Relay: improve types, DRY

src/controllers/nostr/relay.ts

@@ -1,19 +1,25 @@
-import { type Filter } from '@/deps.ts';
 import { getFilters } from '@/db/events.ts';
 import { jsonSchema } from '@/schema.ts';
 import { clientMsgSchema, type ClientREQ } from '@/schemas/nostr.ts';
 
 import type { AppController } from '@/app.ts';
+import type { Filter } from '@/deps.ts';
+import type { SignedEvent } from '@/event.ts';
 
 /** Limit of events returned per-filter. */
 const FILTER_LIMIT = 100;
 
+type RelayMsg =
+  | ['EVENT', string, SignedEvent]
+  | ['NOTICE', string]
+  | ['EOSE', string];
+
 function connectStream(socket: WebSocket) {
   socket.onmessage = (e) => {
     const result = jsonSchema.pipe(clientMsgSchema).safeParse(e.data);
 
     if (!result.success) {
-      socket.send(JSON.stringify(['NOTICE', 'Invalid message.']));
+      send(['NOTICE', 'Invalid message.']);
       return;
     }
 
@@ -23,17 +29,23 @@ function connectStream(socket: WebSocket) {
       case 'REQ':
         handleReq(clientMsg);
         return;
-      default:
-        socket.send(JSON.stringify(['NOTICE', 'Unknown command.']));
+      case 'EVENT':
+        send(['NOTICE', 'EVENT not yet implemented.']);
+        return;
+      case 'CLOSE':
         return;
     }
   };
 
   async function handleReq([_, sub, ...filters]: ClientREQ) {
     for (const event of await getFilters(prepareFilters(filters))) {
-      socket.send(JSON.stringify(['EVENT', sub, event]));
+      send(['EVENT', sub, event]);
     }
-    socket.send(JSON.stringify(['EOSE', sub]));
+    send(['EOSE', sub]);
+  }
+
+  function send(msg: RelayMsg) {
+    socket.send(JSON.stringify(msg));
   }
 }