feat(be): request logger middleware

Author: krystxf

apps/backend/src/app.module.ts

@@ -1,13 +1,14 @@
 import { ApolloDriver, type ApolloDriverConfig } from "@nestjs/apollo";
 import { CacheModule } from "@nestjs/cache-manager";
-import { Module } from "@nestjs/common";
+import { MiddlewareConsumer, Module, NestModule } from "@nestjs/common";
 import { ConfigModule } from "@nestjs/config";
 import { GraphQLModule } from "@nestjs/graphql";
 import { ScheduleModule } from "@nestjs/schedule";
 
 import { cacheModuleConfig } from "src/config/cache-module.config";
 import { configModuleConfig } from "src/config/config-module.config";
 import { GRAPHQL_PATH } from "src/constants/api";
+import { RequestLoggerMiddleware } from "src/middleware/request-logger-middleware";
 import { DepartureModule } from "src/modules/departure/departure.module";
 import { ImportModule } from "src/modules/import/import.module";
 import { LoggerModule } from "src/modules/logger/logger.module";
@@ -38,4 +39,8 @@ import { StopModule } from "src/modules/stop/stop.module";
     controllers: [],
     providers: [],
 })
-export class AppModule {}
+export class AppModule implements NestModule {
+    configure(consumer: MiddlewareConsumer) {
+        consumer.apply(RequestLoggerMiddleware).forRoutes("*");
+    }
+}

apps/backend/src/middleware/request-logger-middleware.ts

@@ -0,0 +1,61 @@
+import { Injectable, NestMiddleware } from "@nestjs/common";
+import { NextFunction, Request, Response } from "express";
+
+import { PrismaService } from "src/modules/prisma/prisma.service";
+
+@Injectable()
+export class RequestLoggerMiddleware implements NestMiddleware {
+    constructor(private readonly prisma: PrismaService) {}
+
+    async use(req: Request, res: Response, next: NextFunction) {
+        const start = Date.now();
+
+        // Intercept the response to capture the body
+        const originalSend = res.send;
+        let responseBody: unknown;
+
+        res.send = (body): Response => {
+            responseBody = body; // Capture the response body
+            return originalSend.call(res, body); // Call the original `send` method
+        };
+
+        // Attach an event listener to log after the response is sent
+        res.on("finish", async () => {
+            const duration = Date.now() - start;
+            const {
+                method,
+                url: path,
+                headers: { "user-agent": userAgent = null },
+            } = req;
+            const { statusCode } = res;
+            const responseString =
+                typeof responseBody === "string"
+                    ? responseBody
+                    : JSON.stringify(responseBody);
+
+            const ignoreResponse = [
+                "/v1/stop/all",
+                "/v1/platform/",
+                "/status",
+            ].some((item) => path.startsWith(item));
+
+            try {
+                // Log the request details to the database
+                await this.prisma.requestLog.create({
+                    data: {
+                        method,
+                        path,
+                        status: statusCode,
+                        duration,
+                        userAgent,
+                        response: ignoreResponse ? null : responseString,
+                    },
+                });
+            } catch (error) {
+                console.error("Failed to log request:", error);
+            }
+        });
+
+        next();
+    }
+}