#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2013 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

// If the library is compiled as a DLL, this ensures symbols are exported
#define NUCLEX_GAME_SOURCE 1

#include "Nuclex/Game/Config.h"

#if defined(NUCLEX_GAME_LINUX)

#include "Nuclex/Game/Timing/LinuxClock.h"
#include <limits>
#include <stdexcept>
#include <cassert>

#include <time.h>

namespace Nuclex { namespace Game { namespace Timing {

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

  std::uint64_t LinuxClock::GetClockTime() {
    struct timespec time;

    int result = ::clock_gettime(CLOCK_MONOTONIC, &time);
    if(result != 0) {
      throw std::runtime_error("Could not query timer");
    }

    std::uint64_t nanoseconds = static_cast<std::uint64_t>(time.tv_sec) * 1000000000;
    nanoseconds += static_cast<std::uint64_t>(time.tv_nsec);

    return nanoseconds;
  }

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

  std::uint64_t LinuxClock::GetClockResolution() {
    struct timespec time;

    int result = ::clock_getres(CLOCK_MONOTONIC, &time);
    if(result != 0) {
      throw std::runtime_error("Could not query timer resolution");
    }

    std::uint64_t nanoseconds = static_cast<std::uint64_t>(time.tv_sec) * 1000000000;
    nanoseconds += static_cast<std::uint64_t>(time.tv_nsec);

    return nanoseconds;
  }

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

  std::uint64_t LinuxClock::GetWraparoundTime() const {
    // This isn't completely accurate. Normally we would need to find the gcd between
    // ((2 ^ 64) - 1) and (10 ^ 9) and modulo the time to that, but since the first wraparound
    // will happen no earlier than after 585 years of continuous uptime, we don't care.
    return std::numeric_limits<std::uint64_t>::max();
  }

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

  std::uint64_t LinuxClock::GetTime() const {
    return LinuxClock::GetClockTime();
  }

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

  std::uint64_t LinuxClock::GetFrequency() const {
    return 1000000000; // This is the frequency, not the resolution!
  }

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

}}} // namespace Nuclex::Game::Timing

#endif // defined(NUCLEX_GAME_LINUX)