Add a getInstanceMetadata function to DRY a few controllers

src/utils/instance.ts

@@ -0,0 +1,37 @@
+import { NostrEvent, NostrMetadata, NSchema as n } from '@nostrify/nostrify';
+
+import { Conf } from '@/config.ts';
+import { serverMetaSchema } from '@/schemas/nostr.ts';
+import { Storages } from '@/storages.ts';
+
+/** Like NostrMetadata, but some fields are required and also contains some extra fields. */
+export interface InstanceMetadata extends NostrMetadata {
+  name: string;
+  about: string;
+  tagline: string;
+  email: string;
+  event?: NostrEvent;
+}
+
+/** Get and parse instance metadata from the kind 0 of the admin user. */
+export async function getInstanceMetadata(signal?: AbortSignal): Promise<InstanceMetadata> {
+  const [event] = await Storages.db.query(
+    [{ kinds: [0], authors: [Conf.pubkey], limit: 1 }],
+    { signal },
+  );
+
+  const meta = n
+    .json()
+    .pipe(serverMetaSchema)
+    .catch({})
+    .parse(event?.content);
+
+  return {
+    ...meta,
+    name: meta.name ?? 'Ditto',
+    about: meta.about ?? 'Nostr community server',
+    tagline: meta.tagline ?? meta.about ?? 'Nostr community server',
+    email: meta.email ?? `postmaster@${Conf.url.host}`,
+    event,
+  };
+}