friendica/mod/subthread.php

<?php
/**
 * @copyright Copyright (C) 2020, Friendica
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

use Friendica\App;
use Friendica\Core\Hook;
use Friendica\Core\Logger;
use Friendica\Core\Session;
use Friendica\Core\System;
use Friendica\Database\DBA;
use Friendica\DI;
use Friendica\Model\Item;
use Friendica\Protocol\Activity;
use Friendica\Util\Security;
use Friendica\Util\Strings;
use Friendica\Util\XML;

function subthread_content(App $a) {

	if (!Session::isAuthenticated()) {
		return;
	}

	$activity = Activity::FOLLOW;

	$item_id = (($a->argc > 1) ? Strings::escapeTags(trim($a->argv[1])) : 0);

	$condition = ["`parent` = ? OR `parent-uri` = ? AND `parent` = `id`", $item_id, $item_id];
	$item = Item::selectFirst([], $condition);

	if (empty($item_id) || !DBA::isResult($item)) {
		Logger::log('subthread: no item ' . $item_id);
		return;
	}

	$owner_uid = $item['uid'];

	if (!Security::canWriteToUserWall($owner_uid)) {
		return;
	}

	$remote_owner = null;

	if (!$item['wall']) {
		// The top level post may have been written by somebody on another system
		$contact = DBA::selectFirst('contact', [], ['id' => $item['contact-id'], 'uid' => $item['uid']]);
		if (!DBA::isResult($contact)) {
			return;
		}
		if (!$contact['self']) {
			$remote_owner = $contact;
		}
	}

	$owner = null;
	// this represents the post owner on this system.

	$r = q("SELECT `contact`.*, `user`.`nickname` FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
		WHERE `contact`.`self` = 1 AND `contact`.`uid` = %d LIMIT 1",
		intval($owner_uid)
	);

	if (DBA::isResult($r)) {
		$owner = $r[0];
	}

	if (!$owner) {
		Logger::log('like: no owner');
		return;
	}

	if (!$remote_owner) {
		$remote_owner = $owner;
	}

	$contact = null;
	// This represents the person posting

	if (local_user() && (local_user() == $owner_uid)) {
		$contact = $owner;
	} else {
		$contact = DBA::selectFirst('contact', [], ['id' => $_SESSION['visitor_id'], 'uid' => $owner_uid]);
		if (!DBA::isResult($contact)) {
			return;
		}
	}

	$uri = Item::newURI($owner_uid);

	$post_type = (($item['resource-id']) ? DI::l10n()->t('photo') : DI::l10n()->t('status'));
	$objtype = (($item['resource-id']) ? Activity\ObjectType::IMAGE : Activity\ObjectType::NOTE );
	$link = XML::escape('<link rel="alternate" type="text/html" href="' . DI::baseUrl() . '/display/' . $item['guid'] . '" />' . "\n");
	$body = $item['body'];

	$obj = <<< EOT

	<object>
		<type>$objtype</type>
		<local>1</local>
		<id>{$item['uri']}</id>
		<link>$link</link>
		<title></title>
		<content>$body</content>
	</object>
EOT;
	$bodyverb = DI::l10n()->t('%1$s is following %2$s\'s %3$s');

	if (!isset($bodyverb)) {
		return;
	}

	$arr = [];

	$arr['guid'] = System::createUUID();
	$arr['uri'] = $uri;
	$arr['uid'] = $owner_uid;
	$arr['contact-id'] = $contact['id'];
	$arr['wall'] = $item['wall'];
	$arr['origin'] = 1;
	$arr['gravity'] = GRAVITY_ACTIVITY;
	$arr['parent'] = $item['id'];
	$arr['parent-uri'] = $item['uri'];
	$arr['thr-parent'] = $item['uri'];
	$arr['owner-name'] = $remote_owner['name'];
	$arr['owner-link'] = $remote_owner['url'];
	$arr['owner-avatar'] = $remote_owner['thumb'];
	$arr['author-name'] = $contact['name'];
	$arr['author-link'] = $contact['url'];
	$arr['author-avatar'] = $contact['thumb'];

	$ulink = '[url=' . $contact['url'] . ']' . $contact['name'] . '[/url]';
	$alink = '[url=' . $item['author-link'] . ']' . $item['author-name'] . '[/url]';
	$plink = '[url=' . DI::baseUrl() . '/display/' . $item['guid'] . ']' . $post_type . '[/url]';
	$arr['body'] =  sprintf( $bodyverb, $ulink, $alink, $plink );

	$arr['verb'] = $activity;
	$arr['object-type'] = $objtype;
	$arr['object'] = $obj;
	$arr['allow_cid'] = $item['allow_cid'];
	$arr['allow_gid'] = $item['allow_gid'];
	$arr['deny_cid'] = $item['deny_cid'];
	$arr['deny_gid'] = $item['deny_gid'];
	$arr['visible'] = 1;
	$arr['unseen'] = 1;

	$post_id = Item::insert($arr);

	if (!$item['visible']) {
		Item::update(['visible' => true], ['id' => $item['id']]);
	}

	$arr['id'] = $post_id;

	Hook::callAll('post_local_end', $arr);

	exit();

}