#include "VirtualNodePoolBuilder.h"
#include <algorithm>
#include "../../inc/tbb/parallel_sort.h"
#include "../../core/Util/BoolArray.h"
#include <numeric>

std::string VirtualNodePoolBuilder::GetFullFileName(const std::string& filename) const
{
	return filename + ".v.pool";
}

size_t VirtualNodePoolBuilder::GetFullNodeSize(const BaseTree* tree, const unsigned8& level, const unsigned8& pointerSize) const
{
	// 1 byte for childmask
	// 1 byte for "virtual mask" (indicating which nodes are virtual)
	// pointerSize bytes for pointer to the first child
	// + Additional node info
	if (level > tree->GetMaxLevel()) return 0;
	return 1 + 1 + pointerSize + tree->GetAdditionalBytesPerNode(level);
}
size_t VirtualNodePoolBuilder::GetVirtualNodeSize(const BaseTree* tree, const unsigned8& level, const unsigned8& pointerSize) const
{
	if (level == 0) return 0;
	return pointerSize;
}

size_t VirtualNodePoolBuilder::GetFullNodeSize(const BaseTree* tree, const unsigned8& level, const std::vector<unsigned8>& pointerSizesPerLevel) const
{
	if (level > tree->GetMaxLevel()) return 0;
	return GetFullNodeSize(tree, level, pointerSizesPerLevel[level]);
}

size_t VirtualNodePoolBuilder::GetVirtualNodeSize(const BaseTree* tree, const unsigned8& level, const std::vector<unsigned8>& pointerSizesPerLevel) const
{
	// pointerSize bytes for pointer to the first child
	return GetVirtualNodeSize(tree, level, pointerSizesPerLevel[level - 1]);
}

size_t VirtualNodePoolBuilder::GetNormalNodeSize(const BaseTree* tree, const unsigned32& nodeId, const std::vector<unsigned8>& pointerSizesPerLevel, std::vector<unsigned8>& additionalPointerInfoSizesPerLevel, const bool& includingAdditionalPointerInfo) const
{
	// 1 byte for childmask
	// Additional node info
	// pointerSize bytes for each pointer needed.
	const Node* node = tree->GetNode(nodeId);
	unsigned8 level = node->GetLevel();
	return 1 + tree->GetAdditionalBytesPerNode(level) + node->GetChildCount() * pointerSizesPerLevel[level] + 
		(includingAdditionalPointerInfo ? (additionalPointerInfoSizesPerLevel[level] * node->GetChildCount()) : 0);
}

std::vector<unsigned8> VirtualNodePoolBuilder::CalculatePointerSizesPerLevel(const BaseTree* tree, const std::vector<size_t>& parentsPerNode, const std::vector<bool>& useVirtualNodes) const
{
	unsigned8 depth = tree->GetMaxLevel();
	
	// Calculate some counts per level (needed to calculate the size of each level)
	std::vector<size_t> virtualNodesPerLevel = CalculateVirtualNodesPerLevel(tree, parentsPerNode);
	std::vector<size_t> fullNodesPerLevel = CalculateFullNodesPerLevel(tree);
	std::vector<size_t> pointersToLevel = CalculatePointersToPerLevel(tree);
	std::vector<unsigned8> additionalBytesPerPointer = tree->GetAdditionalBytesPerPointer();

	// Now bottom-up calculate the pointer sizees required to point to each level
	std::vector<unsigned8> res(depth + 1, 0);
	for (unsigned8 level = depth; level > 0; level--)
	{
		// Keep increasing the pointersize until we can point to all nodes within a level
		bool fits = false;
		while (!fits)
		{
			res[level - 1]++;
			size_t requiredSize = CalculateSizeOfLevel(tree, level, virtualNodesPerLevel[level], fullNodesPerLevel[level],
				pointersToLevel[level], level == depth ? 0 : pointersToLevel[level + 1],
				level == 0 ? 0 : res[level - 1], res[level],
				level == 0 ? 0 : additionalBytesPerPointer[level - 1], additionalBytesPerPointer[level],
				useVirtualNodes[level], level == 0 ? 0 : useVirtualNodes[level - 1]);
			size_t availableSize = BitHelper::Exp2(res[level - 1] * 8); // Available size is how much bytes we can reach with a pointer
			fits = requiredSize < availableSize;
		}
	}
	return res;
}

std::vector<size_t> VirtualNodePoolBuilder::CalculateVirtualNodesPerLevel(const BaseTree* tree, const std::vector<size_t>& parentsPerNode) const
{
	unsigned8 depth = tree->GetMaxLevel();
	unsigned32 nodeCount = (unsigned32)tree->GetNodeCount();
	std::vector<size_t> virtualNodesPerLevel(depth + 1);
	for (unsigned32 i = 0; i < nodeCount; i++)
	{
		const Node* node = tree->GetNode(i);
		unsigned8 level = node->GetLevel();
		if (parentsPerNode[i] > 1)
			virtualNodesPerLevel[level] += parentsPerNode[i] - 1;
	}
	return virtualNodesPerLevel;
}
std::vector<size_t> VirtualNodePoolBuilder::CalculateFullNodesPerLevel(const BaseTree* tree) const
{
	// Every node appears exactly once in full
	return tree->GetNodesPerLevel();
}
std::vector<size_t> VirtualNodePoolBuilder::CalculatePointersToPerLevel(const BaseTree* tree) const
{
	unsigned8 depth = tree->GetMaxLevel();
	unsigned32 nodeCount = (unsigned32)tree->GetNodeCount();
	std::vector<size_t> pointersToPerLevel(depth + 1);
	for (unsigned32 i = 0; i < nodeCount; i++)
	{
		const Node* node = tree->GetNode(i);
		unsigned8 level = node->GetLevel();
		if (level < depth)
			pointersToPerLevel[level + 1] += node->GetChildCount();
	}
	return pointersToPerLevel;
}
size_t VirtualNodePoolBuilder::CalculateSizeOfLevel(const BaseTree* tree, const unsigned8& level,
	const size_t& virtualNodesThisLevel, const size_t& fullNodesThisLevel, const size_t& pointersToThisLevel, const size_t& pointersFromThisLevel,
	const unsigned8& pointerSizeToThisLevel, const unsigned8& pointerSizeFromThisLevel,
	const unsigned8& additionalBytesPointersToThisLevel, const unsigned8& additionalBytesPointersFromThisLevel,
	const bool& useVirtualNodesThisLevel, const bool& useVirtualNodesPreviousLevel) const
{
	size_t requiredSize = 0;
	// Calculate size of virtual nodes placed in this level by the previous level
	if (useVirtualNodesPreviousLevel)
		requiredSize += virtualNodesThisLevel * GetVirtualNodeSize(tree, level, pointerSizeToThisLevel) + pointersToThisLevel * additionalBytesPointersToThisLevel;
	// Calculate the size of full nodes (or normal nodes) occupying this level
	if (useVirtualNodesThisLevel)
		requiredSize += fullNodesThisLevel * GetFullNodeSize(tree, level, pointerSizeFromThisLevel);
	else
		requiredSize += (1 + tree->GetAdditionalBytesPerNode(level)) * fullNodesThisLevel + pointersFromThisLevel * pointerSizeFromThisLevel + pointersFromThisLevel * additionalBytesPointersFromThisLevel;
	return requiredSize;
}
std::vector<size_t> VirtualNodePoolBuilder::CalculateSizePerLevel(const BaseTree* tree, const std::vector<unsigned8> pointerSizesPerLevel, const std::vector<size_t>& parentsPerNode, const std::vector<bool>& useVirtualNodes) const
{
	// Calculate some statistics needed to find the size of each level in memory
	unsigned8 depth = tree->GetMaxLevel();
	std::vector<size_t> virtualNodesPerLevel = CalculateVirtualNodesPerLevel(tree, parentsPerNode);
	std::vector<size_t> fullNodesPerLevel = CalculateFullNodesPerLevel(tree);
	std::vector<size_t> pointersToLevel = CalculatePointersToPerLevel(tree);
	std::vector<unsigned8> additionalBytesPerPointer = tree->GetAdditionalBytesPerPointer();
	
	// Calculate the actual size per level
	std::vector<size_t> sizePerLevel(depth + 1);
	for (unsigned8 level = 0; level <= depth; level++)
		sizePerLevel[level] = CalculateSizeOfLevel(tree, level, virtualNodesPerLevel[level], fullNodesPerLevel[level], 
		pointersToLevel[level], level == depth ? 0 : pointersToLevel[level + 1],
		level == 0 ? 0 : pointerSizesPerLevel[level - 1], pointerSizesPerLevel[level],
		level == 0 ? 0 : additionalBytesPerPointer[level - 1], additionalBytesPerPointer[level],
		useVirtualNodes[level], level == 0 ? 0 : useVirtualNodes[level - 1]);
	return sizePerLevel;
}
std::vector<size_t> VirtualNodePoolBuilder::CalculateApproximateSizePerLevelVirtualNodes(const BaseTree* tree, const std::vector<size_t>& parentsPerNode) const
{
	// Calculate some statistics needed to find the size of each level in memory
	unsigned8 depth = tree->GetMaxLevel();
	std::vector<size_t> virtualNodesPerLevel = CalculateVirtualNodesPerLevel(tree, parentsPerNode);
	std::vector<size_t> fullNodesPerLevel = CalculateFullNodesPerLevel(tree);
	std::vector<size_t> pointersToLevel = CalculatePointersToPerLevel(tree);
	std::vector<unsigned8> pointerSizesPerLevel(depth + 1, 4); // Assume 4 bytes pointers per level
	std::vector<unsigned8> additionalBytesPerPointer = tree->GetAdditionalBytesPerPointer();

	// Calculate the actual size per level
	std::vector<size_t> sizePerLevel(depth + 1);
	for (unsigned8 level = 0; level <= depth; level++)
		sizePerLevel[level] =
		fullNodesPerLevel[level] * GetFullNodeSize(tree, level, pointerSizesPerLevel) + // Full nodes size
		(level == depth ? 0 : (virtualNodesPerLevel[level + 1] * GetVirtualNodeSize(tree, level + 1, pointerSizesPerLevel))) + // Virtual nodes size
		(level == depth ? 0 : (pointersToLevel[level + 1] * additionalBytesPerPointer[level])); // additional pointer bytes size
	return sizePerLevel;
}
std::vector<size_t> VirtualNodePoolBuilder::CalculateApproximateSizePerLevelStandardNodes(const BaseTree* tree) const
{
	unsigned8 depth = tree->GetMaxLevel();
	unsigned32 nodeCount = (unsigned32)tree->GetNodeCount();
	std::vector<unsigned8> pointerSizesPerLevel(depth + 1, 4); // Assume 4 bytes pointers per level
	std::vector<unsigned8> additionalBytesPerPointer = tree->GetAdditionalBytesPerPointer();
	std::vector<size_t> sizePerLevel(depth + 1);
	for (unsigned32 i = 0; i < nodeCount; i++)
	{
		const Node* node = tree->GetNode(i);
		unsigned8 level = node->GetLevel();
		sizePerLevel[level] += GetNormalNodeSize(tree, i, pointerSizesPerLevel, additionalBytesPerPointer, true);;
	}
	return sizePerLevel;
}
std::vector<bool> VirtualNodePoolBuilder::DecideVirtualPointersPerLevel(const BaseTree* tree, const std::vector<size_t>& parentsPerNode) const
{
	unsigned8 depth = tree->GetMaxLevel();
	std::vector<size_t> sizePerStandardLevel = CalculateApproximateSizePerLevelStandardNodes(tree);
	std::vector<size_t> sizePerVirtualNodesLevel = CalculateApproximateSizePerLevelVirtualNodes(tree, parentsPerNode);
	std::vector<bool> useVirtualNodes(depth + 1);
	for (unsigned8 level = 0; level <= depth; level++)
		useVirtualNodes[level] = sizePerVirtualNodesLevel[level] < sizePerStandardLevel[level];
	//useVirtualNodes = std::vector<bool>(depth + 1, false);
	//useVirtualNodes[0] = true;
	//useVirtualNodes[1] = true;
	//useVirtualNodes[2] = true;
	return useVirtualNodes;
}
size_t VirtualNodePoolBuilder::CalculatePoolInfoSize(const BaseTree* tree)
{
	unsigned8 depth = tree->GetMaxLevel();
	// Each tree contains at least the level offsets (4 bytes per level) and pointer sizes per level (1 byte per level)
	// 1 byte per level for sizes of additional information per level
	// 4 bytes are used to indicate which levels use virtual nodes
	size_t poolInfoSize = (depth + 1) * 5 + 4; 
	if (HasAdditionalBytesPerNode(tree)) poolInfoSize += depth + 1;
	if (HasAdditionalBytesPerPointer(tree)) poolInfoSize += depth + 1;
	// Additional pool info from the tree
	poolInfoSize += tree->GetAdditionalTreeInfoSize();
	return poolInfoSize;
}
size_t VirtualNodePoolBuilder::GetPoolSize(const BaseTree* tree)
{
	// Calculate the pool info size
	size_t minSize = CalculatePoolInfoSize(tree);

	// Calculate the main pool size
	std::vector<size_t> parentsPerNode = tree->GetParentCounts();
	std::vector<bool> useVirtualNodes = DecideVirtualPointersPerLevel(tree, parentsPerNode);
	std::vector<unsigned8> pointerSizesPerLevel = CalculatePointerSizesPerLevel(tree, parentsPerNode, useVirtualNodes);
	std::vector<size_t> sizesPerLevel = CalculateSizePerLevel(tree, pointerSizesPerLevel, parentsPerNode, useVirtualNodes);
	minSize += std::accumulate(sizesPerLevel.begin(), sizesPerLevel.end(), size_t(0));
	
	std::vector<size_t> virtualNodesPerLevel = CalculateVirtualNodesPerLevel(tree, parentsPerNode);
	std::vector<size_t> fullNodesPerLevel = CalculateFullNodesPerLevel(tree);
	size_t virtualNodesSum = 0;
	size_t fullNodesSum = 0;
	size_t normalNodesSum = 0;
	for (unsigned8 level = 0; level < tree->GetMaxLevel(); level++)
	{
		if (useVirtualNodes[level]) fullNodesSum += fullNodesPerLevel[level];
		else normalNodesSum += fullNodesPerLevel[level];
		if (level > 0 && useVirtualNodes[level - 1]) virtualNodesSum += virtualNodesPerLevel[level - 1];
	}
	printf("Virtual nodes: %llu, Complete nodes: %llu, Normal Nodes: %llu, Percentage virtual: %f\n", (unsigned64)virtualNodesSum, (unsigned64)fullNodesSum, (unsigned64)normalNodesSum, (double(virtualNodesSum) / double(virtualNodesSum + fullNodesSum)) * 100.0);
	return minSize;
}

//************************************
// Insert all nodes into final node pool and updates pointers
//************************************
bool VirtualNodePoolBuilder::BuildPool(const BaseTree* tree, std::vector<unsigned8>& pool) {
	if (tree == NULL) return false;
	mIsBuilding = true;

	unsigned32 nodeCount = (unsigned32)tree->GetNodeCount();
	unsigned8 depth = tree->GetMaxLevel();

	// Initialize the pool
	pool = std::vector<unsigned8>(GetPoolSize(tree));

	// Acquire some information about the pool
	std::vector<size_t> parentsPerNode = tree->GetParentCounts();
	std::vector<bool> useVirtualNodes = DecideVirtualPointersPerLevel(tree, parentsPerNode);
	std::vector<unsigned8> pointerSizesPerLevel = CalculatePointerSizesPerLevel(tree, parentsPerNode, useVirtualNodes);
	std::vector<size_t> sizePerLevel = CalculateSizePerLevel(tree, pointerSizesPerLevel, parentsPerNode, useVirtualNodes);
	std::vector<unsigned8> additionalBytesPerPointer = tree->GetAdditionalBytesPerPointer();
	std::vector<unsigned8> additionalBytesPerNode = tree->GetAdditionalBytesPerNode();
	std::vector<size_t> nodePointers(nodeCount);

	// Calculate the level offsets
	std::vector<size_t> levelOffsets(depth + 1);
	size_t curIndex = CalculatePoolInfoSize(tree);
	for (unsigned8 level = 0; level <= depth; level++)
	{
		levelOffsets[level] = curIndex;
		curIndex += sizePerLevel[level];
	}

	// Calculate the node pointers for nodes in non-switch levels not using virtual nodes
	bool switchlevel = true;
	for (unsigned8 level = 0; level <= depth; level++)
	{
		if (!switchlevel)
		{
			curIndex = levelOffsets[level];
			for (unsigned32 i = 0; i < nodeCount; i++)
			{
				const Node* node = tree->GetNode(i);
				if (node->GetLevel() == level)
				{
					nodePointers[i] = curIndex;
					curIndex += GetNormalNodeSize(tree, i, pointerSizesPerLevel, additionalBytesPerPointer, true);
				}
			}
		}
		if (useVirtualNodes[level]) switchlevel = true;
		else if (switchlevel == true) switchlevel = false;
	}


	curIndex = 0;
	// Write the level offsets
	for (unsigned8 level = 0; level <= depth; level++)
		BitHelper::SplitInBytesAndMove(levelOffsets[level], pool, level * 4, 4);
	curIndex += 4 * (depth + 1);

	// Write the pointer sizes per level
	for (unsigned8 level = 0; level <= depth; level++)
		pool[curIndex++] = pointerSizesPerLevel[level];

	// Write 4 bytes indicating which levels use virtual nodes
	unsigned32 levelsUsingVirtualNodesMask = 0;
	for (unsigned8 level = 0; level <= depth; level++)
		BitHelper::SetLS(levelsUsingVirtualNodesMask, level, useVirtualNodes[level]);
	BitHelper::SplitInBytesAndMove(levelsUsingVirtualNodesMask, pool, curIndex);
	curIndex += 4;

	// Write additional bytes per node
	if (HasAdditionalBytesPerNode(tree))
	{
		for (unsigned8 level = 0; level <= depth; level++)
			pool[curIndex++] = additionalBytesPerNode[level];
	}

	// Write additional bytes per pointer
	if (HasAdditionalBytesPerPointer(tree))
	{
		for (unsigned8 level = 0; level <= depth; level++)
			pool[curIndex++] = additionalBytesPerPointer[level];
	}

	// Leave some space for the additional pool info.
	// As the actual node pointers are not yet known, we write them later
	size_t additionalTreeInfoStart = curIndex;
	curIndex += tree->GetAdditionalTreeInfoSize();

	// Find all roots (to make sure we write all reachable nodes from any root).
	std::vector<NodeToWrite> nextLevelNodes;
	std::vector<NodeToWrite> thisLevelNodes;
	for (unsigned32 i = 0; i < nodeCount; i++)
		if (tree->GetNode(i)->GetLevel() == 0) thisLevelNodes.push_back(NodeToWrite(i, 0, useVirtualNodes[0] ? FULL : NORMAL, 0, 0));
	size_t nextLevelIndex;
	BoolArray writtenNodes(nodeCount);

	// Write the full node pool
	for (unsigned8 level = 0; level <= depth; level++)
	{
		assert(curIndex = levelOffsets[level]);
		nextLevelNodes.clear();
		nextLevelIndex = 0;
		unsigned8 additionalNodeBytes = additionalBytesPerNode[level];
		unsigned8 additionalBytesForPointersToThisLevel = level > 0 ? additionalBytesPerPointer[level - 1] : 0;
		unsigned8 additionalBytesForPointersFromThisLevel = additionalBytesPerPointer[level];
		size_t childFullNodeSize = GetFullNodeSize(tree, level + 1, pointerSizesPerLevel);
		size_t childVirtualNodeSize = GetVirtualNodeSize(tree, level + 1, pointerSizesPerLevel);
		for (NodeToWrite nodeInfo : thisLevelNodes)
		{
			const Node* node = nodeInfo.GetNode(tree);
			unsigned32 nodeId = nodeInfo.nodeId;
			assert(level == node->GetLevel());
			if (nodeInfo.type == VIRTUAL)
			{ // Write a virtual node
				size_t virtualNodeSize = GetVirtualNodeSize(tree, level, pointerSizesPerLevel);
				BitHelper::SplitInBytesAndMove(nodePointers[nodeId] - levelOffsets[level], pool, curIndex, virtualNodeSize);
				curIndex += virtualNodeSize;
			}
			else if (nodeInfo.type == FULL)
			{  // Write a full node
				assert(useVirtualNodes[level]);
				nodePointers[nodeId] = curIndex;

				WriteFullNode(tree, nodeId, (unsigned32)nextLevelIndex, pointerSizesPerLevel[level], writtenNodes, additionalNodeBytes, pool, curIndex);
				// Tell the next level which nodes should be written and in what order
				unsigned8 vMask = pool[curIndex + 1 + additionalNodeBytes];
				size_t nextLevelNodesOffset = nextLevelNodes.size();
				for (ChildIndex c = 0; c < 8; c++)
					if (node->HasChild(c))
					{
						NodeType type;
						if (!useVirtualNodes[level + 1]) type = BitHelper::GetLS(vMask, c) ? VIRTUAL : NORMAL;
						else type = BitHelper::GetLS(vMask, c) ? VIRTUAL : FULL;
						nextLevelNodes.push_back(NodeToWrite(node->GetChildIndex(c), level + 1, type, nodeId, c));
					}
				// Calculate the size of those nodes in the next layer.
				for (auto c = nextLevelNodes.begin() + nextLevelNodesOffset; c != nextLevelNodes.end(); c++)
				{
					switch (c->type)
					{
					case NORMAL: nextLevelIndex += GetNormalNodeSize(tree, c->nodeId, pointerSizesPerLevel, additionalBytesPerPointer, true); break;
					case FULL: nextLevelIndex += childFullNodeSize; break;
					case VIRTUAL: nextLevelIndex += childVirtualNodeSize; break;
					}
				}
				nextLevelIndex += node->GetChildCount() * additionalBytesForPointersFromThisLevel;
				curIndex += GetFullNodeSize(tree, level, pointerSizesPerLevel);
			}
			else if (nodeInfo.type == NORMAL)
			{
				assert(nodePointers[nodeId] == 0 || nodePointers[nodeId] == curIndex);
				nodePointers[nodeId] = curIndex;
				WriteNormalNode(tree, nodeId, additionalNodeBytes, pointerSizesPerLevel[level], nodePointers, level == depth ? 0 : levelOffsets[level + 1], pool, curIndex);
				curIndex += GetNormalNodeSize(tree, nodeId, pointerSizesPerLevel, additionalBytesPerPointer, false);
				// Write additional bytes per pointer
				for (ChildIndex c = 0; c < 8; c++)
				{
					if (node->HasChild(c))
					{
						WriteAdditionalPointerInfo(tree, nodeId, c, additionalBytesForPointersFromThisLevel, pool, curIndex);
						curIndex += additionalBytesForPointersFromThisLevel;
					}
				}
			}
			if (level > 0 && additionalBytesForPointersToThisLevel != 0 && useVirtualNodes[level - 1])
			{
				WriteAdditionalPointerInfo(tree, nodeInfo.parentId, nodeInfo.childIndexOfParent, additionalBytesForPointersToThisLevel, pool, curIndex);
				curIndex += additionalBytesForPointersToThisLevel;
			}
		}
		if (useVirtualNodes[level])
			thisLevelNodes = nextLevelNodes;
		else
		{
			thisLevelNodes.clear();
			for (unsigned32 i = 0; i < nodeCount; i++)
			{
				const Node* node = tree->GetNode(i);
				if (node->GetLevel() == level + 1)
					thisLevelNodes.push_back(NodeToWrite(i, level + 1, NORMAL, 0, 0));
			}
		}
	}
	std::vector<unsigned8> additionalTreeInfo = tree->GetAdditionalTreeInfo(nodePointers);
	std::move(additionalTreeInfo.begin(), additionalTreeInfo.end(), pool.begin() + additionalTreeInfoStart);
	mIsBuilding = false;
	return true;
}

void VirtualNodePoolBuilder::WriteFullNode(const BaseTree* tree, const unsigned32& nodeId, const unsigned32& childPointer, const unsigned8& childPointerSize, BoolArray& writtenNodes, 
	const unsigned8& additionalNodeBytes, std::vector<unsigned8>& pool, const size_t& offset) const
{
	size_t curIndex = offset;

	const Node* node = tree->GetNode(nodeId);
	pool[curIndex++] = node->GetChildmask().mask;

	// Write additional node info (if any)
	if (additionalNodeBytes != 0)
	{
		auto nodeBytes = tree->GetAdditionalNodeBytes(node);
		std::move(nodeBytes.begin(), nodeBytes.end(), pool.begin() + curIndex);
		assert(nodeBytes.size() == additionalNodeBytes);
		curIndex += additionalNodeBytes;
	}
	
	// Build the "virtual mask" indicating which nodes have already been written in the next level and are virtual in this level
	pool[curIndex++] = GetVMask(tree, nodeId, writtenNodes);

	// Write the pointer to the first child
	BitHelper::SplitInBytesAndMove(childPointer, pool, curIndex, childPointerSize);
	curIndex += 4;
}

void VirtualNodePoolBuilder::WriteNormalNode(const BaseTree* tree, const unsigned32& nodeId, const unsigned8& additionalNodeBytes, const unsigned8& pointerSize, const std::vector<size_t>& nodePointers, const size_t& nextLevelOffset, std::vector<unsigned8>& pool, const size_t& offset) const
{
	size_t curIndex = offset;

	const Node* node = tree->GetNode(nodeId);
	pool[curIndex++] = node->GetChildmask().mask;

	// Write additional node info (if any)
	if (additionalNodeBytes != 0)
	{
		auto nodeBytes = tree->GetAdditionalNodeBytes(node);
		std::move(nodeBytes.begin(), nodeBytes.end(), pool.begin() + curIndex);
		assert(nodeBytes.size() == additionalNodeBytes);
		curIndex += additionalNodeBytes;
	}

	// Write the child pointers
	unsigned32* children = node->GetChildren();
	for (ChildIndex c = 0; c < node->GetChildCount(); c++)
	{
		unsigned32 child = children[c];
		size_t pointer = nodePointers[child] - nextLevelOffset;
		BitHelper::SplitInBytesAndMove(pointer, pool, curIndex, pointerSize);
		curIndex += pointerSize;
	}
}

void VirtualNodePoolBuilder::WriteAdditionalPointerInfo(const BaseTree* tree, const unsigned32& nodeId, const ChildIndex& childId, const unsigned8& additionalPointerBytes, std::vector<unsigned8>& pool, const size_t& offset) const
{
	auto pointerInfo = tree->GetAdditionalPointerBytes(tree->GetNode(nodeId), childId);
	std::move(pointerInfo.begin(), pointerInfo.end(), pool.begin() + offset);
}

unsigned8 VirtualNodePoolBuilder::GetVMask(const BaseTree* tree, const unsigned32& nodeId, BoolArray& writtenNodes) const
{
	const Node* node = tree->GetNode(nodeId);
	unsigned8 vMask = 0;
	for (ChildIndex c = 0; c < 8; c++)
	{
		if (node->HasChild(c))
		{
			unsigned32 childIndex = node->GetChildIndex(c);
			// A node is virtual if it has been written before
			BitHelper::SetLS(vMask, c, writtenNodes[childIndex]);
			writtenNodes.Set(childIndex, true);
		}
	}
	return vMask;
}

bool VirtualNodePoolBuilder::VerifyPool(std::vector<unsigned8>& pool, const unsigned8& treeDepth) const
{
	// TODO: Do some verification here.
	return true;
}