#include "ehs/system/Thread.h"
#include "ehs/system/CPU.h"

#if defined(EHS_OS_WINDOWS)
	#include <avrt.h>
#elif defined(EHS_OS_LINUX)
	#include <pthread.h>
	#include <unistd.h>
#endif

namespace ehs
{
	UInt_32 Thread::mainId = GetCurrentId();

	#ifdef EHS_OS_WINDOWS
		Handle Thread::mainTaskHdl = nullptr;
		UInt_32 Thread::mainTaskIndex = 0;
	#endif

    Thread::~Thread()
    {
        Join();
    }

	Thread::Thread(const UInt_64 stackSize)
		: stackSize(stackSize), hdl(EHS_INVALID_THREAD), id(0)
		#ifdef EHS_OS_WINDOWS
		,taskHdl(nullptr), taskIndex(0)
		#endif
	{
	}
	
	Thread::Thread(const Thread& thread)
		: stackSize(thread.stackSize), hdl(EHS_INVALID_THREAD), id(0)
		#ifdef EHS_OS_WINDOWS
		, taskHdl(nullptr), taskIndex(0)
		#endif
	{
	}
	
	Thread& Thread::operator=(const Thread& thread)
	{
		if (this == &thread)
			return *this;

		stackSize = thread.stackSize;
		hdl = EHS_INVALID_THREAD;
		id = 0;

		#ifdef EHS_OS_WINDOWS
			taskHdl = nullptr;
			taskIndex = 0;
		#endif
		
		return* this;
	}
	
	void Thread::Start(UInt_32 (*cb)(void*), void* args)
	{
		#if defined(EHS_OS_WINDOWS)
			hdl = CreateThread(nullptr, stackSize, (LPTHREAD_START_ROUTINE)cb, args, 0, (DWORD*)&id);
			if (!hdl)
				EHS_LOG_INT("Error", 0, "Failed to start thread with error #" + Str_8::FromNum(GetLastError()) + ".");
        #elif defined(EHS_OS_LINUX)
			UInt_64* rArgs = new UInt_64[sizeof(UInt_64) * 2];
            rArgs[0] = (UInt_64)cb;
            rArgs[1] = (UInt_64)args;

			pthread_create((pthread_t*)&hdl, nullptr, Redirect, (void*)rArgs);
		#endif
	}
	
	bool Thread::Join(const unsigned int timeout)
	{
		if (hdl == EHS_INVALID_THREAD)
			return false;

		#if defined(EHS_WINDOWS)
			unsigned int r = WaitForSingleObject(hdl, timeout);
			if (r == WAIT_ABANDONED)
			{
				EHS_LOG_INT("Error", 0, "Abandoned wait because a mutex was not released.");
				return false;
			}
			else if (r == WAIT_TIMEOUT)
			{
				return false;
			}
			else if (r == WAIT_FAILED)
			{
				EHS_LOG_INT("Error", 1, "Failed to wait for thread with error #" + Str_8::FromNum(GetLastError()) + ".");
				return false;
			}

			mainTaskIndex = 0;
        #elif defined(EHS_OS_LINUX)
			int code = pthread_join((pthread_t)hdl, nullptr);
			if (code != 0)
				EHS_LOG_INT("Error", 1, "Failed to wait for thread with error #" + Str_8::FromNum(code) + ".");

            hdl = EHS_INVALID_THREAD;
		#endif

		return true;
	}
	
	void Thread::Detach()
	{
		if (!hdl)
			return;

		#if defined(EHS_OS_WINDOWS)
            if (!CloseHandle(hdl))
            {
                EHS_LOG_INT("Error", 0, "Failed to detach thread with error #" + Str_8::FromNum(GetLastError()) + ".");
                return;
            }
		#elif defined(EHS_OS_LINUX)
			pthread_detach(hdl);

            hdl = EHS_INVALID_THREAD;
		#endif
	}

	UInt_64 Thread::GetStackSize() const
	{
		return stackSize;
	}
	
	THandle Thread::GetHandle() const
	{
		return hdl;
	}
	
	UInt_32 Thread::GetId() const
	{
		return id;
	}
	
	bool Thread::IsCurrent() const
	{
		return id == GetCurrentId();
	}

	bool Thread::IsValid() const
	{
		return hdl;
	}

	#ifdef EHS_OS_WINDOWS
	void Thread::SetTaskType_32(const Str_32& task)
	{
		if (!IsCurrent())
			return;

		taskHdl = AvSetMmThreadCharacteristicsW(UTF::To_16(task), (LPDWORD)&taskIndex);
		if (!taskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::SetTaskType_16(const Str_16& task)
	{
		if (!IsCurrent())
			return;

		taskHdl = AvSetMmThreadCharacteristicsW(task, (LPDWORD)&taskIndex);
		if (!taskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::SetTaskType_8(const Str_8& task)
	{
		if (!IsCurrent())
			return;

		taskHdl = AvSetMmThreadCharacteristicsW(UTF::To_16(task), (LPDWORD)&taskIndex);
		if (!taskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::RevertTaskType()
	{
		if (!IsCurrent())
			return;

		if (!AvRevertMmThreadCharacteristics(taskHdl))
			EHS_LOG_INT("Error", 0, "Failed to revert the thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");

		taskIndex = 0;
	}
	#endif

	UInt_32 Thread::GetMainId()
	{
		return mainId;
	}

	UInt_64 Thread::GetCurrentId()
	{
		#if defined(EHS_OS_WINDOWS)
			return GetCurrentThreadId();
		#elif defined(EHS_OS_LINUX)
			return pthread_self();
		#endif
	}

	#ifdef EHS_OS_WINDOWS
	void Thread::SetMainTaskType_32(const Str_32& task)
	{
		if (GetCurrentId() != mainId)
			return;

		mainTaskHdl = AvSetMmThreadCharacteristicsW(UTF::To_16(task), (LPDWORD)&mainTaskIndex);
		if (!mainTaskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the main thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::SetMainTaskType_16(const Str_16& task)
	{
		if (GetCurrentId() != mainId)
			return;

		mainTaskHdl = AvSetMmThreadCharacteristicsW(task, (LPDWORD)&mainTaskIndex);
		if (!mainTaskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the main thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::SetMainTaskType_8(const Str_8& task)
	{
		if (GetCurrentId() != mainId)
			return;

		mainTaskHdl = AvSetMmThreadCharacteristicsW(UTF::To_16(task), (LPDWORD)&mainTaskIndex);
		if (!mainTaskHdl)
			EHS_LOG_INT("Error", 0, "Failed to set the main thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");
	}

	void Thread::RevertMainTaskType()
	{
		if (GetCurrentId() != mainId)
			return;

		if (!AvRevertMmThreadCharacteristics(mainTaskHdl))
			EHS_LOG_INT("Error", 0, "Failed to revert the main thread's characteristics with error #" + Str_8::FromNum(GetLastError()) + ".");

		mainTaskIndex = 0;
	}
	#endif
	
	float Thread::HardSleepFor(const float seconds)
	{
		UInt_64 freq = CPU::GetTSC_Freq();
		UInt_64 start = CPU::GetTSC();

		float elapsed = 0.0f;
		while ((elapsed = (float)(CPU::GetTSC() - start) / (float)freq) <= seconds);
		
		return elapsed;
	}
	
	void Thread::SleepFor(const UInt_32 miliseconds)
	{
		#if defined(EHS_OS_WINDOWS)
			Sleep(miliseconds);
		#elif defined(EHS_OS_LINUX)
			timespec req = {miliseconds / 1000, miliseconds % 1000 * 1000000};
			nanosleep(&req, nullptr);
		#endif
	}

    void* Thread::Redirect(void *args)
    {
		UInt_64* rArgs = (UInt_64*)args;
        UInt_32 (*cb)(void*) = (UInt_32 (*)(void*))rArgs[0];
        void* params = (void*)rArgs[1];

        UInt_32* code = new UInt_32();
        *code = cb(params);

        delete[] rArgs;

        return code;
    }
}