From e285a4e634789f129860e11063f91b3edc90cee5 Mon Sep 17 00:00:00 2001
From: Mathis HERRIOT <197931332+0x485254@users.noreply.github.com>
Date: Tue, 20 Jan 2026 09:44:12 +0100
Subject: [PATCH] feat(auth): add detailed logging for login and 2FA operations

Introduce warnings for failed login attempts and invalid 2FA tokens. Add logs for successful logins and 2FA requirements to improve authentication traceability.
---
 backend/src/auth/auth.service.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/backend/src/auth/auth.service.ts b/backend/src/auth/auth.service.ts
index 2133afb..e5adba1 100644
--- a/backend/src/auth/auth.service.ts
+++ b/backend/src/auth/auth.service.ts
@@ -110,6 +110,7 @@ export class AuthService {
 		const user = await this.usersService.findByEmailHash(emailHash);
 
 		if (!user) {
+			this.logger.warn(`Login failed: user not found for email hash`);
 			throw new UnauthorizedException("Invalid credentials");
 		}
 
@@ -119,10 +120,12 @@ export class AuthService {
 		);
 
 		if (!isPasswordValid) {
+			this.logger.warn(`Login failed: invalid password for user ${user.uuid}`);
 			throw new UnauthorizedException("Invalid credentials");
 		}
 
 		if (user.isTwoFactorEnabled) {
+			this.logger.log(`2FA required for user ${user.uuid}`);
 			return {
 				message: "2FA required",
 				requires2FA: true,
@@ -141,6 +144,7 @@ export class AuthService {
 			ip,
 		);
 
+		this.logger.log(`User ${user.uuid} logged in successfully`);
 		return {
 			message: "User logged in successfully",
 			access_token: accessToken,
@@ -165,6 +169,7 @@ export class AuthService {
 
 		const isValid = authenticator.verify({ token, secret });
 		if (!isValid) {
+			this.logger.warn(`2FA verification failed for user ${userId}: invalid token`);
 			throw new UnauthorizedException("Invalid 2FA token");
 		}
 
@@ -179,6 +184,7 @@ export class AuthService {
 			ip,
 		);
 
+		this.logger.log(`User ${userId} logged in successfully via 2FA`);
 		return {
 			message: "User logged in successfully (2FA)",
 			access_token: accessToken,