#include "ViewCellsTree.h"
#include "Timer/PerfTimer.h"
#include <stack>
#include <string>

using namespace std;


// MAGIC of all bin exports
#ifndef MAGIC 
#define MAGIC 0x827923
#endif

#define VIEWCELLS_VERSION 1.0f


namespace CHCDemoEngine
{


ViewCell *ViewCellsTree::GetViewCell(const Vector3 &point) const
{
	ViewCellsTreeNode *node = mRoot;

	while (!node->IsLeaf()) 
	{
		//cout << "pt: " << point[node->mAxis] << " " << node->mPosition << endl;
		if (point[node->mAxis] < node->mPosition)
			node = node->mBack;
		else
			node = node->mFront;
	}

	//cout << "vc: " << node->mViewCell->GetBox() << " pvs " << node->mViewCell->mPvs.Size() << endl;

	return node->mViewCell;
}


bool ViewCellsTree::LoadFromFile(const std::string &filename, float scaleFactor)
{
	cout << "Loading view cells from file '" + filename + "'";

	FILE *fr = fopen(filename.c_str(), "rb");

	if (!fr) 
	{
		cerr << "Error: Cannot open file for reading" << endl;
		return false;
	}

	bool result = _LoadFromFile(fr, scaleFactor);

	cout << "finished loading view cells. " << endl;
	fclose(fr);

	return result;
}


bool ViewCellsTree::_LoadFromFile(FILE *fr, float scaleFactor)
{
	int buffer[256]; 
	fread(buffer, sizeof(int), 2, fr);

	if (buffer[0] != MAGIC) 
	{
		cerr << "Error: Wrong file type" << endl;
		return false;
	}

	if (buffer[1] != (int)(1000 * VIEWCELLS_VERSION)) 
	{
		cerr << "Error: Wrong viewcells version" << endl;
		return false;
	}

	AxisAlignedBox3 box;
	// get the bounding box
	// exchange x and y coordinates and recompute box
	fread(&box, sizeof(AxisAlignedBox3), 1, fr);

	box.Scale(scaleFactor);

	Vector3 v1(box.Min().x, -box.Min().z, box.Min().y);
	Vector3 v2(box.Max().x, -box.Max().z, box.Max().y);
	
	mBox.Initialize();

	mBox.Include(v1);
	mBox.Include(v2);

	stack<ViewCellsTreeNode **> nodeStack;
	nodeStack.push(&mRoot);

	cout << "view cells bounds " << mBox << endl;

	int numViewCells = 0;

	int axes[] = {0, 0, 0};

	while (!nodeStack.empty()) 
	{
		ViewCellsTreeNode *&node = *nodeStack.top();
		nodeStack.pop();
		node = new ViewCellsTreeNode();

		++ numViewCells;

		int axis;
		fread(&axis, sizeof(int), 1, fr);

		// exchange y and z axis like for whole scene
		if (axis == 2) axis = 1;
		else if (axis == 1) axis = 2;

		node->mAxis = axis;

		if (!node->IsLeaf())
		{
			++ axes[node->mAxis];

			float mypos;
			fread(&mypos, sizeof(float), 1, fr);

			mypos *= scaleFactor;

			// changed coordinate system must be considered also here
			if (node->mAxis == 1) 
			{
				node->mPosition = -mypos;

				nodeStack.push(&node->mBack);
				nodeStack.push(&node->mFront);
				//cout << mypos << " ";
			}
			else
			{
				node->mPosition = mypos;
				
				nodeStack.push(&node->mFront);
				nodeStack.push(&node->mBack);
			}
		}
	}

	return true;
}



}