implement webfinger lookups

1 files changed, 33 insertions, 0 deletions

diff --git a/WpfTest/Model/Actor.php b/WpfTest/Model/Actor.php
index 0b0e729..a745a96 100644
--- a/WpfTest/Model/Actor.php
+++ b/WpfTest/Model/Actor.php
@@ -4,6 +4,8 @@ namespace WpfTest\Model;
 use WpfTest\RemoteFetchable;
 
 class Actor extends FetchableModel implements \JsonSerializable {
+    public const REL_URI = "https://pawpub.entities.org.uk/rel/actor.html";
+
     public ?int $id;
     public string $uri;
     public bool $isLocal = false;
@@ -32,6 +34,37 @@ class Actor extends FetchableModel implements \JsonSerializable {
         return self::findWhere('is_local = true AND handle = ?', [$handle]);
     }
 
+    public static function findByWebfinger(string $acct, bool $autoSave = true, bool $forceRefetch = false): ?self {
+        // normalise uri
+        if (!str_starts_with($acct, 'acct:')) {
+            if (str_starts_with($acct, '@')) {
+                $acct = substr($acct, 1);
+            }
+            $acct = "acct:$acct";
+        }
+        // fetch it
+        $domain = explode('@', $acct, 2)[1];
+        $data = @file_get_contents("https://$domain/.well-known/webfinger?resource=$acct",
+            context: stream_context_create([
+                'http' => ['header' => 'Accept: application/jrd+json, application/json']
+            ])
+        );
+        if ($data === false)
+            return null;
+        $data = json_decode($data);
+        if ($data === null)
+            return null;
+        // find the right link
+        if (!isset($data->links))
+            return null;
+        $matching = array_filter($data->links, function (\stdClass $linkObj) {
+            return $linkObj->rel == self::REL_URI;
+        });
+        if (count($matching) == 0)
+            return null;
+        return self::findByUri($matching[0]->href, $autoSave, $forceRefetch);
+    }
+
     public function jsonSerialize(): array {
         return [
             'type' => 'actor',