auth.ts

import NextAuth from "next-auth";
import Credentials from "next-auth/providers/credentials";
import { authConfig } from "./auth.config";
import { z } from "zod";
import { sql } from "@vercel/postgres";
import type { User } from "@/app/lib/definitions";
import bcrypt from "bcrypt";

async function getUser(email: string): Promise<User | undefined>{
    try{
        const user = await sql<User>`SELECT * FROM users WHERE email=${email}`;
        return user.rows[0];
    }catch(error){
        console.error('failed to fetch the user', error);
        throw new Error('failed to fetch the user');
    }
}

export const { auth, signIn, signOut } = NextAuth({
    ...authConfig,
    providers: [
        Credentials({
            async authorize(credentials){
                const parsedCredentials = z.object({ email: z.string().email(), password: z.string().min(6) })
                                            .safeParse(credentials);
                
                if(parsedCredentials.success){
                    const {email, password } = parsedCredentials.data;
                    const user = await getUser(email);
                    if(!user) return null;
                    const passwordMatch = await bcrypt.compare(password, user.password);
                    if(passwordMatch){
                        return user;
                    }
                }
                console.log('invalid credentials');
                return null;
            }
        })
    ]
});