// Production server for DSS Team Portal
import { createServer } from 'http';
import { readFile, stat } from 'fs/promises';
import { join, extname } from 'path';
import { fileURLToPath } from 'url';

const __dirname = fileURLToPath(new URL('.', import.meta.url));
const DIST_DIR = join(__dirname, 'dist');
const PORT = process.env.PORT || 3457;
const API_PROXY = process.env.API_PROXY || 'http://localhost:3456';

const MIME_TYPES = {
  '.html': 'text/html',
  '.css': 'text/css',
  '.js': 'application/javascript',
  '.json': 'application/json',
  '.svg': 'image/svg+xml',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.ico': 'image/x-icon',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2'
};

async function serveFile(res, filePath) {
  try {
    const content = await readFile(filePath);
    const ext = extname(filePath);
    const contentType = MIME_TYPES[ext] || 'application/octet-stream';

    res.writeHead(200, {
      'Content-Type': contentType,
      'Cache-Control': ext === '.html' ? 'no-cache' : 'public, max-age=31536000'
    });
    res.end(content);
  } catch (err) {
    // File not found, serve index.html for SPA routing
    const indexPath = join(DIST_DIR, 'index.html');
    const content = await readFile(indexPath);
    res.writeHead(200, { 'Content-Type': 'text/html', 'Cache-Control': 'no-cache' });
    res.end(content);
  }
}

async function proxyRequest(req, res) {
  const url = new URL(req.url, `http://localhost:${PORT}`);
  const proxyUrl = `${API_PROXY}${url.pathname}${url.search}`;

  try {
    const proxyRes = await fetch(proxyUrl, {
      method: req.method,
      headers: {
        'Content-Type': 'application/json',
        ...Object.fromEntries(
          Object.entries(req.headers).filter(([k]) => !['host', 'connection'].includes(k))
        )
      },
      body: ['POST', 'PUT', 'PATCH'].includes(req.method)
        ? await getRequestBody(req)
        : undefined
    });

    const data = await proxyRes.text();
    res.writeHead(proxyRes.status, { 'Content-Type': 'application/json' });
    res.end(data);
  } catch (err) {
    console.error('[Proxy Error]', err.message);
    res.writeHead(502, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ error: 'Proxy error', message: err.message }));
  }
}

function getRequestBody(req) {
  return new Promise((resolve, reject) => {
    let body = '';
    req.on('data', chunk => body += chunk);
    req.on('end', () => resolve(body));
    req.on('error', reject);
  });
}

const server = createServer(async (req, res) => {
  const url = new URL(req.url, `http://localhost:${PORT}`);

  // Health check
  if (url.pathname === '/health') {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ status: 'ok', service: 'dss-team-portal' }));
    return;
  }

  // Proxy API requests to DSS MCP server
  if (url.pathname.startsWith('/api/')) {
    url.pathname = url.pathname.replace('/api', '');
    req.url = url.pathname + url.search;
    await proxyRequest(req, res);
    return;
  }

  // Serve static files
  const filePath = join(DIST_DIR, url.pathname === '/' ? 'index.html' : url.pathname);
  await serveFile(res, filePath);
});

server.listen(PORT, () => {
  console.log(`[DSS Team Portal] Running on http://localhost:${PORT}`);
  console.log(`[DSS Team Portal] API Proxy: ${API_PROXY}`);
});