import type { NextFunction, Request, Response } from "express";
import { type JWTPayload, jwtVerify, SignJWT } from "jose";
import env from "dotenv";

env.config();
const secret = new TextEncoder().encode(process.env.SECRET_KEY);

export type AuthTokenPayload = JWTPayload & {
  username: string;
};

declare module "express-serve-static-core" {
  interface Request {
    user?: AuthTokenPayload;
  }
}

export async function generateToken(payload: AuthTokenPayload) {
  return await new SignJWT(payload)
    .setProtectedHeader({ alg: "HS256" })
    .setIssuedAt()
    .setExpirationTime("24h")
    .sign(secret);
}

export async function authenticate(
  req: Request,
  res: Response,
  next: NextFunction,
) {
  const authHeader = req.headers["authorization"];
  const token = authHeader && authHeader.split(" ")[1];

  if (token == null) return res.sendStatus(401);

  const { payload } = await jwtVerify<AuthTokenPayload>(token, secret);
  req.user = payload;

  next();
}