#pragma once
#include "function/frame_policy/global.hpp"
#include "model/Model.hpp"
#include <cstdint>
#include <functional>
namespace aethera {
/*
 * 固定帧率、最多一帧在途的策略。Scene 创建具体帧；策略持有并重复使用，
 * stop completion 执行前会排空 Scene/Sink 借用并销毁该帧。
 */
struct Throttled_Latest_only :
Def<Throttled_Latest_only, Root<Throttled_Latest_only>> {
    enum struct Start_Result : std::uint8_t {
        started,
        already_running,
        start_in_progress,
        stop_in_progress,
        dependency_unavailable,
        frame_unavailable,
        invalid_frames_per_second,
        interval_out_of_range
    };
    enum struct Stop_Result : std::uint8_t {
        stopping,
        already_stopped,
        already_stopping,
        start_in_progress,
        completion_missing
    };
    using Stop_Completion = std::function<void()>;
    struct Prop : Prev_Prop {};
    struct Private;
    Throttled_Latest_only(proxy<Periodic_Timer_Service> timer_service,
                          proxy<FP_Scene> scene,
                          proxy<FP_Sink> sink);
    ~Throttled_Latest_only() noexcept;
    Start_Result start(double frames_per_second);
    Stop_Result stop(Stop_Completion completion);
};
}
#include "Throttled_Latest_Only.ipp"