friendica/src/Model/Contact.php

<?php

/**
 * @file src/Model/Contact.php
 */

namespace Friendica\Model;

use Friendica\BaseObject;
use Friendica\Core\Config;
use Friendica\Core\PConfig;
use Friendica\Core\System;
use Friendica\Core\Worker;
use Friendica\Database\DBM;
use Friendica\Network\Probe;
use Friendica\Model\Photo;
use Friendica\Protocol\Diaspora;
use Friendica\Protocol\DFRN;
use Friendica\Protocol\OStatus;
use Friendica\Protocol\PortableContact;
use Friendica\Protocol\Salmon;
use dba;

require_once 'boot.php';
require_once 'include/dba.php';
require_once 'include/text.php';

/**
 * @brief functions for interacting with a contact
 */
class Contact extends BaseObject
{
	/**
	 * @brief Returns a list of contacts belonging in a group
	 *
	 * @param int $gid
	 * @return array
	 */
	public static function getByGroupId($gid)
	{
		$return = [];
		if (intval($gid)) {
			$stmt = dba::p('SELECT `group_member`.`contact-id`, `contact`.*
				FROM `contact`
				INNER JOIN `group_member`
					ON `contact`.`id` = `group_member`.`contact-id`
				WHERE `gid` = ?
				AND `contact`.`uid` = ?
				AND NOT `contact`.`self`
				AND NOT `contact`.`blocked`
				AND NOT `contact`.`pending`
				ORDER BY `contact`.`name` ASC',
				$gid,
				local_user()
			);
			if (DBM::is_result($stmt)) {
				$return = dba::inArray($stmt);
			}
		}

		return $return;
	}

	/**
	 * @brief Returns the count of OStatus contacts in a group
	 *
	 * @param int $gid
	 * @return int
	 */
	public static function getOStatusCountByGroupId($gid)
	{
		$return = 0;
		if (intval($gid)) {
			$contacts = dba::fetch_first('SELECT COUNT(*) AS `count`
				FROM `contact`
				INNER JOIN `group_member`
					ON `contact`.`id` = `group_member`.`contact-id`
				WHERE `gid` = ?
				AND `contact`.`uid` = ?
				AND `contact`.`network` = ?
				AND `contact`.`notify` != ""',
				$gid,
				local_user(),
				NETWORK_OSTATUS
			);
			$return = $contacts['count'];
		}

		return $return;
	}


	/**
	 * Creates the self-contact for the provided user id
	 *
	 * @param int $uid
	 * @return bool Operation success
	 */
	public static function createSelfFromUserId($uid)
	{
		// Only create the entry if it doesn't exist yet
		if (dba::exists('contact', ['uid' => $uid, 'self' => true])) {
			return true;
		}

		$user = dba::select('user', ['uid', 'username', 'nickname'], ['uid' => $uid], ['limit' => 1]);
		if (!DBM::is_result($user)) {
			return false;
		}

		$return = dba::insert('contact', [
			'uid'         => $user['uid'],
			'created'     => datetime_convert(),
			'self'        => 1,
			'name'        => $user['username'],
			'nick'        => $user['nickname'],
			'photo'       => System::baseUrl() . '/photo/profile/' . $user['uid'] . '.jpg',
			'thumb'       => System::baseUrl() . '/photo/avatar/'  . $user['uid'] . '.jpg',
			'micro'       => System::baseUrl() . '/photo/micro/'   . $user['uid'] . '.jpg',
			'blocked'     => 0,
			'pending'     => 0,
			'url'         => System::baseUrl() . '/profile/' . $user['nickname'],
			'nurl'        => normalise_link(System::baseUrl() . '/profile/' . $user['nickname']),
			'addr'        => $user['nickname'] . '@' . substr(System::baseUrl(), strpos(System::baseUrl(), '://') + 3),
			'request'     => System::baseUrl() . '/dfrn_request/' . $user['nickname'],
			'notify'      => System::baseUrl() . '/dfrn_notify/'  . $user['nickname'],
			'poll'        => System::baseUrl() . '/dfrn_poll/'    . $user['nickname'],
			'confirm'     => System::baseUrl() . '/dfrn_confirm/' . $user['nickname'],
			'poco'        => System::baseUrl() . '/poco/'         . $user['nickname'],
			'name-date'   => datetime_convert(),
			'uri-date'    => datetime_convert(),
			'avatar-date' => datetime_convert(),
			'closeness'   => 0
		]);

		return $return;
	}

	/**
	 * @brief Marks a contact for removal
	 *
	 * @param int $id contact id
	 * @return null
	 */
	public static function remove($id)
	{
		// We want just to make sure that we don't delete our "self" contact
		$r = dba::select('contact', array('uid'), array('id' => $id, 'self' => false), array('limit' => 1));

		if (!DBM::is_result($r) || !intval($r['uid'])) {
			return;
		}

		$archive = PConfig::get($r['uid'], 'system', 'archive_removed_contacts');
		if ($archive) {
			dba::update('contact', array('archive' => true, 'network' => 'none', 'writable' => false), array('id' => $id));
			return;
		}

		dba::delete('contact', array('id' => $id));

		// Delete the rest in the background
		Worker::add(PRIORITY_LOW, 'RemoveContact', $id);
	}

	/**
	 * @brief Sends an unfriend message. Does not remove the contact
	 *
	 * @param array $user    User unfriending
	 * @param array $contact Contact unfriended
	 * @return void
	 */
	public static function terminateFriendship(array $user, array $contact)
	{
		if ($contact['network'] === NETWORK_OSTATUS) {
			// create an unfollow slap
			$item = array();
			$item['verb'] = NAMESPACE_OSTATUS . "/unfollow";
			$item['follow'] = $contact["url"];
			$slap = OStatus::salmon($item, $user);

			if ((x($contact, 'notify')) && (strlen($contact['notify']))) {
				Salmon::slapper($user, $contact['notify'], $slap);
			}
		} elseif ($contact['network'] === NETWORK_DIASPORA) {
			Diaspora::sendUnshare($user, $contact);
		} elseif ($contact['network'] === NETWORK_DFRN) {
			DFRN::deliver($user, $contact, 'placeholder', 1);
		}
	}

	/**
	 * @brief Marks a contact for archival after a communication issue delay
	 *
	 * Contact has refused to recognise us as a friend. We will start a countdown.
	 * If they still don't recognise us in 32 days, the relationship is over,
	 * and we won't waste any more time trying to communicate with them.
	 * This provides for the possibility that their database is temporarily messed
	 * up or some other transient event and that there's a possibility we could recover from it.
	 *
	 * @param array $contact contact to mark for archival
	 * @return null
	 */
	public static function markForArchival(array $contact)
	{
		// Contact already archived or "self" contact? => nothing to do
		if ($contact['archive'] || $contact['self']) {
			return;
		}

		if ($contact['term-date'] <= NULL_DATE) {
			dba::update('contact', array('term-date' => datetime_convert()), array('id' => $contact['id']));

			if ($contact['url'] != '') {
				dba::update('contact', array('term-date' => datetime_convert()), array('`nurl` = ? AND `term-date` <= ? AND NOT `self`', normalise_link($contact['url']), NULL_DATE));
			}
		} else {
			/* @todo
			 * We really should send a notification to the owner after 2-3 weeks
			 * so they won't be surprised when the contact vanishes and can take
			 * remedial action if this was a serious mistake or glitch
			 */

			/// @todo Check for contact vitality via probing
			$expiry = $contact['term-date'] . ' + 32 days ';
			if (datetime_convert() > datetime_convert('UTC', 'UTC', $expiry)) {
				/* Relationship is really truly dead. archive them rather than
				 * delete, though if the owner tries to unarchive them we'll start
				 * the whole process over again.
				 */
				dba::update('contact', array('archive' => 1), array('id' => $contact['id']));

				if ($contact['url'] != '') {
					dba::update('contact', array('archive' => 1), array('nurl' => normalise_link($contact['url']), 'self' => false));
				}
			}
		}
	}

	/**
	 * @brief Cancels the archival countdown
	 *
	 * @see Contact::markForArchival()
	 *
	 * @param array $contact contact to be unmarked for archival
	 * @return null
	 */
	public static function unmarkForArchival(array $contact)
	{
		$condition = array('`id` = ? AND (`term-date` > ? OR `archive`)', $contact['id'], NULL_DATE);
		$exists = dba::exists('contact', $condition);

		// We don't need to update, we never marked this contact for archival
		if (!$exists) {
			return;
		}

		// It's a miracle. Our dead contact has inexplicably come back to life.
		$fields = array('term-date' => NULL_DATE, 'archive' => false);
		dba::update('contact', $fields, array('id' => $contact['id']));

		if ($contact['url'] != '') {
			dba::update('contact', $fields, array('nurl' => normalise_link($contact['url'])));
		}
	}

	/**
	 * @brief Get contact data for a given profile link
	 *
	 * The function looks at several places (contact table and gcontact table) for the contact
	 * It caches its result for the same script execution to prevent duplicate calls
	 *
	 * @param string $url     The profile link
	 * @param int    $uid     User id
	 * @param array  $default If not data was found take this data as default value
	 *
	 * @return array Contact data
	 */
	public static function getDetailsByURL($url, $uid = -1, array $default = [])
	{
		static $cache = array();

		if ($url == '') {
			return $default;
		}

		if ($uid == -1) {
			$uid = local_user();
		}

		if (isset($cache[$url][$uid])) {
			return $cache[$url][$uid];
		}

		$ssl_url = str_replace('http://', 'https://', $url);

		// Fetch contact data from the contact table for the given user
		$s = dba::p("SELECT `id`, `id` AS `cid`, 0 AS `gid`, 0 AS `zid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
			`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, `self`
		FROM `contact` WHERE `nurl` = ? AND `uid` = ?", normalise_link($url), $uid);
		$r = dba::inArray($s);

		// Fetch contact data from the contact table for the given user, checking with the alias
		if (!DBM::is_result($r)) {
			$s = dba::p("SELECT `id`, `id` AS `cid`, 0 AS `gid`, 0 AS `zid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
				`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, `self`
			FROM `contact` WHERE `alias` IN (?, ?, ?) AND `uid` = ?", normalise_link($url), $url, $ssl_url, $uid);
			$r = dba::inArray($s);
		}

		// Fetch the data from the contact table with "uid=0" (which is filled automatically)
		if (!DBM::is_result($r)) {
			$s = dba::p("SELECT `id`, 0 AS `cid`, `id` AS `zid`, 0 AS `gid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
			`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, 0 AS `self`
			FROM `contact` WHERE `nurl` = ? AND `uid` = 0", normalise_link($url));
			$r = dba::inArray($s);
		}

		// Fetch the data from the contact table with "uid=0" (which is filled automatically) - checked with the alias
		if (!DBM::is_result($r)) {
			$s = dba::p("SELECT `id`, 0 AS `cid`, `id` AS `zid`, 0 AS `gid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
			`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, 0 AS `self`
			FROM `contact` WHERE `alias` IN (?, ?, ?) AND `uid` = 0", normalise_link($url), $url, $ssl_url);
			$r = dba::inArray($s);
		}

		// Fetch the data from the gcontact table
		if (!DBM::is_result($r)) {
			$s = dba::p("SELECT 0 AS `id`, 0 AS `cid`, `id` AS `gid`, 0 AS `zid`, 0 AS `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, '' AS `xmpp`,
			`keywords`, `gender`, `photo`, `photo` AS `thumb`, `photo` AS `micro`, `community` AS `forum`, 0 AS `prv`, `community`, `contact-type`, `birthday`, 0 AS `self`
			FROM `gcontact` WHERE `nurl` = ?", normalise_link($url));
			$r = dba::inArray($s);
		}

		if (DBM::is_result($r)) {
			// If there is more than one entry we filter out the connector networks
			if (count($r) > 1) {
				foreach ($r as $id => $result) {
					if ($result["network"] == NETWORK_STATUSNET) {
						unset($r[$id]);
					}
				}
			}

			$profile = array_shift($r);

			// "bd" always contains the upcoming birthday of a contact.
			// "birthday" might contain the birthday including the year of birth.
			if ($profile["birthday"] > '0001-01-01') {
				$bd_timestamp = strtotime($profile["birthday"]);
				$month = date("m", $bd_timestamp);
				$day = date("d", $bd_timestamp);

				$current_timestamp = time();
				$current_year = date("Y", $current_timestamp);
				$current_month = date("m", $current_timestamp);
				$current_day = date("d", $current_timestamp);

				$profile["bd"] = $current_year . "-" . $month . "-" . $day;
				$current = $current_year . "-" . $current_month . "-" . $current_day;

				if ($profile["bd"] < $current) {
					$profile["bd"] = ( ++$current_year) . "-" . $month . "-" . $day;
				}
			} else {
				$profile["bd"] = '0001-01-01';
			}
		} else {
			$profile = $default;
		}

		if (($profile["photo"] == "") && isset($default["photo"])) {
			$profile["photo"] = $default["photo"];
		}

		if (($profile["name"] == "") && isset($default["name"])) {
			$profile["name"] = $default["name"];
		}

		if (($profile["network"] == "") && isset($default["network"])) {
			$profile["network"] = $default["network"];
		}

		if (($profile["thumb"] == "") && isset($profile["photo"])) {
			$profile["thumb"] = $profile["photo"];
		}

		if (($profile["micro"] == "") && isset($profile["thumb"])) {
			$profile["micro"] = $profile["thumb"];
		}

		if ((($profile["addr"] == "") || ($profile["name"] == "")) && ($profile["gid"] != 0)
			&& in_array($profile["network"], array(NETWORK_DFRN, NETWORK_DIASPORA, NETWORK_OSTATUS))
		) {
			Worker::add(PRIORITY_LOW, "UpdateGContact", $profile["gid"]);
		}

		// Show contact details of Diaspora contacts only if connected
		if (($profile["cid"] == 0) && ($profile["network"] == NETWORK_DIASPORA)) {
			$profile["location"] = "";
			$profile["about"] = "";
			$profile["gender"] = "";
			$profile["birthday"] = '0001-01-01';
		}

		$cache[$url][$uid] = $profile;

		return $profile;
	}

	/**
	 * @brief Get contact data for a given address
	 *
	 * The function looks at several places (contact table and gcontact table) for the contact
	 *
	 * @param string $addr The profile link
	 * @param int    $uid  User id
	 *
	 * @return array Contact data
	 */
	public static function getDetailsByAddr($addr, $uid = -1)
	{
		static $cache = array();

		if ($addr == '') {
			return array();
		}

		if ($uid == -1) {
			$uid = local_user();
		}

		// Fetch contact data from the contact table for the given user
		$r = q("SELECT `id`, `id` AS `cid`, 0 AS `gid`, 0 AS `zid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
			`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, `self`
		FROM `contact` WHERE `addr` = '%s' AND `uid` = %d", dbesc($addr), intval($uid));

		// Fetch the data from the contact table with "uid=0" (which is filled automatically)
		if (!DBM::is_result($r))
			$r = q("SELECT `id`, 0 AS `cid`, `id` AS `zid`, 0 AS `gid`, `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, `xmpp`,
			`keywords`, `gender`, `photo`, `thumb`, `micro`, `forum`, `prv`, (`forum` | `prv`) AS `community`, `contact-type`, `bd` AS `birthday`, 0 AS `self`
			FROM `contact` WHERE `addr` = '%s' AND `uid` = 0", dbesc($addr));

		// Fetch the data from the gcontact table
		if (!DBM::is_result($r))
			$r = q("SELECT 0 AS `id`, 0 AS `cid`, `id` AS `gid`, 0 AS `zid`, 0 AS `uid`, `url`, `nurl`, `alias`, `network`, `name`, `nick`, `addr`, `location`, `about`, '' AS `xmpp`,
			`keywords`, `gender`, `photo`, `photo` AS `thumb`, `photo` AS `micro`, `community` AS `forum`, 0 AS `prv`, `community`, `contact-type`, `birthday`, 0 AS `self`
			FROM `gcontact` WHERE `addr` = '%s'", dbesc($addr));

		if (!DBM::is_result($r)) {
			$data = Probe::uri($addr);

			$profile = self::getDetailsByURL($data['url'], $uid);
		} else {
			$profile = $r[0];
		}

		return $profile;
	}

	/**
	 * @brief Returns the data array for the photo menu of a given contact
	 *
	 * @param array $contact contact
	 * @param int   $uid     optional, default 0
	 * @return array
	 */
	public static function photoMenu(array $contact, $uid = 0)
	{
		// @todo Unused, to be removed
		$a = get_app();

		$contact_url = '';
		$pm_url = '';
		$status_link = '';
		$photos_link = '';
		$posts_link = '';
		$contact_drop_link = '';
		$poke_link = '';

		if ($uid == 0) {
			$uid = local_user();
		}

		if ($contact['uid'] != $uid) {
			if ($uid == 0) {
				$profile_link = zrl($contact['url']);
				$menu = array('profile' => array(t('View Profile'), $profile_link, true));

				return $menu;
			}

			$r = dba::select('contact', array(), array('nurl' => $contact['nurl'], 'network' => $contact['network'], 'uid' => $uid), array('limit' => 1));
			if ($r) {
				return self::photoMenu($r, $uid);
			} else {
				$profile_link = zrl($contact['url']);
				$connlnk = 'follow/?url=' . $contact['url'];
				$menu = array(
					'profile' => array(t('View Profile'), $profile_link, true),
					'follow' => array(t('Connect/Follow'), $connlnk, true)
				);

				return $menu;
			}
		}

		$sparkle = false;
		if ($contact['network'] === NETWORK_DFRN) {
			$sparkle = true;
			$profile_link = System::baseUrl() . '/redir/' . $contact['id'];
		} else {
			$profile_link = $contact['url'];
		}

		if ($profile_link === 'mailbox') {
			$profile_link = '';
		}

		if ($sparkle) {
			$status_link = $profile_link . '?url=status';
			$photos_link = $profile_link . '?url=photos';
			$profile_link = $profile_link . '?url=profile';
		}

		if (in_array($contact['network'], array(NETWORK_DFRN, NETWORK_DIASPORA))) {
			$pm_url = System::baseUrl() . '/message/new/' . $contact['id'];
		}

		if ($contact['network'] == NETWORK_DFRN) {
			$poke_link = System::baseUrl() . '/poke/?f=&c=' . $contact['id'];
		}

		$contact_url = System::baseUrl() . '/contacts/' . $contact['id'];

		$posts_link = System::baseUrl() . '/contacts/' . $contact['id'] . '/posts';
		$contact_drop_link = System::baseUrl() . '/contacts/' . $contact['id'] . '/drop?confirm=1';

		/**
		 * Menu array:
		 * "name" => [ "Label", "link", (bool)Should the link opened in a new tab? ]
		 */
		$menu = array(
			'status' => array(t("View Status"), $status_link, true),
			'profile' => array(t("View Profile"), $profile_link, true),
			'photos' => array(t("View Photos"), $photos_link, true),
			'network' => array(t("Network Posts"), $posts_link, false),
			'edit' => array(t("View Contact"), $contact_url, false),
			'drop' => array(t("Drop Contact"), $contact_drop_link, false),
			'pm' => array(t("Send PM"), $pm_url, false),
			'poke' => array(t("Poke"), $poke_link, false),
		);


		$args = array('contact' => $contact, 'menu' => &$menu);

		call_hooks('contact_photo_menu', $args);

		$menucondensed = array();

		foreach ($menu as $menuname => $menuitem) {
			if ($menuitem[1] != '') {
				$menucondensed[$menuname] = $menuitem;
			}
		}

		return $menucondensed;
	}

	/**
	 * @brief Returns ungrouped contact count or list for user
	 *
	 * Returns either the total number of ungrouped contacts for the given user
	 * id or a paginated list of ungrouped contacts.
	 *
	 * @param int $uid   uid
	 * @param int $start optional, default 0
	 * @param int $count optional, default 0
	 *
	 * @return array
	 */
	public static function getUngroupedList($uid, $start = 0, $count = 0)
	{
		if (!$count) {
			$r = q(
				"SELECT COUNT(*) AS `total`
				 FROM `contact`
				 WHERE `uid` = %d
				 AND NOT `self`
				 AND NOT `blocked`
				 AND NOT `pending`
				 AND `id` NOT IN (
					SELECT DISTINCT(`contact-id`)
					FROM `group_member`
					WHERE `uid` = %d
				)", intval($uid), intval($uid)
			);

			return $r;
		}

		$r = q(
			"SELECT *
			FROM `contact`
			WHERE `uid` = %d
			AND NOT `self`
			AND NOT `blocked`
			AND NOT `pending`
			AND `id` NOT IN (
				SELECT DISTINCT(`contact-id`)
				FROM `group_member`
				INNER JOIN `group` ON `group`.`id` = `group_member`.`gid`
				WHERE `group`.`uid` = %d
			)
			LIMIT %d, %d", intval($uid), intval($uid), intval($start), intval($count)
		);
		return $r;
	}

	/**
	 * @brief Fetch the contact id for a given url and user
	 *
	 * First lookup in the contact table to find a record matching either `url`, `nurl`,
	 * `addr` or `alias`.
	 *
	 * If there's no record and we aren't looking for a public contact, we quit.
	 * If there's one, we check that it isn't time to update the picture else we
	 * directly return the found contact id.
	 *
	 * Second, we probe the provided $url wether it's http://server.tld/profile or
	 * nick@server.tld. We quit if we can't get any info back.
	 *
	 * Third, we create the contact record if it doesn't exist
	 *
	 * Fourth, we update the existing record with the new data (avatar, alias, nick)
	 * if there's any updates
	 *
	 * @param string  $url       Contact URL
	 * @param integer $uid       The user id for the contact (0 = public contact)
	 * @param boolean $no_update Don't update the contact
	 *
	 * @return integer Contact ID
	 */
	public static function getIdForURL($url, $uid = 0, $no_update = false)
	{
		logger("Get contact data for url " . $url . " and user " . $uid . " - " . System::callstack(), LOGGER_DEBUG);

		$contact_id = 0;

		if ($url == '') {
			return 0;
		}

		/// @todo Verify if we can't use Contact::getDetailsByUrl instead of the following
		// We first try the nurl (http://server.tld/nick), most common case
		$contact = dba::select('contact', array('id', 'avatar-date'), array('nurl' => normalise_link($url), 'uid' => $uid), array('limit' => 1));

		// Then the addr (nick@server.tld)
		if (!DBM::is_result($contact)) {
			$contact = dba::select('contact', array('id', 'avatar-date'), array('addr' => $url, 'uid' => $uid), array('limit' => 1));
		}

		// Then the alias (which could be anything)
		if (!DBM::is_result($contact)) {
			// The link could be provided as http although we stored it as https
			$ssl_url = str_replace('http://', 'https://', $url);
			$r = dba::select('contact', array('id', 'avatar', 'avatar-date'), array('`alias` IN (?, ?, ?) AND `uid` = ?', $url, normalise_link($url), $ssl_url, $uid), array('limit' => 1));
			$contact = dba::fetch($r);
			dba::close($r);
		}

		if (DBM::is_result($contact)) {
			$contact_id = $contact["id"];

			// Update the contact every 7 days
			$update_contact = ($contact['avatar-date'] < datetime_convert('', '', 'now -7 days'));

			// We force the update if the avatar is empty
			if (!x($contact, 'avatar')) {
				$update_contact = true;
			}

			if (!$update_contact || $no_update) {
				return $contact_id;
			}
		} elseif ($uid != 0) {
			// Non-existing user-specific contact, exiting
			return 0;
		}

		$data = Probe::uri($url, "", $uid);

		// Last try in gcontact for unsupported networks
		if (!in_array($data["network"], array(NETWORK_DFRN, NETWORK_OSTATUS, NETWORK_DIASPORA, NETWORK_PUMPIO, NETWORK_MAIL))) {
			if ($uid != 0) {
				return 0;
			}

			// Get data from the gcontact table
			$gcontacts = dba::select('gcontact', array('name', 'nick', 'url', 'photo', 'addr', 'alias', 'network'), array('nurl' => normalise_link($url)), array('limit' => 1));
			if (!DBM::is_result($gcontacts)) {
				return 0;
			}

			$data = array_merge($data, $gcontacts);
		}

		if (!$contact_id && ($data["alias"] != '') && ($data["alias"] != $url)) {
			$contact_id = self::getIdForURL($data["alias"], $uid, true);
		}

		$url = $data["url"];
		if (!$contact_id) {
			dba::insert(
				'contact', array('uid' => $uid, 'created' => datetime_convert(), 'url' => $data["url"],
				'nurl' => normalise_link($data["url"]), 'addr' => $data["addr"],
				'alias' => $data["alias"], 'notify' => $data["notify"], 'poll' => $data["poll"],
				'name' => $data["name"], 'nick' => $data["nick"], 'photo' => $data["photo"],
				'keywords' => $data["keywords"], 'location' => $data["location"], 'about' => $data["about"],
				'network' => $data["network"], 'pubkey' => $data["pubkey"],
				'rel' => CONTACT_IS_SHARING, 'priority' => $data["priority"],
				'batch' => $data["batch"], 'request' => $data["request"],
				'confirm' => $data["confirm"], 'poco' => $data["poco"],
				'name-date' => datetime_convert(), 'uri-date' => datetime_convert(),
				'avatar-date' => datetime_convert(), 'writable' => 1, 'blocked' => 0,
				'readonly' => 0, 'pending' => 0)
			);

			$s = dba::select('contact', array('id'), array('nurl' => normalise_link($data["url"]), 'uid' => $uid), array('order' => array('id'), 'limit' => 2));
			$contacts = dba::inArray($s);
			if (!DBM::is_result($contacts)) {
				return 0;
			}

			$contact_id = $contacts[0]["id"];

			// Update the newly created contact from data in the gcontact table
			$gcontact = dba::select('gcontact', array('location', 'about', 'keywords', 'gender'), array('nurl' => normalise_link($data["url"])), array('limit' => 1));
			if (DBM::is_result($gcontact)) {
				// Only use the information when the probing hadn't fetched these values
				if ($data['keywords'] != '') {
					unset($gcontact['keywords']);
				}
				if ($data['location'] != '') {
					unset($gcontact['location']);
				}
				if ($data['about'] != '') {
					unset($gcontact['about']);
				}
				dba::update('contact', $gcontact, array('id' => $contact_id));
			}

			if (count($contacts) > 1 && $uid == 0 && $contact_id != 0 && $data["url"] != "") {
				dba::delete('contact', array("`nurl` = ? AND `uid` = 0 AND `id` != ? AND NOT `self`",
					normalise_link($data["url"]), $contact_id));
			}
		}

		self::updateAvatar($data["photo"], $uid, $contact_id);

		$fields = array('url', 'nurl', 'addr', 'alias', 'name', 'nick', 'keywords', 'location', 'about', 'avatar-date', 'pubkey');
		$contact = dba::select('contact', $fields, array('id' => $contact_id), array('limit' => 1));

		// This condition should always be true
		if (!DBM::is_result($contact)) {
			return $contact_id;
		}

		$updated = array('addr' => $data['addr'],
			'alias' => $data['alias'],
			'url' => $data['url'],
			'nurl' => normalise_link($data['url']),
			'name' => $data['name'],
			'nick' => $data['nick']);

		// Only fill the pubkey if it was empty before. We have to prevent identity theft.
		if (!empty($contact['pubkey'])) {
			unset($contact['pubkey']);
		} else {
			$updated['pubkey'] = $data['pubkey'];
		}

		if ($data['keywords'] != '') {
			$updated['keywords'] = $data['keywords'];
		}
		if ($data['location'] != '') {
			$updated['location'] = $data['location'];
		}
		if ($data['about'] != '') {
			$updated['about'] = $data['about'];
		}

		if (($data["addr"] != $contact["addr"]) || ($data["alias"] != $contact["alias"])) {
			$updated['uri-date'] = datetime_convert();
		}
		if (($data["name"] != $contact["name"]) || ($data["nick"] != $contact["nick"])) {
			$updated['name-date'] = datetime_convert();
		}

		$updated['avatar-date'] = datetime_convert();

		dba::update('contact', $updated, array('id' => $contact_id), $contact);

		return $contact_id;
	}

	/**
	 * @brief Checks if the contact is blocked
	 *
	 * @param int $cid contact id
	 *
	 * @return boolean Is the contact blocked?
	 */
	public static function isBlocked($cid)
	{
		if ($cid == 0) {
			return false;
		}

		$blocked = dba::select('contact', array('blocked'), array('id' => $cid), array('limit' => 1));
		if (!DBM::is_result($blocked)) {
			return false;
		}
		return (bool) $blocked['blocked'];
	}

	/**
	 * @brief Checks if the contact is hidden
	 *
	 * @param int $cid contact id
	 *
	 * @return boolean Is the contact hidden?
	 */
	public static function isHidden($cid)
	{
		if ($cid == 0) {
			return false;
		}

		$hidden = dba::select('contact', array('hidden'), array('id' => $cid), array('limit' => 1));
		if (!DBM::is_result($hidden)) {
			return false;
		}
		return (bool) $hidden['hidden'];
	}

	/**
	 * @brief Returns posts from a given contact url
	 *
	 * @param string $contact_url Contact URL
	 *
	 * @return string posts in HTML
	 */
	public static function getPostsFromUrl($contact_url)
	{
		$a = self::getApp();

		require_once 'include/conversation.php';

		// There are no posts with "uid = 0" with connector networks
		// This speeds up the query a lot
		$r = q("SELECT `network`, `id` AS `author-id`, `contact-type` FROM `contact`
			WHERE `contact`.`nurl` = '%s' AND `contact`.`uid` = 0", dbesc(normalise_link($contact_url)));

		if (!DBM::is_result($r)) {
			return '';
		}

		if (in_array($r[0]["network"], array(NETWORK_DFRN, NETWORK_DIASPORA, NETWORK_OSTATUS, ""))) {
			$sql = "(`item`.`uid` = 0 OR (`item`.`uid` = %d AND NOT `item`.`global`))";
		} else {
			$sql = "`item`.`uid` = %d";
		}

		$author_id = intval($r[0]["author-id"]);

		$contact = ($r[0]["contact-type"] == ACCOUNT_TYPE_COMMUNITY ? 'owner-id' : 'author-id');

		$r = q(item_query() . " AND `item`.`" . $contact . "` = %d AND " . $sql .
			" AND `item`.`verb` = '%s' ORDER BY `item`.`created` DESC LIMIT %d, %d",
			intval($author_id), intval(local_user()), dbesc(ACTIVITY_POST),
			intval($a->pager['start']), intval($a->pager['itemspage'])
		);


		$o = conversation($a, $r, 'contact-posts', false);

		$o .= alt_pager($a, count($r));

		return $o;
	}

	/**
	 * @brief Returns the account type name
	 *
	 * The function can be called with either the user or the contact array
	 *
	 * @param array $contact contact or user array
	 * @return string
	 */
	public static function getAccountType(array $contact)
	{
		// There are several fields that indicate that the contact or user is a forum
		// "page-flags" is a field in the user table,
		// "forum" and "prv" are used in the contact table. They stand for PAGE_COMMUNITY and PAGE_PRVGROUP.
		// "community" is used in the gcontact table and is true if the contact is PAGE_COMMUNITY or PAGE_PRVGROUP.
		if ((isset($contact['page-flags']) && (intval($contact['page-flags']) == PAGE_COMMUNITY))
			|| (isset($contact['page-flags']) && (intval($contact['page-flags']) == PAGE_PRVGROUP))
			|| (isset($contact['forum']) && intval($contact['forum']))
			|| (isset($contact['prv']) && intval($contact['prv']))
			|| (isset($contact['community']) && intval($contact['community']))
		) {
			$type = ACCOUNT_TYPE_COMMUNITY;
		} else {
			$type = ACCOUNT_TYPE_PERSON;
		}

		// The "contact-type" (contact table) and "account-type" (user table) are more general then the chaos from above.
		if (isset($contact["contact-type"])) {
			$type = $contact["contact-type"];
		}
		if (isset($contact["account-type"])) {
			$type = $contact["account-type"];
		}

		switch ($type) {
			case ACCOUNT_TYPE_ORGANISATION:
				$account_type = t("Organisation");
				break;
			case ACCOUNT_TYPE_NEWS:
				$account_type = t('News');
				break;
			case ACCOUNT_TYPE_COMMUNITY:
				$account_type = t("Forum");
				break;
			default:
				$account_type = "";
				break;
		}

		return $account_type;
	}

	/**
	 * @brief Blocks a contact
	 *
	 * @param int $uid
	 * @return bool
	 */
	public static function block($uid)
	{
		$return = dba::update('contact', ['blocked' => true], ['id' => $uid]);

		return $return;
	}

	/**
	 * @brief Unblocks a contact
	 *
	 * @param int $uid
	 * @return bool
	 */
	public static function unblock($uid)
	{
		$return = dba::update('contact', ['blocked' => false], ['id' => $uid]);

		return $return;
  }

  /**
   * @brief Updates the avatar links in a contact only if needed
	 *
	 * @param string $avatar Link to avatar picture
	 * @param int    $uid    User id of contact owner
	 * @param int    $cid    Contact id
	 * @param bool   $force  force picture update
	 *
	 * @return array Returns array of the different avatar sizes
	 */
	public static function updateAvatar($avatar, $uid, $cid, $force = false)
	{
		// Limit = 1 returns the row so no need for dba:inArray()
		$r = dba::select('contact', array('avatar', 'photo', 'thumb', 'micro', 'nurl'), array('id' => $cid), array('limit' => 1));
		if (!DBM::is_result($r)) {
			return false;
		} else {
			$data = array($r["photo"], $r["thumb"], $r["micro"]);
		}

		if (($r["avatar"] != $avatar) || $force) {
			$photos = Photo::importProfilePhoto($avatar, $uid, $cid, true);

			if ($photos) {
				dba::update(
					'contact',
					array('avatar' => $avatar, 'photo' => $photos[0], 'thumb' => $photos[1], 'micro' => $photos[2], 'avatar-date' => datetime_convert()),
					array('id' => $cid)
				);

				// Update the public contact (contact id = 0)
				if ($uid != 0) {
					$pcontact = dba::select('contact', array('id'), array('nurl' => $r[0]['nurl']), array('limit' => 1));
					if (DBM::is_result($pcontact)) {
						self::updateAvatar($avatar, 0, $pcontact['id'], $force);
					}
				}

				return $photos;
			}
		}

		return $data;
	}

	/**
	 * @param integer $id contact id
	 * @return boolean
	 */
	public static function update($id)
	{
		/*
		Warning: Never ever fetch the public key via Probe::uri and write it into the contacts.
		This will reliably kill your communication with Friendica contacts.
		*/

		$r = dba::select('contact', ['url', 'nurl', 'addr', 'alias', 'batch', 'notify', 'poll', 'poco', 'network'], ['id' => $id], ['limit' => 1]);
		if (!DBM::is_result($r)) {
			return false;
		}

		$ret = Probe::uri($r["url"]);

		// If Probe::uri fails the network code will be different
		if ($ret["network"] != $r["network"]) {
			return false;
		}

		$update = false;

		// make sure to not overwrite existing values with blank entries
		foreach ($ret as $key => $val) {
			if (isset($r[$key]) && ($r[$key] != "") && ($val == ""))
				$ret[$key] = $r[$key];

			if (isset($r[$key]) && ($ret[$key] != $r[$key]))
				$update = true;
		}

		if (!$update) {
			return true;
		}

		dba::update(
			'contact',
			[
				'url' => $ret['url'],
				'nurl' => normalise_link($ret['url']),
				'addr' => $ret['addr'],
				'alias' => $ret['alias'],
				'batch' => $ret['batch'],
				'notify' => $ret['notify'],
				'poll' => $ret['poll'],
				'poco' => $ret['poco']
			],
			['id' => $id]
		);

		// Update the corresponding gcontact entry
		PortableContact::lastUpdated($ret["url"]);

		return true;
	}

	/**
	 * Takes a $uid and a url/handle and adds a new contact
	 * Currently if the contact is DFRN, interactive needs to be true, to redirect to the
	 * dfrn_request page.
	 *
	 * Otherwise this can be used to bulk add statusnet contacts, twitter contacts, etc.
	 *
	 * Returns an array
	 * $return['success'] boolean true if successful
	 * $return['message'] error text if success is false.
	 *
	 * @brief Takes a $uid and a url/handle and adds a new contact
	 * @param int    $uid
	 * @param string $url
	 * @param bool   $interactive
	 * @param string $network
	 * @return boolean|string
	 */
	public static function add($uid, $url, $interactive = false, $network = '')
	{
		$result = array('cid' => -1, 'success' => false, 'message' => '');

		$a = get_app();

		// remove ajax junk, e.g. Twitter
		$url = str_replace('/#!/', '/', $url);

		if (!allowed_url($url)) {
			$result['message'] = t('Disallowed profile URL.');
			return $result;
		}

		if (blocked_url($url)) {
			$result['message'] = t('Blocked domain');
			return $result;
		}

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

		$arr = array('url' => $url, 'contact' => array());

		call_hooks('follow', $arr);

		if (x($arr['contact'], 'name')) {
			$ret = $arr['contact'];
		} else {
			$ret = Probe::uri($url, $network, $uid, false);
		}

		if (($network != '') && ($ret['network'] != $network)) {
			logger('Expected network ' . $network . ' does not match actual network ' . $ret['network']);
			return result;
		}

		if ($ret['network'] === NETWORK_DFRN) {
			if ($interactive) {
				if (strlen($a->path)) {
					$myaddr = bin2hex(System::baseUrl() . '/profile/' . $a->user['nickname']);
				} else {
					$myaddr = bin2hex($a->user['nickname'] . '@' . $a->get_hostname());
				}

				goaway($ret['request'] . "&addr=$myaddr");

				// NOTREACHED
			}
		} elseif (Config::get('system', 'dfrn_only')) {
			$result['message'] = t('This site is not configured to allow communications with other networks.') . EOL;
			$result['message'] != t('No compatible communication protocols or feeds were discovered.') . EOL;
			return $result;
		}

		// This extra param just confuses things, remove it
		if ($ret['network'] === NETWORK_DIASPORA) {
			$ret['url'] = str_replace('?absolute=true', '', $ret['url']);
		}

		// do we have enough information?

		if (!((x($ret, 'name')) && (x($ret, 'poll')) && ((x($ret, 'url')) || (x($ret, 'addr'))))) {
			$result['message'] .= t('The profile address specified does not provide adequate information.') . EOL;
			if (!x($ret, 'poll')) {
				$result['message'] .= t('No compatible communication protocols or feeds were discovered.') . EOL;
			}
			if (!x($ret, 'name')) {
				$result['message'] .= t('An author or name was not found.') . EOL;
			}
			if (!x($ret, 'url')) {
				$result['message'] .= t('No browser URL could be matched to this address.') . EOL;
			}
			if (strpos($url, '@') !== false) {
				$result['message'] .= t('Unable to match @-style Identity Address with a known protocol or email contact.') . EOL;
				$result['message'] .= t('Use mailto: in front of address to force email check.') . EOL;
			}
			return $result;
		}

		if ($ret['network'] === NETWORK_OSTATUS && Config::get('system', 'ostatus_disabled')) {
			$result['message'] .= t('The profile address specified belongs to a network which has been disabled on this site.') . EOL;
			$ret['notify'] = '';
		}

		if (!$ret['notify']) {
			$result['message'] .= t('Limited profile. This person will be unable to receive direct/personal notifications from you.') . EOL;
		}

		$writeable = ((($ret['network'] === NETWORK_OSTATUS) && ($ret['notify'])) ? 1 : 0);

		$subhub = (($ret['network'] === NETWORK_OSTATUS) ? true : false);

		$hidden = (($ret['network'] === NETWORK_MAIL) ? 1 : 0);

		if (in_array($ret['network'], array(NETWORK_MAIL, NETWORK_DIASPORA))) {
			$writeable = 1;
		}

		// check if we already have a contact
		// the poll url is more reliable than the profile url, as we may have
		// indirect links or webfinger links

		$r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `poll` IN ('%s', '%s') AND `network` = '%s' LIMIT 1",
			intval($uid),
			dbesc($ret['poll']),
			dbesc(normalise_link($ret['poll'])),
			dbesc($ret['network'])
		);

		if (!DBM::is_result($r)) {
			$r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `nurl` = '%s' AND `network` = '%s' LIMIT 1",
				intval($uid), dbesc(normalise_link($url)), dbesc($ret['network'])
			);
		}

		if (DBM::is_result($r)) {
			// update contact
			$new_relation = (($r[0]['rel'] == CONTACT_IS_FOLLOWER) ? CONTACT_IS_FRIEND : CONTACT_IS_SHARING);

			$fields = array('rel' => $new_relation, 'subhub' => $subhub, 'readonly' => false);
			dba::update('contact', $fields, array('id' => $r[0]['id']));
		} else {
			$new_relation = ((in_array($ret['network'], array(NETWORK_MAIL))) ? CONTACT_IS_FRIEND : CONTACT_IS_SHARING);

			// create contact record
			dba::insert(
				'contact',
				[
					'uid' => $uid,
					'created' => datetime_convert(),
					'url' => $ret['url'],
					'nurl' => normalise_link($ret['url']),
					'addr' => $ret['addr'],
					'alias' => $ret['alias'],
					'batch' => $ret['batch'],
					`notify` => $ret['notify'],
					`poll` => $ret['poll'],
					`poco` => $ret['poco'],
					`name` => $ret['name'],
					`nick` => $ret['nick'],
					`network` => $ret['network'],
					`pubkey` => $ret['pubkey'],
					`rel` => $new_relation,
					`priority` => $ret['priority'],
					`writable` => $writeable,
					`hidden` => $hidden,
					`blocked` => 0,
					`readonly` => 0,
					`pending` => 0,
					`subhub` => $subhub
				]
			);
		}

		$r = dba::select('contact', ['url' => $ret['url'], 'network' => $ret['network'], 'uid' => $uid], ['limit' => 1]);

		if (!DBM::is_result($r)) {
			$result['message'] .= t('Unable to retrieve contact information.') . EOL;
			return $result;
		}

		$contact = $r;
		$contact_id = $r['id'];
		$result['cid'] = $contact_id;

		Group::addMember(User::getDefaultGroup($uid, $contact["network"]), $contact_id);

		// Update the avatar
		self::updateAvatar($ret['photo'], $uid, $contact_id);

		// pull feed and consume it, which should subscribe to the hub.

		Worker::add(PRIORITY_HIGH, "OnePoll", $contact_id, "force");

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

		if (DBM::is_result($r)) {
			if (($contact['network'] == NETWORK_OSTATUS) && (strlen($contact['notify']))) {
				// create a follow slap
				$item = array();
				$item['verb'] = ACTIVITY_FOLLOW;
				$item['follow'] = $contact["url"];
				$slap = OStatus::salmon($item, $r[0]);
				Salmon::slapper($r[0], $contact['notify'], $slap);
			}

			if ($contact['network'] == NETWORK_DIASPORA) {
				$ret = Diaspora::sendShare($a->user, $contact);
				logger('share returns: ' . $ret);
			}
		}

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