Device Profiling

// Device Profiling (Client-Side)
function getDeviceProfile() {
  return {
    userAgent: navigator.userAgent,
    platform: navigator.platform,
    screenWidth: screen.width,
    screenHeight: screen.height,
    timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
    language: navigator.language,
    plugins: navigator.plugins.length
  };
}

// Create device fingerprint (hash)
function getDeviceFingerprint(profile) {
  const str = JSON.stringify(profile);
  return btoa(str); // Simple base64 fingerprint
}

// Server-side: Check if device is known
function isKnownDevice(userId, fingerprint) {
  const userDevices = devices[userId] || [];
  return userDevices.some(d => d.fingerprint === fingerprint);
}