// Copyright UnexGames 2025. All Rights Reserved.

#include "ThreadUtility.h"
#include "Engine/Engine.h"
#include "ThreadBase.h"
#if WITH_EDITOR
#include "Editor.h"
#else
#include "Misc/CoreDelegates.h"
#endif

#define LOCTEXT_NAMESPACE "UThreadUtility"

#if WITH_EDITOR
FDelegateHandle UThreadUtility::EndPIEHandle = FDelegateHandle();
#else
FDelegateHandle UThreadUtility::PreExitHandle = FDelegateHandle();
#endif
TArray<UObject*> UThreadUtility::RootObjects = {};
int32 UThreadUtility::TaskIndex = 0;
int32 UThreadUtility::MutexIndex = 0;
int32 UThreadUtility::ThreadPoolIndex = 0;

UThreadUtility::UThreadUtility()
{
#if WITH_EDITOR
    EndPIEHandle = FEditorDelegates::PrePIEEnded.AddStatic(&UThreadUtility::OnEndPIE);
#else
    PreExitHandle = FCoreDelegates::OnPreExit.AddStatic(&UThreadUtility::OnPreExit);
#endif
}

UThreadUtility::~UThreadUtility()
{
#if WITH_EDITOR
    FEditorDelegates::PrePIEEnded.Remove(EndPIEHandle);
#else
    FCoreDelegates::OnPreExit.Remove(PreExitHandle);
#endif
    TaskIndex = 0;
    MutexIndex = 0;
    ThreadPoolIndex = 0;
}





UObject* UThreadUtility::GetContextWorld(UObject* WorldContextObject)
{
    return GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::ReturnNull);
}


bool UThreadUtility::CanUseAudioThread()
{
    return (FPlatformMisc::AllowAudioThread());
}



bool UThreadUtility::IsPrintThreadSafe()
{
    return (FPlatformMisc::IsLocalPrintThreadSafe());
}



bool UThreadUtility::IsUseRenderThread()
{
    return (FPlatformMisc::UseRenderThread());
}



bool UThreadUtility::CanSupportMultiThreadedFileHandles()
{
    return (FGenericPlatformMisc::SupportsMultithreadedFileHandles());
}




void UThreadUtility::CancelTask(UThreadBase* Task)
{
    if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
    {
        Task->Cancel();
    }
}



void UThreadUtility::WaitToFinish(UThreadBase* Task)
{
    if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
    {
        Task->WaitToFinish();
    }
}



bool UThreadUtility::IsRunning(UThreadBase* Task)
{
    if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
    {
        return Task->IsRunning();
    }
    return false;
}

bool UThreadUtility::IsCanceled(UThreadBase* Task)
{
    if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
    {
        return Task->IsCanceled();
    }
    return true;
}

int32 UThreadUtility::MixThreeIntegers(int32 Integer1, int32 Integer2, int32 Integer3)
{
    unsigned long a = (unsigned long)Integer1;
    unsigned long b = (unsigned long)Integer2;
    unsigned long c = (unsigned long)Integer3;

    a = a - b;  a = a - c;  a = a ^ (c >> 13);
    b = b - c;  b = b - a;  b = b ^ (a << 8);
    c = c - a;  c = c - b;  c = c ^ (b >> 13);
    a = a - b;  a = a - c;  a = a ^ (c >> 12);
    b = b - c;  b = b - a;  b = b ^ (a << 16);
    c = c - a;  c = c - b;  c = c ^ (b >> 5);
    a = a - b;  a = a - c;  a = a ^ (c >> 3);
    b = b - c;  b = b - a;  b = b ^ (a << 10);
    c = c - a;  c = c - b;  c = c ^ (b >> 15);
    return (int32)c;
}


void UThreadUtility::GetRandomScale(const FVector& Min, const FVector& Max, EScaleType Type, const FRandomStream& RandomStream, FVector& Scale)
{

    TFunction<float(float, int32)> Interpolate = [&](float Alpha, int32 Axis)
    {
        return Min[Axis] + (Alpha * (Max[Axis] - Min[Axis]));
    };

    Scale = FVector(1.0f);
    float LockRand = 0.0f;

    switch (Type)
    {
    case EScaleType::Uniform:
        Scale.X = Interpolate(RandomStream.GetFraction(), 0);
        Scale.Y = Scale.X;
        Scale.Z = Scale.X;
        break;

    case EScaleType::Free:
        Scale.X = Interpolate(RandomStream.GetFraction(), 0);
        Scale.Y = Interpolate(RandomStream.GetFraction(), 1);
        Scale.Z = Interpolate(RandomStream.GetFraction(), 2);
        break;

    case EScaleType::LockXY:
        LockRand = RandomStream.GetFraction();
        Scale.X = Interpolate(LockRand, 0);
        Scale.Y = Interpolate(LockRand, 1);
        Scale.Z = Interpolate(RandomStream.GetFraction(), 2);
        break;

    case EScaleType::LockXZ:
        LockRand = RandomStream.GetFraction();
        Scale.X = Interpolate(LockRand, 0);
        Scale.Y = Interpolate(RandomStream.GetFraction(), 1);
        Scale.Z = Interpolate(LockRand, 2);
        break;

    case EScaleType::LockYZ:
        LockRand = RandomStream.GetFraction();
        Scale.X = Interpolate(RandomStream.GetFraction(), 0);
        Scale.Y = Interpolate(LockRand, 1);
        Scale.Z = Interpolate(LockRand, 2);
        break;
    }
}





bool UThreadUtility::IsSupportsMultithreading()
{
    return(FPlatformProcess::SupportsMultithreading());
}


void UThreadUtility::SetNameToThread(FString ThreadName)
{
    FPlatformProcess::SetThreadName(*ThreadName);
}




void UThreadUtility::AddToRoot(UObject* Object)
{
    if (Object)
    {
        if (!Object->IsRooted())
        {
            if (!RootObjects.Contains(Object))
            {
                RootObjects.Add(Object);
                Object->AddToRoot();
            }
        }
    }
}



void UThreadUtility::RemoveFromRoot(UObject* Object)
{
    if(Object)
    {
        if (Object->IsRooted())
        {
            if (RootObjects.Contains(Object))
            {
                RootObjects.Remove(Object);
                Object->RemoveFromRoot();
            }
        }
    }
}



void UThreadUtility::OnEndPIE(const bool bIsSimulating)
{
    for (auto Object : RootObjects)
    {
        if (Object != nullptr && Object->IsValidLowLevel() && IsValid(Object) && !Object->IsUnreachable())
        {
            if (Object->IsRooted())
            {
                if (RootObjects.Contains(Object))
                {
                    Object->RemoveFromRoot();
                }
            }
        }
    }
    RootObjects.Empty();
}

void UThreadUtility::OnPreExit()
{
    for (auto Object : RootObjects)
    {
        if (Object)
        {
            if (Object->IsRooted())
            {
                if (RootObjects.Contains(Object))
                {
                    Object->RemoveFromRoot();
                }
            }
        }
    }
    RootObjects.Empty();
}


#undef LOCTEXT_NAMESPACE