From 1ee21d54dc83d383ae56b799a31905da37d50f82 Mon Sep 17 00:00:00 2001
From: Jeremy Dormitzer <jdormitzer@hubspot.com>
Date: Thu, 20 Sep 2018 19:10:15 -0400
Subject: [PATCH] Implement follow for inbox

---
 inc/activities/follow.php | 40 ++++++++++++++++++++++++++++++++++++---
 inc/inbox.php             |  8 +++++---
 2 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/inc/activities/follow.php b/inc/activities/follow.php
index f4b0cab..42a08ee 100644
--- a/inc/activities/follow.php
+++ b/inc/activities/follow.php
@@ -4,22 +4,56 @@ namespace activities\follow;
 require_once plugin_dir_path( __FILE__ ) . '/../following.php';
 require_once plugin_dir_path( __FILE__ ) . '/../actors.php';
 require_once plugin_dir_path( __FILE__ ) . '/../objects.php';
+require_once plugin_dir_path( __FILE__ ) . '/../outbox.php';
 
-function handle_outbox( $actor, $activity ) {
+function handle_outbox( $actor_slug, $activity ) {
     if ( !array_key_exists( 'object', $activity ) ) {
         return new \WP_Error(
             'invalid_activity',
-            __( 'Expected an object', 'activitypub' ),
+            __( 'Expected an object', 'pterotype' ),
             array( 'status' => 400 )
         );
     }
     $object = $activity['object'];
     $object_row = \objects\upsert_object( $object );
-    $actor_id = \actors\get_actor_id( $actor );
+    $actor_id = \actors\get_actor_id( $actor_slug );
     $res = \following\request_follow( $actor_id, $object_row->id );
     if ( is_wp_error( $res ) ) {
         return $res;
     }
     return $activity;
 }
+
+function handle_inbox( $actor_slug, $activity ) {
+    // For now, always Accept follow requests
+    // in the future, implement a UI to either accept or reject
+    // (or automatically accept if the user chooses to enable that setting)
+    $accept = make_accept( $actor_slug, $activity );
+    if ( is_wp_error( $accept ) ) {
+        return $accept;
+    }
+    $res = \outbox\handle_activity( $actor_slug, $accept );
+    if ( is_wp_error( $res ) ) {
+        return $res;
+    }
+    return $activity;
+}
+
+function make_accept( $actor_slug, $follow ) {
+    if ( !array_key_exists( 'actor', $follow ) ) {
+        return new \WP_Error(
+            'invalid_activity',
+            __( 'Activity must have an actor', 'pterotype' ),
+            array( 'status' => 400 )
+        );
+    }
+    $accept = array(
+        '@context' => 'https://www.w3.org/ns/activitystreams',
+        'type' => 'Accept',
+        'actor' => \actors\get_actor_by_slug( $actor_slug ),
+        'object' => $follow,
+        'to' => $follow['actor'],
+    );
+    return $accept;
+}
 ?>
diff --git a/inc/inbox.php b/inc/inbox.php
index 69e9308..0b70a40 100644
--- a/inc/inbox.php
+++ b/inc/inbox.php
@@ -13,6 +13,7 @@ require_once plugin_dir_path( __FILE__ ) . '/activities.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/create.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/update.php';
 require_once plugin_dir_path( __FILE__ ) . '/activities/delete.php';
+require_once plugin_dir_path( __FILE__ ) . '/activities/follow.php';
 
 function handle_activity( $actor_slug, $activity ) {
     if ( !array_key_exists( 'type', $activity ) ) {
@@ -25,15 +26,16 @@ function handle_activity( $actor_slug, $activity ) {
     forward_activity( $activity );
     switch ( $activity['type'] ) {
     case 'Create':
-        $activity = \create\handle_inbox( $actor_slug, $activity );
+        $activity = \activities\create\handle_inbox( $actor_slug, $activity );
         break;
     case 'Update':
-        $activity = \update\handle_inbox( $actor_slug, $activity );
+        $activity = \activities\update\handle_inbox( $actor_slug, $activity );
         break;
     case 'Delete':
-        $activity = \delete\handle_inbox( $actor_slug, $activity );
+        $activity = \activities\delete\handle_inbox( $actor_slug, $activity );
         break;
     case 'Follow':
+        $activity = \activities\follow\handle_inbox( $actor_slug, $activity );
         break;
     case 'Accept':
         break;