// Copyright 2020 Phyronnaz

#include "VoxelData/VoxelDataOctree.h"
#include "VoxelData/VoxelDataUtilities.h"
#include "VoxelGenerators/VoxelGeneratorInstance.h"
#include "VoxelGenerators/VoxelGeneratorInstance.inl"

DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelDataOctreesMemory);
DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelUndoRedoMemory);
DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelMultiplayerMemory);
DEFINE_STAT(STAT_VoxelDataOctreesCount);

DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelDataOctreeDirtyValuesMemory);
DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelDataOctreeDirtyMaterialsMemory);

DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelDataOctreeCachedValuesMemory);
DEFINE_VOXEL_MEMORY_STAT(STAT_VoxelDataOctreeCachedMaterialsMemory);

///////////////////////////////////////////////////////////////////////////////
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template<typename T, typename U>
T FVoxelDataOctreeBase::GetFromGeneratorAndAssets(const FVoxelGeneratorInstance& Generator, U X, U Y, U Z, int32 LOD) const
{
	ensureThreadSafe(IsLockedForRead());
	check(IsLeafOrHasNoChildren());
	
	const auto& Assets = ItemHolder->GetAssetItems();
	for (int32 Index = Assets.Num() - 1; Index >= 0; Index--)
	{
		auto& Asset = *Assets[Index];
		if (Asset.Bounds.ContainsTemplate(X, Y, Z))
		{
			return Asset.Generator->Get_Transform<T>(Asset.LocalToWorld, X, Y, Z, LOD, FVoxelItemStack(*ItemHolder, Generator, Index));
		}
	}
	return Generator.Get<T>(X, Y, Z, LOD, FVoxelItemStack(*ItemHolder));
}

template VOXEL_API v_flt          FVoxelDataOctreeBase::GetFromGeneratorAndAssets<v_flt         , v_flt>(const FVoxelGeneratorInstance& Generator, v_flt X, v_flt Y, v_flt Z, int32 LOD) const;
template VOXEL_API v_flt          FVoxelDataOctreeBase::GetFromGeneratorAndAssets<v_flt         , int32>(const FVoxelGeneratorInstance& Generator, int32 X, int32 Y, int32 Z, int32 LOD) const;
template VOXEL_API FVoxelValue    FVoxelDataOctreeBase::GetFromGeneratorAndAssets<FVoxelValue   , int32>(const FVoxelGeneratorInstance& Generator, int32 X, int32 Y, int32 Z, int32 LOD) const;
template VOXEL_API FVoxelMaterial FVoxelDataOctreeBase::GetFromGeneratorAndAssets<FVoxelMaterial, int32>(const FVoxelGeneratorInstance& Generator, int32 X, int32 Y, int32 Z, int32 LOD) const;

template<typename T>
void FVoxelDataOctreeBase::GetFromGeneratorAndAssets(const FVoxelGeneratorInstance& Generator, TVoxelQueryZone<T>& QueryZone, int32 LOD) const
{
	ensureThreadSafe(IsLockedForRead());
	check(IsLeafOrHasNoChildren());
	
	const auto& Assets = ItemHolder->GetAssetItems();

	if (Assets.Num() == 0)
	{
		VOXEL_SLOW_SCOPE_COUNTER("Query Generator");
		Generator.Get(QueryZone, LOD, FVoxelItemStack(*ItemHolder));
		return;
	}

	for (int32 Index = Assets.Num() - 1; Index >= 0; Index--)
	{
		auto& Asset = *Assets[Index];
		if (QueryZone.Bounds.Contains(Asset.Bounds))
		{
			VOXEL_SLOW_SCOPE_COUNTER("Query Asset");
			Asset.Generator->Get_Transform<T>(Asset.LocalToWorld, QueryZone, LOD, FVoxelItemStack(*ItemHolder, Generator, Index));
			return;
		}
		if (QueryZone.Bounds.Intersect(Asset.Bounds))
		{
			break;
		}
	}

	VOXEL_SLOW_SCOPE_COUNTER("Individual Asset & Generator Queries");
	for (VOXEL_QUERY_ZONE_ITERATE(QueryZone, X))
	{
		for (VOXEL_QUERY_ZONE_ITERATE(QueryZone, Y))
		{
			for (VOXEL_QUERY_ZONE_ITERATE(QueryZone, Z))
			{
				T Value;
				for (int32 Index = Assets.Num() - 1; Index >= 0; Index--)
				{
					auto& Asset = *Assets[Index];
					if (Asset.Bounds.Contains(X, Y, Z))
					{
						Value = Asset.Generator->Get_Transform<T>(Asset.LocalToWorld, X, Y, Z, LOD, FVoxelItemStack(*ItemHolder, Generator, Index));
						break;
					}
					if (Index == 0)
					{
						Value = Generator.Get<T>(X, Y, Z, LOD, FVoxelItemStack(*ItemHolder));
					}
				}
				QueryZone.Set(X, Y, Z, Value);
			}
		}
	}
}

template VOXEL_API void FVoxelDataOctreeBase::GetFromGeneratorAndAssets<FVoxelValue   >(const FVoxelGeneratorInstance& Generator, TVoxelQueryZone<FVoxelValue   >& QueryZone, int32 LOD) const;
template VOXEL_API void FVoxelDataOctreeBase::GetFromGeneratorAndAssets<FVoxelMaterial>(const FVoxelGeneratorInstance& Generator, TVoxelQueryZone<FVoxelMaterial>& QueryZone, int32 LOD) const;

template <typename T>
T FVoxelDataOctreeBase::GetCustomOutput(const FVoxelGeneratorInstance& Generator, T DefaultValue, FName Name, v_flt X, v_flt Y, v_flt Z, int32 LOD) const
{
	ensureThreadSafe(IsLockedForRead());
	check(IsLeafOrHasNoChildren());
	
	const auto& Assets = ItemHolder->GetAssetItems();
	for (int32 Index = Assets.Num() - 1; Index >= 0; Index--)
	{
		auto& Asset = *Assets[Index];
		if (Asset.Bounds.ContainsTemplate(X, Y, Z))
		{
			return Asset.Generator->GetCustomOutput_Transform(Asset.LocalToWorld, DefaultValue, Name, X, Y, Z, LOD, FVoxelItemStack(*ItemHolder, Generator, Index));
		}
	}
	return Generator.GetCustomOutput<T>(DefaultValue, Name, X, Y, Z, LOD, FVoxelItemStack(*ItemHolder));
}

template VOXEL_API v_flt FVoxelDataOctreeBase::GetCustomOutput<v_flt>(const FVoxelGeneratorInstance&, v_flt, FName, v_flt, v_flt, v_flt, int32) const;
template VOXEL_API int32 FVoxelDataOctreeBase::GetCustomOutput<int32>(const FVoxelGeneratorInstance&, int32, FName, v_flt, v_flt, v_flt, int32) const;

///////////////////////////////////////////////////////////////////////////////
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///////////////////////////////////////////////////////////////////////////////

void FVoxelDataOctreeParent::CreateChildren()
{
	TVoxelOctreeParent::CreateChildren();

#if DO_THREADSAFE_CHECKS
	for (auto& Child : AsParent().GetChildren())
	{
		Child.Parent = this;
	}
#endif

	if (ItemHolder->NumItems() > 0)
	{
		for (auto& Child : AsParent().GetChildren())
		{
			const FVoxelIntBox ChildBounds = Child.GetBounds();
			ItemHolder->ApplyToAllItems([&](auto& Item)
			{
				if (Item.Bounds.Intersect(ChildBounds))
				{
					Child.ItemHolder->AddItem(Item);
				}
			});
		}
	}
	ItemHolder.Reset();
}

void FVoxelDataOctreeParent::DestroyChildren()
{
	TVoxelOctreeParent::DestroyChildren();

	check(!ItemHolder.IsValid());
	// Always valid on a node with no children
	ItemHolder = MakeUnique<FVoxelPlaceableItemHolder>();
}