function fallbackUuid(): string {
  const bytes = new Uint8Array(16);
  globalThis.crypto.getRandomValues(bytes);
  bytes[6] = (bytes[6] & 0x0f) | 0x40;
  bytes[8] = (bytes[8] & 0x3f) | 0x80;
  const hex = Array.from(bytes, (byte) => byte.toString(16).padStart(2, "0"));
  return [
    hex.slice(0, 4).join(""),
    hex.slice(4, 6).join(""),
    hex.slice(6, 8).join(""),
    hex.slice(8, 10).join(""),
    hex.slice(10).join(""),
  ].join("-");
}

export function createRequestId(): string {
  return typeof globalThis.crypto.randomUUID === "function"
    ? globalThis.crypto.randomUUID()
    : fallbackUuid();
}
