#pragma once

#include <set>
#include <memory>

#include "misc.h"

namespace asyncpp {
namespace timer {

    struct delay;
    struct timer;

    struct registration
    {
    public:
        struct inner
        {
            timer&      owner;
            time_point  timeout;

            /**
             * @brief Constructor.
             */
            inline inner(timer& p_owner, time_point p_timeout);
        };

        using inner_ptr_w = std::weak_ptr<inner>;

    public:
        delay&      owner;
        inner_ptr_w ptr;

        /**
         * @brief Constructor.
         */
        inline registration(delay& p_owner);
    };

    struct timer
    {
    private:
        using inner_ptr_s = std::shared_ptr<registration::inner>;

        struct inner_less_compare
            { constexpr bool operator()(const inner_ptr_s& lhs, const inner_ptr_s& rhs) const; };

        using inner_set = std::set<inner_ptr_s, inner_less_compare>;

    private:
        inner_set _registrations;

    public:
        /**
         * @brief Get the number of resources assigned to this timer.
         */
        inline size_t resource_count() const;

        /**
         * @brief Set the thread local current timer.
         */
        inline void make_current();

        /**
         * @brief Set the thread local current timer.
         */
        inline void clear_current();

    public:
        /**
         * @brief Get the thread local timer instance.
         */
        static inline timer* current();

        /**
         * @brief Register a new resource within this timer.
         */
        static inline void register_resource(registration& p_value);

        /**
         * @brief Register a new resource within this timer.
         */
        static inline void unregister_resource(registration& p_value);

    private:
        /**
         * @brief Add a new resource to the timer.
         */
        inline inner_ptr_s make_inner(registration& p_value);

    private:
        struct storage
        {
            timer* current { nullptr };
        };

        /**
         * @brief Get the thread local storage.
         */
        static inline storage& local_storage();
    };

} }