streams/Zotlabs/Lib/Connect.php

<?php /** @file */

namespace Zotlabs\Lib;

use Zotlabs\Access\Permissions;
use Zotlabs\Daemon\Master;



class Connect {

	/**
	 * Takes a $channel and a $url/handle and adds a new connection
	 *
	 * Returns array
	 *  $return['success'] boolean true if successful
	 *  $return['abook'] Address book entry joined with xchan if successful
	 *  $return['message'] error text if success is false.
	 *
	 * This function does NOT send sync packets to clones. The caller is responsible for doing this
	 */

	static function connect($channel, $url, $sub_channel = false) {

		$uid = $channel['channel_id'];

		$result = [ 'success' => false, 'message' => '' ];

		$my_perms = false;
		$protocol = '';

		if (substr($url,0,1) === '[') {
			$x = strpos($url,']');
			if ($x) {
				$protocol = substr($url,1,$x-1);
				$url = substr($url,$x+1);
			}
		}

		if (! check_siteallowed($url)) {
			$result['message'] = t('Channel is blocked on this site.');
			return $result;
		}

		if (! $url) {
			$result['message'] = t('Channel location missing.');
			return $result;
		}

		// check service class limits

		$r = q("select count(*) as total from abook where abook_channel = %d and abook_self = 0 ",
			intval($uid)
		);
		if ($r) {
			$total_channels = $r[0]['total'];
		}

		if (! service_class_allows($uid,'total_channels',$total_channels)) {
			$result['message'] = upgrade_message();
			return $result;
		}

		$xchan_hash = '';
		$sql_options = (($protocol) ? " and xchan_network = '" . dbesc($protocol) . "' " : '');

		$r = q("select * from xchan where xchan_hash = '%s' or xchan_url = '%s' or xchan_addr = '%s' $sql_options ",
			dbesc($url),
			dbesc($url),
			dbesc($url)
		);

		if ($r) {

			// reset results to the best record or the first if we don't have the best
			// note: this is a single record and not an array of results

			$r = Libzot::zot_record_preferred($r,'xchan_network');

			// Some Hubzilla records were originally stored as activitypub. If we find one, force rediscovery
			// since Zap cannot connect with them.
			
			if ($r['xchan_network'] === 'activitypub' && ! get_config('system','activitypub')) {
				$r = null;
			}
		}


		$singleton = false;
		$d = false;

		if (! $r) {

			// not in cache - try discovery

			$wf = discover_by_webbie($url,$protocol);

			if (! $wf) {
				$feeds = get_config('system','feed_contacts');

				if (($feeds) && (in_array($protocol, [ '', 'feed', 'rss' ]))) {
					$d = discover_feed($url);
				}
				else {
					$result['message'] = t('Remote channel or protocol unavailable.');
					return $result;
				}
			}
		}

		if ($wf || $d) {

			// something was discovered - find the record which was just created.

			$r = q("select * from xchan where xchan_hash = '%s' or xchan_url = '%s' or xchan_addr = '%s' $sql_options",
				dbesc(($wf) ? $wf : $url),
				dbesc($url),
				dbesc($url)
			);

			// convert to a single record (once again preferring a zot solution in the case of multiples)

			if ($r) {
				$r = Libzot::zot_record_preferred($r,'xchan_network');
			}
		}

		// if discovery was a success or the channel was already cached we should have an xchan record in $r

		if ($r) {
			$xchan = $r;
			$xchan_hash = $r['xchan_hash'];
			$their_perms = EMPTY_STR;
		}

		// failure case

		if (! $xchan_hash) {
			$result['message'] = t('Channel discovery failed.');
			logger('follow: ' . $result['message']);
			return $result;
		}

		if (! check_channelallowed($xchan_hash)) {
			$result['message'] = t('Channel is blocked on this site.');
			logger('follow: ' . $result['message']);
			return $result;

		}

		$ap_allowed = get_config('system','activitypub',false) && get_pconfig($uid,'system','activitypub',true);
		
		if ($r['xchan_network'] === 'activitypub')
			if (! $ap_allowed) {
				$result['message'] = t('Protocol not supported');
				return $result;
			}
			$singleton = true;
		}

		// Now start processing the new connection

		$aid = $channel['channel_account_id'];
		$hash = $channel['channel_hash'];
		$default_group = $channel['channel_default_group'];

		if ($hash === $xchan_hash) {
			$result['message'] = t('Cannot connect to yourself.');
			return $result;
		}

		if ($xchan['xchan_network'] === 'rss') {

			// check service class feed limits

			$t = q("select count(*) as total from abook where abook_account = %d and abook_feed = 1 ",
				intval($aid)
			);
			if ($t) {
				$total_feeds = $t[0]['total'];
			}

			if (! service_class_allows($uid,'total_feeds',$total_feeds)) {
				$result['message'] = upgrade_message();
				return $result;
			}

			// Always set these "remote" permissions for feeds since we cannot interact with them
			// to negotiate a suitable permission response

			$p = get_abconfig($uid,$xchan_hash,'system','their_perms',EMPTY_STR);
			if ($p) {
				$p .= ',';
			}
			$p .= 'view_stream,republish';
			set_abconfig($uid,$xchan_hash,'system','their_perms',$p);

		}


		$p = Permissions::connect_perms($uid);

		// parent channels have unencumbered write permission

		if ($sub_channel) {
			$p['perms']['post_wall']     = 1;
			$p['perms']['post_comments'] = 1;
			$p['perms']['write_storage'] = 1;
			$p['perms']['post_like']     = 1;
			$p['perms']['delegate']      = 0;
			$p['perms']['moderated']     = 0;
		}

		$my_perms = Permissions::serialise($p['perms']);
		
		$profile_assign = get_pconfig($uid,'system','profile_assign','');


		// See if we are already connected by virtue of having an abook record

		$r = q("select abook_id, abook_xchan, abook_pending, abook_instance from abook 
			where abook_xchan = '%s' and abook_channel = %d limit 1",
			dbesc($xchan_hash),
			intval($uid)
		);

		if ($r) {

			$abook_instance = $r[0]['abook_instance'];

			// If they are on a non-nomadic network, add them to this location

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

				$x = q("update abook set abook_instance = '%s', abook_not_here = 0 where abook_id = %d",
					dbesc($abook_instance),
					intval($r[0]['abook_id'])
				);
			}

			// if they have a pending connection, we just followed them so approve the connection request

			if (intval($r[0]['abook_pending'])) {
				$x = q("update abook set abook_pending = 0 where abook_id = %d",
					intval($r[0]['abook_id'])
				);
			}
		}
		else {

			// create a new abook record

			$closeness = get_pconfig($uid,'system','new_abook_closeness',80);

			$r = abook_store_lowlevel(
				[
					'abook_account'   => intval($aid),
					'abook_channel'   => intval($uid),
					'abook_closeness' => intval($closeness),
					'abook_xchan'     => $xchan_hash,
					'abook_profile'   => $profile_assign,
					'abook_feed'      => intval(($xchan['xchan_network'] === 'rss') ? 1 : 0),
					'abook_created'   => datetime_convert(),
					'abook_updated'   => datetime_convert(),
					'abook_instance'  => (($singleton) ? z_root() : '')
				]
			);
		}

		if (! $r) {
			logger('abook creation failed');
			$result['message'] = t('error saving data');
			return $result;
		}

		// Set suitable permissions to the connection

		if ($my_perms) {
			set_abconfig($uid,$xchan_hash,'system','my_perms',$my_perms);
		}

		// fetch the entire record

		$r = q("select abook.*, xchan.* from abook left join xchan on abook_xchan = xchan_hash 
			where abook_xchan = '%s' and abook_channel = %d limit 1",
			dbesc($xchan_hash),
			intval($uid)
		);

		if ($r) {
			$result['abook'] = $r[0];
			Master::Summon([ 'Notifier', 'permissions_create', $result['abook']['abook_id'] ]);
		}

		$arr = [ 'channel_id' => $uid, 'channel' => $channel, 'abook' => $result['abook'] ];

		call_hooks('follow', $arr);

		/** If there is a default group for this channel, add this connection to it */

		if ($default_group) {
			$g = AccessList::rec_byhash($uid,$default_group);
			if ($g) {
				AccessList::member_add($uid,'',$xchan_hash,$g['id']);
			}
		}

		$result['success'] = true;
		return $result;
	}
}