Respond correctly to requests with Accept: application/ld+json

includes/init.php

@@ -36,4 +36,5 @@ add_action( 'parse_request', '\pterotype\webfinger\parse_request', 111 );
 add_filter( 'query_vars', '\pterotype\webfinger\query_vars' );
 add_action( 'well_known_webfinger', '\pterotype\webfinger\handle' );
 add_action( 'transition_post_status', '\pterotype\posts\handle_post_status_change', 10, 3 );
+add_action( 'template_redirect', '\pterotype\api\handle_non_api_requests' );
 ?>

includes/server/api.php

@@ -108,4 +108,21 @@ function register_routes() {
         'callback' => __NAMESPACE__ . '\get_shares',
     ) );
 }
+
+function handle_non_api_requests() {
+    global $wp;
+    $accept = $_SERVER['HTTP_ACCEPT'];
+    if ( strpos( $accept, 'application/ld+json' ) !== false ) {
+        $current_url = \trailingslashit(
+            home_url( add_query_arg( $_GET, $wp->request ) )
+        );
+        $objects = \pterotype\objects\get_objects_by( 'url', $current_url );
+        if ( count( $objects ) > 0 ) {
+            $object = $objects[0];
+            header( 'Content-Type: application/activity+json', true );
+            echo wp_json_encode( $object );
+            exit;
+        }
+    }
+}
 ?>

includes/server/objects.php

@@ -205,6 +205,29 @@ function get_object_id( $activitypub_id ) {
     ) );
 }
 
+function get_objects_by( $field, $value ) {
+    global $wpdb;
+    $objects = $wpdb->get_results(
+        $wpdb->prepare(
+            "
+            SELECT object FROM {$wpdb->prefix}pterotype_objects
+            WHERE object->\"$.$field\" = %s
+            ",
+            $value
+        ),
+        ARRAY_A
+    );
+    if ( ! $objects ) {
+        $objects = array();
+    }
+    return array_map(
+        function( $result ) {
+            return json_decode( $result['object'], true );
+        },
+        $objects
+    );
+}
+
 function delete_object( $object ) {
     global $wpdb;
     $object = \pterotype\util\dereference_object( $object );