Create actors for users on plugin update/user registration

inc/actors.php

@@ -60,10 +60,31 @@ function create_actors_table() {
         "
         CREATE TABLE IF NOT EXISTS activitypub_actors(
             id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
-            slug VARCHAR(255) UNIQUE NOT NULL,
-            type VARCHAR(64)
+            slug VARCHAR(64) UNIQUE NOT NULL,
+            type VARCHAR(64) NOT NULL
         );
         "
     );
 }
+
+/*
+For every user in the WP instance, create a new actor row for that user
+if it doesn't already exist
+*/
+function initialize_user_actors() {
+    global $wpdb;
+    $user_slugs = $wpdb->get_col( 
+        "SELECT user_nicename FROM wp_users;"
+    );
+    foreach ( $user_slugs as $user_slug ) {
+        create_actor_from_user( $user_slug );
+    }
+}
+
+function create_actor_from_user( $user_slug ) {
+    global $wpdb;
+    $wpdb->query( $wpdb->prepare(
+        "INSERT IGNORE INTO activitypub_actors(slug, type) VALUES(%s, 'user')", $user_slug
+    ) );
+}
 ?>

inc/api.php

@@ -8,8 +8,7 @@ require_once plugin_dir_path( __FILE__ ) . '/activities.php';
 
 function get_actor( $request ) {
     $actor = $request['actor'];
-    $user = get_user_by( 'slug', $actor );
-    return \actors\get_actor( $user );
+    return \actors\get_actor_by_slug( $user );
 }
 
 function handle_activity( $request ) {

inc/init.php

@@ -11,10 +11,16 @@ add_action( 'rest_api_init', function() {
     \api\register_routes();
 } );
 
+add_action( 'user_register', function( $user_id ) {
+    $slug = get_the_author_meta( 'user_nicename', $user_id );
+    \actors\create_actor_from_user( $slug );
+} );
+
 add_action( 'activitypub_init', function() {
     \activities\create_activities_table();
     \objects\create_object_table();
     \outbox\create_outbox_table();
     \actors\create_actors_table();
+    \actors\initialize_user_actors();
 } );
 ?>