const PEER_ID_KEY = "p2p-poll-peer-id";

/** Generate a UUID v4 */
function generateUUID(): string {
  return crypto.randomUUID();
}

/**
 * Get or create a persistent peer ID.
 * Stored in localStorage so each browser tab/device gets a stable identity.
 */
export function getPeerId(): string {
  if (typeof globalThis.localStorage === "undefined") {
    return generateUUID();
  }
  let id = localStorage.getItem(PEER_ID_KEY);
  if (!id) {
    id = generateUUID();
    localStorage.setItem(PEER_ID_KEY, id);
  }
  return id;
}