import express from 'express';
import path from 'path';
import { fileURLToPath } from 'url';
import nodemailer from 'nodemailer';
import cors from 'cors';
import dotenv from 'dotenv';
import helmet from 'helmet';
import rateLimit from 'express-rate-limit';

dotenv.config();

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
const PORT = process.env.PORT || 3000;

// Security
app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      ...helmet.contentSecurityPolicy.getDefaultDirectives(),
      "img-src": ["'self'", "data:"],
    },
  },
}));
app.use(cors());
app.use(express.json());

// Rate limiting for API
const apiLimiter = rateLimit({
  windowMs: 10 * 60 * 1000, // 10 minutes
  max: 5, // limit each IP to 5 requests per windowMs
  message: 'Zu viele Anfragen von dieser IP, bitte versuchen Sie es später erneut.',
  standardHeaders: true,
  legacyHeaders: false,
});

// API Endpoint
app.post('/api/contact', apiLimiter, async (req, res) => {
  const { name, email, company, message, website } = req.body;

  // Honeypot check
  if (website) {
    console.log('Spam detected (honeypot)');
    return res.status(200).json({ message: 'Ok' }); // Generic success
  }

  // Validation
  if (!name || name.length < 2 || name.length > 100) {
    return res.status(400).json({ error: 'Ungültiger Name' });
  }
  if (!email || !/^\S+@\S+\.\S+$/.test(email)) {
    return res.status(400).json({ error: 'Ungültige E-Mail' });
  }
  if (!message || message.length < 20 || message.length > 4000) {
    return res.status(400).json({ error: 'Nachricht zu kurz oder zu lang' });
  }

  try {
    const transporter = nodemailer.createTransport({
      host: process.env.SMTP_HOST,
      port: parseInt(process.env.SMTP_PORT || '587'),
      secure: process.env.SMTP_SECURE === 'true',
      auth: {
        user: process.env.SMTP_USER,
        pass: process.env.SMTP_PASS,
      },
    });

    await transporter.sendMail({
      from: process.env.SMTP_FROM,
      to: process.env.CONTACT_RECIPIENT,
      replyTo: email,
      subject: `Kontaktanfrage von ${name}`,
      text: `
Name: ${name}
Firma: ${company || 'Nicht angegeben'}
E-Mail: ${email}
Zeitpunkt: ${new Date().toISOString()}

Nachricht:
${message}
      `,
    });

    res.status(200).json({ message: 'Ok' });
  } catch (error) {
    console.error('SMTP Error:', error);
    res.status(500).json({ error: 'Interner Serverfehler' });
  }
});

// Health check
app.get('/healthz', (req, res) => {
  res.status(200).send('OK');
});

// Serve static files from the React app
const distPath = path.join(__dirname, 'dist/frontend');
app.use(express.static(distPath));

// The "catchall" handler: for any request that doesn't
// match one above, send back React's index.html file.
app.get('*', (req, res) => {
  res.sendFile(path.join(distPath, 'index.html'));
});

app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});