feat: add typed moderation broadcaster

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/moderation/broadcaster.ts

@@ -0,0 +1,58 @@
+import type { WebSocket } from "ws";
+import type {
+  AnalysisQueueStatus,
+  AttachmentRecord,
+  MessageRecord,
+  ModerationWsEvent,
+} from "./types";
+
+type ClientLike = Pick<WebSocket, "readyState" | "send">;
+
+function sendJson(clients: Set<ClientLike>, event: ModerationWsEvent): void {
+  const payload = JSON.stringify({ ...event, timestamp: Date.now() });
+  for (const client of clients) {
+    if (client.readyState === 1) client.send(payload);
+  }
+}
+
+export function createBroadcaster() {
+  const clients = new Set<ClientLike>();
+
+  return {
+    addClient(client: ClientLike) {
+      clients.add(client);
+    },
+    removeClient(client: ClientLike) {
+      clients.delete(client);
+    },
+    clientCount() {
+      return clients.size;
+    },
+    uiState(state: unknown) {
+      sendJson(clients, { type: "ui_state", state });
+    },
+    userState(users: unknown[]) {
+      sendJson(clients, { type: "user_state", users });
+    },
+    messageCreated(data: MessageRecord) {
+      sendJson(clients, { type: "message_created", data });
+    },
+    messageUpdated(data: Partial<MessageRecord> & { id: string }) {
+      sendJson(clients, { type: "message_updated", data });
+    },
+    messageDeleted(data: { id: string; deleted_at: number }) {
+      sendJson(clients, { type: "message_deleted", data });
+    },
+    messageAnalyzed(data: MessageRecord) {
+      sendJson(clients, { type: "message_analyzed", data });
+    },
+    attachmentCreated(data: AttachmentRecord) {
+      sendJson(clients, { type: "attachment_created", data });
+    },
+    analysisQueueStatus(data: AnalysisQueueStatus) {
+      sendJson(clients, { type: "analysis_queue_status", data });
+    },
+  };
+}
+
+export type ModerationBroadcaster = ReturnType<typeof createBroadcaster>;