<?php
/**
 * @file include/items.php
 * @brief Items related functions.
 */

use Zotlabs\Lib as Zlib;

require_once('include/bbcode.php');
require_once('include/oembed.php');
require_once('include/crypto.php');
require_once('include/message.php');
require_once('include/feedutils.php');
require_once('include/photo/photo_driver.php');
require_once('include/permissions.php');

/**
 * @brief Collects recipients.
 *
 * @param array $item
 * @param[out] boolean $private_envelope
 * @return array containing the recipients
 */
function collect_recipients($item, &$private_envelope) {

	require_once('include/group.php');

	$private_envelope = ((intval($item['item_private'])) ? true : false);
	$recipients = array();

	if($item['allow_cid'] || $item['allow_gid'] || $item['deny_cid'] || $item['deny_gid']) {

		// it is private

		$allow_people = expand_acl($item['allow_cid']);

		$allow_groups = expand_groups(expand_acl($item['allow_gid']));

		$recipients = array_unique(array_merge($allow_people,$allow_groups));

		// if you specifically deny somebody but haven't allowed anybody, we'll allow everybody in your
		// address book minus the denied connections. The post is still private and can't be seen publicly
		// as that would allow the denied person to see the post by logging out.

		if((! $item['allow_cid']) && (! $item['allow_gid'])) {
			$r = q("select * from abook where abook_channel = %d and abook_self = 0 and abook_pending = 0 and abook_archived = 0 ",
				intval($item['uid'])
			);

			if($r) {
				foreach($r as $rr) {
					$recipients[] = $rr['abook_xchan'];
				}
			}
		}

		$deny_people  = expand_acl($item['deny_cid']);
		$deny_groups  = expand_groups(expand_acl($item['deny_gid']));

		$deny = array_unique(array_merge($deny_people,$deny_groups));

		// Don't deny anybody if nobody was allowed (e.g. they were all filtered out)
		// That would lead to array_diff doing the wrong thing.
		// This will result in a private post that won't be delivered to anybody.

		if($recipients && $deny)
			$recipients = array_diff($recipients,$deny);

		$private_envelope = true;
	}
	else {

		// if the post is marked private but there are no recipients and public_policy/scope = self,
		// only add the author and owner as recipients. The ACL for the post may live on the hub of
		// a different clone. We need to get the post to that hub.

		// The post may be private by virtue of not being visible to anybody on the internet,
		// but there are no envelope recipients, so set this to false. Delivery is controlled
		// by the directives in $item['public_policy'].

		$private_envelope = false;
		require_once('include/channel.php');
		//$sys = get_sys_channel();

		if(array_key_exists('public_policy',$item) && $item['public_policy'] !== 'self') {
			$r = q("select abook_xchan, xchan_network from abook left join xchan on abook_xchan = xchan_hash where abook_channel = %d and abook_self = 0 and abook_pending = 0 and abook_archived = 0 ",
				intval($item['uid'])
			);
			if($r) {

				// filter out restrictive public_policy settings from remote networks
				// which don't have this concept and will treat them as public.

				$policy = substr($item['public_policy'],0,3);
				foreach($r as $rr) {
					switch($policy) {
						case 'net':
						case 'aut':
						case 'sit':
						case 'any':
						case 'con':
							if($rr['xchan_network'] != 'zot')
								break;
						case 'pub':
						case '':
						default:
							$recipients[] = $rr['abook_xchan'];
							break;
					}
				}
			}
// we probably want to check that discovery channel delivery is allowed before uncommenting this.
//			if($policy === 'pub')
//				$recipients[] = $sys['xchan_hash'];
		}

		// Add the authors of any posts in this thread, if they are known to us.
		// This is specifically designed to forward wall-to-wall posts to the original author,
		// in case they aren't a connection but have permission to write on our wall.
		// This is important for issue tracker channels. It should be a no-op for most channels.
		// Whether or not they will accept the delivery is not determined here, but should
		// be taken into account by zot:process_delivery()

		$r = q("select author_xchan from item where parent = %d",
			intval($item['parent'])
		);
		if($r) {
			foreach($r as $rv) {
				if(! in_array($rv['author_xchan'],$recipients)) {
					$recipients[] = $rv['author_xchan'];
				}
			}
		}

	}

	// This is a somewhat expensive operation but important.
	// Don't send this item to anybody who isn't allowed to see it

	$recipients = check_list_permissions($item['uid'],$recipients,'view_stream');

	// remove any upstream recipients from our list.
	// If it is ourself we'll add it back in a second.
	// This should prevent complex delivery chains from getting overly complex by not
	// sending to anybody who is on our list of those who sent it to us.

	if($item['route']) {
		$route = explode(',',$item['route']);
		if(count($route)) {
			$route = array_unique($route);
			$recipients = array_diff($recipients,$route);
		}
	}

	// add ourself just in case we have nomadic clones that need to get a copy.

	$recipients[] = $item['author_xchan'];
	if($item['owner_xchan'] != $item['author_xchan'])
		$recipients[] = $item['owner_xchan'];

	return $recipients;
}

function comments_are_now_closed($item) {
	if($item['comments_closed'] > NULL_DATE) {
		$d = datetime_convert();
		if($d > $item['comments_closed'])
			return true;
	}

	return false;
}

function item_normal() {
	return " and item.item_hidden = 0 and item.item_type = 0 and item.item_deleted = 0
		and item.item_unpublished = 0 and item.item_delayed = 0 and item.item_pending_remove = 0
		and item.item_blocked = 0 and item.obj_type != '" . ACTIVITY_OBJ_FILE . "' ";
}

function item_normal_search() {
	return " and item.item_hidden = 0 and item.item_type in (0,3,6,7) and item.item_deleted = 0
		and item.item_unpublished = 0 and item.item_delayed = 0 and item.item_pending_remove = 0
		and item.item_blocked = 0 and item.obj_type != '" . ACTIVITY_OBJ_FILE . "' ";
}

function item_normal_update() {
	return " and item.item_hidden = 0 and item.item_type = 0
		and item.item_unpublished = 0 and item.item_delayed = 0 and item.item_pending_remove = 0
		and item.item_blocked = 0 and item.obj_type != '" . ACTIVITY_OBJ_FILE . "' ";
}


/**
 * @brief
 *
 * This is a compatibility function primarily for plugins, because
 * in earlier DB schemas this was a much simpler single integer compare
 *
 * @param array $item
 */
function is_item_normal($item) {

	if(intval($item['item_hidden']) || intval($item['item_type']) || intval($item['item_deleted'])
		|| intval($item['item_unpublished']) || intval($item['item_delayed']) || intval($item['item_pending_remove'])
		|| intval($item['item_blocked']) || ($item['obj_type'] == ACTIVITY_OBJ_FILE))
		return false;

	return true;
}

/**
 * @brief Decide if current observer has sufficient privileges to comment on item.
 *
 * This function examines the comment_policy attached to an item and decides if the current observer has
 * sufficient privileges to comment. This will normally be called on a remote site where perm_is_allowed()
 * will not be suitable because the post owner does not have a local channel_id.
 * Generally we should look at the item - in particular the author['abook_flags'] and see if ABOOK_FLAG_SELF is set.
 * If it is, you should be able to use perm_is_allowed( ... 'post_comments'), and if it isn't you need to call
 * can_comment_on_post()
 * We also check the comments_closed date/time on the item if this is set.
 *
 * @param string $observer_xchan
 * @param array $item
 * @return boolean
 */
function can_comment_on_post($observer_xchan, $item) {

//	logger('Comment_policy: ' . $item['comment_policy'], LOGGER_DEBUG);

	$x = [
			'observer_hash' => $observer_xchan,
			'item' => $item,
			'allowed' => 'unset'
	];
	/**
	 * @hooks can_comment_on_post
	 *   Called when deciding whether or not to present a comment box for a post.
	 *   * \e string \b observer_hash
	 *   * \e array \b item
	 *   * \e boolean \b allowed - return value
	 */
	call_hooks('can_comment_on_post', $x);
	if($x['allowed'] !== 'unset')
		return $x['allowed'];

	if(! $observer_xchan)
		return false;

	if($item['comment_policy'] === 'none')
		return false;

	if(comments_are_now_closed($item))
		return false;

	if($observer_xchan === $item['author_xchan'] || $observer_xchan === $item['owner_xchan'])
		return true;

	switch($item['comment_policy']) {
		case 'self':
			if($observer_xchan === $item['author_xchan'] || $observer_xchan === $item['owner_xchan'])
				return true;
			break;
		case 'public':
			// We don't really allow or support public comments yet, but anonymous
			// folks won't ever reach this point (as $observer_xchan will be empty).
			// This means the viewer has an xchan and we can identify them.
			return true;
			break;
		case 'any connections':
		case 'contacts':
		case 'authenticated':
		case '':
			if(array_key_exists('owner',$item) && get_abconfig($item['uid'],$item['owner']['abook_xchan'],'their_perms','post_comments')) {
					return true;
			}
			break;
		default:
			break;
	}
	if(strstr($item['comment_policy'],'network:') && strstr($item['comment_policy'],'red'))
		return true;
	if(strstr($item['comment_policy'],'site:') && strstr($item['comment_policy'],App::get_hostname()))
		return true;

	return false;
}

/**
 * @brief Adds $hash to the item source route specified by $iid.
 *
 * $item['route'] contains a comma-separated list of xchans that sent the current message,
 * somewhat analogous to the * Received: header line in email. We can use this to perform
 * loop detection and to avoid sending a particular item to any "upstream" sender (they
 * already have a copy because they sent it to us).
 *
 * Modifies item in the database pointed to by $iid.
 *
 * @param integer $iid
 *    item['id'] of target item
 * @param string $hash
 *    xchan_hash of the channel that sent the item
 */
function add_source_route($iid, $hash) {
//	logger('add_source_route ' . $iid . ' ' . $hash, LOGGER_DEBUG);

	if((! $iid) || (! $hash))
		return;

	$r = q("select route from item where id = %d limit 1",
		intval($iid)
	);
	if($r) {
		$new_route = (($r[0]['route']) ? $r[0]['route'] . ',' : '') . $hash;
		q("update item set route = '%s' where id = %d",
			(dbesc($new_route)),
			intval($iid)
		);
	}
}


/**
 * @brief Post an activity.
 *
 * In its simplest form one needs only to set $arr['body'] to post a note to the logged in channel's wall.
 * Much more complex activities can be created. Permissions are checked. No filtering, tag expansion
 * or other processing is performed.
 *
 * @param array $arr
 * @param boolean $allow_code (optional) default false
 * @param boolean $deliver (optional) default true
 * @returns array
 *  * \e boolean \b success true or false
 *  * \e array \b activity the resulting activity if successful
 */
function post_activity_item($arr, $allow_code = false, $deliver = true) {

	$ret = array('success' => false);

	$is_comment = false;
	if((($arr['parent']) && $arr['parent'] != $arr['id']) || (($arr['parent_mid']) && $arr['parent_mid'] != $arr['mid']))
		$is_comment = true;

	if(! array_key_exists('item_origin',$arr))
		$arr['item_origin'] = 1;
	if(! array_key_exists('item_wall',$arr) && (! $is_comment))
		$arr['item_wall'] = 1;
	if(! array_key_exists('item_thread_top',$arr) && (! $is_comment))
		$arr['item_thread_top'] = 1;

	$channel  = App::get_channel();
	$observer = App::get_observer();

	$arr['aid'] = ((x($arr,'aid')) ? $arr['aid'] : $channel['channel_account_id']);
	$arr['uid'] = ((x($arr,'uid')) ? $arr['uid'] : $channel['channel_id']);

	if(! perm_is_allowed($arr['uid'],$observer['xchan_hash'],(($is_comment) ? 'post_comments' : 'post_wall'))) {
		$ret['message'] = t('Permission denied');
		return $ret;
	}

	$arr['public_policy'] = ((array_key_exists('public_policy',$arr)) ? escape_tags($arr['public_policy']) : map_scope(\Zotlabs\Access\PermissionLimits::Get($channel['channel_id'],'view_stream'),true));

	if($arr['public_policy'])
		$arr['item_private'] = 1;

	if(! array_key_exists('mimetype',$arr))
		$arr['mimetype'] = 'text/bbcode';

	$arr['mid']          = ((x($arr,'mid')) ? $arr['mid'] : item_message_id());
	$arr['parent_mid']   = ((x($arr,'parent_mid')) ? $arr['parent_mid'] : $arr['mid']);
	$arr['thr_parent']   = ((x($arr,'thr_parent')) ? $arr['thr_parent'] : $arr['mid']);

	$arr['owner_xchan']  = ((x($arr,'owner_xchan'))  ? $arr['owner_xchan']  : $channel['channel_hash']);
	$arr['author_xchan'] = ((x($arr,'author_xchan')) ? $arr['author_xchan'] : $observer['xchan_hash']);

	$arr['verb']         = ((x($arr,'verb')) ? $arr['verb'] : ACTIVITY_POST);
	$arr['obj_type']     = ((x($arr,'obj_type')) ? $arr['obj_type'] : ACTIVITY_OBJ_NOTE);
	if(($is_comment) && ($arr['obj_type'] === ACTIVITY_OBJ_NOTE))
		$arr['obj_type'] = ACTIVITY_OBJ_COMMENT;

	if(! ( array_key_exists('allow_cid',$arr) || array_key_exists('allow_gid',$arr)
		|| array_key_exists('deny_cid',$arr) || array_key_exists('deny_gid',$arr))) {
		$arr['allow_cid']    = $channel['channel_allow_cid'];
		$arr['allow_gid']    = $channel['channel_allow_gid'];
		$arr['deny_cid']     = $channel['channel_deny_cid'];
		$arr['deny_gid']     = $channel['channel_deny_gid'];
	}

	$arr['comment_policy'] = map_scope(\Zotlabs\Access\PermissionLimits::Get($channel['channel_id'],'post_comments'));

	if ((! $arr['plink']) && (intval($arr['item_thread_top']))) {
		$arr['plink'] = substr(z_root() . '/channel/' . $channel['channel_address'] . '/?f=&mid=' . urlencode($arr['mid']),0,190);
	}


	// for the benefit of plugins, we will behave as if this is an API call rather than a normal online post

	$_REQUEST['api_source'] = 1;

	/**
	 * @hooks post_local
	 *   Called when an item has been posted on this machine via mod/item.php (also via API).
	 */
	call_hooks('post_local', $arr);

	if(x($arr, 'cancel')) {
		logger('Post cancelled by plugin.');
		return $ret;
	}

	$post = item_store($arr,$allow_code,$deliver);

	if($post['success']) {
		$post_id = $post['item_id'];
		$ret['success'] = true;
		$ret['item_id'] = $post_id;
		$ret['activity'] = $post['item'];

		/**
		 * @hooks post_local_end
		 *   Called after a local post operation has completed.
		 *   * \e array - the item returned from item_store()
		 */
		call_hooks('post_local_end', $ret['activity']);
	}

	if($post_id && $deliver) {
		Zotlabs\Daemon\Master::Summon(array('Notifier','activity',$post_id));
	}

	$ret['success'] = true;

	return $ret;
}


function validate_item_elements($message,$arr) {

	$result = array('success' => false);

	if(! array_key_exists('created',$arr))
		$result['message'] = 'missing created, possible author/owner lookup failure';

	if((! $arr['mid']) || (! $arr['parent_mid']))
		$result['message'] = 'missing message-id or parent message-id';

	if(array_key_exists('flags',$message) && in_array('relay',$message['flags']) && $arr['mid'] === $arr['parent_mid'])
		$result['message'] = 'relay set on top level post';

	if(! $result['message'])
		$result['success'] = true;

	return $result;
}


/**
 * @brief Limit length on imported system messages.
 *
 * The purpose of this function is to apply system message length limits to
 * imported messages without including any embedded photos in the length.
 *
 * @param string $body
 * @return string
 */
function limit_body_size($body) {

	$maxlen = get_max_import_size();

	// If the length of the body, including the embedded images, is smaller
	// than the maximum, then don't waste time looking for the images
	if($maxlen && (strlen($body) > $maxlen)) {

		$orig_body = $body;
		$new_body = '';
		$textlen = 0;

		$img_start = strpos($orig_body, '[img');
		$img_st_close = ($img_start !== false ? strpos(substr($orig_body, $img_start), ']') : false);
		$img_end = ($img_start !== false ? strpos(substr($orig_body, $img_start), '[/img]') : false);
		while(($img_st_close !== false) && ($img_end !== false)) {

			$img_st_close++; // make it point to AFTER the closing bracket
			$img_end += $img_start;
			$img_end += strlen('[/img]');

			if(! strcmp(substr($orig_body, $img_start + $img_st_close, 5), 'data:')) {
				// This is an embedded image

				if( ($textlen + $img_start) > $maxlen ) {
					if($textlen < $maxlen) {
						logger('The limit happens before an embedded image', LOGGER_DEBUG);
						$new_body = $new_body . substr($orig_body, 0, $maxlen - $textlen);
						$textlen = $maxlen;
					}
				}
				else {
					$new_body = $new_body . substr($orig_body, 0, $img_start);
					$textlen += $img_start;
				}

				$new_body = $new_body . substr($orig_body, $img_start, $img_end - $img_start);
			}
			else {
				if( ($textlen + $img_end) > $maxlen ) {
					if($textlen < $maxlen) {
						$new_body = $new_body . substr($orig_body, 0, $maxlen - $textlen);
						$textlen = $maxlen;
					}
				}
				else {
					$new_body = $new_body . substr($orig_body, 0, $img_end);
					$textlen += $img_end;
				}
			}
			$orig_body = substr($orig_body, $img_end);

			if($orig_body === false) // in case the body ends on a closing image tag
				$orig_body = '';

			$img_start = strpos($orig_body, '[img');
			$img_st_close = ($img_start !== false ? strpos(substr($orig_body, $img_start), ']') : false);
			$img_end = ($img_start !== false ? strpos(substr($orig_body, $img_start), '[/img]') : false);
		}

		if( ($textlen + strlen($orig_body)) > $maxlen) {
			if($textlen < $maxlen) {
				$new_body = $new_body . substr($orig_body, 0, $maxlen - $textlen);
				$textlen = $maxlen;
			}
		}
		else {
			$new_body = $new_body . $orig_body;
			$textlen += strlen($orig_body);
		}

		return $new_body;
	}
	else
		return $body;
}

function title_is_body($title, $body) {

	$title = strip_tags($title);
	$title = trim($title);
	$title = str_replace(array("\n", "\r", "\t", " "), array("","","",""), $title);

	$body = strip_tags($body);
	$body = trim($body);
	$body = str_replace(array("\n", "\r", "\t", " "), array("","","",""), $body);

	if (strlen($title) < strlen($body))
		$body = substr($body, 0, strlen($title));

	if (($title != $body) and (substr($title, -3) == "...")) {
		$pos = strrpos($title, "...");
		if ($pos > 0) {
			$title = substr($title, 0, $pos);
			$body = substr($body, 0, $pos);
		}
	}

	return($title == $body);
}


function get_item_elements($x,$allow_code = false) {

	$arr = array();

	$arr['body'] = $x['body'];

	$maxlen = get_max_import_size();

	if($maxlen && mb_strlen($arr['body']) > $maxlen) {
		$arr['body'] = mb_substr($arr['body'],0,$maxlen,'UTF-8');
		logger('get_item_elements: message length exceeds max_import_size: truncated');
	}

	$arr['created']      = datetime_convert('UTC','UTC',$x['created']);
	$arr['edited']       = datetime_convert('UTC','UTC',$x['edited']);

	if($arr['created'] > datetime_convert())
		$arr['created']  = datetime_convert();
	if($arr['edited'] > datetime_convert())
		$arr['edited']   = datetime_convert();

	$arr['expires']      = ((x($x,'expires') && $x['expires'])
								? datetime_convert('UTC','UTC',$x['expires'])
								: NULL_DATE);

	$arr['commented']    = ((x($x,'commented') && $x['commented'])
								? datetime_convert('UTC','UTC',$x['commented'])
								: $arr['created']);
	$arr['comments_closed']    = ((x($x,'comments_closed') && $x['comments_closed'])
								? datetime_convert('UTC','UTC',$x['comments_closed'])
								: NULL_DATE);

	$arr['title']        = (($x['title'])          ? htmlspecialchars($x['title'],          ENT_COMPAT,'UTF-8',false) : '');

	if(mb_strlen($arr['title']) > 255)
		$arr['title'] = mb_substr($arr['title'],0,255);

	$arr['app']          = (($x['app'])            ? htmlspecialchars($x['app'],            ENT_COMPAT,'UTF-8',false) : '');
	$arr['route']        = (($x['route'])          ? htmlspecialchars($x['route'],          ENT_COMPAT,'UTF-8',false) : '');
	$arr['mid']          = (($x['message_id'])     ? htmlspecialchars($x['message_id'],     ENT_COMPAT,'UTF-8',false) : '');
	$arr['parent_mid']   = (($x['message_top'])    ? htmlspecialchars($x['message_top'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['thr_parent']   = (($x['message_parent']) ? htmlspecialchars($x['message_parent'], ENT_COMPAT,'UTF-8',false) : '');

	$arr['plink']        = (($x['permalink'])      ? htmlspecialchars($x['permalink'],      ENT_COMPAT,'UTF-8',false) : '');
	$arr['location']     = (($x['location'])       ? htmlspecialchars($x['location'],       ENT_COMPAT,'UTF-8',false) : '');
	$arr['coord']        = (($x['longlat'])        ? htmlspecialchars($x['longlat'],        ENT_COMPAT,'UTF-8',false) : '');
	$arr['verb']         = (($x['verb'])           ? htmlspecialchars($x['verb'],           ENT_COMPAT,'UTF-8',false) : '');
	$arr['mimetype']     = (($x['mimetype'])       ? htmlspecialchars($x['mimetype'],       ENT_COMPAT,'UTF-8',false) : '');
	$arr['obj_type']     = (($x['object_type'])    ? htmlspecialchars($x['object_type'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['tgt_type']     = (($x['target_type'])    ? htmlspecialchars($x['target_type'],    ENT_COMPAT,'UTF-8',false) : '');

	$arr['public_policy'] = (($x['public_scope']) ? htmlspecialchars($x['public_scope'], ENT_COMPAT,'UTF-8',false) : '');
	if($arr['public_policy'] === 'public')
		$arr['public_policy'] = '';

	$arr['comment_policy'] = (($x['comment_scope']) ? htmlspecialchars($x['comment_scope'], ENT_COMPAT,'UTF-8',false) : 'contacts');

	$arr['sig']          = (($x['signature']) ? htmlspecialchars($x['signature'],  ENT_COMPAT,'UTF-8',false) : '');

	$arr['obj']          = activity_sanitise($x['object']);
	$arr['target']       = activity_sanitise($x['target']);

	$arr['attach']       = activity_sanitise($x['attach']);
	$arr['term']         = decode_tags($x['tags']);
	$arr['iconfig']      = decode_item_meta($x['meta']);

	$arr['item_private'] = ((array_key_exists('flags',$x) && is_array($x['flags']) && in_array('private',$x['flags'])) ? 1 : 0);

	$arr['item_flags'] = 0;

	if(array_key_exists('flags',$x)) {

		if(in_array('consensus',$x['flags']))
			$arr['item_consensus'] = 1;

		if(in_array('deleted',$x['flags']))
			$arr['item_deleted'] = 1;

		if(in_array('notshown',$x['flags']))
			$arr['item_notshown'] = 1;

		if(in_array('obscured',$x['flags']))
			$arr['item_obscured'] = 1;

		// hidden item are no longer propagated - notshown may be a suitable alternative

		if(in_array('hidden',$x['flags']))
			$arr['item_hidden'] = 1;

	}

	// Here's the deal - the site might be down or whatever but if there's a new person you've never
	// seen before sending stuff to your stream, we MUST be able to look them up and import their data from their
	// hub and verify that they are legit - or else we're going to toss the post. We only need to do this
	// once, and after that your hub knows them. Sure some info is in the post, but it's only a transit identifier
	// and not enough info to be able to look you up from your hash - which is the only thing stored with the post.

	$xchan_hash = import_author_xchan($x['author']);
	if($xchan_hash)
		$arr['author_xchan'] = $xchan_hash;
	else
		return array();

	// save a potentially expensive lookup if author == owner

	if($arr['author_xchan'] === make_xchan_hash($x['owner']['guid'],$x['owner']['guid_sig']))
		$arr['owner_xchan'] = $arr['author_xchan'];
	else {
		$xchan_hash = import_author_xchan($x['owner']);
		if($xchan_hash) {
			$arr['owner_xchan'] = $xchan_hash;
		}
		else {
			return array();
		}
	}

	// Check signature on the body text received.
	// This presents an issue that we aren't verifying the text that is actually displayed
	// on this site. We are however verifying the received text was exactly as received.
	// We have every right to strip content that poses a security risk. You are welcome to
	// create a plugin to verify the content after filtering if this offends you.

	if($arr['sig']) {

		// check the supplied signature against the supplied content.
		// Note that we will purify the content which could change it.

		$r = q("select xchan_pubkey from xchan where xchan_hash = '%s' limit 1",
			dbesc($arr['author_xchan'])
		);
		if($r) {
			if($r[0]['xchan_pubkey']) {
				if(rsa_verify($x['body'],base64url_decode($arr['sig']),$r[0]['xchan_pubkey'])) {
					$arr['item_verified'] = 1;
				}
				else {
					logger('get_item_elements: message verification failed.');
				}
			}
			else {

				// If we don't have a public key, strip the signature so it won't show as invalid.
				// This won't happen in normal use, but could happen if import_author_xchan()
				// failed to load the zot-info packet due to a server failure and had
				// to create an alternate xchan with network 'unknown'

				unset($arr['sig']);
			}
		}
	}

	// if the input is markdown, remove one level of html escaping.
	// It will be re-applied in item_store() and/or item_store_update().
	// Do this after signature checking as the original signature
	// was generated on the escaped content.

	if($arr['mimetype'] === 'text/markdown')
		$arr['body'] = \Zotlabs\Lib\MarkdownSoap::unescape($arr['body']);

	if(array_key_exists('revision',$x)) {

		// extended export encoding

		$arr['revision'] = $x['revision'];
		$arr['allow_cid'] = $x['allow_cid'];
		$arr['allow_gid'] = $x['allow_gid'];
		$arr['deny_cid'] = $x['deny_cid'];
		$arr['deny_gid'] = $x['deny_gid'];
		$arr['layout_mid'] = $x['layout_mid'];
		$arr['postopts'] = $x['postopts'];
		$arr['resource_id'] = $x['resource_id'];
		$arr['resource_type'] = $x['resource_type'];
		$arr['attach'] = $x['attach'];
		$arr['item_origin'] = $x['item_origin'];
		$arr['item_unseen'] = $x['item_unseen'];
		$arr['item_starred'] = $x['item_starred'];
		$arr['item_uplink'] = $x['item_uplink'];
		$arr['item_consensus'] = $x['item_consensus'];
		$arr['item_wall'] = $x['item_wall'];
		$arr['item_thread_top'] = $x['item_thread_top'];
		$arr['item_notshown'] = $x['item_notshown'];
		$arr['item_nsfw'] = $x['item_nsfw'];
		// local only		$arr['item_relay'] = $x['item_relay'];
		$arr['item_mentionsme'] = $x['item_mentionsme'];
		$arr['item_nocomment'] = $x['item_nocomment'];
		$arr['item_obscured'] = $x['item_obscured'];
		// local only $arr['item_verified'] = $x['item_verified'];
		$arr['item_retained'] = $x['item_retained'];
		$arr['item_rss'] = $x['item_rss'];
		$arr['item_deleted'] = $x['item_deleted'];
		$arr['item_type'] = $x['item_type'];
		$arr['item_hidden'] = $x['item_hidden'];
		$arr['item_unpublished'] = $x['item_unpublished'];
		$arr['item_delayed'] = $x['item_delayed'];
		$arr['item_pending_remove'] = $x['item_pending_remove'];
		$arr['item_blocked'] = $x['item_blocked'];
		if(array_key_exists('item_flags',$x)) {
			if($x['item_flags'] & 0x0004)
				$arr['item_starred'] = 1;
			if($x['item_flags'] & 0x0008)
				$arr['item_uplink'] = 1;
			if($x['item_flags'] & 0x0010)
				$arr['item_consensus'] = 1;
			if($x['item_flags'] & 0x0020)
				$arr['item_wall'] = 1;
			if($x['item_flags'] & 0x0040)
				$arr['item_thread_top'] = 1;
			if($x['item_flags'] & 0x0080)
				$arr['item_notshown'] = 1;
			if($x['item_flags'] & 0x0100)
				$arr['item_nsfw'] = 1;
			if($x['item_flags'] & 0x0400)
				$arr['item_mentionsme'] = 1;
			if($x['item_flags'] & 0x0800)
				$arr['item_nocomment'] = 1;
			if($x['item_flags'] & 0x4000)
				$arr['item_retained'] = 1;
			if($x['item_flags'] & 0x8000)
				$arr['item_rss'] = 1;

		}
		if(array_key_exists('item_restrict',$x)) {
			if($x['item_restrict'] & 0x0001)
				$arr['item_hidden'] = 1;
			if($x['item_restrict'] & 0x0002)
				$arr['item_blocked'] = 1;
			if($x['item_restrict'] & 0x0010)
				$arr['item_deleted'] = 1;
			if($x['item_restrict'] & 0x0020)
				$arr['item_unpublished'] = 1;
			if($x['item_restrict'] & 0x0040)
				$arr['item_type'] = ITEM_TYPE_WEBPAGE;
			if($x['item_restrict'] & 0x0080)
				$arr['item_delayed'] = 1;
			if($x['item_restrict'] & 0x0100)
				$arr['item_type'] = ITEM_TYPE_BLOCK;
			if($x['item_restrict'] & 0x0200)
				$arr['item_type'] = ITEM_TYPE_PDL;
			if($x['item_restrict'] & 0x0400)
				$arr['item_type'] = ITEM_TYPE_BUG;
			if($x['item_restrict'] & 0x0800)
				$arr['item_pending_remove'] = 1;
			if($x['item_restrict'] & 0x1000)
				$arr['item_type'] = ITEM_TYPE_DOC;
		}
	}

	return $arr;
}


function import_author_xchan($x) {

	$arr = [
			'xchan' => $x,
			'xchan_hash' => ''
	];
	/**
	 * @hooks import_author_xchan
	 *   Called when looking up an author of a post by xchan_hash to ensure they have an xchan record on our site.
	 *   * \e array \b xchan
	 *   * \e string \b xchan_hash - Thre returned value
	 */
	call_hooks('import_author_xchan', $arr);
	if($arr['xchan_hash'])
		return $arr['xchan_hash'];

	$y = false;

	if((! array_key_exists('network', $x)) || ($x['network'] === 'zot')) {
		$y = import_author_zot($x);
	}

	// if we were told that it's a zot connection, don't probe/import anything else
	if(array_key_exists('network',$x) && $x['network'] === 'zot')
		return $y;

	if($x['network'] === 'rss') {
		$y = import_author_rss($x);
	}

	if(! $y) {
		$y = import_author_unknown($x);
	}

	return($y);
}

/**
 * @brief Imports an author from a RSS feed.
 *
 * @param array $x an associative array with
 *   * \e string \b url
 *   * \e string \b name
 *   * \e string \b guid
 * @return boolean|string
 */
function import_author_rss($x) {
	if(! $x['url'])
		return false;

	$r = q("select xchan_hash from xchan where xchan_network = 'rss' and xchan_url = '%s' limit 1",
		dbesc($x['url'])
	);
	if($r) {
		logger('In cache' , LOGGER_DEBUG);
		return $r[0]['xchan_hash'];
	}
	$name = trim($x['name']);

	$r = xchan_store_lowlevel(
		[
			'xchan_hash'         => $x['guid'],
			'xchan_guid'         => $x['guid'],
			'xchan_url'          => $x['url'],
			'xchan_name'         => (($name) ? $name : t('(Unknown)')),
			'xchan_name_date'    => datetime_convert(),
			'xchan_network'      => 'rss'
		]
	);

	if($r && $x['photo']) {

		$photos = import_xchan_photo($x['photo']['src'],$x['url']);

		if($photos) {
			$r = q("update xchan set xchan_photo_date = '%s', xchan_photo_l = '%s', xchan_photo_m = '%s', xchan_photo_s = '%s', xchan_photo_mimetype = '%s' where xchan_url = '%s' and xchan_network = 'rss'",
				dbesc(datetime_convert()),
				dbesc($photos[0]),
				dbesc($photos[1]),
				dbesc($photos[2]),
				dbesc($photos[3]),
				dbesc($x['url'])
			);
			if($r)
				return $x['url'];
		}
	}

	return false;
}

function import_author_unknown($x) {

	$arr = [
			'author' => $x,
			'result' => false
	];
	/**
	 * @hooks import_author
	 *   * \e array \b author
	 *   * \e boolean|string \b result - Return value, default false
	 */
	call_hooks('import_author', $arr);
	if($arr['result'])
		return $arr['result'];

	if(! $x['url'])
		return false;

	$r = q("select xchan_hash from xchan where xchan_network = 'unknown' and xchan_url = '%s' limit 1",
		dbesc($x['url'])
	);
	if($r) {
		logger('In cache' , LOGGER_DEBUG);
		return $r[0]['xchan_hash'];
	}

	$name = trim($x['name']);

	$r = xchan_store_lowlevel(
		[
			'xchan_hash'         => $x['url'],
			'xchan_guid'         => $x['url'],
			'xchan_url'          => $x['url'],
			'xchan_name'         => (($name) ? $name : t('(Unknown)')),
			'xchan_name_date'    => datetime_convert(),
			'xchan_network'      => 'unknown'
		]
	);

	if($r && $x['photo']) {

		$photos = import_xchan_photo($x['photo']['src'],$x['url']);

		if($photos) {
			$r = q("update xchan set xchan_photo_date = '%s', xchan_photo_l = '%s', xchan_photo_m = '%s', xchan_photo_s = '%s', xchan_photo_mimetype = '%s' where xchan_hash = '%s' and xchan_network = 'unknown'",
				dbesc(datetime_convert()),
				dbesc($photos[0]),
				dbesc($photos[1]),
				dbesc($photos[2]),
				dbesc($photos[3]),
				dbesc($x['url'])
			);
			if($r)
				return $x['url'];
		}
	}

	return false;
}

function empty_acl($item) {
	return (($item['allow_cid'] === EMPTY_STR && $item['allow_gid'] === EMPTY_STR && $item['deny_cid'] === EMPTY_STR && $item['deny_gid'] === EMPTY_STR) ? true : false);
}

function encode_item($item,$mirror = false) {
	$x = array();
	$x['type'] = 'activity';
	$x['encoding'] = 'zot';

//	logger('encode_item: ' . print_r($item,true));

	$r = q("select channel_id from channel where channel_id = %d limit 1",
		intval($item['uid'])
	);

	if($r)
		$comment_scope = \Zotlabs\Access\PermissionLimits::Get($item['uid'],'post_comments');
	else
		$comment_scope = 0;

	$scope = $item['public_policy'];
	if(! $scope)
		$scope = 'public';

	$c_scope = map_scope($comment_scope);

	$key = get_config('system','prvkey');

	// If we're trying to backup an item so that it's recoverable or for export/imprt,
	// add all the attributes we need to recover it

	if($mirror) {
		$x['id'] = $item['id'];
		$x['parent'] = $item['parent'];
		$x['uid'] = $item['uid'];
		$x['allow_cid'] = $item['allow_cid'];
		$x['allow_gid'] = $item['allow_gid'];
		$x['deny_cid'] = $item['deny_cid'];
		$x['deny_gid'] = $item['deny_gid'];
		$x['revision'] = $item['revision'];
		$x['layout_mid'] = $item['layout_mid'];
		$x['postopts'] = $item['postopts'];
		$x['resource_id'] = $item['resource_id'];
		$x['resource_type'] = $item['resource_type'];
		$x['attach'] = $item['attach'];
		$x['item_origin'] = $item['item_origin'];
		$x['item_unseen'] = $item['item_unseen'];
		$x['item_starred'] = $item['item_starred'];
		$x['item_uplink'] = $item['item_uplink'];
		$x['item_consensus'] = $item['item_consensus'];
		$x['item_wall'] = $item['item_wall'];
		$x['item_thread_top'] = $item['item_thread_top'];
		$x['item_notshown'] = $item['item_notshown'];
		$x['item_nsfw'] = $item['item_nsfw'];
		$x['item_relay'] = $item['item_relay'];
		$x['item_mentionsme'] = $item['item_mentionsme'];
		$x['item_nocomment'] = $item['item_nocomment'];
		$x['item_obscured'] = $item['item_obscured'];
		$x['item_verified'] = $item['item_verified'];
		$x['item_retained'] = $item['item_retained'];
		$x['item_rss'] = $item['item_rss'];
		$x['item_deleted'] = $item['item_deleted'];
		$x['item_type'] = $item['item_type'];
		$x['item_hidden'] = $item['item_hidden'];
		$x['item_unpublished'] = $item['item_unpublished'];
		$x['item_delayed'] = $item['item_delayed'];
		$x['item_pending_remove'] = $item['item_pending_remove'];
		$x['item_blocked'] = $item['item_blocked'];
	}

	$x['message_id']      = $item['mid'];
	$x['message_top']     = $item['parent_mid'];
	$x['message_parent']  = $item['thr_parent'];
	$x['created']         = $item['created'];
	$x['edited']          = $item['edited'];
	// always send 0's over the wire
	$x['expires']         = (($item['expires'] == '0001-01-01 00:00:00') ? '0000-00-00 00:00:00' : $item['expires']);
	$x['commented']       = $item['commented'];
	$x['mimetype']        = $item['mimetype'];
	$x['title']           = $item['title'];
	$x['body']            = $item['body'];
	$x['app']             = $item['app'];
	$x['verb']            = $item['verb'];
	$x['object_type']     = $item['obj_type'];
	$x['target_type']     = $item['tgt_type'];
	$x['permalink']       = $item['plink'];
	$x['location']        = $item['location'];
	$x['longlat']         = $item['coord'];
	$x['signature']       = $item['sig'];
	$x['route']           = $item['route'];
	$x['owner']           = encode_item_xchan($item['owner']);
	$x['author']          = encode_item_xchan($item['author']);

	if($item['obj'])
		$x['object']      = json_decode($item['obj'],true);
	if($item['target'])
		$x['target']      = json_decode($item['target'],true);
	if($item['attach'])
		$x['attach']      = json_decode($item['attach'],true);
	if($y = encode_item_flags($item))
		$x['flags']       = $y;

	if($item['comments_closed'] > NULL_DATE)
		$x['comments_closed'] = $item['comments_closed'];

	$x['public_scope']    = $scope;

	if($item['item_nocomment'])
		$x['comment_scope'] = 'none';
	else
		$x['comment_scope'] = $c_scope;

	if($item['term'])
		$x['tags']        = encode_item_terms($item['term'],$mirror);

	if($item['iconfig'])
		$x['meta']        = encode_item_meta($item['iconfig'],$mirror);


	logger('encode_item: ' . print_r($x,true), LOGGER_DATA);

	return $x;
}

/**
 * @brief
 *
 * @param int $scope
 * @param boolean $strip (optional) default false
 * @return string
 */
function map_scope($scope, $strip = false) {
	switch($scope) {
		case 0:
			return 'self';
		case PERMS_PUBLIC:
			if($strip)
				return '';
			return 'public';
		case PERMS_NETWORK:
			return 'network: red';
		case PERMS_AUTHED:
			return 'authenticated';
		case PERMS_SITE:
			return 'site: ' . App::get_hostname();
		case PERMS_PENDING:
			return 'any connections';
		case PERMS_CONTACTS:
		default:
			return 'contacts';
	}
}

/**
 * @brief Returns a descriptive text for a given $scope.
 *
 * @param string $scope
 * @return string translated string describing the scope
 */
function translate_scope($scope) {
	if(! $scope || $scope === 'public')
		return t('Visible to anybody on the internet.');
	if(strpos($scope,'self') === 0)
		return t('Visible to you only.');
	if(strpos($scope,'network:') === 0)
		return t('Visible to anybody in this network.');
	if(strpos($scope,'authenticated') === 0)
		return t('Visible to anybody authenticated.');
	if(strpos($scope,'site:') === 0)
		return sprintf( t('Visible to anybody on %s.'), strip_tags(substr($scope,6)));
	if(strpos($scope,'any connections') === 0)
		return t('Visible to all connections.');
	if(strpos($scope,'contacts') === 0)
		return t('Visible to approved connections.');
	if(strpos($scope,'specific') === 0)
		return t('Visible to specific connections.');
}

/**
 * @brief
 *
 * @param array $xchan
 * @return array an associative array
 */
function encode_item_xchan($xchan) {
	$ret = array();

	$ret['name']     = $xchan['xchan_name'];
	$ret['address']  = $xchan['xchan_addr'];
	$ret['url']      = $xchan['xchan_url'];
	$ret['network']  = $xchan['xchan_network'];
	$ret['photo']    = [ 'mimetype' => $xchan['xchan_photo_mimetype'], 'src' => $xchan['xchan_photo_m'] ];
	$ret['guid']     = $xchan['xchan_guid'];
	$ret['guid_sig'] = $xchan['xchan_guid_sig'];

	return $ret;
}

function encode_item_terms($terms,$mirror = false) {
	$ret = array();

	$allowed_export_terms = array( TERM_UNKNOWN, TERM_HASHTAG, TERM_MENTION, TERM_CATEGORY, TERM_BOOKMARK, TERM_COMMUNITYTAG, TERM_FORUM );

	if($mirror) {
		$allowed_export_terms[] = TERM_PCATEGORY;
		$allowed_export_terms[] = TERM_FILE;
	}

	if($terms) {
		foreach($terms as $term) {
			if(in_array($term['ttype'],$allowed_export_terms))
				$ret[] = array('tag' => $term['term'], 'url' => $term['url'], 'type' => termtype($term['ttype']));
		}
	}

	return $ret;
}

function encode_item_meta($meta,$mirror = false) {
	$ret = array();

	if($meta) {
		foreach($meta as $m) {
			if($m['sharing'] || $mirror)
				$ret[] = array('family' => $m['cat'], 'key' => $m['k'], 'value' => $m['v'], 'sharing' => intval($m['sharing']));
		}
	}

	return $ret;
}

function decode_item_meta($meta) {
	$ret = array();

	if(is_array($meta) && $meta) {
		foreach($meta as $m) {
			$ret[] = array('cat' => escape_tags($m['family']),'k' => escape_tags($m['key']),'v' => $m['value'],'sharing' => $m['sharing']);
		}
	}
	return $ret;
}

/**
 * @brief
 *
 * @param int $t
 * @return string
 */
function termtype($t) {
	$types = array('unknown','hashtag','mention','category','private_category','file','search','thing','bookmark', 'hierarchy', 'communitytag', 'forum');

	return(($types[$t]) ? $types[$t] : 'unknown');
}

/**
 * @brief
 *
 * @param array $t
 * @return array|string empty string or array containing associative arrays with
 *   * \e string \b term
 *   * \e string \b url
 *   * \e int \b type
 */
function decode_tags($t) {
	if($t) {
		$ret = array();
		foreach($t as $x) {
			$tag = array();
			$tag['term'] = htmlspecialchars($x['tag'], ENT_COMPAT, 'UTF-8', false);
			$tag['url']  = htmlspecialchars($x['url'], ENT_COMPAT, 'UTF-8', false);
			switch($x['type']) {
				case 'hashtag':
					$tag['ttype'] = TERM_HASHTAG;
					break;
				case 'mention':
					$tag['ttype'] = TERM_MENTION;
					break;
				case 'category':
					$tag['ttype'] = TERM_CATEGORY;
					break;
				case 'private_category':
					$tag['ttype'] = TERM_PCATEGORY;
					break;
				case 'file':
					$tag['ttype'] = TERM_FILE;
					break;
				case 'search':
					$tag['ttype'] = TERM_SEARCH;
					break;
				case 'thing':
					$tag['ttype'] = TERM_THING;
					break;
				case 'bookmark':
					$tag['ttype'] = TERM_BOOKMARK;
					break;
				case 'communitytag':
					$tag['ttype'] = TERM_COMMUNITYTAG;
					break;
				case 'forum':
					$tag['ttype'] = TERM_FORUM;
					break;
				default:
				case 'unknown':
					$tag['ttype'] = TERM_UNKNOWN;
					break;
			}
			$ret[] = $tag;
		}

		return $ret;
	}

	return '';
}

/**
 * @brief Santise a potentially complex array.
 *
 * @param array $arr
 * @return array|string
 */
function activity_sanitise($arr) {
	if($arr) {
		if(is_array($arr)) {
			$ret = array();
			foreach($arr as $k => $x) {
				if(is_array($x))
					$ret[$k] = activity_sanitise($x);
				else
					$ret[$k] = htmlspecialchars($x, ENT_COMPAT, 'UTF-8', false);
			}
			return $ret;
		}
		else {
			return htmlspecialchars($arr, ENT_COMPAT, 'UTF-8', false);
		}
	}

	return '';
}

/**
 * @brief Sanitise a simple linear array.
 *
 * @param array $arr
 * @return array|string
 */
function array_sanitise($arr) {
	if($arr) {
		$ret = array();
		foreach($arr as $x) {
			$ret[] = htmlspecialchars($x, ENT_COMPAT,'UTF-8',false);
		}
		return $ret;
	}

	return '';
}

function encode_item_flags($item) {

//	most of item_flags and item_restrict are local settings which don't apply when transmitted.
//  We may need those for the case of syncing other hub locations which you are attached to.

	$ret = array();

	if(intval($item['item_deleted']))
		$ret[] = 'deleted';
	if(intval($item['item_hidden']))
		$ret[] = 'hidden';
	if(intval($item['item_notshown']))
		$ret[] = 'notshown';
	if(intval($item['item_thread_top']))
		$ret[] = 'thread_parent';
	if(intval($item['item_nsfw']))
		$ret[] = 'nsfw';
	if(intval($item['item_consensus']))
		$ret[] = 'consensus';
	if(intval($item['item_obscured']))
		$ret[] = 'obscured';
	if(intval($item['item_private']))
		$ret[] = 'private';

	return $ret;
}

function encode_mail($item,$extended = false) {
	$x = array();
	$x['type'] = 'mail';
	$x['encoding'] = 'zot';

	if(array_key_exists('mail_obscured',$item) && intval($item['mail_obscured'])) {
		if($item['title'])
			$item['title'] = base64url_decode(str_rot47($item['title']));
		if($item['body'])
			$item['body'] = base64url_decode(str_rot47($item['body']));
	}

	$x['message_id']     = $item['mid'];
	$x['message_parent'] = $item['parent_mid'];
	$x['created']        = $item['created'];
	$x['expires']        = $item['expires'];
	$x['title']          = $item['title'];
	$x['body']           = $item['body'];
	$x['from']           = encode_item_xchan($item['from']);
	$x['to']             = encode_item_xchan($item['to']);
	$x['raw']            = $item['mail_raw'];
	$x['mimetype']       = $item['mail_mimetype'];

	if($item['attach'])
		$x['attach']     = json_decode($item['attach'],true);

	$x['flags'] = array();

	if(intval($item['mail_recalled'])) {
		$x['flags'][] = 'recalled';
		$x['title'] = '';
		$x['body']  = '';
	}

	if($extended) {
		$x['conv_guid'] = $item['conv_guid'];
		if(intval($item['mail_deleted']))
			$x['flags'][] = 'deleted';
		if(intval($item['mail_replied']))
			$x['flags'][] = 'replied';
		if(intval($item['mail_isreply']))
			$x['flags'][] = 'isreply';
		if(intval($item['mail_seen']))
			$x['flags'][] = 'seen';
	}

	return $x;
}


function get_mail_elements($x) {

	$arr = array();

	if(intval($x['raw'])) {
		$arr['mail_raw'] = intval($x['raw']);
		$arr['body']     = $x['body'];
	}
	else {
		$arr['body']         = (($x['body']) ? htmlspecialchars($x['body'], ENT_COMPAT,'UTF-8',false) : '');

		$maxlen = get_max_import_size();

		if($maxlen && mb_strlen($arr['body']) > $maxlen) {
			$arr['body'] = mb_substr($arr['body'],0,$maxlen,'UTF-8');
			logger('message length exceeds max_import_size: truncated');
		}
	}

	$arr['title']        = (($x['title'])? htmlspecialchars($x['title'],ENT_COMPAT,'UTF-8',false) : '');
	$arr['mail_mimetype'] = (($x['mimetype']) ? htmlspecialchars($x['mimetype'],ENT_COMPAT,'UTF-8',false) : 'text/bbcode');
	$arr['conv_guid']    = (($x['conv_guid'])? htmlspecialchars($x['conv_guid'],ENT_COMPAT,'UTF-8',false) : '');

	$arr['created']      = datetime_convert('UTC','UTC',$x['created']);
	if((! array_key_exists('expires',$x)) || ($x['expires'] <= NULL_DATE))
		$arr['expires'] = NULL_DATE;
	else
		$arr['expires']      = datetime_convert('UTC','UTC',$x['expires']);

	$arr['mail_flags'] = 0;

	if($x['flags'] && is_array($x['flags'])) {
		if(in_array('recalled',$x['flags'])) {
			$arr['mail_recalled'] = 1;
		}
		if(in_array('replied',$x['flags'])) {
			$arr['mail_replied'] = 1;
		}
		if(in_array('isreply',$x['flags'])) {
			$arr['mail_isreply'] = 1;
		}
		if(in_array('seen',$x['flags'])) {
			$arr['mail_seen'] = 1;
		}
		if(in_array('deleted',$x['flags'])) {
			$arr['mail_deleted'] = 1;
		}
	}

	$key = get_config('system','pubkey');
	$arr['mail_obscured'] = 1;
	if($arr['body']) {
		$arr['body']  = str_rot47(base64url_encode($arr['body']));
	}

	if($arr['title']) {
		$arr['title'] = str_rot47(base64url_encode($arr['title']));
	}
	if($arr['created'] > datetime_convert())
		$arr['created']  = datetime_convert();


	$arr['mid']          = (($x['message_id'])     ? htmlspecialchars($x['message_id'],     ENT_COMPAT,'UTF-8',false) : '');
	$arr['parent_mid']   = (($x['message_parent']) ? htmlspecialchars($x['message_parent'], ENT_COMPAT,'UTF-8',false) : '');

	if($x['attach'])
		$arr['attach'] = activity_sanitise($x['attach']);

	if(($xchan_hash = import_author_xchan($x['from'])) !== false)
		$arr['from_xchan'] = $xchan_hash;
	else
		return array();

	if(($xchan_hash = import_author_xchan($x['to'])) !== false)
		$arr['to_xchan'] = $xchan_hash;
	else
		return array();

	return $arr;
}


function get_profile_elements($x) {

	$arr = array();

	if(($xchan_hash = import_author_xchan($x['from'])) !== false)
		$arr['xprof_hash'] = $xchan_hash;
	else
		return array();

	$arr['desc']         = (($x['title']) ? htmlspecialchars($x['title'],ENT_COMPAT,'UTF-8',false) : '');

	$arr['dob']          = datetime_convert('UTC','UTC',$x['birthday'],'Y-m-d');
	$arr['age']          = (($x['age']) ? intval($x['age']) : 0);

	$arr['gender']       = (($x['gender'])    ? htmlspecialchars($x['gender'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['marital']      = (($x['marital'])   ? htmlspecialchars($x['marital'],   ENT_COMPAT,'UTF-8',false) : '');
	$arr['sexual']       = (($x['sexual'])    ? htmlspecialchars($x['sexual'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['locale']       = (($x['locale'])    ? htmlspecialchars($x['locale'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['region']       = (($x['region'])    ? htmlspecialchars($x['region'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['postcode']     = (($x['postcode'])  ? htmlspecialchars($x['postcode'],  ENT_COMPAT,'UTF-8',false) : '');
	$arr['country']      = (($x['country'])   ? htmlspecialchars($x['country'],   ENT_COMPAT,'UTF-8',false) : '');

	$arr['keywords']     = (($x['keywords'] && is_array($x['keywords'])) ? array_sanitise($x['keywords']) : array());

	return $arr;
}


/**
 * @brief Signs an item body.
 *
 * @param[in,out] array $item
 */
function item_sign(&$item) {

	if(array_key_exists('sig',$item) && $item['sig'])
		return;

	$r = q("select channel_prvkey from channel where channel_id = %d and channel_hash = '%s' ",
			intval($item['uid']),
			dbesc($item['author_xchan'])
	);
	if(! $r)
		return;

	$item['sig'] = base64url_encode(rsa_sign($item['body'], $r[0]['channel_prvkey']));
	$item['item_verified'] = 1;
}


/**
 * @brief Stores an item type record.
 *
 * @param array $arr
 * @param boolean $allow_exec (optional) default false
 * @param boolean $deliver (optional) default true
 *
 * @return array
 *   * \e boolean \b success
 *   * \e int \b item_id
 */
function item_store($arr, $allow_exec = false, $deliver = true) {

	$d = [
			'item' => $arr,
			'allow_exec' => $allow_exec
	];
	/**
	 * @hooks item_store
	 *   Called when item_store() stores a record of type item.
	 *   * \e array \b item
	 *   * \e boolean \b allow_exec
	 */
	call_hooks('item_store', $d);
	$arr = $d['item'];
	$allow_exec = $d['allow_exec'];

	$ret = array('success' => false, 'item_id' => 0);

	if(array_key_exists('cancel',$arr) && $arr['cancel']) {
		logger('cancelled by plugin');
		return $ret;
	}

	if(! $arr['uid']) {
		logger('item_store: no uid');
		$ret['message'] = 'No uid.';
		return $ret;
	}

	//$uplinked_comment = false;

	// If a page layout is provided, ensure it exists and belongs to us.

	if(array_key_exists('layout_mid',$arr) && $arr['layout_mid']) {
		$l = q("select item_type from item where mid = '%s' and uid = %d limit 1",
			dbesc($arr['layout_mid']),
			intval($arr['uid'])
		);
		if((! $l) || ($l[0]['item_type'] != ITEM_TYPE_PDL))
			unset($arr['layout_mid']);
	}

	// Don't let anybody set these, either intentionally or accidentally

	if(array_key_exists('id',$arr))
		unset($arr['id']);
	if(array_key_exists('parent',$arr))
		unset($arr['parent']);

	$arr['mimetype']      = ((x($arr,'mimetype'))      ? notags(trim($arr['mimetype']))      : 'text/bbcode');

	if(($arr['mimetype'] == 'application/x-php') && (! $allow_exec)) {
		logger('item_store: php mimetype but allow_exec is denied.');
		$ret['message'] = 'exec denied.';
		return $ret;
	}

	$arr['title'] = ((array_key_exists('title',$arr) && strlen($arr['title']))  ? trim($arr['title']) : '');
	$arr['body']  = ((array_key_exists('body',$arr) && strlen($arr['body']))    ? trim($arr['body'])  : '');

	$arr['allow_cid']     = ((x($arr,'allow_cid'))     ? trim($arr['allow_cid'])             : '');
	$arr['allow_gid']     = ((x($arr,'allow_gid'))     ? trim($arr['allow_gid'])             : '');
	$arr['deny_cid']      = ((x($arr,'deny_cid'))      ? trim($arr['deny_cid'])              : '');
	$arr['deny_gid']      = ((x($arr,'deny_gid'))      ? trim($arr['deny_gid'])              : '');
	$arr['postopts']      = ((x($arr,'postopts'))      ? trim($arr['postopts'])              : '');
	$arr['route']         = ((x($arr,'route'))         ? trim($arr['route'])                 : '');
	$arr['item_private']  = ((x($arr,'item_private'))  ? intval($arr['item_private'])        : 0 );
	$arr['item_wall']     = ((x($arr,'item_wall'))     ? intval($arr['item_wall'])           : 0 );
	$arr['item_type']     = ((x($arr,'item_type'))     ? intval($arr['item_type'])           : 0 );

	// obsolete, but needed so as not to throw not-null constraints on some database driveres
	$arr['item_flags']    = ((x($arr,'item_flags'))    ? intval($arr['item_flags'])          : 0 );


	$arr['lang'] = detect_language($arr['body']);

	// apply the input filter here

	$arr['body'] = trim(z_input_filter($arr['body'],$arr['mimetype'],$allow_exec));

	item_sign($arr);

	if(! array_key_exists('sig',$arr))
		$arr['sig'] = '';

	$allowed_languages = get_pconfig($arr['uid'],'system','allowed_languages');

	if((is_array($allowed_languages)) && ($arr['lang']) && (! array_key_exists($arr['lang'],$allowed_languages))) {
		$translate = [
				'item' => $arr,
				'from' => $arr['lang'],
				'to' => $allowed_languages,
				'translated' => false
		];
		/**
		 * @hooks item_translate
		 *   Called from item_store and item_store_update after the post language has been autodetected.
		 *   * \e array \b item
		 *   * \e string \b from
		 *   * \e string \b to
		 *   * \e boolean \b translated
		 */
		call_hooks('item_translate', $translate);
		if((! $translate['translated']) && (intval(get_pconfig($arr['uid'],'system','reject_disallowed_languages')))) {
			logger('language ' . $arr['lang'] . ' not accepted for uid ' . $arr['uid']);
			$ret['message'] = 'language not accepted';
			return $ret;
		}
		$arr = $translate['item'];
	}

	if((x($arr,'obj')) && is_array($arr['obj'])) {
		activity_sanitise($arr['obj']);
		$arr['obj'] = json_encode($arr['obj']);
	}

	if((x($arr,'target')) && is_array($arr['target'])) {
		activity_sanitise($arr['target']);
		$arr['target'] = json_encode($arr['target']);
	}

	if((x($arr,'attach')) && is_array($arr['attach'])) {
		activity_sanitise($arr['attach']);
		$arr['attach'] = json_encode($arr['attach']);
	}

	$arr['aid']           = ((x($arr,'aid'))           ? intval($arr['aid'])                           : 0);
	$arr['mid']           = ((x($arr,'mid'))           ? notags(trim($arr['mid']))                     : random_string());
	$arr['revision']      = ((x($arr,'revision') && intval($arr['revision']) > 0)   ? intval($arr['revision']) : 0);

	$arr['author_xchan']  = ((x($arr,'author_xchan'))  ? notags(trim($arr['author_xchan']))  : '');
	$arr['owner_xchan']   = ((x($arr,'owner_xchan'))   ? notags(trim($arr['owner_xchan']))   : '');
	$arr['created']       = ((x($arr,'created') !== false) ? datetime_convert('UTC','UTC',$arr['created']) : datetime_convert());
	$arr['edited']        = ((x($arr,'edited')  !== false) ? datetime_convert('UTC','UTC',$arr['edited'])  : datetime_convert());
	$arr['expires']       = ((x($arr,'expires')  !== false) ? datetime_convert('UTC','UTC',$arr['expires'])  : NULL_DATE);
	$arr['commented']     = ((x($arr,'commented')  !== false) ? datetime_convert('UTC','UTC',$arr['commented'])  : datetime_convert());
	$arr['comments_closed'] = ((x($arr,'comments_closed')  !== false) ? datetime_convert('UTC','UTC',$arr['comments_closed'])  : NULL_DATE);
	$arr['html'] = ((array_key_exists('html',$arr)) ? $arr['html'] : '');

	if($deliver) {
		$arr['received']      = datetime_convert();
		$arr['changed']       = datetime_convert();
	}
	else {

		// When deliver flag is false, we are *probably* performing an import or bulk migration.
		// If one updates the changed timestamp it will be made available to zotfeed and delivery
		// will still take place through backdoor methods. Since these fields are rarely used
		// otherwise, just preserve the original timestamp.

		$arr['received']      = ((x($arr,'received')  !== false) ? datetime_convert('UTC','UTC',$arr['received'])  : datetime_convert());
		$arr['changed']       = ((x($arr,'changed')  !== false) ? datetime_convert('UTC','UTC',$arr['changed'])  : datetime_convert());
	}

	$arr['location']      = ((x($arr,'location'))      ? notags(trim($arr['location']))      : '');
	$arr['coord']         = ((x($arr,'coord'))         ? notags(trim($arr['coord']))         : '');
	$arr['parent_mid']    = ((x($arr,'parent_mid'))    ? notags(trim($arr['parent_mid']))    : '');
	$arr['thr_parent']    = ((x($arr,'thr_parent'))    ? notags(trim($arr['thr_parent']))    : $arr['parent_mid']);
	$arr['verb']          = ((x($arr,'verb'))          ? notags(trim($arr['verb']))          : ACTIVITY_POST);
	$arr['obj_type']      = ((x($arr,'obj_type'))      ? notags(trim($arr['obj_type']))      : ACTIVITY_OBJ_NOTE);
	$arr['obj']           = ((x($arr,'obj'))           ? trim($arr['obj'])                   : '');
	$arr['tgt_type']      = ((x($arr,'tgt_type'))      ? notags(trim($arr['tgt_type']))      : '');
	$arr['target']        = ((x($arr,'target'))        ? trim($arr['target'])                : '');
	$arr['plink']         = ((x($arr,'plink'))         ? notags(trim($arr['plink']))         : '');
	$arr['attach']        = ((x($arr,'attach'))        ? notags(trim($arr['attach']))        : '');
	$arr['app']           = ((x($arr,'app'))           ? notags(trim($arr['app']))           : '');

	$arr['public_policy'] = ((x($arr,'public_policy')) ? notags(trim($arr['public_policy']))  : '' );

	$arr['comment_policy'] = ((x($arr,'comment_policy')) ? notags(trim($arr['comment_policy']))  : 'contacts' );

	if(! array_key_exists('item_unseen',$arr))
		$arr['item_unseen'] = 1;

	if((! array_key_exists('item_nocomment',$arr)) && ($arr['comment_policy'] == 'none'))
		$arr['item_nocomment'] = 1;

	// handle time travelers
	// Allow a bit of fudge in case somebody just has a slightly slow/fast clock

	$d1 = new DateTime('now +10 minutes', new DateTimeZone('UTC'));
	$d2 = new DateTime($arr['created'] . '+00:00');
	if($d2 > $d1)
		$arr['item_delayed'] = 1;

	$arr['llink'] = z_root() . '/display/' . gen_link_id($arr['mid']);

	if(! $arr['plink'])
		$arr['plink'] = $arr['llink'];

	if($arr['parent_mid'] === $arr['mid']) {
		$parent_id = 0;
		$parent_deleted = 0;
		$allow_cid = $arr['allow_cid'];
		$allow_gid = $arr['allow_gid'];
		$deny_cid  = $arr['deny_cid'];
		$deny_gid  = $arr['deny_gid'];
		$public_policy = $arr['public_policy'];
		$comments_closed = $arr['comments_closed'];
		$arr['item_thread_top'] = 1;
	}
	else {

		// find the parent and snarf the item id and ACL's
		// and anything else we need to inherit

		$r = q("SELECT * FROM item WHERE mid = '%s' AND uid = %d ORDER BY id ASC LIMIT 1",
			dbesc($arr['parent_mid']),
			intval($arr['uid'])
		);

		if($r) {

			// in case item_store was killed before the parent's parent attribute got set,
			// set it now. This happens with some regularity on Dreamhost. This will keep
			// us from getting notifications for threads that exist but which we can't see.

			if(($r[0]['mid'] === $r[0]['parent_mid']) && (! intval($r[0]['parent']))) {
				q("update item set parent = id where id = %d",
					intval($r[0]['id'])
				);
			}

			if(comments_are_now_closed($r[0])) {
				logger('item_store: comments closed');
				$ret['message'] = 'Comments closed.';
				return $ret;
			}

			if(($arr['obj_type'] == ACTIVITY_OBJ_NOTE) && (! $arr['obj']))
				$arr['obj_type'] = ACTIVITY_OBJ_COMMENT;

			// is the new message multi-level threaded?
			// even though we don't support it now, preserve the info
			// and re-attach to the conversation parent.

			if($r[0]['mid'] != $r[0]['parent_mid']) {
				$arr['parent_mid'] = $r[0]['parent_mid'];
				$z = q("SELECT * FROM item WHERE mid = '%s' AND parent_mid = '%s' AND uid = %d
					ORDER BY id ASC LIMIT 1",
					dbesc($r[0]['parent_mid']),
					dbesc($r[0]['parent_mid']),
					intval($arr['uid'])
				);
				if($z && count($z))
					$r = $z;
			}

			$parent_id       = $r[0]['id'];
			$parent_deleted  = $r[0]['item_deleted'];
			$allow_cid       = $r[0]['allow_cid'];
			$allow_gid       = $r[0]['allow_gid'];
			$deny_cid        = $r[0]['deny_cid'];
			$deny_gid        = $r[0]['deny_gid'];
			$public_policy   = $r[0]['public_policy'];
			$comments_closed = $r[0]['comments_closed'];

			if(intval($r[0]['item_wall']))
				$arr['item_wall'] = 1;

			// An uplinked comment might arrive with a downstream owner.
			// Fix it.

			if($r[0]['owner_xchan'] !== $arr['owner_xchan']) {
				$arr['owner_xchan'] = $r[0]['owner_xchan'];
				//				$uplinked_comment = true;
			}

			// if the parent is private, force privacy for the entire conversation

			if($r[0]['item_private'])
				$arr['item_private'] = $r[0]['item_private'];

			// Edge case. We host a public forum that was originally posted to privately.
			// The original author commented, but as this is a comment, the permissions
			// weren't fixed up so it will still show the comment as private unless we fix it here.

			if(intval($r[0]['item_uplink']) && (! $r[0]['item_private']))
				$arr['item_private'] = 0;
		}
		else {
			logger('item_store: item parent was not found - ignoring item');
			$ret['message'] = 'parent not found.';
			return $ret;
		}
	}

	if($parent_deleted)
		$arr['item_deleted'] = 1;

	$r = q("SELECT id FROM item WHERE mid = '%s' AND uid = %d and revision = %d LIMIT 1",
		dbesc($arr['mid']),
		intval($arr['uid']),
		intval($arr['revision'])
	);
	if($r) {
		logger('duplicate item ignored. ' . print_r($arr,true));
		$ret['message'] = 'duplicate post.';
		return $ret;
	}

	/**
	 * @hooks item_store
	 *   Called when item_store() stores a record of type item.
	 */
	call_hooks('item_store', $arr);

	/**
	 * @hooks post_remote
	 *   Called when an activity arrives from another site.
	 *   This hook remains for backward compatibility.
	 */
	call_hooks('post_remote', $arr);

	if(x($arr, 'cancel')) {
		logger('Post cancelled by plugin.');
		$ret['message'] = 'cancelled.';
		return $ret;
	}

	// pull out all the taxonomy stuff for separate storage

	$terms = null;
	if(array_key_exists('term',$arr)) {
		$terms = $arr['term'];
		unset($arr['term']);
	}

	$meta = null;
	if(array_key_exists('iconfig',$arr)) {
		$meta = $arr['iconfig'];
		unset($arr['iconfig']);
	}


 	if(strlen($allow_cid) || strlen($allow_gid) || strlen($deny_cid) || strlen($deny_gid) || strlen($public_policy))
		$private = 1;
	else
		$private = $arr['item_private'];

	$arr['parent']          = $parent_id;
	$arr['allow_cid']       = $allow_cid;
	$arr['allow_gid']       = $allow_gid;
	$arr['deny_cid']        = $deny_cid;
	$arr['deny_gid']        = $deny_gid;
	$arr['public_policy']   = $public_policy;
	$arr['item_private']    = $private;
	$arr['comments_closed'] = $comments_closed;

	logger('item_store: ' . print_r($arr,true), LOGGER_DATA);


	create_table_from_array('item',$arr);

	// find the item we just created

	$r = q("SELECT * FROM item WHERE mid = '%s' AND uid = %d and revision = %d ORDER BY id ASC ",
		$arr['mid'],           // already dbesc'd
		intval($arr['uid']),
		intval($arr['revision'])
	);

	if($r) {
		// This will gives us a fresh copy of what's now in the DB and undo the db escaping,
		// which really messes up the notifications

		$current_post = $r[0]['id'];
		$arr = $r[0];
		logger('item_store: created item ' . $current_post, LOGGER_DEBUG);
	}
	else {
		logger('item_store: could not locate stored item');
		$ret['message'] = 'unable to retrieve.';
		return $ret;
	}
	if(count($r) > 1) {
		logger('item_store: duplicated post occurred. Removing duplicates.');
		q("DELETE FROM item WHERE mid = '%s' AND uid = %d AND id != %d ",
			$arr['mid'],
			intval($arr['uid']),
			intval($current_post)
		);
	}

	$arr['id'] = $current_post;

	if(! intval($r[0]['parent'])) {
		$x = q("update item set parent = id where id = %d",
			intval($r[0]['id'])
		);
		$arr['parent'] = $r[0]['id'];
	}


	// Store taxonomy

	if(($terms) && (is_array($terms))) {
		foreach($terms as $t) {
			q("insert into term (uid,oid,otype,ttype,term,url)
				values(%d,%d,%d,%d,'%s','%s') ",
				intval($arr['uid']),
				intval($current_post),
				intval(TERM_OBJ_POST),
				intval($t['ttype']),
				dbesc($t['term']),
				dbesc($t['url'])
			);
		}

		$arr['term'] = $terms;
	}

	if($meta) {
		foreach($meta as $m) {
			set_iconfig($current_post,$m['cat'],$m['k'],$m['v'],$m['sharing']);
		}
		$arr['iconfig'] = $meta;
	}


	$ret['item'] = $arr;

	/**
	 * @hooks post_remote_end
	 *   Called after processing a remote post.
	 */
	call_hooks('post_remote_end', $arr);

	item_update_parent_commented($arr);

	// If _creating_ a deleted item, don't propagate it further or send out notifications.
	// We need to store the item details just in case the delete came in before the original post,
	// so that we have an item in the DB that's marked deleted and won't store a fresh post
	// that isn't aware that we were already told to delete it.

	if(($deliver) && (! intval($arr['item_deleted']))) {
		send_status_notifications($current_post,$arr);
		tag_deliver($arr['uid'],$current_post);
	}

	$ret['success'] = true;
	$ret['item_id'] = $current_post;

	return $ret;
}


/**
 * @brief Update a stored item.
 *
 * @param array $arr an item
 * @param boolean $allow_exec (optional) default false
 * @param boolean $deliver (optional) default true
 * @return array
 */
function item_store_update($arr, $allow_exec = false, $deliver = true) {

	$d = [
			'item' => $arr,
			'allow_exec' => $allow_exec
	];
	/**
	 * @hooks item_store_update
	 *   Called when item_store_update() is called to update a stored item. It
	 *   overwrites the function's parameters $arr and $allow_exec.
	 *   * \e array \b item
	 *   * \e boolean \b allow_exec
	 */
	call_hooks('item_store_update', $d);
	$arr = $d['item'];
	$allow_exec = $d['allow_exec'];

	$ret = array('success' => false, 'item_id' => 0);

	if(array_key_exists('cancel',$arr) && $arr['cancel']) {
		logger('cancelled by plugin');
		return $ret;
	}

	if(! intval($arr['uid'])) {
		logger('no uid');
		$ret['message'] = 'no uid.';
		return $ret;
	}
	if(! intval($arr['id'])) {
		logger('no id');
		$ret['message'] = 'no id.';
		return $ret;
	}

	$orig_post_id = $arr['id'];
	$uid = $arr['uid'];

	$orig = q("select * from item where id = %d and uid = %d limit 1",
		intval($orig_post_id),
		intval($uid)
	);
	if(! $orig) {
		logger('Original post not found: ' . $orig_post_id);
		$ret['message'] = 'no original';
		return $ret;
	}

	// override the unseen flag with the original

	$arr['item_unseen'] = $orig[0]['item_unseen'];


	if(array_key_exists('edit',$arr))
		unset($arr['edit']);

	$arr['mimetype']      = ((x($arr,'mimetype'))      ? notags(trim($arr['mimetype']))      : 'text/bbcode');

	if(($arr['mimetype'] == 'application/x-php') && (! $allow_exec)) {
		logger('item_store: php mimetype but allow_exec is denied.');
		$ret['message'] = 'exec denied.';
		return $ret;
	}

	$arr['lang'] = detect_language($arr['body']);

	// apply the input filter here

	$arr['body'] = trim(z_input_filter($arr['body'],$arr['mimetype'],$allow_exec));

	item_sign($arr);

	$allowed_languages = get_pconfig($arr['uid'],'system','allowed_languages');

	if((is_array($allowed_languages)) && ($arr['lang']) && (! array_key_exists($arr['lang'],$allowed_languages))) {
		$translate = [
				'item' => $arr,
				'from' => $arr['lang'],
				'to' => $allowed_languages,
				'translated' => false
		];
		/**
		 * @hooks item_translate
		 *   Called from item_store() and item_store_update() after the post language has been autodetected.
		 *   * \e array \b item - returned value
		 *   * \e string \b from
		 *   * \e string \b to
		 *   * \e boolean \b translated - default false, set true if hook translated it and provide it in item
		 */
		call_hooks('item_translate', $translate);
		if((! $translate['translated']) && (intval(get_pconfig($arr['uid'],'system','reject_disallowed_languages')))) {
			logger('item_store: language ' . $arr['lang'] . ' not accepted for uid ' . $arr['uid']);
			$ret['message'] = 'language not accepted';
			return $ret;
		}
		$arr = $translate['item'];
	}

	if((array_key_exists('obj',$arr)) && is_array($arr['obj'])) {
		activity_sanitise($arr['obj']);
		$arr['obj'] = json_encode($arr['obj']);
	}

	if((array_key_exists('target',$arr)) && is_array($arr['target'])) {
		activity_sanitise($arr['target']);
		$arr['target'] = json_encode($arr['target']);
	}

	if((array_key_exists('attach',$arr)) && is_array($arr['attach'])) {
		activity_sanitise($arr['attach']);
		$arr['attach'] = json_encode($arr['attach']);
	}

	unset($arr['id']);
	unset($arr['uid']);
	unset($arr['aid']);
	unset($arr['mid']);
	unset($arr['parent']);
	unset($arr['parent_mid']);
	unset($arr['created']);
	unset($arr['author_xchan']);
	unset($arr['owner_xchan']);
	unset($arr['thr_parent']);
	unset($arr['llink']);

	$arr['edited']        = ((x($arr,'edited')  !== false) ? datetime_convert('UTC','UTC',$arr['edited'])  : datetime_convert());
	$arr['expires']       = ((x($arr,'expires')  !== false) ? datetime_convert('UTC','UTC',$arr['expires'])  : $orig[0]['expires']);

	$arr['revision']      = ((x($arr,'revision') && $arr['revision'] > 0)   ? intval($arr['revision']) : 0);

	if(array_key_exists('comments_closed',$arr) && $arr['comments_closed'] > NULL_DATE)
		$arr['comments_closed'] = datetime_convert('UTC','UTC',$arr['comments_closed']);
	else
		$arr['comments_closed'] = $orig[0]['comments_closed'];

	$arr['commented']     = $orig[0]['commented'];

	$arr['received']      = $orig[0]['received'];
	$arr['changed']       = $orig[0]['changed'];

	$arr['route']         = ((array_key_exists('route',$arr)) ? trim($arr['route'])          : $orig[0]['route']);

	$arr['location']      = ((x($arr,'location'))      ? notags(trim($arr['location']))      : $orig[0]['location']);
	$arr['coord']         = ((x($arr,'coord'))         ? notags(trim($arr['coord']))         : $orig[0]['coord']);
	$arr['verb']          = ((x($arr,'verb'))          ? notags(trim($arr['verb']))          : $orig[0]['verb']);
	$arr['obj_type']      = ((x($arr,'obj_type'))      ? notags(trim($arr['obj_type']))      : $orig[0]['obj_type']);
	$arr['obj']           = ((x($arr,'obj'))           ? trim($arr['obj'])                   : $orig[0]['obj']);
	$arr['tgt_type']      = ((x($arr,'tgt_type'))      ? notags(trim($arr['tgt_type']))      : $orig[0]['tgt_type']);
	$arr['target']        = ((x($arr,'target'))        ? trim($arr['target'])                : $orig[0]['target']);
	$arr['plink']         = ((x($arr,'plink'))         ? notags(trim($arr['plink']))         : $orig[0]['plink']);

	$arr['allow_cid']     = ((array_key_exists('allow_cid',$arr))  ? trim($arr['allow_cid']) : $orig[0]['allow_cid']);
	$arr['allow_gid']     = ((array_key_exists('allow_gid',$arr))  ? trim($arr['allow_gid']) : $orig[0]['allow_gid']);
	$arr['deny_cid']      = ((array_key_exists('deny_cid',$arr))   ? trim($arr['deny_cid'])  : $orig[0]['deny_cid']);
	$arr['deny_gid']      = ((array_key_exists('deny_gid',$arr))   ? trim($arr['deny_gid'])  : $orig[0]['deny_gid']);
	$arr['item_private']  = ((array_key_exists('item_private',$arr)) ? intval($arr['item_private']) : $orig[0]['item_private']);

	$arr['title'] = ((array_key_exists('title',$arr) && strlen($arr['title']))  ? trim($arr['title']) : '');
	$arr['body']  = ((array_key_exists('body',$arr) && strlen($arr['body']))    ? trim($arr['body'])  : '');
	$arr['html']  = ((array_key_exists('html',$arr) && strlen($arr['html']))    ? trim($arr['html'])  : '');

	$arr['attach']        = ((array_key_exists('attach',$arr))        ? notags(trim($arr['attach']))        : $orig[0]['attach']);
	$arr['app']           = ((array_key_exists('app',$arr))           ? notags(trim($arr['app']))           : $orig[0]['app']);

	$arr['item_origin']    = ((array_key_exists('item_origin',$arr))    ? intval($arr['item_origin'])          : $orig[0]['item_origin'] );
	$arr['item_unseen']    = ((array_key_exists('item_unseen',$arr))    ? intval($arr['item_unseen'])          : $orig[0]['item_unseen'] );
	$arr['item_starred']    = ((array_key_exists('item_starred',$arr))    ? intval($arr['item_starred'])          : $orig[0]['item_starred'] );
	$arr['item_uplink']    = ((array_key_exists('item_uplink',$arr))    ? intval($arr['item_uplink'])          : $orig[0]['item_uplink'] );
	$arr['item_consensus']    = ((array_key_exists('item_consensus',$arr))    ? intval($arr['item_consensus'])          : $orig[0]['item_consensus'] );
	$arr['item_wall']    = ((array_key_exists('item_wall',$arr))    ? intval($arr['item_wall'])          : $orig[0]['item_wall'] );
	$arr['item_thread_top']    = ((array_key_exists('item_thread_top',$arr))    ? intval($arr['item_thread_top'])          : $orig[0]['item_thread_top'] );
	$arr['item_notshown']    = ((array_key_exists('item_notshown',$arr))    ? intval($arr['item_notshown'])          : $orig[0]['item_notshown'] );
	$arr['item_nsfw']    = ((array_key_exists('item_nsfw',$arr))    ? intval($arr['item_nsfw'])          : $orig[0]['item_nsfw'] );
	$arr['item_relay']    = ((array_key_exists('item_relay',$arr))    ? intval($arr['item_relay'])          : $orig[0]['item_relay'] );
	$arr['item_mentionsme']    = ((array_key_exists('item_mentionsme',$arr))    ? intval($arr['item_mentionsme'])          : $orig[0]['item_mentionsme'] );
	$arr['item_nocomment']    = ((array_key_exists('item_nocomment',$arr))    ? intval($arr['item_nocomment'])          : $orig[0]['item_nocomment'] );
	$arr['item_obscured']    = ((array_key_exists('item_obscured',$arr))    ? intval($arr['item_obscured'])          : $orig[0]['item_obscured'] );
	$arr['item_verified']    = ((array_key_exists('item_verified',$arr))    ? intval($arr['item_verified'])          : $orig[0]['item_verified'] );
	$arr['item_retained']    = ((array_key_exists('item_retained',$arr))    ? intval($arr['item_retained'])          : $orig[0]['item_retained'] );
	$arr['item_rss']    = ((array_key_exists('item_rss',$arr))    ? intval($arr['item_rss'])          : $orig[0]['item_rss'] );
	$arr['item_deleted']    = ((array_key_exists('item_deleted',$arr))    ? intval($arr['item_deleted'])          : $orig[0]['item_deleted'] );
	$arr['item_type']    = ((array_key_exists('item_type',$arr))    ? intval($arr['item_type'])          : $orig[0]['item_type'] );
	$arr['item_hidden']    = ((array_key_exists('item_hidden',$arr))    ? intval($arr['item_hidden'])          : $orig[0]['item_hidden'] );
	$arr['item_unpublished']    = ((array_key_exists('item_unpublished',$arr))    ? intval($arr['item_unpublished'])          : $orig[0]['item_unpublished'] );
	$arr['item_delayed']    = ((array_key_exists('item_delayed',$arr))    ? intval($arr['item_delayed'])          : $orig[0]['item_delayed'] );
	$arr['item_pending_remove']    = ((array_key_exists('item_pending_remove',$arr))    ? intval($arr['item_pending_remove'])          : $orig[0]['item_pending_remove'] );
	$arr['item_blocked']    = ((array_key_exists('item_blocked',$arr))    ? intval($arr['item_blocked'])          : $orig[0]['item_blocked'] );

	$arr['sig']           = ((x($arr,'sig'))           ? $arr['sig']                         : '');
	$arr['layout_mid']    = ((array_key_exists('layout_mid',$arr)) ? dbesc($arr['layout_mid'])           : $orig[0]['layout_mid'] );

	$arr['public_policy'] = ((x($arr,'public_policy')) ? notags(trim($arr['public_policy']))  : $orig[0]['public_policy'] );
	$arr['comment_policy'] = ((x($arr,'comment_policy')) ? notags(trim($arr['comment_policy']))  : $orig[0]['comment_policy'] );

	/**
	 * @hooks post_remote_update
	 *   Called when processing a remote post that involved an edit or update.
	 */
	call_hooks('post_remote_update', $arr);

	if(x($arr, 'cancel')) {
		logger('Post cancelled by plugin.');
		$ret['message'] = 'cancelled.';
		return $ret;
	}

	// pull out all the taxonomy stuff for separate storage

	$terms = null;
	if(array_key_exists('term',$arr)) {
		$terms = $arr['term'];
		unset($arr['term']);
	}

	$meta = null;
	if(array_key_exists('iconfig',$arr)) {
		$meta = $arr['iconfig'];
		unset($arr['iconfig']);
	}


	if(! dbesc_array($arr)) {
		$ret['message'] = 'DB array malformed';
		return $ret;
	}

	logger('item_store_update: ' . print_r($arr,true), LOGGER_DATA);

	$str = '';
	foreach($arr as $k => $v) {
		if($str)
			$str .= ",";
		$str .= " " . TQUOT . $k . TQUOT . " = '" . $v . "' ";
	}

	$r = dbq("update item set " . $str . " where id = " . $orig_post_id );

	if($r)
		logger('Updated item ' . $orig_post_id, LOGGER_DEBUG);
	else {
		logger('Could not update item');
		$ret['message'] = 'DB update failed.';
		return $ret;
	}

	// fetch an unescaped complete copy of the stored item

	$r = q("select * from item where id = %d",
		intval($orig_post_id)
	);
	if($r)
		$arr = $r[0];


	$r = q("delete from term where oid = %d and otype = %d",
		intval($orig_post_id),
		intval(TERM_OBJ_POST)
	);

	if(is_array($terms)) {
		foreach($terms as $t) {
			q("insert into term (uid,oid,otype,ttype,term,url)
				values(%d,%d,%d,%d,'%s','%s') ",
				intval($uid),
				intval($orig_post_id),
				intval(TERM_OBJ_POST),
				intval($t['ttype']),
				dbesc($t['term']),
				dbesc($t['url'])
			);
		}
		$arr['term'] = $terms;
	}

	$r = q("delete from iconfig where iid = %d",
		intval($orig_post_id)
	);

	if($meta) {
		foreach($meta as $m) {
			set_iconfig($orig_post_id,$m['cat'],$m['k'],$m['v'],$m['sharing']);
		}
		$arr['iconfig'] = $meta;
	}

	$ret['item'] = $arr;

	/**
	 * @hooks post_remote_update_end
	 *   Called after processing a remote post that involved an edit or update.
	 */
	call_hooks('post_remote_update_end', $arr);

	if($deliver) {
		send_status_notifications($orig_post_id,$arr);
		tag_deliver($uid,$orig_post_id);
	}

	$ret['success'] = true;
	$ret['item_id'] = $orig_post_id;

	return $ret;
}

function item_update_parent_commented($item) {


	$update_parent = true;

	// update the commented timestamp on the parent 
	// - unless this is a moderated comment or a potential clone of an older item
	// which we don't wish to bring to the surface. As the queue only holds deliveries 
	// for 3 days, it's suspected of being an older cloned item if the creation time 
	//is older than that.

	if(intval($item['item_blocked']) === ITEM_MODERATED)
		$update_parent = false;
 
	if($item['created'] < datetime_convert('','','now - 4 days'))
		$update_parent = false;

	if($update_parent) {
		$z = q("select max(created) as commented from item where parent_mid = '%s' and uid = %d and item_delayed = 0 ",
			dbesc($item['parent_mid']),
			intval($item['uid'])
		);

		q("UPDATE item set commented = '%s', changed = '%s' WHERE id = %d",
			dbesc(($z) ? $z[0]['commented'] : datetime_convert()),
			dbesc(datetime_convert()),
			intval($item['parent'])
		);
	}
}


function send_status_notifications($post_id,$item) {

	// only send notifications for comments

	if($item['mid'] == $item['parent_mid'])
		return;

	$notify = false;
	$unfollowed = false;

	$parent = 0;

	if(array_key_exists('verb',$item) && (activity_match($item['verb'], ACTIVITY_LIKE) || activity_match($item['verb'], ACTIVITY_DISLIKE))) {

		$r = q("select id from item where mid = '%s' and uid = %d limit 1",
			dbesc($item['thr_parent']),
			intval($item['uid'])
		);

		$thr_parent_id = $r[0]['id'];
	}

	$r = q("select channel_hash from channel where channel_id = %d limit 1",
		intval($item['uid'])
	);
	if(! $r)
		return;

	// my own post - no notification needed
	if($item['author_xchan'] === $r[0]['channel_hash'])
		return;


	// I'm the owner - notify me

	if($item['owner_hash'] === $r[0]['channel_hash'])
		$notify = true;

	// Was I involved in this conversation?

	$x = q("select * from item where parent_mid = '%s' and uid = %d",
		dbesc($item['parent_mid']),
		intval($item['uid'])
	);
	if($x) {
		foreach($x as $xx) {
			if($xx['author_xchan'] === $r[0]['channel_hash']) {

				$notify = true;

				// check for an unfollow thread activity - we should probably decode the obj and check the id
				// but it will be extremely rare for this to be wrong.

				if(($xx['verb'] === ACTIVITY_UNFOLLOW)
					&& ($xx['obj_type'] === ACTIVITY_OBJ_NOTE || $xx['obj_type'] === ACTIVITY_OBJ_PHOTO)
					&& ($xx['parent'] != $xx['id']))
					$unfollowed = true;
			}
			if($xx['id'] == $xx['parent']) {
				$parent = $xx['parent'];
			}
		}
	}

	if($unfollowed)
		return;

	$link =  z_root() . '/display/' . gen_link_id($item['mid']);

	$y = q("select id from notify where link = '%s' and uid = %d limit 1",
		dbesc($link),
		intval($item['uid'])
	);

	if($y)
		$notify = false;

	if(! $notify)
		return;


	Zlib\Enotify::submit(array(
		'type'         => NOTIFY_COMMENT,
		'from_xchan'   => $item['author_xchan'],
		'to_xchan'     => $r[0]['channel_hash'],
		'item'         => $item,
		'link'         => $link,
		'verb'         => $item['verb'],
		'otype'        => 'item',
		'parent'       => $thr_parent_id ? $thr_parent_id : $parent,
		'parent_mid'   => $thr_parent_id ? $item['thr_parent'] : $item['parent_mid']
	));
}


function get_item_contact($item,$contacts) {
	if(! count($contacts) || (! is_array($item)))
		return false;

	foreach($contacts as $contact) {
		if($contact['id'] == $item['contact-id']) {
			return $contact;
			break; // NOTREACHED
		}
	}

	return false;
}

/**
 * @brief Called when we deliver things that might be tagged in ways that require delivery processing.
 *
 * Handles community tagging of posts and also look for mention tags and sets up
 * a second delivery chain if appropriate.
 *
 * @param int $uid
 * @param int $item_id
 */
function tag_deliver($uid, $item_id) {

	$mention = false;

	/*
	 * Fetch stuff we need - a channel and an item
	 */

	$u = q("select * from channel left join xchan on channel_hash = xchan_hash where channel_id = %d limit 1",
		intval($uid)
	);
	if(! $u)
		return;

	$i = q("select * from item where id = %d and uid = %d limit 1",
		intval($item_id),
		intval($uid)
	);
	if(! $i)
		return;

	$i = fetch_post_tags($i);

	$item = $i[0];

	if(($item['source_xchan']) && intval($item['item_uplink'])
		&& intval($item['item_thread_top']) && ($item['edited'] != $item['created'])) {

		// this is an update (edit) to a post which was already processed by us and has a second delivery chain
		// Just start the second delivery chain to deliver the updated post
		// after resetting ownership and permission bits
		logger('updating edited tag_deliver post for ' . $u[0]['channel_address']);
		start_delivery_chain($u[0], $item, $item_id, 0);
		return;
	}

	/*
	 * Seems like a good place to plug in a poke notification.
	 */

	if (stristr($item['verb'],ACTIVITY_POKE)) {
		$poke_notify = true;

		if(($item['obj_type'] == "") || ($item['obj_type'] !== ACTIVITY_OBJ_PERSON) || (! $item['obj']))
			$poke_notify = false;

		$obj = json_decode($item['obj'],true);
		if($obj) {
			if($obj['id'] !== $u[0]['channel_hash'])
				$poke_notify = false;
		}
		if(intval($item['item_deleted']))
			$poke_notify = false;

		$verb = urldecode(substr($item['verb'],strpos($item['verb'],'#')+1));
		if($poke_notify) {
			Zlib\Enotify::submit(array(
				'to_xchan'     => $u[0]['channel_hash'],
				'from_xchan'   => $item['author_xchan'],
				'type'         => NOTIFY_POKE,
				'item'         => $item,
				'link'         => $i[0]['llink'],
				'verb'         => ACTIVITY_POKE,
				'activity'     => $verb,
				'otype'        => 'item'
			));
		}
	}

	/*
	 * Do community tagging
	 */

	if($item['obj_type'] === ACTIVITY_OBJ_TAGTERM) {
		item_community_tag($u[0],$item);
	}

	/*
	 * A "union" is a message which our channel has sourced from another channel.
	 * This sets up a second delivery chain just like forum tags do.
	 * Find out if this is a source-able post.
	 */

	$union = check_item_source($uid,$item);
	if($union)
		logger('check_item_source returns true');


	// This might be a followup (e.g. comment) by the original post author to a tagged forum
	// If so setup a second delivery chain

	if( ! intval($item['item_thread_top'])) {
		$x = q("select * from item where id = parent and parent = %d and uid = %d limit 1",
			intval($item['parent']),
			intval($uid)
		);

		if(($x) && intval($x[0]['item_uplink'])) {
			start_delivery_chain($u[0],$item,$item_id,$x[0]);
		}
	}


	/*
	 * Now we've got those out of the way. Let's see if this is a post that's tagged for re-delivery
	 */

	$terms = array_merge(get_terms_oftype($item['term'],TERM_MENTION),get_terms_oftype($item['term'],TERM_FORUM));

	if($terms)
		logger('Post mentions: ' . print_r($terms,true), LOGGER_DATA);


	$max_forums = get_config('system','max_tagged_forums',2);
	$matched_forums = 0;


	$link = normalise_link($u[0]['xchan_url']);


	if($terms) {
		foreach($terms as $term) {
			if(! link_compare($term['url'],$link)) {
				continue;
			}

			$mention = true;

			logger('Mention found for ' . $u[0]['channel_name']);

			$r = q("update item set item_mentionsme = 1 where id = %d",
				intval($item_id)
			);

			// At this point we've determined that the person receiving this post was mentioned in it or it is a union.
			// Now let's check if this mention was inside a reshare so we don't spam a forum
			// If it's private we may have to unobscure it momentarily so that we can parse it.

			$body = preg_replace('/\[share(.*?)\[\/share\]/','',$item['body']);

			$tagged = false;
			$plustagged = false;
			$matches = array();

			$pattern = '/[\!@]\!?\[zrl\=' . preg_quote($term['url'],'/') . '\]' . preg_quote($term['term'],'/') . '\[\/zrl\]/';
			if(preg_match($pattern,$body,$matches))
				$tagged = true;

			// original red forum tagging sequence @forumname+
			// standard forum tagging sequence !forumname

			$pluspattern = '/@\!?\[zrl\=([^\]]*?)\]((?:.(?!\[zrl\=))*?)\+\[\/zrl\]/';

			$forumpattern = '/\!\!?\[zrl\=([^\]]*?)\]((?:.(?!\[zrl\=))*?)\[\/zrl\]/';

			$found = false;

			$matches = array();

			if(preg_match_all($pluspattern,$body,$matches,PREG_SET_ORDER)) {
				foreach($matches as $match) {
					$matched_forums ++;
					if($term['url'] === $match[1] && $term['term'] === $match[2] && intval($term['ttype']) === TERM_MENTION) {
						if($matched_forums <= $max_forums) {
							$plustagged = true;
							$found = true;
							break;
						}
						logger('forum ' . $term['term'] . ' exceeded max_tagged_forums - ignoring');
					}
				}
			}

			if(preg_match_all($forumpattern,$body,$matches,PREG_SET_ORDER)) {
				foreach($matches as $match) {
					$matched_forums ++;
					if($term['url'] === $match[1] && $term['term'] === $match[2] && intval($term['ttype']) === TERM_FORUM) {
						if($matched_forums <= $max_forums) {
							$plustagged = true;
							$found = true;
							break;
						}
						logger('forum ' . $term['term'] . ' exceeded max_tagged_forums - ignoring');
					}
				}
			}

			if(! ($tagged || $plustagged)) {
				logger('Mention was in a reshare or exceeded max_tagged_forums - ignoring');
				continue;
			}

			$arr = [
					'channel_id' => $uid,
					'item' => $item,
					'body' => $body
			];
			/**
			 * @hooks tagged
			 *   Called when a delivery is processed which results in you being tagged.
			 *   * \e number \b channel_id
			 *   * \e array \b item
			 *   * \e string \b body
			 */
			call_hooks('tagged', $arr);

			/*
			 * Kill two birds with one stone. As long as we're here, send a mention notification.
			 */

			Zlib\Enotify::submit(array(
				'to_xchan'     => $u[0]['channel_hash'],
				'from_xchan'   => $item['author_xchan'],
				'type'         => NOTIFY_TAGSELF,
				'item'         => $item,
				'link'         => $i[0]['llink'],
				'verb'         => ACTIVITY_TAG,
				'otype'        => 'item'
			));

			// Just a normal tag?

			if(! $plustagged) {
				logger('Not a plus tag', LOGGER_DEBUG);
				continue;
			}

			// plustagged - keep going, next check permissions

			if(! perm_is_allowed($uid,$item['author_xchan'],'tag_deliver')) {
				logger('tag_delivery denied for uid ' . $uid . ' and xchan ' . $item['author_xchan']);
				continue;
			}


			if(! $mention) {
				logger('No mention for ' . $u[0]['channel_name']);
				continue;
			}

			// tgroup delivery - setup a second delivery chain
			// prevent delivery looping - only proceed
			// if the message originated elsewhere and is a top-level post


			if(intval($item['item_wall']) || intval($item['item_origin']) || (! intval($item['item_thread_top'])) || ($item['id'] != $item['parent'])) {
				logger('Item was local or a comment. rejected.');
				continue;
			}

			logger('Creating second delivery chain.');
			start_delivery_chain($u[0],$item,$item_id,null);

		}
	}

	if($union) {
		if(intval($item['item_wall']) || intval($item['item_origin']) || (! intval($item['item_thread_top'])) || ($item['id'] != $item['parent'])) {
			logger('Item was local or a comment. rejected.');
			return;
		}

		logger('Creating second delivery chain.');
		start_delivery_chain($u[0],$item,$item_id,null);

	}

}


function item_community_tag($channel,$item) {


	// We received a community tag activity for a post.
	// See if we are the owner of the parent item and have given permission to tag our posts.
	// If so tag the parent post.

	logger('tag_deliver: community tag activity received: channel: ' . $channel['channel_name']);

	$tag_the_post = false;
	$p = null;

	$j_obj = json_decode($item['obj'],true);
	$j_tgt = json_decode($item['target'],true);
	if($j_tgt && $j_tgt['id']) {
		$p = q("select * from item where mid = '%s' and uid = %d limit 1",
			dbesc($j_tgt['id']),
			intval($channel['channel_id'])
		);
	}
	if($p) {
		xchan_query($p);
		$items = fetch_post_tags($p,true);
		$pitem = $items[0];
		$auth = get_iconfig($item,'system','communitytagauth');
		if($auth) {
			if(rsa_verify('tagauth.' . $item['mid'],base64url_decode($auth),$pitem['owner']['xchan_pubkey']) || rsa_verify('tagauth.' . $item['mid'],base64url_decode($auth),$pitem['author']['xchan_pubkey'])) {
				logger('tag_deliver: tagging the post: ' . $channel['channel_name']);
				$tag_the_post = true;
			}
		}
		else {
			if(($pitem['owner_xchan'] === $channel['channel_hash']) && (! intval(get_pconfig($channel['channel_id'],'system','blocktags')))) {
				logger('tag_deliver: community tag recipient: ' . $channel['channel_name']);
				$tag_the_post = true;
				$sig = rsa_sign('tagauth.' . $item['mid'],$channel['channel_prvkey']);
				logger('tag_deliver: setting iconfig for ' . $item['id']);
				set_iconfig($item['id'],'system','communitytagauth',base64url_encode($sig),1);
			}
		}

		if($tag_the_post) {
			store_item_tag($channel['channel_id'],$pitem['id'],TERM_OBJ_POST,TERM_COMMUNITYTAG,$j_obj['title'],$j_obj['id']);
		}
		else {
			logger('Tag permission denied for ' . $channel['channel_address']);
		}
	}

}


/**
 * @brief This function is called pre-deliver to see if a post matches the criteria to be tag delivered.
 *
 * We don't actually do anything except check that it matches the criteria.
 * This is so that the channel with tag_delivery enabled can receive the post even if they turn off
 * permissions for the sender to send their stream. tag_deliver() can't be called until the post is actually stored.
 * By then it would be too late to reject it.
 *
 * @param number $uid A chnnel_id
 * @param array $item
 * @return boolean
 */
function tgroup_check($uid, $item) {

	$mention = false;

	// check that the message originated elsewhere and is a top-level post
	// or is a followup and we have already accepted the top level post as an uplink

	if($item['mid'] != $item['parent_mid']) {
		$r = q("select id from item where mid = '%s' and uid = %d and item_uplink = 1 limit 1",
			dbesc($item['parent_mid']),
			intval($uid)
		);
		if($r)
			return true;

		return false;
	}

	// see if we already have this item. Maybe it is being updated.

	$r = q("select id from item where mid = '%s' and uid = %d limit 1",
		dbesc($item['mid']),
		intval($uid)
	);
	if($r)
		return true;

	if(! perm_is_allowed($uid,$item['author_xchan'],'tag_deliver'))
		return false;

	$u = q("select * from channel left join xchan on channel_hash = xchan_hash where channel_id = %d limit 1",
		intval($uid)
	);

	if(! $u)
		return false;


	$terms = array_merge(get_terms_oftype($item['term'],TERM_MENTION),get_terms_oftype($item['term'],TERM_FORUM));

	if($terms)
		logger('tgroup_check: post mentions: ' . print_r($terms,true), LOGGER_DATA);

	$max_forums = get_config('system','max_tagged_forums',2);
	$matched_forums = 0;

	$link = normalise_link($u[0]['xchan_url']);

	if($terms) {
		foreach($terms as $term) {
			if(! link_compare($term['url'],$link)) {
				continue;
			}

			$mention = true;
			logger('tgroup_check: mention found for ' . $u[0]['channel_name']);

			// At this point we've determined that the person receiving this post was mentioned in it.
			// Now let's check if this mention was inside a reshare so we don't spam a forum
			// note: $term has been set to the matching term


			$body = preg_replace('/\[share(.*?)\[\/share\]/','',$item['body']);


			$pluspattern = '/@\!?\[zrl\=([^\]]*?)\]((?:.(?!\[zrl\=))*?)\+\[\/zrl\]/';

			$forumpattern = '/\!\!?\[zrl\=([^\]]*?)\]((?:.(?!\[zrl\=))*?)\[\/zrl\]/';

			$found = false;

			$matches = array();

			if(preg_match_all($pluspattern,$body,$matches,PREG_SET_ORDER)) {
				foreach($matches as $match) {
					$matched_forums ++;
					if($term['url'] === $match[1] && $term['term'] === $match[2] && intval($term['ttype']) === TERM_MENTION) {
						if($matched_forums <= $max_forums) {
							$found = true;
							break;
						}
						logger('forum ' . $term['term'] . ' exceeded max_tagged_forums - ignoring');
					}
				}
			}

			if(preg_match_all($forumpattern,$body,$matches,PREG_SET_ORDER)) {
				foreach($matches as $match) {
					$matched_forums ++;
					if($term['url'] === $match[1] && $term['term'] === $match[2] && intval($term['ttype']) === TERM_FORUM) {
						if($matched_forums <= $max_forums) {
							$found = true;
							break;
						}
						logger('forum ' . $term['term'] . ' exceeded max_tagged_forums - ignoring');
					}
				}
			}

			if(! $found) {
				logger('tgroup_check: mention was in a reshare or exceeded max_tagged_forums - ignoring');
				continue;
			}

			return true;
		}
	}

	return false;

}

/**
 * Sourced and tag-delivered posts are re-targetted for delivery to the connections of the channel
 * receiving the post. This starts the second delivery chain, by resetting permissions and ensuring
 * that ITEM_UPLINK is set on the parent post, and storing the current owner_xchan as the source_xchan.
 * We'll become the new owner. If called without $parent, this *is* the parent post.
 *
 * @param array $channel
 * @param array $item
 * @param int $item_id
 * @param boolean $parent
 */
function start_delivery_chain($channel, $item, $item_id, $parent) {

	$sourced = check_item_source($channel['channel_id'],$item);

	if($sourced) {
		$r = q("select * from source where src_channel_id = %d and ( src_xchan = '%s' or src_xchan = '*' ) limit 1",
			intval($channel['channel_id']),
			dbesc(($item['source_xchan']) ?  $item['source_xchan'] : $item['owner_xchan'])
		);
		if($r) {
			$t = trim($r[0]['src_tag']);
			if($t) {
				$tags = explode(',',$t);
				if($tags) {
					foreach($tags as $tt) {
						$tt = trim($tt);
						if($tt) {
							q("insert into term (uid,oid,otype,ttype,term,url)
								values(%d,%d,%d,%d,'%s','%s') ",
								intval($channel['channel_id']),
								intval($item_id),
								intval(TERM_OBJ_POST),
								intval(TERM_CATEGORY),
								dbesc($tt),
								dbesc(z_root() . '/channel/' . $channel['channel_address'] . '?f=&cat=' . urlencode($tt))
							);
						}
					}
				}
			}
		}
	}

	// Change this copy of the post to a forum head message and deliver to all the tgroup members
	// also reset all the privacy bits to the forum default permissions

	$private = (($channel['channel_allow_cid'] || $channel['channel_allow_gid']
		|| $channel['channel_deny_cid'] || $channel['channel_deny_gid']) ? 1 : 0);

	$new_public_policy = map_scope(\Zotlabs\Access\PermissionLimits::Get($channel['channel_id'],'view_stream'),true);

	if((! $private) && $new_public_policy)
		$private = 1;

	$item_wall = 1;
	$item_origin = 1;
	$item_uplink = 0;
	$item_nocomment = 0;

	$flag_bits = $item['item_flags'];

	// maintain the original source, which will be the original item owner and was stored in source_xchan
	// when we created the delivery fork

	if($parent) {
		$r = q("update item set source_xchan = '%s' where id = %d",
			dbesc($parent['source_xchan']),
			intval($item_id)
		);
	}
	else {
		$item_uplink = 1;
		$r = q("update item set source_xchan = owner_xchan where id = %d",
			intval($item_id)
		);
	}

	$title = $item['title'];
	$body  = $item['body'];

	$r = q("update item set item_uplink = %d, item_nocomment = %d, item_flags = %d, owner_xchan = '%s', allow_cid = '%s', allow_gid = '%s',
		deny_cid = '%s', deny_gid = '%s', item_private = %d, public_policy = '%s', comment_policy = '%s', title = '%s', body = '%s', item_wall = %d, item_origin = %d  where id = %d",
		intval($item_uplink),
		intval($item_nocomment),
		intval($flag_bits),
		dbesc($channel['channel_hash']),
		dbesc($channel['channel_allow_cid']),
		dbesc($channel['channel_allow_gid']),
		dbesc($channel['channel_deny_cid']),
		dbesc($channel['channel_deny_gid']),
		intval($private),
		dbesc($new_public_policy),
		dbesc(map_scope(\Zotlabs\Access\PermissionLimits::Get($channel['channel_id'],'post_comments'))),
		dbesc($title),
		dbesc($body),
		intval($item_wall),
		intval($item_origin),
		intval($item_id)
	);


	if($r)
		Zotlabs\Daemon\Master::Summon(array('Notifier','tgroup',$item_id));
	else {
		logger('start_delivery_chain: failed to update item');
		// reset the source xchan to prevent loops
		$r = q("update item set source_xchan = '' where id = %d",
			intval($item_id)
		);
	}
}

/**
 * @brief
 *
 * Checks to see if this item owner is referenced as a source for this channel and if the post
 * matches the rules for inclusion in this channel. Returns true if we should create a second delivery
 * chain and false if none of the rules apply, or if the item is private.
 *
 * @param int $uid
 * @param array $item
 */
function check_item_source($uid, $item) {

	logger('source: uid: ' . $uid, LOGGER_DEBUG);
	$xchan = (($item['source_xchan']) ?  $item['source_xchan'] : $item['owner_xchan']);

	$r = q("select * from source where src_channel_id = %d and ( src_xchan = '%s' or src_xchan = '*' ) limit 1",
		intval($uid),
		dbesc($xchan)
	);

	if(! $r) {
		logger('source: no source record for this channel and source', LOGGER_DEBUG);
		return false;
	}

	$x = q("select abook_feed from abook where abook_channel = %d and abook_xchan = '%s' limit 1",
		intval($uid),
		dbesc($xchan)
	);

	if(! $x) {
		logger('source: not connected to this channel.');
		return false;
	}

	if(! get_abconfig($uid,$xchan,'their_perms','republish')) {
		logger('source: no republish permission');
		return false;
	}

	if($item['item_private'] && (! intval($x[0]['abook_feed']))) {
		logger('source: item is private');
		return false;
	}

	if($r[0]['src_channel_xchan'] === $xchan) {
		logger('source: cannot source yourself');
		return false;
	}

	if (! $r[0]['src_patt']) {
		logger('source: success');
		return true;
	}

	if (\Zotlabs\Lib\MessageFilter::evaluate($item, $r[0]['src_patt'], EMPTY_STR)) {
		logger('source: text filter success');
		return true;
	}

	logger('source: filter fail');
	return false;
}

function post_is_importable($item,$abook) {

	if(! $abook)
		return true;

	if(($abook['abook_channel']) && (! feature_enabled($abook['abook_channel'],'connfilter')))
		return true;

	if(! $item)
		return false;

	if(! ($abook['abook_incl'] || $abook['abook_excl']))
		return true;

	return \Zotlabs\Lib\MessageFilter::evaluate($item,$abook['abook_incl'],$abook['abook_excl']);

}


function mail_store($arr) {

	if(! $arr['channel_id']) {
		logger('mail_store: no uid');
		return 0;
	}

	$channel = channelx_by_n($arr['channel_id']);

	if(! $arr['mail_obscured']) {
		if((strpos($arr['body'],'<') !== false) || (strpos($arr['body'],'>') !== false))
			$arr['body'] = escape_tags($arr['body']);
	}

	if(array_key_exists('attach',$arr)) {
		if(is_array($arr['attach'])) {
			$arr['attach'] = json_encode($arr['attach']);
		}
	}
	else {
		$arr['attach'] = '';
	}

	$arr['account_id']    = ((x($arr,'account_id'))           ? intval($arr['account_id'])                 : 0);
	$arr['mid']           = ((x($arr,'mid'))           ? notags(trim($arr['mid']))           : random_string());
	$arr['from_xchan']    = ((x($arr,'from_xchan'))  ? notags(trim($arr['from_xchan']))  : '');
	$arr['to_xchan']      = ((x($arr,'to_xchan'))   ? notags(trim($arr['to_xchan']))   : '');
	$arr['created']       = ((x($arr,'created') !== false) ? datetime_convert('UTC','UTC',$arr['created']) : datetime_convert());
	$arr['expires']       = ((x($arr,'expires') !== false) ? datetime_convert('UTC','UTC',$arr['expires']) : NULL_DATE);
	$arr['title']         = ((x($arr,'title'))         ? trim($arr['title'])         : '');
	$arr['parent_mid']    = ((x($arr,'parent_mid'))    ? notags(trim($arr['parent_mid']))    : '');
	$arr['body']          = ((x($arr,'body'))          ? trim($arr['body'])                  : '');
	$arr['sig']           = ((x($arr,'sig'))           ? trim($arr['sig'])                   : '');
	$arr['conv_guid']     = ((x($arr,'conv_guid'))     ? trim($arr['conv_guid'])             : '');
	$arr['mail_mimetype'] = ((x($arr,'mail_mimetype')) ? trim($arr['mail_mimetype'])         : 'text/bbcode');

	$arr['mail_flags']    = ((x($arr,'mail_flags'))    ? intval($arr['mail_flags'])          : 0 );
	$arr['mail_raw']      = ((x($arr,'mail_raw'))      ? intval($arr['mail_raw'])            : 0 );


	if($arr['parent_mid']) {
		$parent_item = q("select * from mail where mid = '%s' and channel_id = %d limit 1",
			dbesc($arr['parent_mid']),
			intval($arr['channel_id'])
		);
		if(($parent_item) && (! $arr['conv_guid'])) {
			$arr['conv_guid'] = $parent_item[0]['conv_guid'];
		}
	}
	else {
		logger('mail_store: missing parent');
		$arr['parent_mid'] = $arr['mid'];
	}

	if($arr['from_xchan'] === $channel['channel_hash'])
		$conversant = $arr['to_xchan'];
	else
		$conversant = $arr['from_xchan'];


	if(! $arr['conv_guid']) {
		$x = create_conversation($channel,$conversant,(($arr['title']) ? base64url_decode(str_rot47($arr['title'])) : ''));
		$arr['conv_guid'] = (($x) ? $x['guid'] : '');
	}


	$r = q("SELECT id FROM mail WHERE mid = '%s' AND channel_id = %d LIMIT 1",
		dbesc($arr['mid']),
		intval($arr['channel_id'])
	);

	if($r) {
		logger('Duplicate item ignored. ' . print_r($arr,true));
		return 0;
	}

	if(! $r && $arr['mail_recalled'] == 1) {
		logger('Recalled item not found. ' . print_r($arr,true));
		return 0;
	}

	/**
	 * @hooks post_mail
	 *   Called when a mail message has been composed.
	 */
	call_hooks('post_mail', $arr);

	if(x($arr,'cancel')) {
		logger('Post cancelled by plugin.');
		return 0;
	}

	logger('mail_store: ' . print_r($arr,true), LOGGER_DATA);

	create_table_from_array('mail', $arr);

	// find the item we just created

	$r = q("SELECT id FROM mail WHERE mid = '%s' AND channel_id = %d ORDER BY id ASC ",
		$arr['mid'],           // already dbesc'd
		intval($arr['channel_id'])
	);

	if($r) {
		$current_post = $r[0]['id'];
		logger('Created item ' . $current_post, LOGGER_DEBUG);
		$arr['id'] = $current_post; // for notification
	}
	else {
		logger('Could not locate created item');
		return 0;
	}
	if(count($r) > 1) {
		logger('Duplicated post occurred. Removing duplicates.');
		q("DELETE FROM mail WHERE mid = '%s' AND channel_id = %d AND id != %d ",
			$arr['mid'],
			intval($arr['channel_id']),
			intval($current_post)
		);
	}
	else {

		$notif_params = array(
			'from_xchan' => $arr['from_xchan'],
			'to_xchan'   => $arr['to_xchan'],
			'type'       => NOTIFY_MAIL,
			'item'       => $arr,
			'verb'       => ACTIVITY_POST,
			'otype'      => 'mail'
		);

		Zlib\Enotify::submit($notif_params);
	}

	if($arr['conv_guid']) {
		$c = q("update conv set updated = '%s' where guid = '%s' and uid = %d",
			dbesc(datetime_convert()),
			dbesc($arr['conv_guid']),
			intval($arr['channel_id'])
		);
	}

	/**
	 * @hooks post_mail_end
	 *   Called when a mail message has been delivered.
	 */
	call_hooks('post_mail_end', $arr);
	return $current_post;
}


function fix_private_photos($s, $uid, $item = null, $cid = 0) {

	logger('fix_private_photos', LOGGER_DEBUG);
	$site = substr(z_root(),strpos(z_root(),'://'));

	$orig_body = $s;
	$new_body = '';

	$img_start = strpos($orig_body, '[zmg');
	$img_st_close = ($img_start !== false ? strpos(substr($orig_body, $img_start), ']') : false);
	$img_len = ($img_start !== false ? strpos(substr($orig_body, $img_start + $img_st_close + 1), '[/zmg]') : false);
	while( ($img_st_close !== false) && ($img_len !== false) ) {

		$img_st_close++; // make it point to AFTER the closing bracket
		$image = substr($orig_body, $img_start + $img_st_close, $img_len);

		logger('Found photo ' . $image, LOGGER_DEBUG);

		if(stristr($image , $site . '/photo/')) {
			// Only embed locally hosted photos
			$replace = false;
			$i = basename($image);
			$x = strpos($i,'-');

			if($x) {
				$res = substr($i,$x+1);
				$i = substr($i,0,$x);
				$r = q("SELECT * FROM photo WHERE resource_id = '%s' AND imgscale = %d AND uid = %d",
					dbesc($i),
					intval($res),
					intval($uid)
				);
				if(count($r)) {

					// Check to see if we should replace this photo link with an embedded image
					// 1. No need to do so if the photo is public
					// 2. If there's a contact-id provided, see if they're in the access list
					//    for the photo. If so, embed it.
					// 3. Otherwise, if we have an item, see if the item permissions match the photo
					//    permissions, regardless of order but first check to see if they're an exact
					//    match to save some processing overhead.

					if(has_permissions($r[0])) {
						if($cid) {
							$recips = enumerate_permissions($r[0]);
							if(in_array($cid, $recips)) {
								$replace = true;
							}
						}
						elseif($item) {
							if(compare_permissions($item,$r[0]))
								$replace = true;
						}
					}
					if($replace) {
						$data = $r[0]['data'];
						$type = $r[0]['type'];

						// If a custom width and height were specified, apply before embedding
						if(preg_match("/\[zmg\=([0-9]*)x([0-9]*)\]/is", substr($orig_body, $img_start, $img_st_close), $match)) {
							logger('Scaling photo', LOGGER_DEBUG);

							$width = intval($match[1]);
							$height = intval($match[2]);

							$ph = photo_factory($data, $type);
							if($ph->is_valid()) {
								$ph->scaleImage(max($width, $height));
								$data = $ph->imageString();
								$type = $ph->getType();
							}
						}

						logger('Replacing photo', LOGGER_DEBUG);
						$image = 'data:' . $type . ';base64,' . base64_encode($data);
						logger('Replaced: ' . $image, LOGGER_DATA);
					}
				}
			}
		}

		$new_body = $new_body . substr($orig_body, 0, $img_start + $img_st_close) . $image . '[/zmg]';
		$orig_body = substr($orig_body, $img_start + $img_st_close + $img_len + strlen('[/zmg]'));
		if($orig_body === false)
			$orig_body = '';

		$img_start = strpos($orig_body, '[zmg');
		$img_st_close = ($img_start !== false ? strpos(substr($orig_body, $img_start), ']') : false);
		$img_len = ($img_start !== false ? strpos(substr($orig_body, $img_start + $img_st_close + 1), '[/zmg]') : false);
	}

	$new_body = $new_body . $orig_body;

	return($new_body);
}


function has_permissions($obj) {
	if(($obj['allow_cid'] != '') || ($obj['allow_gid'] != '') || ($obj['deny_cid'] != '') || ($obj['deny_gid'] != ''))
		return true;

	return false;
}

function compare_permissions($obj1,$obj2) {
	// first part is easy. Check that these are exactly the same.
	if(($obj1['allow_cid'] == $obj2['allow_cid'])
		&& ($obj1['allow_gid'] == $obj2['allow_gid'])
		&& ($obj1['deny_cid'] == $obj2['deny_cid'])
		&& ($obj1['deny_gid'] == $obj2['deny_gid']))
		return true;

	// This is harder. Parse all the permissions and compare the resulting set.

	$recipients1 = enumerate_permissions($obj1);
	$recipients2 = enumerate_permissions($obj2);
	sort($recipients1);
	sort($recipients2);
	if($recipients1 == $recipients2)
		return true;
	return false;
}

/**
 * @brief Returns an array of contact-ids that are allowed to see this object.
 *
 * @param object $obj
 * @return array
 */
function enumerate_permissions($obj) {
	require_once('include/group.php');

	$allow_people = expand_acl($obj['allow_cid']);
	$allow_groups = expand_groups(expand_acl($obj['allow_gid']));
	$deny_people  = expand_acl($obj['deny_cid']);
	$deny_groups  = expand_groups(expand_acl($obj['deny_gid']));
	$recipients   = array_unique(array_merge($allow_people,$allow_groups));
	$deny         = array_unique(array_merge($deny_people,$deny_groups));
	$recipients   = array_diff($recipients,$deny);

	return $recipients;
}

function item_getfeedtags($item) {

	$terms = get_terms_oftype($item['term'],array(TERM_HASHTAG,TERM_MENTION,TERM_COMMUNITYTAG));
	$ret = array();

	if(count($terms)) {
		foreach($terms as $term) {
			if(($term['ttype'] == TERM_HASHTAG) || ($term['ttype'] == TERM_COMMUNITYTAG))
				$ret[] = array('#',$term['url'],$term['term']);
			else
				$ret[] = array('@',$term['url'],$term['term']);
		}
	}

	return $ret;
}

function item_getfeedattach($item) {
	$ret = '';
	$arr = explode(',',$item['attach']);
	if(count($arr)) {
		foreach($arr as $r) {
			$matches = false;
			$cnt = preg_match('|\[attach\]href=\"(.*?)\" length=\"(.*?)\" type=\"(.*?)\" title=\"(.*?)\"\[\/attach\]|',$r,$matches);
			if($cnt) {
				$ret .= '<link rel="enclosure" href="' . xmlify($matches[1]) . '" type="' . xmlify($matches[3]) . '" ';
				if(intval($matches[2]))
					$ret .= 'length="' . intval($matches[2]) . '" ';
				if($matches[4] !== ' ')
					$ret .= 'title="' . xmlify(trim($matches[4])) . '" ';
				$ret .= ' />' . "\r\n";
			}
		}
	}

	return $ret;
}


function item_expire($uid,$days,$comment_days = 7) {

	if((! $uid) || ($days < 1))
		return;

	if(! $comment_days)
		$comment_days = 7;
	
	// $expire_network_only = save your own wall posts
	// and just expire conversations started by others
	// do not enable this until we can pass bulk delete messages through zot
	//	$expire_network_only = get_pconfig($uid,'expire','network_only');

	$expire_network_only = 1;

	$sql_extra = ((intval($expire_network_only)) ? " AND item_wall = 0 " : "");

	$expire_limit = get_config('system','expire_limit');
	if(! intval($expire_limit))
		$expire_limit = 5000;

	$item_normal = item_normal();

	$r = q("SELECT id FROM item
		WHERE uid = %d
		AND created < %s - INTERVAL %s
		AND commented < %s - INTERVAL %s
		AND item_retained = 0
		AND item_thread_top = 1
		AND resource_type = ''
		AND item_starred = 0
		$sql_extra $item_normal LIMIT $expire_limit ",
		intval($uid),
		db_utcnow(),
		db_quoteinterval(intval($days) . ' DAY'),
		db_utcnow(),
		db_quoteinterval(intval($comment_days) . ' DAY')
	);

	if(! $r)
		return;

	$r = fetch_post_tags($r,true);

	foreach($r as $item) {

		// don't expire filed items

		$terms = get_terms_oftype($item['term'],TERM_FILE);
		if($terms) {
			retain_item($item['id']);
			continue;
		}

		drop_item($item['id'],false);
	}

}

function retain_item($id) {
	$r = q("update item set item_retained = 1 where id = %d",
		intval($id)
	);
}

function drop_items($items,$interactive = false,$stage = DROPITEM_NORMAL,$force = false) {
	$uid = 0;

	if(! local_channel() && ! remote_channel())
		return;

	if(count($items)) {
		foreach($items as $item) {
			$owner = drop_item($item,$interactive,$stage,$force);
			if($owner && ! $uid)
				$uid = $owner;
		}
	}

	// multiple threads may have been deleted, send an expire notification

	if($uid)
		Zotlabs\Daemon\Master::Summon(array('Notifier','expire',$uid));
}


// Delete item with given item $id. $interactive means we're running interactively, and must check
// permissions to carry out this act. If it is non-interactive, we are deleting something at the
// system's request and do not check permission. This is very important to know.

// Some deletion requests (those coming from remote sites) must be staged.
// $stage = 0 => unstaged
// $stage = 1 => set deleted flag on the item and perform intial notifications
// $stage = 2 => perform low level delete at a later stage

function drop_item($id,$interactive = true,$stage = DROPITEM_NORMAL,$force = false) {

	// These resource types have linked items that should only be removed at the same time
	// as the linked resource; if we encounter one set it to item_hidden rather than item_deleted.

	$linked_resource_types = [ 'photo' ];

	// locate item to be deleted

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

	if((! $r) || (intval($r[0]['item_deleted']) && ($stage === DROPITEM_NORMAL))) {
		if(! $interactive)
			return 0;
		notice( t('Item not found.') . EOL);
		goaway(z_root() . '/' . $_SESSION['return_url']);
	}

	$item = $r[0];

	$linked_item = (($item['resource_id'] && $item['resource_type'] && in_array($item['resource_type'], $linked_resource_types)) ? true : false);

	$ok_to_delete = false;

	// system deletion
	if(! $interactive)
		$ok_to_delete = true;

	// owner deletion
	if(local_channel() && local_channel() == $item['uid'])
		$ok_to_delete = true;

	// sys owned item, requires site admin to delete
	$sys = get_sys_channel();
	if(is_site_admin() && $sys['channel_id'] == $item['uid'])
		$ok_to_delete = true;

	// author deletion
	$observer = App::get_observer();
	if($observer && $observer['xchan_hash'] && ($observer['xchan_hash'] === $item['author_xchan']))
		$ok_to_delete = true;

	if($ok_to_delete) {

		// set the deleted flag immediately on this item just in case the
		// hook calls a remote process which loops. We'll delete it properly in a second.

		if(($linked_item) && (! $force)) {
			$r = q("UPDATE item SET item_hidden = 1 WHERE id = %d",
				intval($item['id'])
			);
		}
		else {
			$r = q("UPDATE item SET item_deleted = 1 WHERE id = %d",
				intval($item['id'])
			);
		}

		$arr = [
				'item' => $item,
				'interactive' => $interactive,
				'stage' => $stage
		];
		/**
		 * @hooks drop_item
		 *   Called when an 'item' is removed.
		 */
		call_hooks('drop_item', $arr);

		$notify_id = intval($item['id']);

		$items = q("select * from item where parent = %d and uid = %d",
			intval($item['id']),
			intval($item['uid'])
		);
		if($items) {
			foreach($items as $i)
				delete_item_lowlevel($i,$stage,$force);
		}
		else
			delete_item_lowlevel($item,$stage,$force);

		if(! $interactive)
			return 1;

		// send the notification upstream/downstream as the case may be
		// only send notifications to others if this is the owner's wall item.

		// This isn't optimal. We somehow need to pass to this function whether or not
		// to call the notifier, or we need to call the notifier from the calling function.
		// We'll rely on the undocumented behaviour that DROPITEM_PHASE1 is (hopefully) only
		// set if we know we're going to send delete notifications out to others.

		if((intval($item['item_wall']) && ($stage != DROPITEM_PHASE2)) || ($stage == DROPITEM_PHASE1))
			Zotlabs\Daemon\Master::Summon(array('Notifier','drop',$notify_id));

		goaway(z_root() . '/' . $_SESSION['return_url']);
	}
	else {
		if(! $interactive)
			return 0;
		notice( t('Permission denied.') . EOL);
		goaway(z_root() . '/' . $_SESSION['return_url']);
	}
}

/**
 * @warning This function does not check for permission and does not send
 * notifications and does not check recursion.
 * It merely destroys all resources associated with an item.
 * Please do not use without a suitable wrapper.
 *
 * @param array $item
 * @param int $stage
 * @param boolean $force
 * @return boolean
 */
function delete_item_lowlevel($item, $stage = DROPITEM_NORMAL, $force = false) {

	$linked_item = (($item['resource_id']) ? true : false);

	logger('item: ' . $item['id'] . ' stage: ' . $stage . ' force: ' . $force, LOGGER_DATA);

	switch($stage) {
		case DROPITEM_PHASE2:
			$r = q("UPDATE item SET item_pending_remove = 1, body = '', title = '',
				changed = '%s', edited = '%s'  WHERE id = %d",
				dbesc(datetime_convert()),
				dbesc(datetime_convert()),
				intval($item['id'])
			);
			break;

		case DROPITEM_PHASE1:
			if($linked_item && ! $force) {
				$r = q("UPDATE item SET item_hidden = 1,
					changed = '%s', edited = '%s'  WHERE id = %d",
					dbesc(datetime_convert()),
					dbesc(datetime_convert()),
					intval($item['id'])
				);
			}
			else {
				$r = q("UPDATE item set item_deleted = 1, changed = '%s', edited = '%s' where id = %d",
					dbesc(datetime_convert()),
					dbesc(datetime_convert()),
					intval($item['id'])
				);
			}

			break;

		case DROPITEM_NORMAL:
		default:
			if($linked_item && ! $force) {
				$r = q("UPDATE item SET item_hidden = 1,
					changed = '%s', edited = '%s'  WHERE id = %d",
					dbesc(datetime_convert()),
					dbesc(datetime_convert()),
					intval($item['id'])
				);
			}
			else {
				$r = q("UPDATE item SET item_deleted = 1, body = '', title = '',
					changed = '%s', edited = '%s'  WHERE id = %d",
					dbesc(datetime_convert()),
					dbesc(datetime_convert()),
					intval($item['id'])
				);
			}
			break;
	}

	// immediately remove any undesired profile likes.

	q("delete from likes where iid = %d and channel_id = %d",
		intval($item['id']),
		intval($item['uid'])
	);

	// remove delivery reports

	$c = q("select channel_hash from channel where channel_id = %d limit 1",
		intval($item['uid'])
	);
	if($c) {
		q("delete from dreport where dreport_xchan = '%s' and  dreport_mid = '%s'",
			dbesc($c[0]['channel_hash']),
			dbesc($item['mid'])
		);
	}

	// network deletion request. Keep the message structure so that we can deliver delete notifications.
	// Come back after several days (or perhaps a month) to do the lowlevel delete (DROPITEM_PHASE2).

	if($stage == DROPITEM_PHASE1)
		return true;

	$r = q("delete from term where otype = %d and oid = %d",
		intval(TERM_OBJ_POST),
		intval($item['id'])
	);

	q("delete from iconfig where iid = %d",
		intval($item['id'])
	);

	q("delete from term where oid = %d and otype = %d",
		intval($item['id']),
		intval(TERM_OBJ_POST)
	);

	/** @FIXME remove notifications for this item */

	return true;
}

/**
 * @brief Return the first post date.
 *
 * @param int $uid
 * @param boolean $wall (optional) default false
 * @return string|boolean date string, otherwise false
 */
function first_post_date($uid, $wall = false) {

	$wall_sql = (($wall) ? " and item_wall = 1 " : "" );
	$item_normal = item_normal();

	$r = q("select id, created from item
		where uid = %d and id = parent $item_normal $wall_sql
		order by created asc limit 1",
		intval($uid)
	);
	if($r) {
//		logger('first_post_date: ' . $r[0]['id'] . ' ' . $r[0]['created'], LOGGER_DATA);
		return substr(datetime_convert('',date_default_timezone_get(),$r[0]['created']),0,10);
	}

	return false;
}

/**
 * modified posted_dates() {below} to arrange the list in years, which we'll eventually
 * use to make a menu of years with collapsible sub-menus for the months instead of the
 * current flat list of all representative dates.
 *
 * @param int $uid
 * @param boolean $wall
 * @param string $mindate
 * @return array
 */
function list_post_dates($uid, $wall, $mindate) {
	$dnow = datetime_convert('',date_default_timezone_get(),'now','Y-m-d');

	if($mindate)
		$dthen = datetime_convert('',date_default_timezone_get(), $mindate);
	else
		$dthen = first_post_date($uid, $wall);
	if(! $dthen)
		return array();

	// If it's near the end of a long month, backup to the 28th so that in
	// consecutive loops we'll always get a whole month difference.

	if(intval(substr($dnow,8)) > 28)
		$dnow = substr($dnow,0,8) . '28';
	if(intval(substr($dthen,8)) > 28)
		$dthen = substr($dthen,0,8) . '28';

	$ret = array();
	// Starting with the current month, get the first and last days of every
	// month down to and including the month of the first post
	while(substr($dnow, 0, 7) >= substr($dthen, 0, 7)) {
		$dyear = intval(substr($dnow,0,4));
		$dstart = substr($dnow,0,8) . '01';
		$dend = substr($dnow,0,8) . get_dim(intval($dnow),intval(substr($dnow,5)));
		$start_month = datetime_convert('','',$dstart,'Y-m-d');
		$end_month = datetime_convert('','',$dend,'Y-m-d');
		$str = day_translate(datetime_convert('','',$dnow,'F'));
		if(! $ret[$dyear])
			$ret[$dyear] = array();
 		$ret[$dyear][] = array($str,$end_month,$start_month);
		$dnow = datetime_convert('','',$dnow . ' -1 month', 'Y-m-d');
	}

	return $ret;
}


function posted_dates($uid,$wall) {
	$dnow = datetime_convert('',date_default_timezone_get(),'now','Y-m-d');

	$dthen = first_post_date($uid,$wall);
	if(! $dthen)
		return array();

	// If it's near the end of a long month, backup to the 28th so that in
	// consecutive loops we'll always get a whole month difference.

	if(intval(substr($dnow,8)) > 28)
		$dnow = substr($dnow,0,8) . '28';
	if(intval(substr($dthen,8)) > 28)
		$dthen = substr($dthen,0,8) . '28';

	$ret = array();
	// Starting with the current month, get the first and last days of every
	// month down to and including the month of the first post
	while(substr($dnow, 0, 7) >= substr($dthen, 0, 7)) {
		$dstart = substr($dnow,0,8) . '01';
		$dend = substr($dnow,0,8) . get_dim(intval($dnow),intval(substr($dnow,5)));
		$start_month = datetime_convert('','',$dstart,'Y-m-d');
		$end_month = datetime_convert('','',$dend,'Y-m-d');
		$str = day_translate(datetime_convert('','',$dnow,'F Y'));
 		$ret[] = array($str,$end_month,$start_month);
		$dnow = datetime_convert('','',$dnow . ' -1 month', 'Y-m-d');
	}
	return $ret;
}

/**
 * @brief Extend an item array with the associated tags of the posts.
 *
 * @param array $items
 * @param boolean $link (optional) default false
 * @return array Return the provided $items array after extended the posts with tags
 */
function fetch_post_tags($items, $link = false) {

	$tag_finder = array();
	if($items) {
		foreach($items as $item) {
			if(is_array($item)) {
				if(array_key_exists('item_id',$item)) {
					if(! in_array($item['item_id'],$tag_finder))
						$tag_finder[] = $item['item_id'];
				}
				else {
					if(! in_array($item['id'],$tag_finder))
						$tag_finder[] = $item['id'];
				}
			}
		}
	}
	$tag_finder_str = implode(', ', $tag_finder);

	if(strlen($tag_finder_str)) {
		$tags = q("select * from term where oid in ( %s ) and otype = %d",
			dbesc($tag_finder_str),
			intval(TERM_OBJ_POST)
		);
		$imeta = q("select * from iconfig where iid in ( %s )",
			dbesc($tag_finder_str)
		);
	}

	for($x = 0; $x < count($items); $x ++) {
		if($tags) {
			foreach($tags as $t) {
				if(($link) && ($t['ttype'] == TERM_MENTION))
					$t['url'] = chanlink_url($t['url']);
				if(array_key_exists('item_id',$items[$x])) {
					if($t['oid'] == $items[$x]['item_id']) {
						if(! is_array($items[$x]['term']))
							$items[$x]['term'] = array();
						$items[$x]['term'][] = $t;
					}
				}
				else {
					if($t['oid'] == $items[$x]['id']) {
						if(! is_array($items[$x]['term']))
							$items[$x]['term'] = array();
						$items[$x]['term'][] = $t;
					}
				}
			}
		}
		if($imeta) {
			foreach($imeta as $i) {
				if(array_key_exists('item_id',$items[$x])) {
					if($i['iid'] == $items[$x]['item_id']) {
						if(! is_array($items[$x]['iconfig']))
							$items[$x]['iconfig'] = array();
						$i['v'] = ((preg_match('|^a:[0-9]+:{.*}$|s',$i['v'])) ? unserialize($i['v']) : $i['v']);
						$items[$x]['iconfig'][] = $i;
					}
				}
				else {
					if($i['iid'] == $items[$x]['id']) {
						if(! is_array($items[$x]['iconfig']))
							$items[$x]['iconfig'] = array();
						$i['v'] = ((preg_match('|^a:[0-9]+:{.*}$|s',$i['v'])) ? unserialize($i['v']) : $i['v']);
						$items[$x]['iconfig'][] = $i;
					}
				}
			}
		}
	}

	return $items;
}


/**
 * @brief
 *
 * @param int $uid
 * @param string $observer_hash
 * @param array $arr
 * @return array
 */
function zot_feed($uid, $observer_hash, $arr) {

	$result = array();
	$mindate = null;
	$message_id = null;

	require_once('include/security.php');

	if(array_key_exists('mindate',$arr)) {
		$mindate = datetime_convert('UTC','UTC',$arr['mindate']);
	}

	if(array_key_exists('message_id',$arr)) {
		$message_id = $arr['message_id'];
	}

	if(! $mindate)
		$mindate = NULL_DATE;

	$mindate = dbesc($mindate);

	logger('zot_feed: requested for uid ' . $uid . ' from observer ' . $observer_hash, LOGGER_DEBUG);
	if($message_id)
		logger('message_id: ' . $message_id,LOGGER_DEBUG);

	if(! perm_is_allowed($uid,$observer_hash,'view_stream')) {
		logger('zot_feed: permission denied.');
		return $result;
	}

	if(! is_sys_channel($uid))
		$sql_extra = item_permissions_sql($uid,$observer_hash);

	$limit = " LIMIT 5000 ";

	if($mindate > NULL_DATE) {
		$sql_extra .= " and ( created > '$mindate' or changed > '$mindate' ) ";
	}

	if($message_id) {
		$sql_extra .= " and mid = '" . dbesc($message_id) . "' ";
		$limit = '';
	}


	$items = [];

	$item_normal = item_normal();

	if(is_sys_channel($uid)) {

		$nonsys_uids = q("SELECT channel_id FROM channel WHERE channel_system = 0");
		$nonsys_uids_str = ids_to_querystr($nonsys_uids,'channel_id');

		$r = q("SELECT parent, postopts FROM item
			WHERE uid IN ( %s )
			AND item_wall = 1
			AND item_private = 0
			$item_normal
			$sql_extra ORDER BY created ASC $limit",
			intval($nonsys_uids_str)
		);
	}
	else {
		$r = q("SELECT parent, postopts FROM item
			WHERE uid = %d
			AND item_wall = 1
			$item_normal
			$sql_extra ORDER BY created ASC $limit",
			intval($uid)
		);
	}

	$parents = [];

	if($r) {
		foreach($r as $rv) {
			if(array_key_exists($rv['parent'],$parents))
				continue;
			if(strpos($rv['postopts'],'nodeliver') !== false)
				continue;
			$parents[$rv['parent']] = $rv;
			if(count($parents) > 200)
				break;
		}

		$parents_str = ids_to_querystr($parents,'parent');
		$sys_query = ((is_sys_channel($uid)) ? $sql_extra : '');
		$item_normal = item_normal();

		$items = q("SELECT item.*, item.id AS item_id FROM item
			WHERE item.parent IN ( %s ) $item_normal $sys_query ",
			dbesc($parents_str)
		);
	}

	if($items) {
		xchan_query($items);
		$items = fetch_post_tags($items);
		require_once('include/conversation.php');
		$items = conv_sort($items,'ascending');
	}
	else
		$items = array();

	logger('zot_feed: number items: ' . count($items),LOGGER_DEBUG);

	foreach($items as $item)
		$result[] = encode_item($item);

	return $result;
}


function items_fetch($arr,$channel = null,$observer_hash = null,$client_mode = CLIENT_MODE_NORMAL,$module = 'network') {

	$result = array('success' => false);

	$sql_extra = '';
	$sql_nets = '';
	$sql_options = '';
	$sql_extra2 = '';
	$sql_extra3 = '';
	$def_acl = '';

	$item_uids = ' true ';
	$item_normal = item_normal();

	if($arr['uid']) {
		$uid = $arr['uid'];
	}

	if($channel) {
		$uid = $channel['channel_id'];
		$uidhash = $channel['channel_hash'];
		$item_uids = " item.uid = " . intval($uid) . " ";
	}

	if($arr['star'])
		$sql_options .= " and item_starred = 1 ";

	if($arr['wall'])
		$sql_options .= " and item_wall = 1 ";

	if($arr['item_id'])
		$sql_options .= " and parent = " . intval($arr['item_id']) . " ";

	if($arr['mid'])
		$sql_options .= " and parent_mid = '" . dbesc($arr['mid']) . "' ";

	$sql_extra = " AND item.parent IN ( SELECT parent FROM item WHERE item_thread_top = 1 $sql_options $item_normal ) ";

	if($arr['since_id'])
		$sql_extra .= " and item.id > " . $since_id . " ";

	if($arr['cat'])
		$sql_extra .= protect_sprintf(term_query('item', $arr['cat'], TERM_CATEGORY));

	if($arr['gid'] && $uid) {
		$r = q("SELECT * FROM groups WHERE id = %d AND uid = %d LIMIT 1",
			intval($arr['group']),
			intval($uid)
		);
		if(! $r) {
			$result['message']  = t('Privacy group not found.');
			return $result;
		}

		$contact_str = '';

		$contacts = group_get_members($r[0]['id']);
		if ($contacts) {
			foreach($contacts as $c) {
				if($contact_str)
					$contact_str .= ',';

				$contact_str .= "'" . $c['xchan'] . "'";
			}
		} else {
			$contact_str = ' 0 ';
			$result['message'] = t('Privacy group is empty.');
			return $result;
		}

		$sql_extra = " AND item.parent IN ( SELECT DISTINCT parent FROM item WHERE true $sql_options AND (( author_xchan IN ( $contact_str ) OR owner_xchan in ( $contact_str)) or allow_gid like '" . protect_sprintf('%<' . dbesc($r[0]['hash']) . '>%') . "' ) and id = parent $item_normal ) ";

		$x = group_rec_byhash($uid,$r[0]['hash']);
		$result['headline'] = sprintf( t('Privacy group: %s'),$x['gname']);
	}
	elseif($arr['cid'] && $uid) {

		$r = q("SELECT abook.*, xchan.* from abook left join xchan on abook_xchan = xchan_hash where abook_id = %d and abook_channel = %d and abook_blocked = 0 limit 1",
			intval($arr['cid']),
			intval(local_channel())
		);
		if ($r) {
			$sql_extra = " AND item.parent IN ( SELECT DISTINCT parent FROM item WHERE true $sql_options AND uid = " . intval($arr['uid']) . " AND ( author_xchan = '" . dbesc($r[0]['abook_xchan']) . "' or owner_xchan = '" . dbesc($r[0]['abook_xchan']) . "' ) $item_normal ) ";
			$result['headline'] = sprintf( t('Connection: %s'),$r[0]['xchan_name']);
		} else {
			$result['message'] = t('Connection not found.');
			return $result;
		}
	}

	if($channel && intval($arr['compat']) === 1) {
		$sql_extra = " AND author_xchan = '" . $channel['channel_hash'] . "' and item_private = 0 $item_normal ";
	}

	if ($arr['datequery']) {
		$sql_extra3 .= protect_sprintf(sprintf(" AND item.created <= '%s' ", dbesc(datetime_convert('UTC','UTC',$arr['datequery']))));
	}
	if ($arr['datequery2']) {
		$sql_extra3 .= protect_sprintf(sprintf(" AND item.created >= '%s' ", dbesc(datetime_convert('UTC','UTC',$arr['datequery2']))));
	}

	if($arr['search']) {
		if(strpos($arr['search'],'#') === 0)
			$sql_extra .= term_query('item',substr($arr['search'],1),TERM_HASHTAG,TERM_COMMUNITYTAG);
		else
			$sql_extra .= sprintf(" AND item.body like '%s' ",
				dbesc(protect_sprintf('%' . $arr['search'] . '%'))
			);
	}

	if(strlen($arr['file'])) {
		$sql_extra .= term_query('item',$arr['files'],TERM_FILE);
	}

	if($arr['conv'] && $channel) {
		$sql_extra .= sprintf(" AND parent IN (SELECT distinct parent from item where ( author_xchan like '%s' or item_mentionsme = 1 )) ",
			dbesc(protect_sprintf($uidhash))
		);
	}

	if (($client_mode & CLIENT_MODE_UPDATE) && (! ($client_mode & CLIENT_MODE_LOAD))) {
		// only setup pagination on initial page view
		$pager_sql = '';
	} else {
		$itemspage = (($channel) ? get_pconfig($uid,'system','itemspage') : 20);
		App::set_pager_itemspage(((intval($itemspage)) ? $itemspage : 20));
		$pager_sql = sprintf(" LIMIT %d OFFSET %d ", intval(App::$pager['itemspage']), intval(App::$pager['start']));
	}

	if (isset($arr['start']) && isset($arr['records']))
		$pager_sql = sprintf(" LIMIT %d OFFSET %d ", intval($arr['records']), intval($arr['start']));

	if (array_key_exists('cmin',$arr) || array_key_exists('cmax',$arr)) {
		if (($arr['cmin'] != 0) || ($arr['cmax'] != 99)) {

			// Not everybody who shows up in the network stream will be in your address book.
			// By default those that aren't are assumed to have closeness = 99; but this isn't
			// recorded anywhere. So if cmax is 99, we'll open the search up to anybody in
			// the stream with a NULL address book entry.

			$sql_nets .= " AND ";

			if ($arr['cmax'] == 99)
				$sql_nets .= " ( ";

			$sql_nets .= "( abook.abook_closeness >= " . intval($arr['cmin']) . " ";
			$sql_nets .= " AND abook.abook_closeness <= " . intval($arr['cmax']) . " ) ";

			if ($arr['cmax'] == 99)
				$sql_nets .= " OR abook.abook_closeness IS NULL ) ";
		}
	}

	$simple_update = (($client_mode & CLIENT_MODE_UPDATE) ? " and item.item_unseen = 1 " : '');
	if($client_mode & CLIENT_MODE_LOAD)
		$simple_update = '';

	//$start = dba_timer();

	require_once('include/security.php');
	$sql_extra .= item_permissions_sql($channel['channel_id'],$observer_hash);


	if($arr['pages'])
		$item_restrict = " AND item_type = " . ITEM_TYPE_WEBPAGE . " ";
	else
		$item_restrict = " AND item_type = 0 ";

	if($arr['item_type'] === '*')
		$item_restrict = '';

	if ((($arr['compat']) || ($arr['nouveau'] && ($client_mode & CLIENT_MODE_LOAD))) && $channel) {

		// "New Item View" - show all items unthreaded in reverse created date order

		$items = q("SELECT item.*, item.id AS item_id FROM item
				WHERE $item_uids $item_restrict
				$simple_update
				$sql_extra $sql_nets $sql_extra3
				ORDER BY item.received DESC $pager_sql"
		);

		require_once('include/items.php');

		xchan_query($items);

		$items = fetch_post_tags($items,true);
	} else {

		// Normal conversation view

		if($arr['order'] === 'post')
			$ordering = "created";
		else
			$ordering = "commented";

		if(($client_mode & CLIENT_MODE_LOAD) || ($client_mode == CLIENT_MODE_NORMAL)) {

			// Fetch a page full of parent items for this page

			$r = q("SELECT distinct item.id AS item_id, item.$ordering FROM item
				left join abook on item.author_xchan = abook.abook_xchan
				WHERE $item_uids $item_restrict
				AND item.parent = item.id
				and (abook.abook_blocked = 0 or abook.abook_flags is null)
				$sql_extra3 $sql_extra $sql_nets
				ORDER BY item.$ordering DESC $pager_sql "
			);
		}
		else {
			// update
			$r = q("SELECT item.parent AS item_id FROM item
				left join abook on item.author_xchan = abook.abook_xchan
				WHERE $item_uids $item_restrict $simple_update
				and (abook.abook_blocked = 0 or abook.abook_flags is null)
				$sql_extra3 $sql_extra $sql_nets "
			);
		}

		//$first = dba_timer();

		// Then fetch all the children of the parents that are on this page

		if($r) {

			$parents_str = ids_to_querystr($r,'item_id');

			if($arr['top'])
				$sql_extra = ' and id = parent ' . $sql_extra;

			$items = q("SELECT item.*, item.id AS item_id FROM item
				WHERE $item_uids $item_restrict
				AND item.parent IN ( %s )
				$sql_extra ",
				dbesc($parents_str)
			);

			//$second = dba_timer();

			xchan_query($items);

			//$third = dba_timer();

			$items = fetch_post_tags($items,false);

			//$fourth = dba_timer();

			require_once('include/conversation.php');
			$items = conv_sort($items,$ordering);

			//logger('items: ' . print_r($items,true));
		} else {
			$items = array();
		}

		if($parents_str && $arr['mark_seen'])
			$update_unseen = ' AND parent IN ( ' . dbesc($parents_str) . ' )';
			/** @FIXME finish mark unseen sql */
	}

	return $items;
}

function webpage_to_namespace($webpage) {

	if($webpage == ITEM_TYPE_WEBPAGE)
		$page_type = 'WEBPAGE';
	elseif($webpage == ITEM_TYPE_BLOCK)
		$page_type = 'BUILDBLOCK';
	elseif($webpage == ITEM_TYPE_PDL)
		$page_type = 'PDL';
	elseif($webpage == ITEM_TYPE_CARD)
		$page_type = 'CARD';
	elseif($webpage == ITEM_TYPE_ARTICLE)
		$page_type = 'ARTICLE';
	elseif($webpage == ITEM_TYPE_DOC)
		$page_type = 'docfile';
	else
		$page_type = 'unknown';

	return $page_type;
}


function update_remote_id($channel,$post_id,$webpage,$pagetitle,$namespace,$remote_id,$mid) {

	if(! $post_id)
		return;

	$page_type = webpage_to_namespace($webpage);

	if($page_type == 'unknown' && $namespace && $remote_id) {
		$page_type = $namespace;
		$pagetitle = $remote_id;
	}
	else {
		$page_type = '';
	}

	if($page_type) {

		// store page info as an alternate message_id so we can access it via
		//    https://sitename/page/$channelname/$pagetitle
		// if no pagetitle was given or it couldn't be transliterated into a url, use the first
		// sixteen bytes of the mid - which makes the link portable and not quite as daunting
		// as the entire mid. If it were the post_id the link would be less portable.

		\Zotlabs\Lib\IConfig::Set(
			intval($post_id),
			'system',
			$page_type,
			($pagetitle) ? $pagetitle : substr($mid,0,16),
			false
		);
	}
}


/**
 * @brief Change access control for item with message_id $mid and channel_id $uid.
 *
 * @param string $xchan_hash
 * @param string $mid
 * @param int $uid
 */
function item_add_cid($xchan_hash, $mid, $uid) {
	$r = q("select id from item where mid = '%s' and uid = %d and allow_cid like '%s'",
		dbesc($mid),
		intval($uid),
		dbesc('<' . $xchan_hash . '>')
	);
	if(! $r) {
		$r = q("update item set allow_cid = concat(allow_cid,'%s') where mid = '%s' and uid = %d",
			dbesc('<' . $xchan_hash . '>'),
			dbesc($mid),
			intval($uid)
		);
	}
}

function item_remove_cid($xchan_hash,$mid,$uid) {
	$r = q("select allow_cid from item where mid = '%s' and uid = %d and allow_cid like '%s'",
		dbesc($mid),
		intval($uid),
		dbesc('<' . $xchan_hash . '>')
	);
	if($r) {
		$x = q("update item set allow_cid = '%s' where mid = '%s' and uid = %d",
			dbesc(str_replace('<' . $xchan_hash . '>','',$r[0]['allow_cid'])),
			dbesc($mid),
			intval($uid)
		);
	}
}

// Set item permissions based on results obtained from linkify_tags()
function set_linkified_perms($linkified, &$str_contact_allow, &$str_group_allow, $profile_uid, $parent_item = false, &$private) {
	$first_access_tag = true;

	foreach($linkified as $x) {
		$access_tag = $x['access_tag'];
		if(($access_tag) && (! $parent_item)) {
			logger('access_tag: ' . $tag . ' ' . print_r($access_tag,true), LOGGER_DATA);
			if ($first_access_tag && (! get_pconfig($profile_uid,'system','no_private_mention_acl_override'))) {

				// This is a tough call, hence configurable. The issue is that one can type in a @!privacy mention
				// and also have a default ACL (perhaps from viewing a collection) and could be suprised that the
				// privacy mention wasn't the only recipient. So the default is to wipe out the existing ACL if a
				// private mention is found. This can be over-ridden if you wish private mentions to be in
				// addition to the current ACL settings.

				$str_contact_allow = '';
				$str_group_allow = '';
				$first_access_tag = false;
			}
			if(strpos($access_tag,'cid:') === 0) {
				$str_contact_allow .= '<' . substr($access_tag,4) . '>';
				$access_tag = '';
				$private = 1;
			}
			elseif(strpos($access_tag,'gid:') === 0) {
				$str_group_allow .= '<' . substr($access_tag,4) . '>';
				$access_tag = '';
				$private = 1;
			}
		}
	}
}

/**
 * We can't trust ITEM_ORIGIN to tell us if this is a local comment
 * which needs to be relayed, because it was misconfigured at one point for several
 * months and set for some remote items (in alternate delivery chains). This could
 * cause looping, so use this hackish but accurate method.
 *
 * @param array $item
 * @return boolean
 */
function comment_local_origin($item) {
	if(stripos($item['mid'], App::get_hostname()) && ($item['parent'] != $item['id']))
		return true;

	return false;
}


function send_profile_photo_activity($channel,$photo,$profile) {

	// for now only create activities for the default profile

	if(! intval($profile['is_default']))
		return;

	$arr = array();
	$arr['item_thread_top'] = 1;
	$arr['item_origin'] = 1;
	$arr['item_wall'] = 1;
	$arr['obj_type'] = ACTIVITY_OBJ_PHOTO;
	$arr['verb'] = ACTIVITY_UPDATE;

	$arr['obj'] = json_encode(array(
		'type' => $arr['obj_type'],
		'id' => z_root() . '/photo/profile/l/' . $channel['channel_id'],
		'link' => array('rel' => 'photo', 'type' => $photo['type'], 'href' => z_root() . '/photo/profile/l/' . $channel['channel_id'])
	));

	if(stripos($profile['gender'],t('female')) !== false)
		$t = t('%1$s updated her %2$s');
	elseif(stripos($profile['gender'],t('male')) !== false)
		$t = t('%1$s updated his %2$s');
	else
		$t = t('%1$s updated their %2$s');

	$ptext = '[zrl=' . z_root() . '/photos/' . $channel['channel_address'] . '/image/' . $photo['resource_id'] . ']' . t('profile photo') . '[/zrl]';

	$ltext = '[zrl=' . z_root() . '/profile/' . $channel['channel_address'] . ']' . '[zmg=150x150]' . z_root() . '/photo/' . $photo['resource_id'] . '-4[/zmg][/zrl]';

	$arr['body'] = sprintf($t,$channel['channel_name'],$ptext) . "\n\n" . $ltext;

	$acl = new Zotlabs\Access\AccessList($channel);
	$x = $acl->get();
	$arr['allow_cid'] = $x['allow_cid'];

	$arr['allow_gid'] = $x['allow_gid'];
	$arr['deny_cid'] = $x['deny_cid'];
	$arr['deny_gid'] = $x['deny_gid'];

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

	$arr['owner_xchan'] = $channel['channel_hash'];
	$arr['author_xchan'] = $channel['channel_hash'];

	post_activity_item($arr);
}


function sync_an_item($channel_id,$item_id) {

	$r = q("select * from item where id = %d",
		intval($item_id)
	);
	if($r) {
		xchan_query($r);
		$sync_item = fetch_post_tags($r);
		build_sync_packet($channel_d,array('item' => array(encode_item($sync_item[0],true))));
	}
}


function fix_attached_photo_permissions($uid,$xchan_hash,$body,
	$str_contact_allow,$str_group_allow,$str_contact_deny,$str_group_deny) {

	if(get_pconfig($uid,'system','force_public_uploads')) {
		$str_contact_allow = $str_group_allow = $str_contact_deny = $str_group_deny = '';
	}

	$match = null;
	// match img and zmg image links
	if(preg_match_all("/\[[zi]mg(.*?)\](.*?)\[\/[zi]mg\]/",$body,$match)) {
		$images = $match[2];
		if($images) {
			foreach($images as $image) {
				if(! stristr($image,z_root() . '/photo/'))
					continue;
				$image_uri = substr($image,strrpos($image,'/') + 1);
				if(strpos($image_uri,'-') !== false)
					$image_uri = substr($image_uri,0, strpos($image_uri,'-'));
				if(strpos($image_uri,'.') !== false)
					$image_uri = substr($image_uri,0, strpos($image_uri,'.'));
				if(! strlen($image_uri))
					continue;
				$srch = '<' . $xchan_hash . '>';

				$r = q("select folder from attach where hash = '%s' and uid = %d limit 1",
					dbesc($image_uri),
					intval($uid)
				);
				if($r && $r[0]['folder']) {
					$f = q("select * from attach where hash = '%s' and is_dir = 1 and uid = %d limit 1",
						dbesc($r[0]['folder']),
						intval($uid)
					);
					if(($f) && (($f[0]['allow_cid']) || ($f[0]['allow_gid']) || ($f[0]['deny_cid']) || ($f[0]['deny_gid']))) {
						$str_contact_allow = $f[0]['allow_cid'];
						$str_group_allow = $f[0]['allow_gid'];
						$str_contact_deny = $f[0]['deny_cid'];
						$str_group_deny = $f[0]['deny_gid'];
					}
				}

				$r = q("SELECT id FROM photo
					WHERE allow_cid = '%s' AND allow_gid = '' AND deny_cid = '' AND deny_gid = ''
					AND resource_id = '%s' AND uid = %d LIMIT 1",
					dbesc($srch),
					dbesc($image_uri),
					intval($uid)
				);

				if($r) {
					$r = q("UPDATE photo SET allow_cid = '%s', allow_gid = '%s', deny_cid = '%s', deny_gid = '%s'
						WHERE resource_id = '%s' AND uid = %d ",
						dbesc($str_contact_allow),
						dbesc($str_group_allow),
						dbesc($str_contact_deny),
						dbesc($str_group_deny),
						dbesc($image_uri),
						intval($uid)
					);

					// also update the linked item (which is probably invisible)

					$r = q("select id from item
						WHERE allow_cid = '%s' AND allow_gid = '' AND deny_cid = '' AND deny_gid = ''
						AND resource_id = '%s' and resource_type = 'photo' AND uid = %d LIMIT 1",
						dbesc($srch),
						dbesc($image_uri),
						intval($uid)
					);
					if($r) {
						$private = (($str_contact_allow || $str_group_allow || $str_contact_deny || $str_group_deny) ? true : false);

						$r = q("UPDATE item SET allow_cid = '%s', allow_gid = '%s', deny_cid = '%s', deny_gid = '%s', item_private = %d
							WHERE id = %d AND uid = %d",
							dbesc($str_contact_allow),
							dbesc($str_group_allow),
							dbesc($str_contact_deny),
							dbesc($str_group_deny),
							intval($private),
							intval($r[0]['id']),
							intval($uid)
						);
					}
					$r = q("select id from attach where hash = '%s' and uid = %d limit 1",
						dbesc($image_uri),
						intval($uid)
					);
					if($r) {
						q("update attach SET allow_cid = '%s', allow_gid = '%s', deny_cid = '%s', deny_gid = '%s'
							WHERE id = %d AND uid = %d",
							dbesc($str_contact_allow),
							dbesc($str_group_allow),
							dbesc($str_contact_deny),
							dbesc($str_group_deny),
							intval($r[0]['id']),
							intval($uid)
						);
					}
				}
			}
		}
	}
}


function fix_attached_file_permissions($channel,$observer_hash,$body,
	$str_contact_allow,$str_group_allow,$str_contact_deny,$str_group_deny) {

	if(get_pconfig($channel['channel_id'],'system','force_public_uploads')) {
		$str_contact_allow = $str_group_allow = $str_contact_deny = $str_group_deny = '';
	}

	$match = false;

	if(preg_match_all("/\[attachment\](.*?)\[\/attachment\]/",$body,$match)) {
		$attaches = $match[1];
		if($attaches) {
			foreach($attaches as $attach) {
				$hash = substr($attach,0,strpos($attach,','));
				$rev = intval(substr($attach,strpos($attach,',')));
				attach_store($channel,$observer_hash,$options = 'update', array(
					'hash'      => $hash,
					'revision'  => $rev,
					'allow_cid' => $str_contact_allow,
					'allow_gid'  => $str_group_allow,
					'deny_cid'  => $str_contact_deny,
					'deny_gid'  => $str_group_deny
				));
			}
		}
	}
}


function item_create_edit_activity($post) {

	if((! $post) || (! $post['item']) || ($post['item']['item_type'] != ITEM_TYPE_POST))
		return;

	$update_item = $post['item'];

	$new_item = $update_item;

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


	$new_item['id'] = 0;
	$new_item['parent'] = 0;
	$new_item['mid'] = item_message_id();

	$new_item['body'] = sprintf( t('[Edited %s]'), (($update_item['item_thread_top']) ? t('Post','edit_activity') : t('Comment','edit_activity')));

	$new_item['body'] .= "\n\n";
	$new_item['body'] .= $update_item['body'];

	$new_item['sig'] = '';

	$new_item['verb'] = ACTIVITY_UPDATE;
	$new_item['item_thread_top'] = 0;
	$new_item['created'] = $new_item['edited'] = datetime_convert();
	$new_item['obj_type'] = (($update_item['item_thread_top']) ? ACTIVITY_OBJ_NOTE : ACTIVITY_OBJ_COMMENT);
	$new_item['obj'] = json_encode(array(
		'type'    => $new_item['obj_type'],
		'id'      => $update_item['mid'],
		'parent'  => $update_item['parent_mid'],
		'link'    => array(array('rel' => 'alternate','type' => 'text/html', 'href' => $update_item['plink'])),
		'title'   => $update_item['title'],
		'content' => $update_item['body'],
		'created' => $update_item['created'],
		'edited'  => $update_item['edited'],
		'author'  => array(
			'name'     => $item_author['xchan_name'],
			'address'  => $item_author['xchan_addr'],
			'guid'     => $item_author['xchan_guid'],
			'guid_sig' => $item_author['xchan_guid_sig'],
			'link'     => array(
				array('rel' => 'alternate', 'type' => 'text/html', 'href' => $item_author['xchan_url']),
				array('rel' => 'photo', 'type' => $item_author['xchan_photo_mimetype'], 'href' => $item_author['xchan_photo_m'])),
			),
	));


	$x = post_activity_item($new_item);

	$post_id = $x['id'];
	if($post_id) {
		$r = q("select * from item where id = %d",
					intval($post_id)
		);
		if($r) {
			xchan_query($r);
			$sync_item = fetch_post_tags($r);
			build_sync_packet($new_item['uid'],array('item' => array(encode_item($sync_item[0],true))));
		}
	}

	\Zotlabs\Daemon\Master::Summon(array('Notifier', 'edit_activity', $post_id));
}

/**
 * @brief copies an entire conversation from the pubstream to this channel's stream
 * which will allow you to interact with it.
 */


function copy_of_pubitem($channel,$mid) {

	$result = null;
	$syschan = get_sys_channel();

	// logger('copy_of_pubitem: ' . $channel['channel_id'] . ' mid: ' . $mid);

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

	if($r) {
		logger('exists');
		$item = fetch_post_tags($r,true);
		return $item[0];
	}


	$r = q("select * from item where parent_mid = (select parent_mid from item where mid = '%s' and uid = %d ) order by id ",
		dbesc($mid),
		intval($syschan['channel_id'])
	);
		
	if($r) {
		$items = fetch_post_tags($r,true);
		foreach($items as $rv) {
			$d = q("select id from item where mid = '%s' and uid = %d limit 1",
				dbesc($rv['mid']),
				intval($channel['channel_id'])
			);
			if($d) {
				continue;
			}

			unset($rv['id']);
			unset($rv['parent']);
			$rv['aid'] = $channel['channel_account_id'];
			$rv['uid'] = $channel['channel_id'];
			$rv['item_wall'] = 0;
			$rv['item_origin'] = 0;

			$x = item_store($rv);
			if($x['item_id'] && $x['item']['mid'] === $mid) {
				$result = $x['item'];
			}

		}
	}
	return $result;		
}