import { randomBytes } from "crypto";
import type { Visibility } from "#server/constants/visibility";

/** URL-safe token, ~43 chars */
export function newShareToken(): string {
  return randomBytes(32).toString("base64url");
}

/**
 * `unlisted` 需要 token；切回 public/private 时清空 token（分享链失效）。
 */
export function visibilityShareToken(visibility: Visibility, previousToken: string | null | undefined): string | null {
  if (visibility === "unlisted") {
    return previousToken && previousToken.length > 0 ? previousToken : newShareToken();
  }
  return null;
}