From 8480194479e68277f65b032ca3b96db80d8a6b89 Mon Sep 17 00:00:00 2001
From: Diogo Cordeiro <diogo@fc.up.pt>
Date: Thu, 10 May 2018 16:01:14 +0100
Subject: [PATCH] Add implementation of Followers endpoint

---
 ActivityPubPlugin.php              |   8 +++
 actions/apactorfollowers.php       | 100 +++++++++++++++++++++++++++++
 actions/apactorlikedcollection.php |   2 +-
 actions/apactorprofile.php         |   4 +-
 4 files changed, 111 insertions(+), 3 deletions(-)
 create mode 100644 actions/apactorfollowers.php

diff --git a/ActivityPubPlugin.php b/ActivityPubPlugin.php
index 920665b..187cec4 100644
--- a/ActivityPubPlugin.php
+++ b/ActivityPubPlugin.php
@@ -47,6 +47,14 @@ class ActivityPubPlugin extends Plugin
         $m->connect(':nickname/liked.json',
                     ['action'    => 'apActorLikedCollection'],
                     ['nickname'  => Nickname::DISPLAY_FMT]);
+        
+        $m->connect(':nickname/followers.json',
+                    ['action'    => 'apActorFollowers'],
+                    ['nickname'  => Nickname::DISPLAY_FMT]);
+        
+        /*$m->connect(':nickname/following.json',
+                    ['action'    => 'apActorFollowing'],
+                    ['nickname'  => Nickname::DISPLAY_FMT]);*/
     }
 
     public function onPluginVersion(array &$versions)
diff --git a/actions/apactorfollowers.php b/actions/apactorfollowers.php
new file mode 100644
index 0000000..42f0c70
--- /dev/null
+++ b/actions/apactorfollowers.php
@@ -0,0 +1,100 @@
+<?php
+/**
+ * GNU social - a federating social network
+ *
+ * Todo: Description
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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 <http://www.gnu.org/licenses/>.
+ *
+ * @category  Plugin
+ * @package   GNUsocial
+ * @author    Diogo Cordeiro <diogo@fc.up.pt>
+ * @author    Daniel Supernault <danielsupernault@gmail.com>
+ * @copyright 2015 Free Software Foundaction, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      https://gnu.io/social
+ */
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+class apActorFollowersAction extends ManagedAction
+{
+    protected $needLogin = false;
+    protected $canPost   = true;
+
+    protected function handle()
+    {
+        $nickname = $this->trimmed('nickname');
+        try {
+          $user    = User::getByNickname($nickname);
+          $profile = $user->getProfile();
+          $url     = $profile->profileurl;
+        } catch (Exception $e) {
+          throw new \Exception('Invalid username');
+        }
+        
+        $page = intval($this->trimmed('page'));
+        
+        if ($page <= 0)
+            throw new \Exception('Invalid page number');        
+        
+        /* Fetch Followers */
+        try {
+            $since = ($page-1) * PROFILES_PER_MINILIST;
+            $limit = (($page-1) == 0 ? 1 : $page)*PROFILES_PER_MINILIST;
+            $sub = $profile->getSubscribers($since, $limit);
+        } catch (NoResultException $e) {
+            throw new \Exception('This user has no followers');
+        }
+
+        /* Calculate total items */
+        $total_subs  = $profile->subscriberCount();
+        $total_pages = ceil($total_subs/PROFILES_PER_MINILIST);
+        
+        if ($total_pages == 0)
+            throw new \Exception('This user has no followers');
+        
+        if ($page > $total_pages)
+            throw new \Exception("There are only {$total_pages} pages");
+        
+        /* Get followers' URLs */
+        $subs = [];
+        while ($sub->fetch())
+          $subs[] = $this->pretty_sub (clone($sub));
+        
+        $res = [
+          '@context'          => [
+            "https://www.w3.org/ns/activitystreams",
+            "https://w3id.org/security/v1",
+          ],
+          'id'                => "{$url}/followers.json",
+          'type'              => ($page == 0 ? 'OrderedCollection' : 'OrderedCollectionPage'),
+          'totalItems'        => $total_subs,
+          'next'              => $page+1 > $total_pages ? null : "{$url}/followers.json?page=".($page+1 == 1 ? 2 : $page+1),
+          'prev'              => $page == 1 ? null : "{$url}/followers.json?page=".($page-1 <= 0 ? 1 : $page-1),
+          'orderedItems'      => $subs
+        ];
+
+        header('Content-Type: application/activity+json');
+
+        echo json_encode($res, JSON_UNESCAPED_SLASHES | (isset($_GET["pretty"]) ? JSON_PRETTY_PRINT : null));
+    }
+    
+    protected function pretty_sub ($sub_object)
+    {
+        return $sub_object->profileurl;
+    }
+}
diff --git a/actions/apactorlikedcollection.php b/actions/apactorlikedcollection.php
index e36a332..c41c842 100644
--- a/actions/apactorlikedcollection.php
+++ b/actions/apactorlikedcollection.php
@@ -78,7 +78,7 @@ class apActorLikedCollectionAction extends ManagedAction
           'orderedItems'      => $faves
         ];
 
-        header('Content-Type: application/json');
+        header('Content-Type: application/activity+json');
 
         echo json_encode($res, JSON_UNESCAPED_SLASHES | (isset($_GET["pretty"]) ? JSON_PRETTY_PRINT : null));
     }
diff --git a/actions/apactorprofile.php b/actions/apactorprofile.php
index b89de7c..68cab8c 100644
--- a/actions/apactorprofile.php
+++ b/actions/apactorprofile.php
@@ -31,7 +31,7 @@
 if (!defined('GNUSOCIAL')) { exit(1); }
 
 class apActorProfileAction extends ManagedAction
-{
+{    
     protected $needLogin = false;
     protected $canPost   = true;
 
@@ -45,7 +45,7 @@ class apActorProfileAction extends ManagedAction
           throw new \Exception('Invalid username');
         }
 
-        header('Content-Type: application/json');
+        header('Content-Type: application/activity+json');
 
         $res = Activitypub_profile::profileToObject($profile);