import { existsSync, readFileSync } from 'node:fs';
import { resolve, sep } from 'node:path';

const distDir = resolve('./dist');
const indexPath = resolve(distDir, 'index.html');

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

function responseFromFile(filePath, headers) {
  try {
    return new Response(readFileSync(filePath), { headers });
  } catch (error) {
    if (error?.code === 'ENOENT') {
      return new Response('Not Found', { status: 404 });
    }

    console.error('File read error:', error);
    return new Response('Internal Server Error', { status: 500 });
  }
}

function serveIndex() {
  return responseFromFile(indexPath, {
    'Content-Type': contentTypes.html,
    'Cache-Control': 'no-cache',
  });
}

function serveFile(filePath, pathname) {
  const ext = filePath.split('.').pop() || '';
  return responseFromFile(filePath, {
    'Content-Type': contentTypes[ext] || 'application/octet-stream',
    'Cache-Control': pathname.startsWith('/assets/')
      ? 'public, max-age=31536000, immutable'
      : 'no-cache',
  });
}

Bun.serve({
  port: 80,
  hostname: '0.0.0.0',
  fetch(req) {
    const url = new URL(req.url);
    const pathname = url.pathname;
    const filePath = resolve(distDir, pathname.slice(1));
    const insideDist = filePath === distDir || filePath.startsWith(`${distDir}${sep}`);

    if (!insideDist) {
      return new Response('Forbidden', { status: 403 });
    }

    if (pathname !== '/' && existsSync(filePath)) {
      return serveFile(filePath, pathname);
    }

    if (!pathname.includes('.') && existsSync(indexPath)) {
      return serveIndex();
    }

    return new Response('Not Found', { status: 404 });
  },
});