#include "SceneGraph.h"
#include "KdTree.h"
#include "SamplingPreprocessor.h"
#include "X3dExporter.h"
#include "Environment.h"
#include "MutualVisibility.h"
#include "Polygon3.h"
#include "ViewCell.h"
#include "ViewCellsManager.h"
#include "RenderSimulator.h"



namespace GtpVisibilityPreprocessor {


SamplingPreprocessor::SamplingPreprocessor(): mPass(0)
{
  // this should increase coherence of the samples
  Environment::GetSingleton()->GetIntValue("SamplingPreprocessor.samplesPerPass", mSamplesPerPass);
  Environment::GetSingleton()->GetIntValue("SamplingPreprocessor.totalSamples", mTotalSamples);
  
  mStats.open("stats.log");
}

SamplingPreprocessor::~SamplingPreprocessor()
{
  CLEAR_CONTAINER(mSampleRays);
  CLEAR_CONTAINER(mVssSampleRays);
}

Intersectable *
SamplingPreprocessor::CastRay(
							  const Vector3 &origin,
							  const Vector3 &direction
							  )
{
  static Ray ray;
  AxisAlignedBox3 box = mViewCellsManager->GetViewSpaceBox();
  
  AxisAlignedBox3 sbox = box;
  sbox.Enlarge(Vector3(-Limits::Small));
  if (!sbox.IsInside(origin))
	return 0;
	
  ray.intersections.clear();
  // do not store anything else then intersections at the ray
  ray.Init(origin, direction, Ray::LOCAL_RAY);

  ray.mFlags &= ~Ray::CULL_BACKFACES;



  // cast ray to KD tree to find intersection with other objects
  Intersectable *objectA = NULL;
  Vector3 pointA;
  float bsize = Magnitude(box.Size());
  
  if (mKdTree->CastRay(ray)) {
	if (!mDetectEmptyViewSpace || DotProd(ray.intersections[0].mNormal, direction) < 0) {
	  objectA = ray.intersections[0].mObject;
	  pointA = ray.Extrap(ray.intersections[0].mT);
	}
  }
  return objectA;
}

void
SamplingPreprocessor::HoleSamplingPass()
{
  vector<KdLeaf *> leaves;
  mKdTree->CollectLeaves(leaves);
  
  // go through all the leaves and evaluate their passing contribution
  for (int i=0 ; i < leaves.size(); i++) {
    KdLeaf *leaf = leaves[i];
    cout<<leaf->mPassingRays<<endl;
  }
}


void
SamplingPreprocessor::VerifyVisibility(Intersectable *object)
{
	// mail all nodes from the pvs
  Intersectable::NewMail();
  KdPvsMap::iterator i = object->mKdPvs.mEntries.begin();
  for (; i != object->mKdPvs.mEntries.end(); i++) {
	KdNode *node = (*i).first;
	node->Mail();
  }
  Debug << "Get all neighbours from PVS" << endl;
  vector<KdNode *> invisibleNeighbors;
  // get all neighbors of all PVS nodes
  i = object->mKdPvs.mEntries.begin();
  for (; i != object->mKdPvs.mEntries.end(); i++) {
	KdNode *node = (*i).first;
	mKdTree->FindNeighbors(node, invisibleNeighbors, true);
	AxisAlignedBox3 box = object->GetBox();
	for (int j=0; j < invisibleNeighbors.size(); j++) {
	  int visibility = ComputeBoxVisibility(mSceneGraph,
											mKdTree,
											box,
											mKdTree->GetBox(invisibleNeighbors[j]),
											1e-6f);
	  //	      exit(0);
	}
	// now rank all the neighbors according to probability that a new
	// sample creates some contribution
  }
}

bool
SamplingPreprocessor::ComputeVisibility()
{
  
  Debug << "type: sampling" << endl;
  
  cout<<"Sampling Preprocessor started\n"<<flush;
  //  cout<<"Memory/ray "<<sizeof(VssRay)+sizeof(RssTreeNode::RayInfo)<<endl;

  Randomize(0);
  
  long startTime = GetTime();
  
  int totalSamples = 0;

  // if not already loaded, construct view cells from file
  if (!mLoadViewCells)
  {
	mViewCellsManager->SetViewSpaceBox(mKdTree->GetBox());

	// construct view cells using it's own set of samples
	mViewCellsManager->Construct(this);
	
	//-- several visualizations and statistics
	Debug << "view cells construction finished: " << endl;
	mViewCellsManager->PrintStatistics(Debug);
  }
  

  
  int samples = 0;
  int i=0;
  while (samples < mTotalSamples) {
	for (i=0; i < mSamplesPerPass; i++, samples++) {
	  
	  if (i%10000 == 0)
		cout<<"+";
	  
	  Vector3 origin, direction;
	  mViewCellsManager->GetViewPoint(origin);
	  direction = UniformRandomVector();

	  
	  ViewCell *viewcell = mViewCellsManager->GetViewCell(origin);
	  
	  if (viewcell && viewcell->GetValid()) {
		// cast rays in both directions to make the number of samples comparable
		// with the global sampling method which also casts a "double" ray per sample
		for (int j=0; j < 2; j++) {
		  Intersectable *object = CastRay(origin, direction);
		  if (object) {
			// if ray not outside of view space
			float contribution;
			int pvsContribution = 0;
			float relativePvsContribution = 0;
			if (object) {
			  float pdf = 1.0f;
			  if (viewcell->GetPvs().GetSampleContribution(object,
														   pdf,
														   contribution))
				++pvsContribution;
			  relativePvsContribution += contribution;
			  viewcell->GetPvs().AddSample(object, pdf);
			}
		  }
		  direction = -direction;
		}
	  }
	  
	  if (samples > mTotalSamples)
		break;
	}
	
	//	mVssRays.PrintStatistics(mStats);
	mStats <<
	  "#Time\n" << TimeDiff(startTime, GetTime())*1e-3<<endl<<
	  "#TotalSamples\n" <<samples<<endl;

	mViewCellsManager->PrintPvsStatistics(mStats);
	// ComputeRenderError();
  }
  
  //  HoleSamplingPass();
	if (0) {
	  Exporter *exporter = Exporter::GetExporter("ray-density.x3d"); 
	  exporter->SetExportRayDensity(true);
	  exporter->ExportKdTree(*mKdTree);
	  delete exporter;
	}
	
	
	// $$JB temporary removed
	//	mViewCellsManager->PostProcess(objects, mSampleRays);
	
	//-- several visualizations and statistics
	Debug << "view cells after post processing: " << endl;
	mViewCellsManager->PrintStatistics(Debug);
	
	//-- render simulation after merge
	cout << "\nevaluating bsp view cells render time after merge ... ";
	
	mRenderSimulator->RenderScene();
	SimulationStatistics ss;
	mRenderSimulator->GetStatistics(ss);
	
	cout << " finished" << endl;
	cout << ss << endl;
	Debug << ss << endl;
	
	// $$JB temporary removed
	//mViewCellsManager->Visualize(objects, mSampleRays);	
	
	return true;
}


}