auth.ts

import NextAuth from "next-auth";
import GitHub from "next-auth/providers/github";

import type { NextAuthConfig } from "next-auth";

declare module "next-auth" {
  interface Session {
    accessToken?: string;
    user: {
      id?: string;
      name?: string | null;
      email?: string | null;
      image?: string | null;
      username?: string;
    };
  }
}

declare module "@auth/core/jwt" {
  interface JWT {
    accessToken?: string;
    username?: string;
  }
}

export const authConfig: NextAuthConfig = {
  providers: [
    GitHub({
      clientId: process.env.AUTH_GITHUB_ID,
      clientSecret: process.env.AUTH_GITHUB_SECRET,
    }),
  ],
  callbacks: {
    async jwt({ token, account, profile }) {
      if (account) {
        token.accessToken = account.access_token;
      }
      if (profile) {
        token.username = (profile as { login?: string }).login;
      }
      return token;
    },
    async session({ session, token }) {
      session.accessToken = token.accessToken;
      if (session.user) {
        session.user.username = token.username;
      }
      return session;
    },
  },
  pages: {
    signIn: "/login",
  },
  session: {
    strategy: "jwt",
  },
};

export const { handlers, auth, signIn, signOut } = NextAuth(authConfig);