import http from 'node:http';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

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

const distDir = path.join(__dirname, 'dist');
const port = Number(process.env.PORT || 3000);
const host = process.env.HOST || '127.0.0.1';

const mimeTypes = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'application/javascript; charset=utf-8',
  '.mjs': 'application/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.json': 'application/json; charset=utf-8',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.webp': 'image/webp',
  '.ico': 'image/x-icon',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.pdf': 'application/pdf',
};

const sendFile = (res, filePath) => {
  fs.readFile(filePath, (error, content) => {
    if (error) {
      res.writeHead(404, { 'Content-Type': 'text/plain; charset=utf-8' });
      res.end('Not found');
      return;
    }

    const ext = path.extname(filePath).toLowerCase();
    res.writeHead(200, {
      'Content-Type': mimeTypes[ext] || 'application/octet-stream',
      'Cache-Control': ext === '.html' ? 'no-cache' : 'public, max-age=31536000, immutable',
    });
    res.end(content);
  });
};

const server = http.createServer((req, res) => {
  const urlPath = decodeURIComponent((req.url || '/').split('?')[0]);
  const safePath = path.normalize(urlPath).replace(/^(\.\.[/\\])+/, '');
  let filePath = path.join(distDir, safePath === '/' ? 'index.html' : safePath);

  if (!filePath.startsWith(distDir)) {
    res.writeHead(403, { 'Content-Type': 'text/plain; charset=utf-8' });
    res.end('Forbidden');
    return;
  }

  fs.stat(filePath, (err, stats) => {
    if (!err && stats.isDirectory()) {
      filePath = path.join(filePath, 'index.html');
    }

    fs.access(filePath, fs.constants.F_OK, (accessError) => {
      if (accessError) {
        sendFile(res, path.join(distDir, 'index.html'));
        return;
      }
      sendFile(res, filePath);
    });
  });
});

server.listen(port, host, () => {
  console.log(`LinkedSign frontend running on http://${host}:${port}`);
});