<?php

namespace Zotlabs\Lib;


use App;
use Zotlabs\Daemon\Master;
use Zotlabs\Lib\Config;

class Libsync {

	/**
	 * @brief Builds and sends a sync packet.
	 *
	 * Send a zot packet to all hubs where this channel is duplicated, refreshing
	 * such things as personal settings, channel permissions, address book updates, etc.
	 *
	 * @param int $uid (optional) default 0
	 * @param array $packet (optional) default null
	 * @param boolean $groups_changed (optional) default false
	 */

	static function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {

		logger('build_sync_packet');

		$keychange = (($packet && array_key_exists('keychange', $packet)) ? true : false);
		if ($keychange) {
			logger('keychange sync');
		}

		if (!$uid)
			$uid = local_channel();

		if (!$uid)
			return;

		$r = q("select * from channel where channel_id = %d limit 1",
			intval($uid)
		);
		if (!$r)
			return;

		$channel = $r[0];

		// don't provide these in the export

		unset($channel['channel_active']);
		unset($channel['channel_password']);
		unset($channel['channel_salt']);


		if (intval($channel['channel_removed']))
			return;

		$h = q("select hubloc.*, site.site_crypto from hubloc left join site on site_url = hubloc_url where hubloc_hash = '%s' and hubloc_deleted = 0",
			dbesc(($keychange) ? $packet['keychange']['old_hash'] : $channel['channel_hash'])
		);

		if (!$h)
			return;

		$synchubs = [];

		foreach ($h as $x) {
			if ($x['hubloc_host'] == App::get_hostname())
				continue;

			$y = q("select site_dead from site where site_url = '%s' limit 1",
				dbesc($x['hubloc_url'])
			);

			if ((!$y) || ($y[0]['site_dead'] == 0))
				$synchubs[] = $x;
		}

		if (!$synchubs)
			return;

		$env_recips = [$channel['channel_hash']];

		if ($packet)
			logger('packet: ' . print_r($packet, true), LOGGER_DATA, LOG_DEBUG);

		$info             = (($packet) ? $packet : []);
		$info['type']     = 'sync';
		$info['encoding'] = 'hz'; // note: not zot, this packet is very platform specific
		$info['relocate'] = ['channel_address' => $channel['channel_address'], 'url' => z_root()];

		if (array_key_exists($uid, App::$config) && array_key_exists('transient', App::$config[$uid])) {
			$settings = App::$config[$uid]['transient'];
			if ($settings) {
				$info['config'] = $settings;
			}
		}

		if ($channel) {
			$info['channel'] = [];
			foreach ($channel as $k => $v) {

				// filter out any joined tables like xchan

				if (strpos($k, 'channel_') !== 0)
					continue;

				// don't pass these elements, they should not be synchronised


				$disallowed = [
					'channel_id', 'channel_account_id', 'channel_primary', 'channel_address',
					'channel_deleted', 'channel_removed', 'channel_system'
				];

				if (!$keychange) {
					$disallowed[] = 'channel_prvkey';
				}

				if (in_array($k, $disallowed))
					continue;

				$info['channel'][$k] = $v;
			}
		}

		if ($groups_changed) {
			$r = q("select hash as collection, visible, deleted, gname as name from pgrp where uid = %d",
				intval($uid)
			);
			if ($r)
				$info['collections'] = $r;

			$r = q("select pgrp.hash as collection, pgrp_member.xchan as member from pgrp left join pgrp_member on pgrp.id = pgrp_member.gid where pgrp_member.uid = %d",
				intval($uid)
			);
			if ($r)
				$info['collection_members'] = $r;
		}

		$interval = Config::Get('queueworker', 'queue_interval', 500000);

		logger('Packet: ' . print_r($info, true), LOGGER_DATA, LOG_DEBUG);

		$total = count($synchubs);
		foreach ($synchubs as $hub) {
			$hash = new_uuid();
			$n    = Libzot::build_packet($channel, 'sync', $env_recips, json_encode($info), 'hz', $hub['hubloc_sitekey'], $hub['site_crypto']);
			Queue::insert([
				'hash'       => $hash,
				'account_id' => $channel['channel_account_id'],
				'channel_id' => $channel['channel_id'],
				'posturl'    => $hub['hubloc_callback'],
				'driver'     => $hub['hubloc_network'],
				'notify'     => $n,
				'msg'        => EMPTY_STR
			]);


			/*
			$x = q("select count(outq_hash) as total from outq where outq_delivered = 0");

			if (intval($x[0]['total']) > intval(Config::Get('system', 'force_queue_threshold', 3000))) {
				logger('immediate delivery deferred.', LOGGER_DEBUG, LOG_INFO);
				Queue::update($hash);
				continue;
			}
			*/

			Master::Summon(['Deliver', $hash]);

			/*
			$total = $total - 1;
			*/

			if ($interval) {
				usleep($interval);
			}

		}
	}

	/**
	 * @brief
	 *
	 * @param string $sender
	 * @param array $arr
	 * @param array $deliveries
	 * @return array
	 */

	static function process_channel_sync_delivery($sender, $arr, $deliveries) {

		require_once('include/import.php');

		$result = [];
		$keychange = ((array_key_exists('keychange', $arr)) ? true : false);

		foreach ($deliveries as $d) {
			$r = q("select * from channel where channel_hash = '%s' limit 1",
				dbesc($sender)
			);

			$mid = 'sync';


			$DR = new DReport(z_root(), $sender, $d, $mid);

			if (!$r) {
				$DR->update('recipient not found');
				$result[] = $DR->get();
				continue;
			}

			$channel = $r[0];


			$DR->set_name($channel['channel_name'] . ' <' . channel_reddress($channel) . '>');

			$max_friends = service_class_fetch($channel['channel_id'], 'total_channels');
			$max_feeds   = account_service_class_fetch($channel['channel_account_id'], 'total_feeds');

			if ($channel['channel_hash'] != $sender) {
				logger('Possible forgery. Sender ' . $sender . ' is not ' . $channel['channel_hash']);
				$DR->update('channel mismatch');
				$result[] = $DR->get();
				continue;
			}

			if ($keychange) {
				self::keychange($channel, $arr);
				continue;
			}

			// if the clone is active, so are we

			if (substr($channel['channel_active'], 0, 10) !== substr(datetime_convert(), 0, 10)) {
				q("UPDATE channel set channel_active = '%s' where channel_id = %d",
					dbesc(datetime_convert()),
					intval($channel['channel_id'])
				);
			}

			if (array_key_exists('config', $arr) && is_array($arr['config']) && count($arr['config'])) {
				foreach ($arr['config'] as $cat => $k) {
					$pconfig_updated = [];

					foreach($arr['config'][$cat] as $k => $v) {
						if ($cat === 'hz_delpconfig' && strpos($k, 'b64.') === 0) {
							$delpconfig = explode(':', unpack_link_id($k));

							// delete the provided pconfig
							del_pconfig($channel['channel_id'], $delpconfig[0], $delpconfig[1], $v);

							// delete the messenger pconfig
							del_pconfig($channel['channel_id'], 'hz_delpconfig', $k);
						}

						if (strpos($k,'pcfgud:') === 0) {
							$realk = substr($k,7);
							$pconfig_updated[$realk] = $v;
							unset($arr['config'][$cat][$k]);
						}
					}

					foreach($arr['config'][$cat] as $k => $v) {
						if (!isset($pconfig_updated[$k])) {
							$pconfig_updated[$k] = NULL;
						}

						if ($cat !== 'hz_delpconfig') {
							set_pconfig($channel['channel_id'], $cat, $k, $v, $pconfig_updated[$k]);
						}
					}
				}
			}

			if (array_key_exists('obj', $arr) && $arr['obj'])
				sync_objs($channel, $arr['obj']);

			if (array_key_exists('likes', $arr) && $arr['likes'])
				import_likes($channel, $arr['likes']);

			if (array_key_exists('app', $arr) && $arr['app'])
				sync_apps($channel, $arr['app']);

			if (array_key_exists('sysapp',$arr) && $arr['sysapp']) {
				sync_sysapps($channel, $arr['sysapp']);
			}

			if (array_key_exists('addressbook', $arr) && $arr['addressbook'])
				sync_addressbook($channel, $arr['addressbook']);

			if (array_key_exists('calendar', $arr) && $arr['calendar'])
				sync_calendar($channel, $arr['calendar']);

			if (array_key_exists('chatroom', $arr) && $arr['chatroom'])
				sync_chatrooms($channel, $arr['chatroom']);

			//if (array_key_exists('mail', $arr) && $arr['mail'])
			//	sync_mail($channel, $arr['mail']);

			if (array_key_exists('event', $arr) && $arr['event'])
				sync_events($channel, $arr['event']);

			if (array_key_exists('event_item', $arr) && $arr['event_item'])
				sync_items($channel, $arr['event_item'], ((array_key_exists('relocate', $arr)) ? $arr['relocate'] : null));

			if (array_key_exists('item', $arr) && $arr['item']) {
				sync_items($channel, $arr['item'], ((array_key_exists('relocate', $arr)) ? $arr['relocate'] : null));
				$mid = $arr['item'][0]['message_id'] . '#sync';
			}

			// deprecated, maintaining for a few months for upward compatibility
			// this should sync webpages, but the logic is a bit subtle

			//if (array_key_exists('item_id', $arr) && $arr['item_id'])
			//	sync_items($channel, $arr['item_id']);

			if (array_key_exists('menu', $arr) && $arr['menu'])
				sync_menus($channel, $arr['menu']);

			if (array_key_exists('file', $arr) && $arr['file'])
				sync_files($channel, $arr['file']);

			if (array_key_exists('wiki', $arr) && $arr['wiki'])
				sync_items($channel, $arr['wiki'], ((array_key_exists('relocate', $arr)) ? $arr['relocate'] : null));

			if (array_key_exists('channel', $arr) && is_array($arr['channel']) && count($arr['channel'])) {

				if (array_key_exists('channel_pageflags', $arr['channel'])) {

					// Several pageflags are site-specific and cannot be sync'd.
					// Only allow those bits which are shareable from the remote and then
					// logically OR with the local flags

					$arr['channel']['channel_pageflags'] = $arr['channel']['channel_pageflags'] & (PAGE_HIDDEN | PAGE_AUTOCONNECT | PAGE_APPLICATION | PAGE_PREMIUM | PAGE_ADULT);
					$arr['channel']['channel_pageflags'] = $arr['channel']['channel_pageflags'] | $channel['channel_pageflags'];

				}

				$columns = db_columns('channel');

				$disallowed = [
					'channel_id', 'channel_account_id', 'channel_primary', 'channel_prvkey',
					'channel_address', 'channel_notifyflags', 'channel_removed', 'channel_deleted',
					'channel_system', 'channel_r_stream', 'channel_r_profile', 'channel_r_abook',
					'channel_r_storage', 'channel_r_pages', 'channel_w_stream', 'channel_w_wall',
					'channel_w_comment', 'channel_w_mail', 'channel_w_like', 'channel_w_tagwall',
					'channel_w_chat', 'channel_w_storage', 'channel_w_pages', 'channel_a_republish',
					'channel_a_delegate'
				];

				if (empty($channel['channel_epubkey']) && empty($channel['channel_eprvkey'])) {
					$eckey = sodium_crypto_sign_keypair();
					$channel['channel_epubkey'] = sodium_bin2base64(sodium_crypto_sign_publickey($eckey), SODIUM_BASE64_VARIANT_ORIGINAL_NO_PADDING);
					$channel['channel_eprvkey'] = sodium_bin2base64(sodium_crypto_sign_secretkey($eckey), SODIUM_BASE64_VARIANT_ORIGINAL_NO_PADDING);
				}

				foreach ($arr['channel'] as $k => $v) {
					if (in_array($k, $disallowed)) {
						continue;
					}
					if (!in_array($k, $columns)) {
						continue;
					}
					$r = dbq("UPDATE channel set " . dbesc($k) . " = '" . dbesc($v)
						. "' where channel_id = " . intval($channel['channel_id']));
				}
			}

			if (array_key_exists('abook', $arr) && is_array($arr['abook']) && count($arr['abook'])) {
				$total_friends = 0;
				$total_feeds   = 0;

				$r = q("select abook_id, abook_feed from abook where abook_channel = %d",
					intval($channel['channel_id'])
				);
				if ($r) {
					// don't count yourself
					$total_friends = ((count($r) > 0) ? count($r) - 1 : 0);
					foreach ($r as $rr)
						if (intval($rr['abook_feed']))
							$total_feeds++;
				}


				$disallowed = ['abook_id', 'abook_account', 'abook_channel', 'abook_rating', 'abook_rating_text', 'abook_not_here'];

				$fields = db_columns('abook');

				foreach ($arr['abook'] as $abook) {

					$abconfig = null;

					if (array_key_exists('abconfig', $abook) && is_array($abook['abconfig']) && count($abook['abconfig']))
						$abconfig = $abook['abconfig'];

					if (!array_key_exists('abook_blocked', $abook)) {
						// convert from redmatrix
						$abook['abook_blocked']     = (($abook['abook_flags'] & 0x0001) ? 1 : 0);
						$abook['abook_ignored']     = (($abook['abook_flags'] & 0x0002) ? 1 : 0);
						$abook['abook_hidden']      = (($abook['abook_flags'] & 0x0004) ? 1 : 0);
						$abook['abook_archived']    = (($abook['abook_flags'] & 0x0008) ? 1 : 0);
						$abook['abook_pending']     = (($abook['abook_flags'] & 0x0010) ? 1 : 0);
						$abook['abook_unconnected'] = (($abook['abook_flags'] & 0x0020) ? 1 : 0);
						$abook['abook_self']        = (($abook['abook_flags'] & 0x0080) ? 1 : 0);
						$abook['abook_feed']        = (($abook['abook_flags'] & 0x0100) ? 1 : 0);
					}

					$clean = [];
					if ($abook['abook_xchan'] && $abook['entry_deleted']) {
						logger('Removing abook entry for ' . $abook['abook_xchan']);

						$r = q("select abook_id, abook_feed from abook where abook_xchan = '%s' and abook_channel = %d and abook_self = 0 limit 1",
							dbesc($abook['abook_xchan']),
							intval($channel['channel_id'])
						);
						if ($r) {
							contact_remove($channel['channel_id'], $r[0]['abook_id']);
							if ($total_friends)
								$total_friends--;
							if (intval($r[0]['abook_feed']))
								$total_feeds--;
						}
						continue;
					}

					// Perform discovery if the referenced xchan hasn't ever been seen on this hub.
					// This relies on the undocumented behaviour that red sites send xchan info with the abook
					// and import_author_xchan will look them up on all federated networks

					$found = false;
					if ($abook['abook_xchan'] && $abook['xchan_addr'] && (! in_array($abook['xchan_network'], [ 'token', 'unknown' ]))) {
						$h = Libzot::get_hublocs($abook['abook_xchan']);
						if ($h) {
							$found = true;
						}
						else {
							$xhash = import_author_xchan(encode_item_xchan($abook));
							if ($xhash) {
								$found = true;
							}
							else {
								logger('Import of ' . $abook['xchan_addr'] . ' failed.');
							}
						}
					}

					if (!$found && !in_array($abook['xchan_network'], ['zot6', 'activitypub', 'diaspora'])) {
						// just import the record.
						$xc = [];
						foreach ($abook as $k => $v) {
							if (strpos($k,'xchan_') === 0) {
								$xc[$k] = $v;
							}
						}
						$r = q("select * from xchan where xchan_hash = '%s'",
							dbesc($xc['xchan_hash'])
						);
						if (! $r) {
							xchan_store_lowlevel($xc);
						}
					}


					foreach ($abook as $k => $v) {
						if (in_array($k, $disallowed) || (strpos($k, 'abook_') !== 0)) {
							continue;
						}
						if (!in_array($k, $fields)) {
							continue;
						}
						$clean[$k] = $v;
					}

					if (!array_key_exists('abook_xchan', $clean))
						continue;

					if (array_key_exists('abook_instance', $clean) && $clean['abook_instance'] && strpos($clean['abook_instance'], z_root()) === false) {
						$clean['abook_not_here'] = 1;

						// guest pass or access token - don't try to probe since it is one-way
						// we are relying on the undocumented behaviour that the abook record also contains the xchan
						if ($abook['xchan_network'] === 'token') {
							$clean['abook_instance'] .= ',';
							$clean['abook_instance'] .= z_root();
						}
					}


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

					// make sure we have an abook entry for this xchan on this system

					if (!$r) {
						if ($max_friends !== false && $total_friends > $max_friends) {
							logger('total_channels service class limit exceeded');
							continue;
						}
						if ($max_feeds !== false && intval($clean['abook_feed']) && $total_feeds > $max_feeds) {
							logger('total_feeds service class limit exceeded');
							continue;
						}
						abook_store_lowlevel(
							[
								'abook_xchan'   => $clean['abook_xchan'],
								'abook_account' => $channel['channel_account_id'],
								'abook_channel' => $channel['channel_id']
							]
						);
						$total_friends++;
						if (intval($clean['abook_feed']))
							$total_feeds++;
					}

					if (count($clean)) {
						foreach ($clean as $k => $v) {
							if ($k == 'abook_dob')
								$v = dbescdate($v);
							dbq("UPDATE abook set " . dbesc($k) . " = '" . dbesc($v) . "' where abook_xchan = '" . dbesc($clean['abook_xchan']) . "' and abook_channel = " . intval($channel['channel_id']));
						}
					}

					// This will set abconfig vars if the sender is using old-style fixed permissions
					// using the raw abook record as passed to us. New-style permissions will fall through
					// and be set using abconfig

					// translate_abook_perms_inbound($channel,$abook);

					if ($abconfig) {
						/// @fixme does not handle sync of del_abconfig
						foreach ($abconfig as $abc) {
							set_abconfig($channel['channel_id'], $abc['xchan'], $abc['cat'], $abc['k'], $abc['v']);
						}
					}
				}
			}

			// sync collections (privacy groups) oh joy...

			if (array_key_exists('collections', $arr) && is_array($arr['collections']) && count($arr['collections'])) {
				$x = q("select * from pgrp where uid = %d",
					intval($channel['channel_id'])
				);
				foreach ($arr['collections'] as $cl) {
					$found = false;
					if ($x) {
						foreach ($x as $y) {
							if ($cl['collection'] == $y['hash']) {
								$found = true;
								break;
							}
						}
						if ($found) {
							if (($y['gname'] != $cl['name'])
								|| ($y['visible'] != $cl['visible'])
								|| ($y['deleted'] != $cl['deleted'])) {
								q("update pgrp set gname = '%s', visible = %d, deleted = %d where hash = '%s' and uid = %d",
									dbesc($cl['name']),
									intval($cl['visible']),
									intval($cl['deleted']),
									dbesc($cl['collection']),
									intval($channel['channel_id'])
								);
							}
							if (intval($cl['deleted']) && (!intval($y['deleted']))) {
								q("delete from pgrp_member where gid = %d",
									intval($y['id'])
								);
							}
						}
					}
					if (!$found) {
						q("INSERT INTO pgrp ( hash, uid, visible, deleted, gname )
							VALUES( '%s', %d, %d, %d, '%s' ) ",
							dbesc($cl['collection']),
							intval($channel['channel_id']),
							intval($cl['visible']),
							intval($cl['deleted']),
							dbesc($cl['name'])
						);
					}

					// now look for any collections locally which weren't in the list we just received.
					// They need to be removed by marking deleted and removing the members.
					// This shouldn't happen except for clones created before this function was written.

					if ($x) {
						$found_local = false;
						foreach ($x as $y) {
							foreach ($arr['collections'] as $cl) {
								if ($cl['collection'] == $y['hash']) {
									$found_local = true;
									break;
								}
							}
							if (!$found_local) {
								q("delete from pgrp_member where gid = %d",
									intval($y['id'])
								);
								q("update pgrp set deleted = 1 where id = %d and uid = %d",
									intval($y['id']),
									intval($channel['channel_id'])
								);
							}
						}
					}
				}

				// reload the group list with any updates
				$x = q("select * from pgrp where uid = %d",
					intval($channel['channel_id'])
				);

				// now sync the members

				if (array_key_exists('collection_members', $arr)
					&& is_array($arr['collection_members'])
					&& count($arr['collection_members'])) {

					// first sort into groups keyed by the group hash
					$members = [];
					foreach ($arr['collection_members'] as $cm) {
						if (!array_key_exists($cm['collection'], $members))
							$members[$cm['collection']] = [];

						$members[$cm['collection']][] = $cm['member'];
					}

					// our group list is already synchronised
					if ($x) {
						foreach ($x as $y) {

							// for each group, loop on members list we just received
							if (isset($y['hash']) && isset($members[$y['hash']])) {
								foreach ($members[$y['hash']] as $member) {
									$found = false;
									$z     = q("select xchan from pgrp_member where gid = %d and uid = %d and xchan = '%s' limit 1",
										intval($y['id']),
										intval($channel['channel_id']),
										dbesc($member)
									);
									if ($z)
										$found = true;

									// if somebody is in the group that wasn't before - add them

									if (!$found) {
										q("INSERT INTO pgrp_member (uid, gid, xchan)
											VALUES( %d, %d, '%s' ) ",
											intval($channel['channel_id']),
											intval($y['id']),
											dbesc($member)
										);
									}
								}
							}

							// now retrieve a list of members we have on this site
							$m = q("select xchan from pgrp_member where gid = %d and uid = %d",
								intval($y['id']),
								intval($channel['channel_id'])
							);
							if ($m) {
								foreach ($m as $mm) {
									// if the local existing member isn't in the list we just received - remove them
									if (!in_array($mm['xchan'], $members[$y['hash']])) {
										q("delete from pgrp_member where xchan = '%s' and gid = %d and uid = %d",
											dbesc($mm['xchan']),
											intval($y['id']),
											intval($channel['channel_id'])
										);
									}
								}
							}
						}
					}
				}
			}

			if (array_key_exists('profile', $arr) && is_array($arr['profile']) && count($arr['profile'])) {

				$disallowed = ['id', 'aid', 'uid', 'guid'];

				foreach ($arr['profile'] as $profile) {

					$x = q("select * from profile where profile_guid = '%s' and uid = %d limit 1",
						dbesc($profile['profile_guid']),
						intval($channel['channel_id'])
					);
					if (!$x) {
						profile_store_lowlevel(
							[
								'aid'          => $channel['channel_account_id'],
								'uid'          => $channel['channel_id'],
								'profile_guid' => $profile['profile_guid'],
							]
						);

						$x = q("select * from profile where profile_guid = '%s' and uid = %d limit 1",
							dbesc($profile['profile_guid']),
							intval($channel['channel_id'])
						);
						if (!$x)
							continue;
					}
					$clean = [];
					foreach ($profile as $k => $v) {
						if (in_array($k, $disallowed))
							continue;

						if ($profile['is_default'] && in_array($k, ['photo', 'thumb']))
							continue;

						if ($k === 'name')
							$clean['fullname'] = $v;
						elseif ($k === 'with')
							$clean['partner'] = $v;
						elseif ($k === 'work')
							$clean['employment'] = $v;
						elseif (array_key_exists($k, $x[0]))
							$clean[$k] = $v;

						/**
						 * @TODO
						 * We also need to import local photos if a custom photo is selected
						 */

						if ((strpos($profile['thumb'], '/photo/profile/l/') !== false) || intval($profile['is_default'])) {
							$profile['photo'] = z_root() . '/photo/profile/l/' . $channel['channel_id'];
							$profile['thumb'] = z_root() . '/photo/profile/m/' . $channel['channel_id'];
						}
						else {
							$profile['photo'] = z_root() . '/photo/' . basename($profile['photo']);
							$profile['thumb'] = z_root() . '/photo/' . basename($profile['thumb']);
						}
					}

					if (count($clean)) {
						foreach ($clean as $k => $v) {
							dbq("UPDATE profile set " . TQUOT . dbesc($k) . TQUOT . " = '" . dbesc($v)
								. "' where profile_guid = '" . dbesc($profile['profile_guid'])
								. "' and uid = " . intval($channel['channel_id']));
						}
					}
				}
			}

			$addon = ['channel' => $channel, 'data' => $arr];
			/**
			 * @hooks process_channel_sync_delivery
			 *   Called when accepting delivery of a 'sync packet' containing structure and table updates from a channel clone.
			 *   * \e array \b channel
			 *   * \e array \b data
			 */
			call_hooks('process_channel_sync_delivery', $addon);

			$DR = new DReport(z_root(), $d, $d, $mid, 'channel sync processed');

			$DR->set_name($channel['channel_name'] . ' <' . channel_reddress($channel) . '>');

			$result[] = $DR->get();
		}
		return $result;
	}

	/**
	 * @brief Synchronises locations.
	 *
	 * @param array $sender
	 * @param array $arr
	 * @return array
	 */

	static function sync_locations($sender, $arr) {

		$ret = [
			'change_message' => '',
			'changed' => false,
			'message' => ''
		];

		$what = '';
		$changed = false;

		// If a sender reports that the channel has been deleted, delete its hubloc
		if (isset($arr['deleted_locally']) && intval($arr['deleted_locally'])) {
			q("UPDATE hubloc SET hubloc_deleted = 1, hubloc_updated = '%s' WHERE hubloc_hash = '%s' AND hubloc_url = '%s'",
				dbesc(datetime_convert()),
				dbesc($sender['hash']),
				dbesc($sender['site']['url'])
			);
		}

		if (isset($arr['locations']) && $arr['locations']) {

			$xisting = q("select * from hubloc where hubloc_hash = '%s' and hubloc_deleted = 0",
				dbesc($sender['hash'])
			);

			if(!$xisting)
				$xisting = [];

			// See if a primary is specified

			$has_primary = false;
			foreach ($arr['locations'] as $location) {
				if ($location['primary']) {
					$has_primary = true;
					break;
				}
			}

			// Ensure that they have one primary hub

			if (!$has_primary)
				$arr['locations'][0]['primary'] = true;

			foreach ($arr['locations'] as $location) {
				if (!Libzot::verify($location['url'], $location['url_sig'], $sender['public_key'])) {
					logger('Unable to verify site signature for ' . $location['url']);
					$ret['message'] .= sprintf(t('Unable to verify site signature for %s'), $location['url']) . EOL;
					continue;
				}

				for ($x = 0; $x < count($xisting); $x++) {
					if (($xisting[$x]['hubloc_url'] === $location['url'])
						&& ($xisting[$x]['hubloc_sitekey'] === $location['sitekey'])) {
						$xisting[$x]['updated'] = true;
					}
				}

				if (!$location['sitekey']) {
					logger('Empty hubloc sitekey. ' . print_r($location, true));
					continue;
				}

				// Catch some malformed entries from the past which still exist

				if (strpos($location['address'], '/') !== false)
					$location['address'] = substr($location['address'], 0, strpos($location['address'], '/'));

				// match as many fields as possible in case anything at all changed.

				$r = q("select * from hubloc where hubloc_hash = '%s' and hubloc_guid = '%s' and hubloc_guid_sig = '%s' and hubloc_id_url = '%s' and hubloc_url = '%s' and hubloc_url_sig = '%s' and hubloc_host = '%s' and hubloc_addr = '%s' and hubloc_callback = '%s' and hubloc_sitekey = '%s' ",
					dbesc($sender['hash']),
					dbesc($sender['id']),
					dbesc($sender['id_sig']),
					dbesc($location['id_url']),
					dbesc($location['url']),
					dbesc($location['url_sig']),
					dbesc($location['host']),
					dbesc($location['address']),
					dbesc($location['callback']),
					dbesc($location['sitekey'])
				);
				if ($r) {
					logger('Hub exists: ' . $location['url'], LOGGER_DEBUG);

					// generate a new hubloc_site_id if it's wrong due to historical bugs 2021-11-30

					if ($r[0]['hubloc_site_id'] !== $location['site_id']) {
						q("update hubloc set hubloc_site_id = '%s' where hubloc_id = %d",
							dbesc(Libzot::make_xchan_hash($location['url'], $location['sitekey'])),
							intval($r[0]['hubloc_id'])
						);
					}

					// Update connection timestamp if this is the site we're talking to.
					// Also mark all entries from the current site with different sitekeys
					// deleted (the site has been re-installed)
					// This only happens when called from import_xchan

					$current_site = false;

					$t = datetime_convert('UTC', 'UTC', 'now - 15 minutes');

					if (array_key_exists('site', $arr) && $location['url'] == $arr['site']['url']) {
						q("update hubloc set hubloc_connected = '%s', hubloc_updated = '%s' where hubloc_id = %d and hubloc_updated < '%s'",
							dbesc(datetime_convert()),
							dbesc(datetime_convert()),
							intval($r[0]['hubloc_id']),
							dbesc($t)
						);

						q("update hubloc set hubloc_error = 1, hubloc_deleted = 1 where hubloc_url = '%s' and hubloc_sitekey != '%s' and hubloc_network = 'zot6'",
							dbesc($r[0]['hubloc_url']),
							dbesc($r[0]['hubloc_sitekey'])
						);

						$current_site = true;
					}

					if ($current_site && intval($r[0]['hubloc_error'])) {
						q("update hubloc set hubloc_error = 0 where hubloc_id = %d",
							intval($r[0]['hubloc_id'])
						);
						if (intval($r[0]['hubloc_orphancheck'])) {
							q("update hubloc set hubloc_orphancheck = 0 where hubloc_id = %d",
								intval($r[0]['hubloc_id'])
							);
						}
						q("update xchan set xchan_orphan = 0 where xchan_orphan = 1 and xchan_hash = '%s'",
							dbesc($sender['hash'])
						);
					}

					// Remove pure duplicates
					if (count($r) > 1) {
						for ($h = 1; $h < count($r); $h++) {
							q("delete from hubloc where hubloc_id = %d",
								intval($r[$h]['hubloc_id'])
							);
							$what    .= 'duplicate_hubloc_removed ';
							$changed = true;
						}
					}

					if (intval($r[0]['hubloc_primary']) && (!$location['primary'])) {
						q("update hubloc set hubloc_primary = 0, hubloc_updated = '%s' where hubloc_id_url = '%s'",
							dbesc(datetime_convert()),
							dbesc($r[0]['hubloc_id_url'])
						);
						$r[0]['hubloc_primary'] = intval($location['primary']);
						hubloc_change_primary($r[0]);
						$what    .= 'primary_hub ';
						$changed = true;
					}
					elseif ((!intval($r[0]['hubloc_primary'])) && ($location['primary'])) {
						q("update hubloc set hubloc_primary = 1, hubloc_updated = '%s' where hubloc_id = %d",
							dbesc(datetime_convert()),
							intval($r[0]['hubloc_id'])
						);
						// make sure hubloc_change_primary() has current data
						$r[0]['hubloc_primary'] = intval($location['primary']);
						hubloc_change_primary($r[0]);
						$what    .= 'primary_hub ';
						$changed = true;
					}

					if (intval($r[0]['hubloc_deleted']) && (!intval($location['deleted']))) {
						q("update hubloc set hubloc_deleted = 0, hubloc_updated = '%s' where hubloc_id_url = '%s'",
							dbesc(datetime_convert()),
							dbesc($r[0]['hubloc_id_url'])
						);
						$what    .= 'undelete_hub ';
						$changed = true;
					}
					elseif ((!intval($r[0]['hubloc_deleted'])) && (intval($location['deleted']))) {
						logger('deleting hubloc: ' . $r[0]['hubloc_addr']);
						q("update hubloc set hubloc_deleted = 1, hubloc_updated = '%s' where hubloc_id_url = '%s'",
							dbesc(datetime_convert()),
							dbesc($r[0]['hubloc_id_url'])
						);
						$what    .= 'delete_hub ';
						$changed = true;
					}

					continue;
				}

				// Existing hubs are dealt with. Now let's process any new ones.
				// New hub claiming to be primary. Make it so by removing any existing primaries.

				if (intval($location['primary'])) {
					q("update hubloc set hubloc_primary = 0, hubloc_updated = '%s' where hubloc_hash = '%s' and hubloc_primary = 1",
						dbesc(datetime_convert()),
						dbesc($sender['hash'])
					);
				}

				logger('New hub: ' . $location['url']);

				hubloc_store_lowlevel(
					[
						'hubloc_guid'      => $sender['id'],
						'hubloc_guid_sig'  => $sender['id_sig'],
						'hubloc_id_url'    => $location['id_url'],
						'hubloc_hash'      => $sender['hash'],
						'hubloc_addr'      => $location['address'],
						'hubloc_network'   => 'zot6',
						'hubloc_primary'   => intval($location['primary']),
						'hubloc_url'       => $location['url'],
						'hubloc_url_sig'   => $location['url_sig'],
						'hubloc_site_id'   => Libzot::make_xchan_hash($location['url'], $location['sitekey']),
						'hubloc_host'      => $location['host'],
						'hubloc_callback'  => $location['callback'],
						'hubloc_sitekey'   => $location['sitekey'],
						'hubloc_updated'   => datetime_convert(),
						'hubloc_connected' => datetime_convert()
					]
				);

				$what    .= 'newhub ';
				$changed = true;

				if ($location['primary']) {
					$r = q("select * from hubloc where hubloc_addr = '%s' and hubloc_sitekey = '%s'",
						dbesc($location['address']),
						dbesc($location['sitekey'])
					);
					if ($r) {
						$r = Libzot::zot_record_preferred($r);
						hubloc_change_primary($r);
					}
				}
			}

			// get rid of any hublocs we have for this channel which weren't reported.

			if ($xisting) {
				foreach ($xisting as $x) {
					if (!array_key_exists('updated', $x)) {
						logger('Deleting unreferenced hub location ' . $x['hubloc_addr']);
						q("update hubloc set hubloc_deleted = 1, hubloc_updated = '%s' where hubloc_id_url = '%s'",
							dbesc(datetime_convert()),
							dbesc($x['hubloc_id_url'])
						);
						$what    .= 'removed_hub ';
						$changed = true;
					}
				}
			}
		}
		else {
			logger('No locations to sync!');
		}

		$ret['change_message'] = $what;
		$ret['changed']        = $changed;

		return $ret;
	}


	static function keychange($channel, $arr) {

		// verify the keychange operation
		if (!Libzot::verify($arr['channel']['channel_pubkey'], $arr['keychange']['new_sig'], $channel['channel_prvkey'])) {
			logger('sync keychange: verification failed');
			return;
		}

		$sig  = Libzot::sign($channel['channel_guid'], $arr['channel']['channel_prvkey']);
		$hash = Libzot::make_xchan_hash($channel['channel_guid'], $arr['channel']['channel_pubkey']);


		$r = q("update channel set channel_prvkey = '%s', channel_pubkey = '%s', channel_guid_sig = '%s',
			channel_hash = '%s' where channel_id = %d",
			dbesc($arr['channel']['channel_prvkey']),
			dbesc($arr['channel']['channel_pubkey']),
			dbesc($sig),
			dbesc($hash),
			intval($channel['channel_id'])
		);
		if (!$r) {
			logger('keychange sync: channel update failed');
			return;
		}

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

		if (!$r) {
			logger('keychange sync: channel retrieve failed');
			return;
		}

		$channel = $r[0];

		$h = q("select * from hubloc where hubloc_hash = '%s' and hubloc_url = '%s' ",
			dbesc($arr['keychange']['old_hash']),
			dbesc(z_root())
		);

		if ($h) {
			foreach ($h as $hv) {
				$hv['hubloc_guid_sig'] = $sig;
				$hv['hubloc_hash']     = $hash;
				$hv['hubloc_url_sig']  = Libzot::sign(z_root(), $channel['channel_prvkey']);
				hubloc_store_lowlevel($hv);
			}
		}

		$x = q("select * from xchan where xchan_hash = '%s' ",
			dbesc($arr['keychange']['old_hash'])
		);

		$check = q("select * from xchan where xchan_hash = '%s'",
			dbesc($hash)
		);

		if (($x) && (!$check)) {
			$oldxchan = $x[0];
			foreach ($x as $xv) {
				$xv['xchan_guid_sig'] = $sig;
				$xv['xchan_hash']     = $hash;
				$xv['xchan_pubkey']   = $channel['channel_pubkey'];
				xchan_store_lowlevel($xv);
				$newxchan = $xv;
			}
		}

		$a = q("select * from abook where abook_xchan = '%s' and abook_self = 1",
			dbesc($arr['keychange']['old_hash'])
		);

		if ($a) {
			q("update abook set abook_xchan = '%s' where abook_id = %d",
				dbesc($hash),
				intval($a[0]['abook_id'])
			);
		}

		xchan_change_key($oldxchan, $newxchan, $arr['keychange']);

	}

}