import { compare } from 'bcryptjs';
import { getServerSession, type NextAuthOptions } from 'next-auth';
import Credentials from 'next-auth/providers/credentials';
import { getUserByUsername, hasAnyUser } from '@/src/lib/db/user';

export const authOptions: NextAuthOptions = {
  providers: [
    Credentials({
      credentials: {
        username: { label: 'Benutzername', type: 'text' },
        password: { label: 'Passwort', type: 'password' },
      },
      async authorize(credentials) {
        if (!credentials?.username || !credentials?.password) {
          return null;
        }

        const username = credentials.username.trim();
        const password = credentials.password;
        if (process.env.DATABASE_URL) {
          try {
            const dbUser = await getUserByUsername(username);

            if (dbUser) {
              const isPasswordValid = await compare(password, dbUser.passwordHash);
              if (!isPasswordValid) {
                return null;
              }

              return {
                id: String(dbUser.id),
                name: username,
                email: `${username}@homelab.local`,
                username,
              };
            }

            if (await hasAnyUser()) {
              return null;
            }
          } catch (error) {
            console.error('Database authentication error:', error);
            return null;
          }
        }

        const adminUsername = process.env.ADMIN_USERNAME || 'admin';
        const adminPasswordHash = process.env.ADMIN_PASSWORD_HASH;

        if (!adminPasswordHash || username !== adminUsername) {
          return null;
        }

        try {
          const isPasswordValid = await compare(password, adminPasswordHash);

          if (!isPasswordValid) {
            return null;
          }

          return {
            id: '1',
            name: 'Admin',
            email: 'admin@homelab.local',
            username: adminUsername,
          };
        } catch (error) {
          console.error('Password comparison error:', error);
          return null;
        }
      },
    }),
  ],
  pages: {
    signIn: '/login',
  },
  callbacks: {
    async jwt({ token, user }) {
      if (user && user.username) {
        token.username = user.username;
      }
      return token;
    },
    async session({ session, token }) {
      if (session.user) {
        session.user.username = token.username;
      }
      return session;
    },
  },
  session: {
    strategy: 'jwt',
    maxAge: 24 * 60 * 60,
  },
  secret: process.env.NEXTAUTH_SECRET,
};

export function auth() {
  return getServerSession(authOptions);
}