implement user authentication with login functionality and database integration

backend/services/tokenService.js

@@ -0,0 +1,26 @@
+import { SignJWT, jwtVerify } from "jose";
+import env from "dotenv";
+env.config();
+const secret = new TextEncoder().encode(process.env.SECRET_KEY);
+
+export async function generateToken(payload) {
+  const newToken = await new SignJWT(payload)
+    .setProtectedHeader({ alg: "HS256" })
+    .setIssuedAt()
+    .setExpirationTime("2h") // Token valid for 2 hours
+    .sign(secret);
+  console.log("Generated token: ", newToken);
+  return newToken;
+}
+
+export async function authenticate(req, res, next) {
+  const authHeader = req.headers["authorization"];
+  const token = authHeader && authHeader.split(" ")[1]; // Bearer <token>
+
+  if (token == null) return res.sendStatus(401); // No token present
+
+  const { payload } = await jwtVerify(token, secret);
+  req.user = payload;
+
+  next();
+}