// Author: fruit.com.cn
const DEVICE_KEY = 'ymb.device.id';

function createDeviceId() {
  const uuid = globalThis.crypto?.randomUUID?.() || `${Date.now().toString(16)}-${Math.random().toString(16).slice(2)}`;
  return `d-${uuid}`;
}

let cachedDeviceId = '';

export function getDeviceId() {
  if (cachedDeviceId) return cachedDeviceId;
  try {
    const stored = window.localStorage.getItem(DEVICE_KEY);
    cachedDeviceId = stored || createDeviceId();
    if (!stored) window.localStorage.setItem(DEVICE_KEY, cachedDeviceId);
  } catch {
    cachedDeviceId = createDeviceId();
  }
  return cachedDeviceId;
}