Feat/notification throttling

src/email/email-report.service.ts

@@ -0,0 +1,34 @@
+import { Injectable } from '@nestjs/common';
+import { PrismaService } from '../prisma/prisma.service';
+
+@Injectable()
+export class EmailReportService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  async recordDelivery(emailId: string, status: 'delivered' | 'bounced' | 'opened' | 'clicked') {
+    return this.prisma.emailReport.create({
+      data: {
+        emailId,
+        delivered: status === 'delivered',
+        bounced: status === 'bounced',
+        opened: status === 'opened',
+        clicked: status === 'clicked',
+      },
+    });
+  }
+
+  async getMetrics() {
+    const total = await this.prisma.emailReport.count();
+    const delivered = await this.prisma.emailReport.count({ where: { delivered: true } });
+    const bounced = await this.prisma.emailReport.count({ where: { bounced: true } });
+    const opened = await this.prisma.emailReport.count({ where: { opened: true } });
+    const clicked = await this.prisma.emailReport.count({ where: { clicked: true } });
+
+    return {
+      deliveryRate: delivered / total,
+      bounceRate: bounced / total,
+      openRate: opened / total,
+      clickRate: clicked / total,
+    };
+  }
+}

src/email/email.controller.ts

@@ -0,0 +1,12 @@
+import { Controller, Get } from '@nestjs/common';
+import { EmailReportService } from './email-report.service';
+
+@Controller('emails')
+export class EmailController {
+  constructor(private readonly reportService: EmailReportService) {}
+
+  @Get('reports')
+  async getReports() {
+    return this.reportService.getMetrics();
+  }
+}

src/utils/observability.ts

@@ -0,0 +1,10 @@
+export function logEmailEvent(emailId: string, event: string, correlationId?: string) {
+  console.log(JSON.stringify({
+    level: 'info',
+    type: 'email',
+    emailId,
+    event,
+    correlationId,
+    timestamp: new Date().toISOString(),
+  }));
+}