import { Router } from 'express';
import bcrypt from 'bcryptjs';
import { getAdmin, updateAdminPassword } from '../db.js';
import { requireAuth, signToken } from '../auth.js';

const router = Router();
const loginAttempts = new Map();

function checkRateLimit(ip) {
  const now = Date.now();
  const record = loginAttempts.get(ip) || { count: 0, resetAt: now + 60000 };
  if (now > record.resetAt) {
    loginAttempts.set(ip, { count: 1, resetAt: now + 60000 });
    return true;
  }
  if (record.count >= 5) return false;
  record.count++;
  loginAttempts.set(ip, record);
  return true;
}

router.post('/login', (req, res) => {
  const ip = req.ip;
  if (!checkRateLimit(ip)) {
    return res.status(429).json({ error: 'Too many login attempts', code: 'RATE_LIMITED' });
  }

  const { username, password } = req.body;
  if (!username || !password) {
    return res.status(400).json({ error: 'Username and password required', code: 'VALIDATION' });
  }

  const admin = getAdmin();
  if (!admin || username !== admin.username || !bcrypt.compareSync(password, admin.passwordHash)) {
    return res.status(401).json({ error: 'Invalid credentials', code: 'UNAUTHORIZED' });
  }

  const token = signToken(username);
  const expiresAt = new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString();
  res.json({ token, expiresAt });
});

router.get('/me', requireAuth, (req, res) => {
  res.json({ username: req.user.username });
});

router.put('/password', requireAuth, (req, res) => {
  const { currentPassword, newPassword } = req.body;
  if (!currentPassword || !newPassword || newPassword.length < 6) {
    return res.status(400).json({ error: 'Valid current and new password (min 6 chars) required', code: 'VALIDATION' });
  }

  const admin = getAdmin();
  if (!bcrypt.compareSync(currentPassword, admin.passwordHash)) {
    return res.status(401).json({ error: 'Current password is incorrect', code: 'UNAUTHORIZED' });
  }

  updateAdminPassword(bcrypt.hashSync(newPassword, 12));
  res.json({ message: 'Password updated' });
});

export default router;