import express from 'express';
import nodemailer from 'nodemailer';

const app = express();
app.use(express.json());

// Rate limiter: max 5 requests/min per IP
const rateLimiter = new Map();
function checkRateLimit(ip) {
  const now = Date.now();
  const window = 60_000;
  const max = 5;
  const entry = rateLimiter.get(ip) ?? { count: 0, start: now };
  if (now - entry.start > window) {
    entry.count = 0;
    entry.start = now;
  }
  entry.count++;
  rateLimiter.set(ip, entry);
  return entry.count <= max;
}

// Prune rate limiter every 5 minutes
setInterval(() => {
  const cutoff = Date.now() - 60_000;
  for (const [ip, entry] of rateLimiter) {
    if (entry.start < cutoff) rateLimiter.delete(ip);
  }
}, 300_000);

const transporter = nodemailer.createTransport({
  host: 'smtp.fastmail.com',
  port: 465,
  secure: true,
  auth: {
    user: process.env.SMTP_USER,
    pass: process.env.SMTP_PASS,
  },
});

app.post('/api/contact', async (req, res) => {
  const ip =
    (req.headers['x-forwarded-for'] ?? '').split(',')[0].trim() ||
    req.socket.remoteAddress;

  if (!checkRateLimit(ip)) {
    return res.status(429).json({ error: 'Too many requests' });
  }

  const { name, email, message, company } = req.body ?? {};

  if (!name || typeof name !== 'string' || !name.trim()) {
    return res.status(400).json({ error: 'name required' });
  }
  if (!email || typeof email !== 'string' || !email.includes('@')) {
    return res.status(400).json({ error: 'valid email required' });
  }
  if (!message || typeof message !== 'string' || message.trim().length < 5) {
    return res.status(400).json({ error: 'message too short' });
  }

  // Honeypot
  if (company) {
    return res.json({ ok: true });
  }

  try {
    await transporter.sendMail({
      from: 'oskar@gethumanai.com',
      to: 'oskar@gethumanai.com',
      replyTo: email,
      subject: `Kontakt od ${name.trim()}`,
      text: `Imię: ${name.trim()}\nEmail: ${email}\n\n${message.trim()}`,
    });
    res.json({ ok: true });
  } catch (err) {
    console.error('SMTP error:', err);
    res.status(502).json({ error: 'mail delivery failed' });
  }
});

app.listen(3000, () => console.log('mailer listening on :3000'));