From 2b65940e73697eec4cb1c8592d7e89ccdd583ab4 Mon Sep 17 00:00:00 2001
From: Dries Augustyns <inbox@driaug.com>
Date: Thu, 4 Dec 2025 19:44:20 +0100
Subject: [PATCH] Only send bounce event every 20 emails

---
 apps/api/src/services/NtfyService.ts | 74 +++++++++++++++++++++++++---
 1 file changed, 67 insertions(+), 7 deletions(-)

diff --git a/apps/api/src/services/NtfyService.ts b/apps/api/src/services/NtfyService.ts
index ec33d1e..0aaf2c8 100644
--- a/apps/api/src/services/NtfyService.ts
+++ b/apps/api/src/services/NtfyService.ts
@@ -276,6 +276,7 @@ export class NtfyService {
 
   /**
    * Notify about email bounce - LOW priority (high volume)
+   * Rate-limited to only send notification every 20 bounces with per-project breakdown
    */
   public static async notifyEmailBounce(
     projectName: string,
@@ -283,13 +284,72 @@ export class NtfyService {
     recipientEmail: string,
     bounceType?: string,
   ): Promise<void> {
-    const bounceInfo = bounceType ? ` (${bounceType})` : '';
-    await this.send({
-      title: 'Email Bounced',
-      message: `Email to ${recipientEmail} bounced${bounceInfo} in project "${projectName}" (${projectId})`,
-      priority: NtfyPriority.LOW,
-      tags: [NtfyTag.WARNING],
-    });
+    // Import redis at runtime to avoid circular dependencies
+    const {redis} = await import('../database/redis.js');
+
+    // Use Redis counters to track bounce count globally and per-project
+    const globalCountKey = `ntfy:bounce:count`;
+    const projectCountKey = `ntfy:bounce:count:${projectId}`;
+    const projectListKey = `ntfy:bounce:projects`;
+
+    // Increment global counter
+    const globalCount = await redis.incr(globalCountKey);
+
+    // Increment project-specific counter
+    await redis.incr(projectCountKey);
+
+    // Add project to the set of projects with bounces (for tracking)
+    await redis.sadd(projectListKey, projectId);
+
+    // Set expiry on first increment (24 hour rolling window)
+    if (globalCount === 1) {
+      await redis.expire(globalCountKey, 86400);
+      await redis.expire(projectListKey, 86400);
+    }
+    // Always refresh project counter expiry to match global window
+    await redis.expire(projectCountKey, 86400);
+
+    // Only send notification every 20 bounces
+    if (globalCount % 20 === 0) {
+      // Get all projects with bounces
+      const projectIds = await redis.smembers(projectListKey);
+
+      // Get bounce counts for each project
+      const projectCounts: Array<{projectId: string; count: number; name: string}> = [];
+      for (const pid of projectIds) {
+        const count = await redis.get(`ntfy:bounce:count:${pid}`);
+        if (count) {
+          // Fetch project name from database
+          const {prisma} = await import('../database/prisma.js');
+          const project = await prisma.project.findUnique({
+            where: {id: pid},
+            select: {name: true},
+          });
+
+          projectCounts.push({
+            projectId: pid,
+            count: parseInt(count, 10),
+            name: project?.name || 'Unknown',
+          });
+        }
+      }
+
+      // Sort by count descending
+      projectCounts.sort((a, b) => b.count - a.count);
+
+      // Build breakdown message
+      const breakdown = projectCounts
+        .map((p) => `  • ${p.name} (${p.projectId}): ${p.count}`)
+        .join('\n');
+
+      const bounceInfo = bounceType ? ` (${bounceType})` : '';
+      await this.send({
+        title: 'Email Bounces',
+        message: `20 email bounces detected (total: ${globalCount})\n\nBreakdown by project:\n${breakdown}\n\nLatest: ${recipientEmail}${bounceInfo} in "${projectName}"`,
+        priority: NtfyPriority.LOW,
+        tags: [NtfyTag.WARNING],
+      });
+    }
   }
 
   /**