auth.ts

import {Account, getServerSession, Profile, Session, User} from "next-auth"
import Google from "next-auth/providers/google"
import {JWT} from "next-auth/jwt";
import {AdapterUser} from "next-auth/adapters";
import {NextApiRequest, NextApiResponse} from "next";
import {NextRequest} from "next/server";

// Read more at: https://next-auth.js.org/getting-started/typescript#module-augmentation
declare module "next-auth/jwt" {
    interface JWT {
        /** The user's role. */
        userRole?: "admin"
    }
}

export const config = {
    providers: [
        Google({ clientId: process.env.AUTH_GOOGLE_ID, clientSecret: process.env.AUTH_GOOGLE_SECRET })
    ],
    callbacks: {
        async jwt({ token }: {
            token: JWT;
            user: User | AdapterUser;
            account: Account | null;
            profile?: Profile | undefined;
            trigger?: "signIn" | "signUp" | "update" | undefined;
            isNewUser?: boolean | undefined;     session?: any; }) {
            token.userRole = "admin"
            return token
        },
    },
};

// Helper function to get session without passing config every time
// https://next-auth.js.org/configuration/nextjs#getserversession
export function auth(request: NextRequest, response: Response|null): Promise<Session|null> {
    const res = response ? response : new Response(null, {});
    return getServerSession(request as unknown as NextApiRequest, {
        ...res,
        getHeader: (name: string) => res.headers?.get(name),
        setHeader: (name: string, value: string) => res.headers?.set(name, value),
    } as unknown as NextApiResponse, config as any)
}

// We recommend doing your own environment variable validation
declare global {
    namespace NodeJS {
        export interface ProcessEnv {
            NEXTAUTH_SECRET: string

            AUTH_GOOGLE_ID: string
            AUTH_GOOGLE_SECRET: string
        }
    }
}