From 6f4cd4f4c17288e4c25c902c7d50a4919d2df8b7 Mon Sep 17 00:00:00 2001
From: Leothosine <tosirano007@gmail.com>
Date: Fri, 26 Jun 2026 20:15:46 +0100
Subject: [PATCH 1/3] Add analytics batch cap and request deduplication
 interceptor

Closes #870, #869
---
 .../services/batch-size-guard.service.ts      | 23 +++++++++++++
 .../interceptors/request-dedup.interceptor.ts | 32 +++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 src/analytics/services/batch-size-guard.service.ts
 create mode 100644 src/common/interceptors/request-dedup.interceptor.ts

diff --git a/src/analytics/services/batch-size-guard.service.ts b/src/analytics/services/batch-size-guard.service.ts
new file mode 100644
index 00000000..92214d6a
--- /dev/null
+++ b/src/analytics/services/batch-size-guard.service.ts
@@ -0,0 +1,23 @@
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class BatchSizeGuardService {
+  private readonly maxSize: number = 10000;
+  private droppedCount: number = 0;
+
+  canAdd(currentSize: number): boolean {
+    if (currentSize >= this.maxSize) {
+      this.droppedCount++;
+      return false;
+    }
+    return true;
+  }
+
+  getDroppedCount(): number {
+    return this.droppedCount;
+  }
+
+  resetDroppedCount(): void {
+    this.droppedCount = 0;
+  }
+}
diff --git a/src/common/interceptors/request-dedup.interceptor.ts b/src/common/interceptors/request-dedup.interceptor.ts
new file mode 100644
index 00000000..1648fb82
--- /dev/null
+++ b/src/common/interceptors/request-dedup.interceptor.ts
@@ -0,0 +1,32 @@
+import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common';
+import { Observable, of } from 'rxjs';
+import { tap } from 'rxjs/operators';
+
+@Injectable()
+export class RequestDedupInterceptor implements NestInterceptor {
+  private cache = new Map<string, { response: any; timestamp: number }>();
+  private readonly ttlMs = 60000;
+
+  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
+    const req = context.switchToHttp().getRequest();
+    if (req.method !== 'POST') return next.handle();
+
+    const key = this.fingerprint(req);
+    const cached = this.cache.get(key);
+    if (cached && Date.now() - cached.timestamp < this.ttlMs) {
+      const res = context.switchToHttp().getResponse();
+      res.setHeader('X-Duplicate-Request', 'true');
+      return of(cached.response);
+    }
+
+    return next.handle().pipe(
+      tap((response) => {
+        this.cache.set(key, { response, timestamp: Date.now() });
+      }),
+    );
+  }
+
+  private fingerprint(req: any): string {
+    return ${req.method}:::;
+  }
+}

From ddda1b54c6b40134b14c641806977cb5da13e59a Mon Sep 17 00:00:00 2001
From: Leothosine <tosirano007@gmail.com>
Date: Fri, 26 Jun 2026 21:54:59 +0100
Subject: [PATCH 2/3] fix: ci syntax error

---
 src/common/interceptors/request-dedup.interceptor.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/common/interceptors/request-dedup.interceptor.ts b/src/common/interceptors/request-dedup.interceptor.ts
index 1648fb82..45724326 100644
--- a/src/common/interceptors/request-dedup.interceptor.ts
+++ b/src/common/interceptors/request-dedup.interceptor.ts
@@ -27,6 +27,10 @@ export class RequestDedupInterceptor implements NestInterceptor {
   }
 
   private fingerprint(req: any): string {
-    return ${req.method}:::;
+    const method = req.method;
+    const path = req.path;
+    const body = JSON.stringify(req.body);
+    const userId = req.user ? req.user.id : 'anon';
+    return method + ':' + path + ':' + body + ':' + userId;
   }
 }

From f36ca7670f8589d4d716e85a23ac705c0c032fd9 Mon Sep 17 00:00:00 2001
From: Leothosine <tosirano007@gmail.com>
Date: Fri, 26 Jun 2026 22:12:03 +0100
Subject: [PATCH 3/3] fix: use template literal for fingerprint

---
 src/common/interceptors/request-dedup.interceptor.ts | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/common/interceptors/request-dedup.interceptor.ts b/src/common/interceptors/request-dedup.interceptor.ts
index 45724326..99ccb7c1 100644
--- a/src/common/interceptors/request-dedup.interceptor.ts
+++ b/src/common/interceptors/request-dedup.interceptor.ts
@@ -27,10 +27,7 @@ export class RequestDedupInterceptor implements NestInterceptor {
   }
 
   private fingerprint(req: any): string {
-    const method = req.method;
-    const path = req.path;
-    const body = JSON.stringify(req.body);
-    const userId = req.user ? req.user.id : 'anon';
-    return method + ':' + path + ':' + body + ':' + userId;
+    const id = req.user ? req.user.id : 'anon';
+    return `${req.method}:${req.path}:${JSON.stringify(req.body)}:${id}`;
   }
 }