#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"
#include "VssRay.h"
#include "SamplingStrategy.h"



namespace GtpVisibilityPreprocessor {


SamplingPreprocessor::SamplingPreprocessor(): Preprocessor(), mPass(0)
{
  // this should increase coherence of the samples
  
}

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




void
SamplingPreprocessor::VerifyVisibility(Intersectable *object)
{
#if 0 // 6.10. 2006 due to kdPVS removal from intersectable
  // 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
  }
#endif
}

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

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

  // if not already loaded, construct view cells from file
  if (!mLoadViewCells) {
	ConstructViewCells();
  }

  int intersectables, faces;
  mSceneGraph->GetStatistics(intersectables, faces);
  HaltonSequence posHalton;
  
  int samples = 0;
  int rssSamples = 0;

  map<ViewCell *, HaltonSequence> dirHalton;
  
  while (samples < mTotalSamples) {
	for (int i=0; i < mSamplesPerEvaluation;) {
	  SimpleRayContainer rays;
	  VssRayContainer vssRays;
	  //	  vector<ViewCell *> viewcells;
	  
	  float r[5];
	  Vector3 origin, direction;
	  posHalton.GetNext(3, r);

	  mViewCellsManager->GetViewPoint(origin, Vector3(r[0], r[1], r[2]));
	  ViewCell *viewcell = mViewCellsManager->GetViewCell(origin);
	  
	  if (!viewcell || !viewcell->GetValid())
		continue;
	  
	  for (; rays.size() < 16; ) {
		if (i%100000 == 0)
		  cout<<"+";
		
		//		dirHalton.GetNext(2, r);
		dirHalton[viewcell].GetNext(2, r);
		direction = UniformRandomVector(r[0],r[1]);
		//direction = UniformRandomVector();
		
		//		viewcells.push_back(viewcell);
		// 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
		rays.push_back(SimpleRay(origin,
								 direction,
								 SamplingStrategy::DIRECTION_BASED_DISTRIBUTION,
								 1.0f));
		i++;
		samples++;
	  }
	  
	  CastRays(rays,
			   vssRays,
			   true,
			   true);
	  
	  // 	  if (vssRays.size()!=32) {
	  // 		cerr<<"wrong number of rays "<<(int)vssRays.size()<<endl;
	  // 		exit(1);
	  // 	  }

	  rssSamples+=vssRays.size();
	  for (int j=0; j < vssRays.size(); j++)
		if (vssRays[j]->mFlags & VssRay::Valid) {
		  Intersectable *obj = mViewCellsManager->GetIntersectable(*(vssRays[j]),
																   true);
		  if (obj) {
			// if ray not outside of view space
			float pdf = 1.0f;
			//			ViewCell *viewcell = viewcells[j/2];

			ObjectPvs &pvs = viewcell->GetPvs();
			pvs.AddSampleDirtyCheck(obj, pdf);
			
			if (pvs.RequiresResort())  {
			  pvs.SimpleSort();
			}
		  }
		}
	  
	  CLEAR_CONTAINER(vssRays);
	  
	  if (samples > mTotalSamples)
		break;
	}

#if 0
	Debug<<"Valid viewcells before set validity: "<<mViewCellsManager->CountValidViewcells()<<endl;
	mViewCellsManager->SetValidity(0, intersectables/2);
	Debug<<"Valid viewcells after set validity: "<<mViewCellsManager->CountValidViewcells()<<endl;
#endif
	
	//	mVssRays.PrintStatistics(mStats);
	mStats <<
	  "#Time\n" << TimeDiff(startTime, GetTime())*1e-3<<endl<<
	  "#TotalSamples\n" <<samples<<endl<<
	  "#RssSamples\n" <<rssSamples<<endl;
		  
	mViewCellsManager->PrintPvsStatistics(mStats);
	// ComputeRenderError();
  }
  
  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);
  
  EvalViewCellHistogram();

  //-- 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;
}


}