#include "SceneGraph.h"
#include "KdTree.h"
#include "SamplingPreprocessor.h"
#include "X3dExporter.h"
#include "Environment.h"
#include "MutualVisibility.h"

SamplingPreprocessor::SamplingPreprocessor()
{
  // this should increase coherence of the samples
  environment->GetIntValue("Sampling.samplesPerPass", mSamplesPerPass);
  environment->GetIntValue("Sampling.totalSamples", mTotalSamples);
  mKdPvsDepth = 100;

}

void
SamplingPreprocessor::SetupRay(Ray &ray, const Vector3 &point, const Vector3 &direction)
{
  ray.intersections.clear();
  ray.leaves.clear();
  ray.meshes.clear();
  //  cout<<point<<" "<<direction<<endl;
  ray.Init(point, direction, Ray::LOCAL_RAY);
}

KdNode *
SamplingPreprocessor::GetNodeForPvs(KdLeaf *leaf)
{
  KdNode *node = leaf;
  while (node->mParent && node->mDepth > mKdPvsDepth)
    node = node->mParent;
  return node;
}

int
SamplingPreprocessor::AddNodeSamples(Intersectable *object,
				     const Ray &ray,
				     const int pass)
{
  int contributingSamples = 0;
  int j;
  for (j=0; j < ray.leaves.size(); j++) {
    KdNode *node = GetNodeForPvs( ray.leaves[j] );
    contributingSamples += object->mKdPvs.AddNodeSample(node);
  }
  
  if (pass > 10)
    for (j=1; j < ray.leaves.size() - 1; j++) {
      ray.leaves[j]->AddPassingRay(ray, contributingSamples ? 1 : 0);
    }
  
  return contributingSamples;
}


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;
  }
}

bool
SamplingPreprocessor::ComputeVisibility()
{

  // pickup an object
  ObjectContainer objects;
  
  mSceneGraph->CollectObjects(&objects);

  Vector3 point, normal, direction;
  Ray ray;

  long startTime = GetTime();
  
  int i;
  int pass = 0;
  int totalSamples = 0;

  int pvsOut = Min((int)objects.size(), 10);
  
  vector<Ray> rays[10];
  
  while (totalSamples < mTotalSamples) {

    int passContributingSamples = 0;
    int passSampleContributions = 0;
    int passSamples = 0;
    int index = 0;

    for (i =0; i < objects.size(); i++) {
      KdNode *nodeToSample = NULL;
      Intersectable *object = objects[i];
      
      int pvsSize = object->mKdPvs.GetSize();
      
      if (0 && pvsSize) {
	// 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();
	}
	int maxTries = 2*pvsSize;
	
	for (int tries = 0; tries < 10; tries++) {
	  index = RandomValue(0, pvsSize - 1);
	  KdPvsData data;
	  KdNode *node;
	  object->mKdPvs.GetData(index, node, data);
	  nodeToSample = mKdTree->FindRandomNeighbor(node, true);
	  if (nodeToSample)
	    break;
	}
      }
      
      if (0 && pvsSize && pass == 100 ) {
	// 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();
	}
	
	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(mKdTree,
						  box,
						  mKdTree->GetBox(invisibleNeighbors[j]),
						  1.0f);
	    
	  }
	  
	
	  // now rank all the neighbors according to probability that a new
	  // sample creates some contribution
	}
      }

      for (int k=0; k < mSamplesPerPass; k++) {
	object->GetRandomSurfacePoint(point, normal);
	if (nodeToSample) {
	  int maxTries = 5;
	  for (int tries = 0; tries < maxTries; tries++) {
	    direction = mKdTree->GetBox(nodeToSample).GetRandomPoint() - point;
	    if (DotProd(direction, normal) > Limits::Small)
	      break;
	  }
		
	  if (tries == maxTries)
	    direction = UniformRandomVector(normal);
	} else
	  direction = UniformRandomVector(normal);
	
	// construct a ray
	SetupRay(ray, point, direction);
	mKdTree->CastRay(ray);

	if (i < pvsOut)
	  rays[i].push_back(ray);
	
	int sampleContributions = 0;
	
		  
	if (ray.leaves.size()) {
	  sampleContributions += AddNodeSamples(object, ray, pass);
	  
	  if (ray.intersections.size()) {
	    sampleContributions += AddNodeSamples(ray.intersections[0].mObject, ray, pass);
	    // check whether we can add this to the rays
	    for (int j = 0; j < pvsOut; j++) {
	      if (objects[j] == ray.intersections[0].mObject) {
		rays[j].push_back(ray);
	      }
	    }
	  }
		
	  passSamples++;
			
	  if (sampleContributions) {
	    passContributingSamples++;
	    passSampleContributions += sampleContributions;
	  }
	}
      }
    }


    totalSamples += passSamples;

    //    if (pass>10)
    //      HoleSamplingPass();
    

    pass++;
    
    int pvsSize = 0;
    for (i=0; i < objects.size(); i++) {
      Intersectable *object = objects[i];
      pvsSize += object->mKdPvs.GetSize();
    }
    
    cout<<"pass "<<pass<<" : t = "<<TimeDiff(startTime, GetTime())*1e-3<<"s"<<endl;
    cout<<"#totalSamples="<<totalSamples/1000<<
      "k   #sampleContributions="<<passSampleContributions<<
      " ("<<100*passContributingSamples/(float)passSamples<<"%)"<<
      " avgPVS="<<pvsSize/(float)objects.size()<<endl<<
      "avg ray contrib="<<passSampleContributions/(float)passContributingSamples<<
      endl;
  }

  int totalPvsSize = mKdTree->CollectLeafPvs();
  cout<<"#totalPvsSize="<<totalPvsSize<<endl;
  
  //  HoleSamplingPass();
  if (1) {
    Exporter *exporter = Exporter::GetExporter("ray-density.x3d");
    exporter->SetExportRayDensity(true);
    exporter->ExportKdTree(*mKdTree);
    delete exporter;
  }
  
  bool exportRays = false;
  if (exportRays) {
    Exporter *exporter = NULL;
    exporter = Exporter::GetExporter("sample-rays.x3d");
    exporter->SetWireframe();
    exporter->ExportKdTree(*mKdTree);
    for (i=0; i < pvsOut; i++) 
      exporter->ExportRays(rays[i], 1000, RgbColor(1, 0, 0));
    exporter->SetFilled();
    delete exporter;
  }

  if (1) {
    for (int k=0; k < pvsOut; k++) {
      Intersectable *object = objects[k];
      char s[64];
      sprintf(s, "sample-pvs%04d.x3d", k);
      Exporter *exporter = Exporter::GetExporter(s);
      exporter->SetWireframe();
      KdPvsMap::iterator i = object->mKdPvs.mEntries.begin();
      Intersectable::NewMail();
      // avoid adding the object to the list
      object->Mail();
      ObjectContainer visibleObjects;
      for (; i != object->mKdPvs.mEntries.end(); i++) {
	KdNode *node = (*i).first;
	exporter->ExportBox(mKdTree->GetBox(node));
	mKdTree->CollectObjects(node, visibleObjects);
      }
      
      exporter->ExportRays(rays[k], 1000, RgbColor(0, 1, 0));
      exporter->SetFilled();

      for (int j = 0; j < visibleObjects.size(); j++)
	exporter->ExportIntersectable(visibleObjects[j]);
	
      Material m;
      m.mDiffuseColor = RgbColor(1, 0, 0);
      exporter->SetForcedMaterial(m);
      exporter->ExportIntersectable(object);
      
      delete exporter;
    }
    
  }
  
  return true;
}