src/Model/ContactRelation.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Model;
  23
  24 use Friendica\Core\Logger;
  25 use Friendica\Core\Protocol;
  26 use Friendica\Database\DBA;
  27 use Friendica\DI;
  28 use Friendica\Protocol\ActivityPub;
  29 use Friendica\Util\DateTimeFormat;
  30 use Friendica\Util\Strings;
  31
  32 class ContactRelation
  33 {
  34         /**
  35          * No discovery of followers/followings
  36          */
  37         const DISCOVERY_NONE = 0;
  38         /**
  39          * Discover followers/followings of local contacts
  40          */
  41         const DISCOVERY_LOCAL = 1;
  42         /**
  43          * Discover followers/followings of local contacts and contacts that visibly interacted on the system
  44          */
  45         const DISCOVERY_INTERACTOR = 2;
  46         /**
  47          * Discover followers/followings of all contacts
  48          */
  49         const DISCOVERY_ALL = 3;
  50
  51         public static function store(int $target, int $actor, string $interaction_date)
  52         {
  53                 if ($actor == $target) {
  54                         return;
  55                 }
  56
  57                 DBA::update('contact-relation', ['last-interaction' => $interaction_date], ['cid' => $target, 'relation-cid' => $actor], true);
  58         }
  59
  60         /**
  61          * Fetches the followers of a given profile and adds them
  62          *
  63          * @param string $url URL of a profile
  64          * @return void
  65          */
  66         public static function discoverByUrl(string $url)
  67         {
  68                 $contact = Contact::getByURL($url);
  69                 if (empty($contact)) {
  70                         return;
  71                 }
  72
  73                 if (!self::isDiscoverable($url, $contact)) {
  74                         return;
  75                 }
  76
  77                 $apcontact = APContact::getByURL($url, false);
  78
  79                 if (!empty($apcontact['followers']) && is_string($apcontact['followers'])) {
  80                         $followers = ActivityPub::fetchItems($apcontact['followers']);
  81                 } else {
  82                         $followers = [];
  83                 }
  84
  85                 if (!empty($apcontact['following']) && is_string($apcontact['following'])) {
  86                         $followings = ActivityPub::fetchItems($apcontact['following']);
  87                 } else {
  88                         $followings = [];
  89                 }
  90
  91                 if (empty($followers) && empty($followings)) {
  92                         DBA::update('contact', ['last-discovery' => DateTimeFormat::utcNow()], ['id' => $contact['id']]);
  93                         Logger::info('The contact does not offer discoverable data', ['id' => $contact['id'], 'url' => $url, 'network' => $contact['network']]);
  94                         return;
  95                 }
  96
  97                 $target = $contact['id'];
  98
  99                 if (!empty($followers)) {
 100                         // Clear the follower list, since it will be recreated in the next step
 101                         DBA::update('contact-relation', ['follows' => false], ['cid' => $target]);
 102                 }
 103
 104                 $contacts = [];
 105                 foreach (array_merge($followers, $followings) as $contact) {
 106                         if (is_string($contact)) {
 107                                 $contacts[] = $contact;
 108                         } elseif (!empty($contact['url']) && is_string($contact['url'])) {
 109                                 $contacts[] = $contact['url'];
 110                         }
 111                 }
 112                 $contacts = array_unique($contacts);
 113
 114                 $follower_counter = 0;
 115                 $following_counter = 0;
 116
 117                 Logger::info('Discover contacts', ['id' => $target, 'url' => $url, 'contacts' => count($contacts)]);
 118                 foreach ($contacts as $contact) {
 119                         $actor = Contact::getIdForURL($contact);
 120                         if (!empty($actor)) {
 121                                 if (in_array($contact, $followers)) {
 122                                         $fields = ['cid' => $target, 'relation-cid' => $actor];
 123                                         DBA::update('contact-relation', ['follows' => true, 'follow-updated' => DateTimeFormat::utcNow()], $fields, true);
 124                                         $follower_counter++;
 125                                 }
 126
 127                                 if (in_array($contact, $followings)) {
 128                                         $fields = ['cid' => $actor, 'relation-cid' => $target];
 129                                         DBA::update('contact-relation', ['follows' => true, 'follow-updated' => DateTimeFormat::utcNow()], $fields, true);
 130                                         $following_counter++;
 131                                 }
 132                         }
 133                 }
 134
 135                 if (!empty($followers)) {
 136                         // Delete all followers that aren't followers anymore (and aren't interacting)
 137                         DBA::delete('contact-relation', ['cid' => $target, 'follows' => false, 'last-interaction' => DBA::NULL_DATETIME]);
 138                 }
 139
 140                 DBA::update('contact', ['last-discovery' => DateTimeFormat::utcNow()], ['id' => $target]);
 141                 Logger::info('Contacts discovery finished', ['id' => $target, 'url' => $url, 'follower' => $follower_counter, 'following' => $following_counter]);
 142                 return;
 143         }
 144
 145         /**
 146          * Tests if a given contact url is discoverable
 147          *
 148          * @param string $url     Contact url
 149          * @param array  $contact Contact array
 150          * @return boolean True if contact is discoverable
 151          */
 152         public static function isDiscoverable(string $url, array $contact = [])
 153         {
 154                 $contact_discovery = DI::config()->get('system', 'contact_discovery');
 155
 156                 if ($contact_discovery == self::DISCOVERY_NONE) {
 157                         return false;
 158                 }
 159
 160                 if (empty($contact)) {
 161                         $contact = Contact::getByURL($url);
 162                 }
 163
 164                 if (empty($contact)) {
 165                         return false;
 166                 }
 167
 168                 if ($contact['last-discovery'] > DateTimeFormat::utc('now - 1 month')) {
 169                         Logger::info('No discovery - Last was less than a month ago.', ['id' => $contact['id'], 'url' => $url, 'discovery' => $contact['last-discovery']]);
 170                         return false;
 171                 }
 172
 173                 if ($contact_discovery != self::DISCOVERY_ALL) {
 174                         $local = DBA::exists('contact', ["`nurl` = ? AND `uid` != ?", Strings::normaliseLink($url), 0]);
 175                         if (($contact_discovery == self::DISCOVERY_LOCAL) && !$local) {
 176                                 Logger::info('No discovery - This contact is not followed/following locally.', ['id' => $contact['id'], 'url' => $url]);
 177                                 return false;
 178                         }
 179
 180                         if ($contact_discovery == self::DISCOVERY_INTERACTOR) {
 181                                 $interactor = DBA::exists('contact-relation', ["`relation-cid` = ? AND `last-interaction` > ?", $contact['id'], DBA::NULL_DATETIME]);
 182                                 if (!$local && !$interactor) {
 183                                         Logger::info('No discovery - This contact is not interacting locally.', ['id' => $contact['id'], 'url' => $url]);
 184                                         return false;
 185                                 }
 186                         }
 187                 } elseif ($contact['created'] > DateTimeFormat::utc('now - 1 day')) {
 188                         // Newly created contacts are not discovered to avoid DDoS attacks
 189                         Logger::info('No discovery - Contact record is less than a day old.', ['id' => $contact['id'], 'url' => $url, 'discovery' => $contact['created']]);
 190                         return false;
 191                 }
 192
 193                 if (!in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::OSTATUS])) {
 194                         $apcontact = APContact::getByURL($url, false);
 195                         if (empty($apcontact)) {
 196                                 Logger::info('No discovery - The contact does not seem to speak ActivityPub.', ['id' => $contact['id'], 'url' => $url, 'network' => $contact['network']]);
 197                                 return false;
 198                         }
 199                 }
 200
 201                 return true;
 202         }
 203 }