chore: use redis cache service for the new email notify

src/modules/email-utils/email-utils.module.ts

@@ -10,12 +10,14 @@ import { EMAIL_QUEUE_CONSTANTS } from "../email/constants/email-events.constant"
 import { EmailGatewayModule } from "../email-gateway/email-gateway.module";
 import { MailServerModule } from "../mail-server/mail-server.module";
 import { NotificationModule } from "../notifications/notifications.module";
+import { UtilsModule } from "../utils/utils.module";
 
 @Module({
   imports: [
     NotificationModule,
     MailServerModule,
     EmailGatewayModule,
+    UtilsModule,
     BullModule.forRootAsync(bullMqConfig()),
     BullModule.registerQueue({
       name: EMAIL_QUEUE_CONSTANTS.EMAIL_POLLING_QUEUE,

src/modules/email-utils/queue/email-polling.processor.ts

@@ -7,6 +7,7 @@ import { WorkerProcessor } from "../../../common/queues/worker.processor";
 import { EMAIL_QUEUE_CONSTANTS } from "../../email/constants/email-events.constant";
 import { EmailGateway } from "../../email-gateway/email.gateway";
 import { MailServerService } from "../../mail-server/services/mail-server.service";
+import { CacheService } from "../../utils/services/cache.service";
 import { EmailPollingJobData } from "../interfaces/email-polling-job.interface";
 import { EmailNotificationService } from "../services/email-notification.service";
 import { MailboxResolverService } from "../services/mailbox-resolver.service";
@@ -15,28 +16,24 @@ import { MailboxResolverService } from "../services/mailbox-resolver.service";
 export class EmailPollingProcessor extends WorkerProcessor {
   protected readonly logger = new Logger(EmailPollingProcessor.name);
 
-  // Track notified emails to prevent duplicates - key: userId, value: Set of messageIds
-  private notifiedEmails = new Map<string, Set<number>>();
+  private readonly CACHE_KEY = "email-polling-notified-emails";
 
   constructor(
     private readonly emailGateway: EmailGateway,
     private readonly emailNotificationService: EmailNotificationService,
     private readonly mailboxResolverService: MailboxResolverService,
     private readonly mailServerService: MailServerService,
+    private readonly cacheService: CacheService,
   ) {
     super();
   }
 
   async process(job: Job<EmailPollingJobData>): Promise<void> {
-    const { wildduckUserId, userId, lastCheckTimestamp, connectionId } = job.data;
-
-    this.logger.debug(`Processing email polling job for user ${userId} (connection: ${connectionId})`);
+    const { wildduckUserId, userId, lastCheckTimestamp } = job.data;
 
     try {
       if (!this.emailGateway.isUserConnected(userId)) {
-        this.logger.debug(`User ${userId} no longer connected, skipping email check and cleaning up notified emails`);
-        // Clean up notified emails for disconnected user
-        this.notifiedEmails.delete(userId);
+        await this.cacheService.del(`${this.CACHE_KEY}:${userId}`);
         return;
       }
 
@@ -49,18 +46,14 @@ export class EmailPollingProcessor extends WorkerProcessor {
       const checkSince = lastCheckTimestamp ? new Date(lastCheckTimestamp) : new Date(Date.now() - 5 * 60 * 1000);
       const now = new Date();
 
-      this.logger.debug(`Checking emails for user ${userId} since ${checkSince.toISOString()}`);
-
       const newEmails = await this.getRecentEmails(wildduckUserId, mailboxIds.inbox, checkSince);
 
       if (newEmails.length > 0) {
         this.logger.log(`Found ${newEmails.length} potential new emails for user ${wildduckUserId}`);
 
-        // Get or initialize the set of notified emails for this user
-        if (!this.notifiedEmails.has(userId)) {
-          this.notifiedEmails.set(userId, new Set());
-        }
-        const userNotifiedEmails = this.notifiedEmails.get(userId)!;
+        // Get notified emails from cache (stored as array, converted to Set for operations)
+        const notifiedEmailIds = await this.getNotifiedEmailIds(userId);
+        const userNotifiedEmails = new Set(notifiedEmailIds);
 
         // Filter out emails that have already been notified about
         const trulyNewEmails = newEmails.filter((email) => !userNotifiedEmails.has(email.id));
@@ -91,18 +84,22 @@ export class EmailPollingProcessor extends WorkerProcessor {
             userNotifiedEmails.add(email.id);
           }
 
+          // Clean up old notified emails periodically (keep only last 500 per user to prevent memory/cache bloat)
+          let finalNotifiedEmails = userNotifiedEmails;
+          if (userNotifiedEmails.size > 1000) {
+            const sortedIds = Array.from(userNotifiedEmails).sort((a, b) => b - a);
+            const recentIds = sortedIds.slice(0, 500); // Keep most recent 500
+            finalNotifiedEmails = new Set(recentIds);
+            this.logger.debug(`Cleaned up ${userNotifiedEmails.size - finalNotifiedEmails.size} old notification records for user ${userId}`);
+          }
+
+          // Update cache with new notified email IDs
+          await this.setNotifiedEmailIds(userId, Array.from(finalNotifiedEmails));
+
           this.logger.log(`Notified user ${userId} of ${trulyNewEmails.length} new emails`);
         } else {
           this.logger.debug(`No new emails to notify for user ${userId} - all ${newEmails.length} emails already notified`);
         }
-
-        // Clean up old notified emails periodically (keep only last 1000 per user to prevent memory leaks)
-        if (userNotifiedEmails.size > 1000) {
-          const sortedIds = Array.from(userNotifiedEmails).sort((a, b) => b - a);
-          const toRemove = sortedIds.slice(500); // Keep most recent 500
-          toRemove.forEach((id) => userNotifiedEmails.delete(id));
-          this.logger.debug(`Cleaned up ${toRemove.length} old notification records for user ${userId}`);
-        }
       } else {
         this.logger.debug(`No new emails found for user ${userId}`);
       }
@@ -142,4 +139,30 @@ export class EmailPollingProcessor extends WorkerProcessor {
       return [];
     }
   }
+
+  //=======================================================
+  private async getNotifiedEmailIds(userId: string): Promise<number[]> {
+    try {
+      const cached = await this.cacheService.get<string>(`${this.CACHE_KEY}:${userId}`);
+      if (!cached) {
+        return [];
+      }
+      return JSON.parse(cached) as number[];
+    } catch (error) {
+      this.logger.error(`Error getting notified email IDs for user ${userId}:`, error);
+      return [];
+    }
+  }
+
+  //=======================================================
+  private async setNotifiedEmailIds(userId: string, emailIds: number[]): Promise<void> {
+    try {
+      // Set with 24 hour TTL to prevent indefinite cache growth
+      await this.cacheService.set(`${this.CACHE_KEY}:${userId}`, JSON.stringify(emailIds), 24 * 60 * 60);
+    } catch (error) {
+      this.logger.error(`Error setting notified email IDs for user ${userId}:`, error);
+    }
+  }
+
+  //=======================================================
 }