class Scheduler {
    ThreadPool pool_{4};       // 工作线程池
    Timer timer_;              // 定时器

public:
    // 立即执行（线程池的任务）
    template <typename F>
    auto execute(F&& f) {
        return pool_.enqueue(std::forward<F>(f));
    }

    // 延迟执行（先经过定时器，到时间后丢给线程池）
    template <typename F>
    auto executeAfter(std::chrono::milliseconds delay, F&& f) {
        using ReturnType = std::invoke_result_t<F>;
        auto promise = std::make_shared<std::promise<ReturnType>>();
        auto future = promise->get_future();

        timer_.addTimer(delay, [this, f = std::forward<F>(f), promise]() mutable {
            pool_.enqueue([f = std::move(f), promise]() mutable {
                if constexpr (std::is_void_v<ReturnType>) {
                    f();
                    promise->set_value();
                } else {
                    promise->set_value(f());
                }
            });
        });

        return future;
    }

    // 周期执行
    template <typename F>
    void executeEvery(std::chrono::milliseconds interval, F&& f) {
        timer_.addTimer(interval, interval, [this, f = std::forward<F>(f)]() mutable {
            pool_.enqueue(f);
        });
    }
};