auth.ts

import NextAuth, { type DefaultSession } from "next-auth";

import authConfig from "./auth.config";
import { PrismaAdapter } from "@auth/prisma-adapter";
import { prisma } from "./lib/prisma";
import { getUserById } from "./lib/db/user";
import { JWT } from "next-auth/jwt";

declare module "next-auth/jwt" {
  /** Returned by the `jwt` callback and `auth`, when using JWT sessions */
  interface JWT {
    /** OpenID ID Token */
    role: "USER" | "ADMIN";
  }
}
declare module "next-auth" {
  /**
   * Returned by `auth`, `useSession`, `getSession` and received as a prop on the `SessionProvider` React Context
   */
  interface Session {
    user: {
      /** The user's postal address. */
      role: "USER" | "ADMIN";
      /**
       * By default, TypeScript merges new interface properties and overwrites existing ones.
       * In this case, the default session user properties will be overwritten,
       * with the new ones defined above. To keep the default session user properties,
       * you need to add them back into the newly declared interface.
       */
    } & DefaultSession["user"];
  }
}

export const { handlers, signIn, signOut, auth } = NextAuth({
  ...authConfig,
  adapter: PrismaAdapter(prisma),
  session: {
    strategy: "jwt",
  },
  pages: {
    signIn: "/auth/login",
    error: "/auth/error",
  },
  events: {
    async linkAccount({ user, account }) {
      if (account.provider === "google" || account.provider === "github") {
        await prisma.user.update({
          where: {
            id: user.id,
          },
          data: {
            emailVerified: new Date(),
          },
        });
      }
    },
  },
  callbacks: {
    async signIn({ user, account }) {
      if (account?.provider !== "credentials") {
        return true;
      }
      if (!user.id) {
        return false;
      }
      const existingUser = await getUserById(user.id);

      if (!existingUser || !existingUser.emailVerified) {
        return false;
      }
      return true;
    },
    async jwt({ token }) {
      if (!token.sub) {
        return token;
      }
      const existingUser = await getUserById(token.sub);
      if (!existingUser) {
        return token;
      }
      token.role = existingUser.role;

      return token;
    },
    async session({ session, token }) {
      if (token.sub && session.user) {
        session.user.id = token.sub;
      }
      if (token.role && session.user) {
        session.user.role = token.role;
      }

      return session;
    },
  },
});