import NextAuth from 'next-auth';
import Credentials from 'next-auth/providers/credentials';
import { prisma } from '@repo/db';
import { authenticateCredential } from '@repo/api';
import type { SessionUser } from '@repo/api';
import { env } from '../env';
import { authConfig } from './auth.config';

/**
 * ============================================================================
 *  Auth.js v5 — operator authentication (v0.2).
 * ============================================================================
 *
 *  The Credentials provider below verifies an operator's PIN against the
 *  scrypt hash in User.passwordHash (via authenticateCredential, which also
 *  enforces role and account lockout). Only OPERATOR users may sign in here.
 *
 *  Auto sign-in
 *  ------------
 *  See `resolveUser()` below. When AUTH_DEV_AUTOLOGIN=true, server-side code
 *  that has no session falls back to the seeded admin user. This is a dev/CI
 *  back door, gated TWICE: by an explicit env flag (default FALSE in
 *  .env.example) AND by NODE_ENV — it is IGNORED when NODE_ENV=production.
 *
 *      !!! NEVER set AUTH_DEV_AUTOLOGIN=true in production. !!!
 *
 *  In production (or with the flag off), requests without a signed Auth.js
 *  session resolve to user=null, and protectedProcedure throws 401.
 * ============================================================================
 */

export const { handlers, auth, signIn, signOut } = NextAuth({
  ...authConfig,
  secret: env.AUTH_SECRET,
  providers: [
    Credentials({
      name: 'Operador (PIN)',
      credentials: {
        email: { label: 'Email', type: 'text' },
        pin: { label: 'PIN', type: 'password' },
      },
      async authorize(credentials) {
        const email = credentials?.email;
        const pin = credentials?.pin;
        if (typeof email !== 'string' || typeof pin !== 'string') return null;
        const u = await authenticateCredential({
          email,
          secret: pin,
          allowedRoles: ['OPERATOR'],
        });
        if (!u) return null;
        return {
          id: u.id,
          email: u.email,
          name: u.email,
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          role: u.role as any,
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          tenantId: u.tenantId as any,
        };
      },
    }),
  ],
});

/**
 * Resolve the current user for server-side code (RSC, route handlers, tRPC).
 * Single chokepoint that combines the real Auth.js session with the dev-only
 * auto-login fallback. Application code MUST use this and not call `auth()`
 * directly when it expects to honour AUTH_DEV_AUTOLOGIN.
 */
export async function resolveUser(): Promise<SessionUser | null> {
  const session = await auth();
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const u = session?.user as any;
  if (u?.id && u?.tenantId) {
    return { id: u.id, email: u.email, role: u.role, tenantId: u.tenantId };
  }

  const autologinAllowed = env.AUTH_DEV_AUTOLOGIN && process.env.NODE_ENV !== 'production';
  if (autologinAllowed) {
    // Dev back door. Disabled in production even if the env flag is set.
    const admin = await prisma.user.findFirst({ where: { email: 'admin@demo.local' } });
    if (admin) {
      return {
        id: admin.id,
        email: admin.email,
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        role: admin.role as any,
        tenantId: admin.tenantId,
      };
    }
  }

  return null;
}