/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include "Host/SystemInfo.hpp"
#include "Base/Logger.hpp"
#include <iostream>
#include <Windows.h>
#include <Psapi.h>

namespace openVulkanoCpp
{
	namespace
	{
		enum class SYS_MEM_TYPE { TOTAL_PHYS, AVAIL_PHYS };

		size_t ReadSystemMemInfo(SYS_MEM_TYPE type)
		{
			MEMORYSTATUSEX status;
			status.dwLength = sizeof(status);
			if (GlobalMemoryStatusEx(&status))
			{
				switch (type)
				{
					case SYS_MEM_TYPE::TOTAL_PHYS: return status.ullTotalPhys;
					case SYS_MEM_TYPE::AVAIL_PHYS: return status.ullAvailPhys;
				}
			}
			Logger::PERF->error("Failed to get system RAM info");
			return 0;
		}

		enum class APP_MEM_TYPE { VM_MAX, USED };

		size_t ReadAppMemInfo(APP_MEM_TYPE type)
		{
			PROCESS_MEMORY_COUNTERS_EX counters;
			if (GetProcessMemoryInfo(GetCurrentProcess(), reinterpret_cast<PROCESS_MEMORY_COUNTERS*>(&counters), sizeof(counters)))
			{
				switch(type)
				{
					case APP_MEM_TYPE::VM_MAX return counters.PeakWorkingSetSize;
					case APP_MEM_TYPE::USED: return counters.PrivateUsage;
				}
			}
			Logger::PERF->error("Failed to get process memory info");
			return 0;
		}
	}

	size_t SystemInfo::GetSystemRam()
	{
		return ReadSystemMemInfo(MEM_TYPE::TOTAL_PHYS);
	}

	size_t SystemInfo::GetSystemRamAvailable()
	{
		return ReadSystemMemInfo(MEM_TYPE::AVAIL_PHYS);
	}

	size_t SystemInfo::GetAppRamMax()
	{
		return std::min(GetSystemRam(), GetAppVirtualMemoryMax());
	}

	size_t SystemInfo::GetAppRamAvailable()
	{
		return std::min(GetSystemRamAvailable(), GetAppVirtualMemoryMax() - GetAppRamUsed());
	}

	size_t SystemInfo::GetAppRamUsed()
	{
		return ReadAppMemInfo(APP_MEM_TYPE::USED);
	}

	size_t SystemInfo::GetAppVirtualMemoryMax()
	{
		return ReadAppMemInfo(APP_MEM_TYPE::VM_MAX);
	}
}