server.js

const http = require('http');
const https = require('https');
const fs = require('fs');
const path = require('path');
const zlib = require('zlib');

const PORT = 8081;
const CDN_BASE = 'https://cdn.zetaoffice.net';

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

const server = http.createServer((req, res) => {
    console.log(`${req.method} ${req.url}`);
    
    // Set COOP/COEP headers for cross-origin isolation
    res.setHeader('Cross-Origin-Opener-Policy', 'same-origin');
    res.setHeader('Cross-Origin-Embedder-Policy', 'require-corp');
    
    // Proxy CDN requests
    if (req.url.startsWith('/cdn/')) {
        const cdnPath = req.url.replace('/cdn/', '/');
        const cdnUrl = CDN_BASE + cdnPath;
        
        console.log(`Proxying to: ${cdnUrl}`);
        
        https.get(cdnUrl, (proxyRes) => {
            // Add CORP header to allow embedding
            res.setHeader('Cross-Origin-Resource-Policy', 'cross-origin');
            res.setHeader('Access-Control-Allow-Origin', '*');
            
            // Copy content type
            const contentType = proxyRes.headers['content-type'];
            if (contentType) {
                res.setHeader('Content-Type', contentType);
            }
            
            // Copy caching headers
            const cacheControl = proxyRes.headers['cache-control'];
            if (cacheControl) {
                res.setHeader('Cache-Control', cacheControl);
            }
            
            const encoding = proxyRes.headers['content-encoding'];
            console.log(`Response encoding: ${encoding}, status: ${proxyRes.statusCode}`);
            
            // Handle compressed responses
            let stream = proxyRes;
            if (encoding === 'gzip') {
                stream = proxyRes.pipe(zlib.createGunzip());
            } else if (encoding === 'deflate') {
                stream = proxyRes.pipe(zlib.createInflate());
            } else if (encoding === 'br') {
                stream = proxyRes.pipe(zlib.createBrotliDecompress());
            }
            
            res.writeHead(proxyRes.statusCode);
            stream.pipe(res);
        }).on('error', (err) => {
            console.error('Proxy error:', err);
            res.writeHead(500);
            res.end('Proxy error');
        });
        return;
    }
    
    // Serve local files
    let filePath = req.url === '/' ? '/index.html' : req.url;
    filePath = path.join(__dirname, filePath.split('?')[0]);
    
    const ext = path.extname(filePath);
    const contentType = MIME_TYPES[ext] || 'application/octet-stream';
    
    fs.readFile(filePath, (err, content) => {
        if (err) {
            if (err.code === 'ENOENT') {
                res.writeHead(404);
                res.end('Not found');
            } else {
                res.writeHead(500);
                res.end('Server error');
            }
            return;
        }
        
        res.setHeader('Content-Type', contentType);
        res.setHeader('Cross-Origin-Resource-Policy', 'same-origin');
        res.writeHead(200);
        res.end(content);
    });
});

server.listen(PORT, () => {
    console.log(`Server running at http://localhost:${PORT}`);
    console.log('CDN proxy available at /cdn/...');
});