redis pt 4: presence & more cache invalidation

src/ws/state/ws-notification.service.ts

@@ -1,10 +1,14 @@
-import { Injectable, Logger, Inject } from '@nestjs/common';
+import { Inject, Injectable, Logger } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
 import Redis from 'ioredis';
 import { Server } from 'socket.io';
-import { UserSocketService } from './user-socket.service';
+import { UserEvents } from '../../users/events/user.events';
 import type { AuthenticatedSocket } from '../../types/socket';
 import { REDIS_CLIENT } from '../../database/redis.module';
 import { REDIS_CHANNEL } from './ws-events';
+import { UserSocketService } from './user-socket.service';
+
+const PRESENCE_UPDATE_THROTTLE_MS = 15_000;
 
 @Injectable()
 export class WsNotificationService {
@@ -42,6 +46,11 @@ export class WsNotificationService {
     this.io.to(socketId).emit(event, payload);
   }
 
+  @OnEvent(UserEvents.PROFILE_UPDATED)
+  async handleUserProfileUpdated(payload: { userId: string }) {
+    await this.publishUserProfileCacheInvalidate(payload.userId);
+  }
+
   async updateFriendsCache(
     userId: string,
     friendId: string,
@@ -126,4 +135,63 @@ export class WsNotificationService {
       );
     }
   }
+
+  async publishUserProfileCacheInvalidate(userId: string) {
+    if (this.redisClient) {
+      try {
+        await this.redisClient.publish(
+          REDIS_CHANNEL.USER_PROFILE_CACHE_INVALIDATE,
+          JSON.stringify({ userId }),
+        );
+        return;
+      } catch (error) {
+        this.logger.warn(
+          'Redis publish failed for user profile cache invalidate; applying local update only',
+          error as Error,
+        );
+      }
+    }
+
+    await this.clearSenderNameCache(userId);
+  }
+
+  async clearSenderNameCache(userId: string) {
+    if (!this.io) {
+      return;
+    }
+
+    const socketId = await this.userSocketService.getSocket(userId);
+    if (!socketId) {
+      return;
+    }
+
+    const socket = this.io.sockets.sockets.get(socketId) as
+      | AuthenticatedSocket
+      | undefined;
+    if (!socket?.data) {
+      return;
+    }
+
+    socket.data.senderName = undefined;
+    socket.data.senderNameCachedAt = undefined;
+  }
+
+  async maybeTouchPresence(client: AuthenticatedSocket): Promise<void> {
+    const userId = client.data.userId;
+    if (!userId) {
+      return;
+    }
+
+    const now = Date.now();
+    const lastSeenAt = client.data.lastSeenAt;
+    if (
+      typeof lastSeenAt === 'number' &&
+      now - lastSeenAt < PRESENCE_UPDATE_THROTTLE_MS
+    ) {
+      return;
+    }
+
+    client.data.lastSeenAt = now;
+    await this.userSocketService.touchLastSeen(userId);
+  }
 }