#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2023 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#pragma endregion // CPL License

#ifndef NUCLEX_SUPPORT_PLATFORM_POSIXTIMEAPI_H
#define NUCLEX_SUPPORT_PLATFORM_POSIXTIMEAPI_H

#include "Nuclex/Support/Config.h"

#if !defined(NUCLEX_SUPPORT_WINDOWS)

#include "PosixApi.h"

#include <cassert> // for assert()
#include <chrono> // for std::chrono::microseconds, std::chrono::milliseconds

#include <sys/time.h> // for ::timespec

namespace Nuclex { namespace Support { namespace Platform {

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Wraps the Posix time API</summary>
  class PosixTimeApi {

    /// <summary>
    ///   Returns a time point that lies the specified number if microseconds in the future
    /// </summary>
    /// <param name="clock">Which clock to query (i.e. <code>CLOCK_MONOTONIC</code>)</param>
    /// <param name="addedTime">Amount of microseconds that will be added</param>
    /// <returns>
    ///   A time point that lies the specified number of microsends in the future from
    ///   the moment the method is called.
    /// </returns>
    public: static struct ::timespec GetTimePlus(
      ::clockid_t clock, std::chrono::microseconds addedTime
    );

    /// <summary>
    ///   Returns a time point that lies the specified number if milliseconds in the future
    /// </summary>
    /// <param name="clock">Which clock to query (i.e. <code>CLOCK_MONOTONIC</code>)</param>
    /// <param name="addedTime">Amount of milliseconds that will be added</param>
    /// <returns>
    ///   A time point that lies the specified number of milliseconds in the future from
    ///   the moment the method is called.
    /// </returns>
    public: static struct ::timespec GetTimePlus(
      ::clockid_t clock, std::chrono::milliseconds addedTime
    );

    /// <summary>
    ///   Calculates the remaining relative timeout from the current clock time
    /// </summary>
    /// <param name="clock">Clock on which the timeout is being counted down</param>
    /// <param name="startTime">Time at which the timeout began</param>
    /// <param name="timeout">Timeout that is being counted down</param>
    /// <returns>
    ///   The remaining (relative) time until the timeout. Will return zero if
    ///   the timeout has already elapsed and never a negative time.
    /// </returns>
    public: static struct ::timespec GetRemainingTimeout(
      ::clockid_t clock,
      const struct ::timespec &startTime,
      std::chrono::microseconds timeout
    );

    /// <summary>Checks whether the specified end time has been reached yet</summary>
    /// <param name="clock">Clock against which the end time will be checked</param>
    /// <param name="endTime">Time after which this method will return true</param>
    /// <returns>
    ///   True if the current time is equal to or later than the specified end time,
    ///   false if the current time is still earlier.
    /// </returns>
    public: static bool HasTimedOut(::clockid_t clock, const struct ::timespec &endTime);

    /// <summary>
    ///   Returns a pthread conditional variable attribute that lets the conditional variable
    ///   use CLOCK_MONOTONIC instead of CLOCK_REALTIME
    /// </summary>
    /// <returns>A pre-configured conditional variable attribute</returns>
    public: static ::pthread_condattr_t *GetMonotonicClockAttribute();

  };

  // ------------------------------------------------------------------------------------------- //

}}} // namespace Nuclex::Support::Platform

#endif // !defined(NUCLEX_SUPPORT_WINDOWS)

#endif // NUCLEX_SUPPORT_PLATFORM_POSIXTIMEAPI_H