fix(api): fix duplicate billing notification emails

api/src/billing/billing-notifications.service.ts

@@ -28,23 +28,35 @@ export class BillingNotificationsService {
   ) {}
 
   async notifyOnce({ userId, type, title, message, meta = {}, sendEmail = true }: NotifyOnceInput) {
-    const recent = await this.findRecentSimilar(userId, type)
-    if (recent) {
-      return recent
+    const windowMs = this.getDedupeWindowMs(type)
+    const existing = await this.notificationModel.findOne({
+      user: new Types.ObjectId(userId),
+      type,
+    })
+
+    if (existing) {
+      const lastSentAt = existing.lastEmailSentAt || existing.createdAt
+      if (lastSentAt && lastSentAt.getTime() >= Date.now() - windowMs) {
+        return existing
+      }
     }
 
-    const created = await this.createNotification(userId, type, title, message, meta)
+    const updated = await this.notificationModel.findOneAndUpdate(
+      { user: new Types.ObjectId(userId), type },
+      { $set: { title, message, meta }, $setOnInsert: { user: new Types.ObjectId(userId), type } },
+      { upsert: true, new: true, setDefaultsOnInsert: true },
+    )
 
     await this.billingQueue.add(
       'send',
       {
-        notificationId: created._id,
-        userId: created.user,
-        type: created.type,
-        title: created.title,
-        message: created.message,
-        meta: created.meta,
-        createdAt: created.createdAt,
+        notificationId: updated._id,
+        userId: updated.user,
+        type: updated.type,
+        title: updated.title,
+        message: updated.message,
+        meta: updated.meta,
+        createdAt: updated.createdAt,
         sendEmail,
       },
       {
@@ -52,10 +64,11 @@ export class BillingNotificationsService {
         attempts: 3,
         removeOnComplete: true,
         backoff: { type: 'exponential', delay: 2000 },
+        jobId: updated._id.toString(),
       },
     )
 
-    return created
+    return updated
   }
 
   async listForUser(userId: Types.ObjectId | string, { limit = 50 } = {}) {
@@ -78,30 +91,7 @@ export class BillingNotificationsService {
     return hours * 60 * 60 * 1000
   }
 
-  private async findRecentSimilar(userId: Types.ObjectId | string, type: BillingNotificationType) {
-    const since = new Date(Date.now() - this.getDedupeWindowMs(type))
-    return this.notificationModel.findOne({
-      user: new Types.ObjectId(userId),
-      type,
-      createdAt: { $gte: since },
-    })
-  }
-
-  private async createNotification(
-    userId: Types.ObjectId | string,
-    type: BillingNotificationType,
-    title: string,
-    message: string,
-    meta: Record<string, any>,
-  ) {
-    return this.notificationModel.create({
-      user: new Types.ObjectId(userId),
-      type,
-      title,
-      message,
-      meta,
-    })
-  }
+  // upsert-based single-document per user+type; dedupe controlled by window
 
 }
 

api/src/billing/billing.service.ts

@@ -605,39 +605,31 @@ export class BillingService {
         }
 
         //if plan is pro and monthly limit is exceeded, give them 30% more monthly limit
-        if (plan.name?.startsWith('pro') && monthlyExceeded && !dailyExceeded && !bulkExceeded) {
+        if (
+          plan.name?.startsWith('pro') &&
+          monthlyExceeded &&
+          !dailyExceeded &&
+          !bulkExceeded
+        ) {
           const extendedMonthlyLimit = Math.floor(plan.monthlyLimit * 1.3)
           const exceedsExtended =
             processedSmsLastMonth + value > extendedMonthlyLimit
           if (!exceedsExtended) {
             return true
           }
-          throw new HttpException(
-            {
-              message: message,
-              hasReachedLimit: true,
-              dailyLimit: plan.dailyLimit,
-              dailyRemaining: plan.dailyLimit - processedSmsToday,
-              monthlyRemaining: plan.monthlyLimit - processedSmsLastMonth,
-              bulkSendLimit: plan.bulkSendLimit,
-              monthlyLimit: plan.monthlyLimit,
-            },
-            HttpStatus.TOO_MANY_REQUESTS,
-          )
-        } else {
-          throw new HttpException(
-            {
-              message: message,
-              hasReachedLimit: true,
-              dailyLimit: plan.dailyLimit,
-              dailyRemaining: plan.dailyLimit - processedSmsToday,
-              monthlyRemaining: plan.monthlyLimit - processedSmsLastMonth,
-              bulkSendLimit: plan.bulkSendLimit,
-              monthlyLimit: plan.monthlyLimit,
-            },
-            HttpStatus.TOO_MANY_REQUESTS,
-          )
         }
+        throw new HttpException(
+          {
+            message: message,
+            hasReachedLimit: true,
+            dailyLimit: plan.dailyLimit,
+            dailyRemaining: plan.dailyLimit - processedSmsToday,
+            monthlyRemaining: plan.monthlyLimit - processedSmsLastMonth,
+            bulkSendLimit: plan.bulkSendLimit,
+            monthlyLimit: plan.monthlyLimit,
+          },
+          HttpStatus.TOO_MANY_REQUESTS,
+        )
       }
 
       return true

api/src/billing/queue/billing-notifications.processor.ts

@@ -40,6 +40,15 @@ export class BillingNotificationsProcessor {
       return
     }
 
+    // Ensure we do not resend within the dedupe window
+    const notif = await this.notificationModel.findById(payload.notificationId)
+    if (!notif) return
+    const windowMs = this.getDedupeWindowMs(payload.type as any)
+    const lastSentAt = notif.lastEmailSentAt || notif.createdAt
+    if (lastSentAt && lastSentAt.getTime() >= Date.now() - windowMs) {
+      return
+    }
+
     const subject = this.subjectForType(payload.type, payload.title)
     const ctaUrlBase = process.env.FRONTEND_URL || 'https://app.textbee.dev'
     const isEmailVerification = payload.type === 'email_verification_required'
@@ -69,6 +78,19 @@ export class BillingNotificationsProcessor {
     )
   }
 
+  private getDedupeWindowMs(type: string) {
+    const map: Record<string, number> = {
+      email_verification_required: 24,
+      daily_limit_reached: 12,
+      monthly_limit_reached: 48,
+      bulk_sms_limit_reached: 12,
+      daily_limit_approaching: 24,
+      monthly_limit_approaching: 48,
+    }
+    const hours = map[type] ?? 24
+    return hours * 60 * 60 * 1000
+  }
+
   private subjectForType(type: string, fallback: string) {
     switch (type) {
       case 'daily_limit_reached':