broke down ws

src/ws/state/cursor/handler.ts

@@ -0,0 +1,55 @@
+import { Logger } from '@nestjs/common';
+import type { AuthenticatedSocket } from '../../../types/socket';
+import { CursorPositionDto } from '../../dto/cursor-position.dto';
+import { WS_EVENT } from '../ws-events';
+import { Validator } from '../utils/validation';
+import { Throttler } from '../utils/throttling';
+import { Broadcaster } from '../utils/broadcasting';
+
+const CURSOR_THROTTLE_MS = 100;
+
+export class CursorHandler {
+  private readonly logger = new Logger(CursorHandler.name);
+
+  constructor(
+    private readonly broadcaster: Broadcaster,
+    private readonly throttler: Throttler,
+  ) {}
+
+  async handleCursorReportPosition(
+    client: AuthenticatedSocket,
+    data: CursorPositionDto,
+  ) {
+    Validator.validateUser(client);
+
+    const currentUserId = client.data.userId;
+
+    if (!currentUserId) {
+      // User has not initialized yet
+      return;
+    }
+
+    // Do not broadcast cursor position if user has no active doll
+    if (!client.data.activeDollId) {
+      return;
+    }
+
+    if (this.throttler.isThrottled(currentUserId, CURSOR_THROTTLE_MS)) {
+      return;
+    }
+
+    // Broadcast to online friends
+    const friends = client.data.friends;
+    if (friends) {
+      const payload = {
+        userId: currentUserId,
+        position: data,
+      };
+      await this.broadcaster.broadcastToFriends(
+        friends,
+        WS_EVENT.FRIEND_CURSOR_POSITION,
+        payload,
+      );
+    }
+  }
+}