// 放弃表单确认的唯一生命周期所有者。页面只负责把 visible 同步到自己的 ref；
// 重复返回复用同一 Promise，确认、取消或卸载都会先清空内部状态再释放等待者。
export const createDiscardConfirmation = (setVisible) => {
  if (typeof setVisible !== "function") {
    throw new TypeError("createDiscardConfirmation 的 setVisible 必须是函数");
  }

  let pendingPromise = null;
  let resolvePending = null;

  const settle = (confirmed) => {
    const resolve = resolvePending;
    resolvePending = null;
    pendingPromise = null;
    setVisible(false);
    resolve?.(confirmed === true);
  };

  const request = () => {
    if (pendingPromise) return pendingPromise;
    setVisible(true);
    pendingPromise = new Promise((resolve) => {
      resolvePending = resolve;
    });
    return pendingPromise;
  };

  return Object.freeze({
    request,
    confirm: () => settle(true),
    cancel: () => settle(false),
    dispose: () => settle(false),
  });
};