['hubloc_sitekey'], $hub_env)) {
							$hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']] = [];
						}
						$hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']][] = $er;
					}
				}
			}


			if($hub['hubloc_network'] == 'zot') {
				if(! in_array($hub['hubloc_sitekey'],$keys)) {
					$hublist[] = $hub['hubloc_host'] . ' ' . $hub['hubloc_network'];
					$dhubs[]   = $hub;
					$keys[]    = $hub['hubloc_sitekey'];
				}
			}
			else {
				if(! in_array($hub['hubloc_url'],$urls)) {
					if($hub['hubloc_url'] === z_root()) {
						//deliver to local hub first
						array_unshift($hublist, $hub['hubloc_host'] . ' ' . $hub['hubloc_network']);
						array_unshift($dhubs, $hub);
					}
					else {
						$hublist[] = $hub['hubloc_host'] . ' ' . $hub['hubloc_network'];
						$dhubs[] = $hub;
					}
					$urls[] = $hub['hubloc_url'];
				}
			}
		}

		logger('notifier: will notify/deliver to these hubs: ' . print_r($hublist,true), LOGGER_DEBUG, LOG_DEBUG);

		foreach($dhubs as $hub) {

			logger('notifier_hub: ' . $hub['hubloc_url'],LOGGER_DEBUG);

			if(! in_array($hub['hubloc_network'], [ 'zot','zot6' ])) {
				$narr = [
					'channel'        => $channel,
					'upstream'       => $upstream,
					'env_recips'     => $env_recips,
					'packet_recips'  => $packet_recips,
					'recipients'     => $recipients,
					'item'           => $item,
					'target_item'    => $target_item,
					'parent_item'    => $parent_item,
					'hub'            => $hub,
					'top_level_post' => $top_level_post,
					'private'        => $private,
					'relay_to_owner' => $relay_to_owner,
					'uplink'         => $uplink,
					'cmd'            => $cmd,
					'mail'           => $mail,
					'single'         => (($cmd === 'single_mail' || $cmd === 'single_activity') ? true : false),
					'location'       => $location,
					'request'        => $request,
					'normal_mode'    => $normal_mode,
					'packet_type'    => $packet_type,
					'walltowall'     => $walltowall,
					'queued'         => []
				];


				call_hooks('notifier_hub',$narr);
				if($narr['queued']) {
					foreach($narr['queued'] as $pq)
						$deliveries[] = $pq;
				}
				continue;

			}

			// singleton deliveries by definition 'not got zot'.
			// Single deliveries are other federated networks (plugins) and we're essentially
			// delivering only to those that have this site url in their abook_instance
			// and only from within a sync operation. This means if you post from a clone,
			// and a connection is connected to one of your other clones; assuming that hub
			// is running it will receive a sync packet. On receipt of this sync packet it
			// will invoke a delivery to those connections which are connected to just that
			// hub instance.

			if($cmd === 'single_mail' || $cmd === 'single_activity') {
				continue;
			}

			if(! in_array($hub['hubloc_network'], [ 'zot','zot6' ])) {
				continue;
			}

			// Do not change this to a uuid as long as we have traditional zot servers
			// in the loop. The signature verification step can't handle dashes in the
			// hashes.

			$hash   = random_string(48);

			$packet = null;
			$pmsg   = '';

			if($packet_type === 'refresh' || $packet_type === 'purge') {
				if($hub['hubloc_network'] === 'zot6') {
					$packet = Libzot::build_packet($channel, $packet_type, ids_to_array($packet_recips,'hash'));
				}
				else {
					$packet = zot_build_packet($channel,$packet_type,(($packet_recips) ? $packet_recips : null));
				}
			}
			if($packet_type === 'keychange' && $hub['hubloc_network'] === 'zot') {
				$pmsg = get_pconfig($channel['channel_id'],'system','keychange');
				$packet = zot_build_packet($channel,$packet_type,(($packet_recips) ? $packet_recips : null));
			}
			elseif($packet_type === 'request' && $hub['hubloc_network'] === 'zot') {
				$env = (($hub_env && $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']]) ? $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']] : '');
				$packet = zot_build_packet($channel,$packet_type,$env,$hub['hubloc_sitekey'],$hub['site_crypto'],
					$hash, array('message_id' => $request_message_id)
				);
			}

			if($packet) {
				Queue::insert(
					[
						'hash'       => $hash,
						'account_id' => $channel['channel_account_id'],
						'channel_id' => $channel['channel_id'],
						'posturl'    => $hub['hubloc_callback'],
						'driver'     => $hub['hubloc_network'],
						'notify'     => $packet,
						'msg'        => (($pmsg) ? json_encode($pmsg) : '')
					]
				);
			}
			else {
				$env = (($hub_env && $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']]) ? $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']] : '');


				if($hub['hubloc_network'] === 'zot6') {
					$zenv = [];
					if($env) {
						foreach($env as $e) {
							$zenv[] = $e['hash'];
						}
					}

					$packet_type = (($upstream || $uplink) ? 'response' : 'activity');

					// block zot private reshares from zot6, as this could cause a number of privacy issues
					// due to parenting differences between the reshare implementations. In zot a reshare is
					// a standalone parent activity and in zot6 it is a followup/child of the original activity.
					// For public reshares, some comments to the reshare on the zot fork will not make it to zot6
					// due to these different message models. This cannot be prevented at this time.

					if($packet_type === 'activity' && $activity['type'] === 'Announce' && intval($target_item['item_private'])) {
						continue;
					}

					$packet = Libzot::build_packet($channel,$packet_type,$zenv,$activity,'activitystreams',(($private) ? $hub['hubloc_sitekey'] : null),$hub['site_crypto']);
				}
				else {
					// currently zot6 delivery is only performed on normal items and not sync items or mail or anything else
					// Eventually we will do this for all deliveries, but for now ensure this is precisely what we are dealing
					// with before switching to zot6 as the primary zot6 handler checks for the existence of a message delivery report
					// to trigger dequeue'ing

					$z6 = (($encoded_item && $encoded_item['type'] === 'activity' && (! array_key_exists('allow_cid',$encoded_item))) ? true : false);
					if($z6) {
						$packet = zot6_build_packet($channel,'notify',$env, json_encode($encoded_item), (($private) ? $hub['hubloc_sitekey'] : null), $hub['site_crypto'],$hash);
					}
					else {
						$packet = zot_build_packet($channel,'notify',$env, (($private) ? $hub['hubloc_sitekey'] : null), $hub['site_crypto'],$hash);

					}
				}


				// remove this after most hubs have updated to version 5.0
				if(stripos($hub['site_project'], 'hubzilla') !== false && version_compare($hub['site_version'], '4.7.3', '<=')) {
					if($encoded_item['type'] === 'mail') {
						$encoded_item['from']['network'] = 'zot';
						$encoded_item['from']['guid_sig'] = str_replace('sha256.', '', $encoded_item['from']['guid_sig']);
					}
					else {
						$encoded_item['owner']['network'] = 'zot';
						$encoded_item['owner']['guid_sig'] = str_replace('sha256.', '', $encoded_item['owner']['guid_sig']);
						if(strpos($encoded_item['author']['url'], z_root()) === 0) {
							$encoded_item['author']['network'] = 'zot';
							$encoded_item['author']['guid_sig'] = str_replace('sha256.', '', $encoded_item['author']['guid_sig']);
						}
					}
				}

				Queue::insert(
					[
						'hash'       => $hash,
						'account_id' => $target_item['aid'],
						'channel_id' => $target_item['uid'],
						'posturl'    => $hub['hubloc_callback'],
						'driver'     => $hub['hubloc_network'],
						'notify'     => $packet,
						'msg'        => json_encode($encoded_item)
					]
				);

				// only create delivery reports for normal undeleted items
				if(is_array($target_item) && array_key_exists('postopts',$target_item) && (! $target_item['item_deleted']) && (! get_config('system','disable_dreport'))) {
					q("insert into dreport ( dreport_mid, dreport_site, dreport_recip, dreport_result, dreport_time, dreport_xchan, dreport_queue ) values ( '%s','%s','%s','%s','%s','%s','%s' ) ",
						dbesc($target_item['mid']),
						dbesc($hub['hubloc_host']),
						dbesc($hub['hubloc_host']),
						dbesc('queued'),
						dbesc(datetime_convert()),
						dbesc($channel['channel_hash']),
						dbesc($hash)
					);
				}
			}

			$deliveries[] = $hash;
		}

		if($normal_mode) {
			$x = q("select * from hook where hook = 'notifier_normal'");
			if($x) {
				Master::Summon( [ 'Deliver_hooks', $target_item['id'] ] );
			}
		}

		if($deliveries)
			do_delivery($deliveries);

		logger('notifier: basic loop complete.', LOGGER_DEBUG);

		if ($dead) {
			foreach ($dead as $deceased) {
				if (is_array($target_item) && (! $target_item['item_deleted']) && (! get_config('system','disable_dreport'))) {
					q("insert into dreport ( dreport_mid, dreport_site, dreport_recip, dreport_name, dreport_result, dreport_time, dreport_xchan, dreport_queue )
						values ( '%s', '%s','%s','%s','%s','%s','%s','%s' ) ",
						dbesc($target_item['mid']),
						dbesc($deceased['hubloc_host']),
						dbesc($deceased['hubloc_host']),
						dbesc($deceased['hubloc_host']),
						dbesc('undeliverable/unresponsive site'),
						dbesc(datetime_convert()),
						dbesc($channel['channel_hash']),
						dbesc(random_string(48))
					);
				}
			}
		}

		call_hooks('notifier_end',$target_item);

		logger('notifer: complete.');
		return;

	}
}