#include "SceneGraph.h"
#include "Exporter.h"
#include "UnigraphicsParser.h"
#include "X3dParser.h"
#include "Preprocessor.h"
#include "ViewCell.h"
#include "Environment.h"
#include "ViewCellsManager.h"
#include "ViewCellBsp.h"
#include "VspBspTree.h"
#include "VspKdTree.h"
#include "RenderSimulator.h"
#include "GlRenderer.h"

Preprocessor *preprocessor;

Preprocessor::Preprocessor():
mKdTree(NULL),
mBspTree(NULL),
mVspKdTree(NULL),
mVspBspTree(NULL),
mViewCellsManager(NULL)
{
  environment->GetBoolValue("Preprocessor.useGlRenderer", mUseGlRenderer);
  
  // renderer will be constructed when the scene graph and viewcell manager will be known
  renderer = NULL;
  
  environment->GetBoolValue("Preprocessor.useGlDebugger", mUseGlDebugger);
}


Preprocessor::~Preprocessor()
{
  Debug<<"Deleting view cells manager...\n";
  DEL_PTR(mViewCellsManager);
  Debug<<"done.\n";
  Debug<<"Deleting bsp tree...\n";
  DEL_PTR(mBspTree);
  Debug<<"done.\n";
  Debug<<"Deleting kd tree...\n";
  DEL_PTR(mKdTree);
  Debug<<"done.\n";
  Debug<<"Deleting vspkd tree...\n";
  DEL_PTR(mVspKdTree);
  Debug<<"done.\n";
  Debug<<"Deleting vspbsp tree...\n";
  DEL_PTR(mVspBspTree);
  Debug<<"done.\n";
}

int
SplitFilenames(const string str, vector<string> &filenames)
{
	int pos = 0;

	while(1) {
		int npos = (int)str.find(';', pos);
		
		if (npos < 0 || npos - pos < 1)
			break;
		filenames.push_back(string(str, pos, npos - pos));
		pos = npos + 1;
	}
	
	filenames.push_back(string(str, pos, str.size() - pos));
	return (int)filenames.size();
}

bool
Preprocessor::LoadScene(const string filename)
{
	// use leaf nodes of the original spatial hiearrchy as occludees
	mSceneGraph = new SceneGraph;
  
	Parser *parser;
	vector<string> filenames;
	int files = SplitFilenames(filename, filenames);
	cout<<files<<endl;
	bool result = false;
	if (files == 1) {
		
		if (strstr(filename.c_str(), ".x3d"))
			parser = new X3dParser;
		else
			parser = new UnigraphicsParser;

		cout<<filename<<endl;
		result = parser->ParseFile(filename, &mSceneGraph->mRoot);

		delete parser;

	} else {
		// root for different files
		mSceneGraph->mRoot = new SceneGraphNode;
		for (int i= 0; i < filenames.size(); i++) {
			if (strstr(filenames[i].c_str(), ".x3d"))
				parser = new X3dParser;
			else
				parser = new UnigraphicsParser;
			
			SceneGraphNode *node;
			if (parser->ParseFile(filenames[i], &node)) {
				mSceneGraph->mRoot->mChildren.push_back(node);
				// at least one file parsed
				result = true;
			}
			delete parser;
		}
	}
	

	if (result) {
	  
	  mSceneGraph->AssignObjectIds();
	  int intersectables, faces;
	  mSceneGraph->GetStatistics(intersectables, faces);
	  cout<<filename<<" parsed successfully."<<endl;
	  cout<<"#NUM_OBJECTS (Total numner of objects)\n"<<intersectables<<endl;
	  cout<<"#NUM_FACES (Total numner of faces)\n"<<faces<<endl;
	  mSceneGraph->CollectObjects(&mObjects);
	  mSceneGraph->mRoot->UpdateBox();
	}
	
	
	return result;
}

bool
Preprocessor::ExportPreprocessedData(const string filename)
{
  return false;
}

bool
Preprocessor::BuildKdTree()
{
  mKdTree = new KdTree;
  // add mesh instances of the scene graph to the root of the tree
  KdLeaf *root = (KdLeaf *)mKdTree->GetRoot();
  mSceneGraph->CollectObjects(&root->mObjects);
  
  mKdTree->Construct();
  return true;
}

void
Preprocessor::KdTreeStatistics(ostream &s)
{
  s<<mKdTree->GetStatistics();
}

void
Preprocessor::BspTreeStatistics(ostream &s)
{
	s << mBspTree->GetStatistics();
}

bool
Preprocessor::Export( const string filename,
					  const bool scene,
					  const bool kdtree,
					  const bool bsptree
					  )
{
  Exporter *exporter = Exporter::GetExporter(filename);
	
  if (exporter) {
    if (scene)
      exporter->ExportScene(mSceneGraph->mRoot);

    if (kdtree) {
      exporter->SetWireframe();
      exporter->ExportKdTree(*mKdTree);
    }

	if (bsptree) {
		//exporter->SetWireframe();
		exporter->ExportBspTree(*mBspTree);
	}

    delete exporter;
    return true;
  }

  return false;
}


bool Preprocessor::PrepareViewCells()
{
	//-- parse type of view cell container
	char viewCellsStr[64];
	environment->GetStringValue("ViewCells.type", viewCellsStr);

	mViewCellsManager = CreateViewCellsManager(viewCellsStr);

	float objRenderCost = 0, vcOverhead = 0, moveSpeed = 0;

	environment->GetFloatValue("Simulation.objRenderCost",objRenderCost);
	environment->GetFloatValue("Simulation.vcOverhead", vcOverhead);
	environment->GetFloatValue("Simulation.moveSpeed", moveSpeed);

	mRenderSimulator = 
		new RenderSimulator(mViewCellsManager, objRenderCost, vcOverhead, moveSpeed);

	mViewCellsManager->SetRenderer(mRenderSimulator);

	//-- parse view cells construction method
	environment->GetBoolValue("ViewCells.loadFromFile", mLoadViewCells);
	char buf[100];

	if (mLoadViewCells)
	{
		environment->GetStringValue("ViewCells.filename", buf);
		mViewCellsFilename = buf;
	}

	if (mUseGlRenderer || mUseGlDebugger)
	{
		// NOTE: render texture should be power of 2 and square
		// renderer must be initialised
		renderer = new GlRendererBuffer(1024, 768, mSceneGraph, mViewCellsManager, mKdTree);
		//		renderer->makeCurrent();
	}


	environment->GetBoolValue("Preprocessor.detectEmptyViewSpace", mDetectEmptyViewSpace);
	


	return true;
}


ViewCellsManager *Preprocessor::CreateViewCellsManager(const char *name)
{
	if (strcmp(name, "kdTree") == 0)
	{
		mViewCellsManager = new KdViewCellsManager(mKdTree);
	}
	else if (strcmp(name, "bspTree") == 0)
	{
		mBspTree = new BspTree();

		Debug << "view cell type: Bsp" << endl;

		mViewCellsManager = new BspViewCellsManager(mBspTree);
	}
	else if (strcmp(name, "vspBspTree") == 0)
	{
		mVspBspTree = new VspBspTree();

		Debug << "view cell type: VspBsp" << endl;

		mViewCellsManager = new VspBspViewCellsManager(mVspBspTree);
	}
	else if (strcmp(name, "vspKdTree") == 0)
	{
		mVspKdTree = new VspKdTree();		
	
		mViewCellsManager = new VspKdViewCellsManager(mVspKdTree);
	}
	else if (strcmp(name, "sceneDependent") == 0)
	{
		//TODO
		mBspTree = new BspTree();

		Debug << "view cell type: Bsp" << endl;
		
		mViewCellsManager = new BspViewCellsManager(mBspTree);
	}
	else
	{
		cerr<<"Wrong view cells type" << name << endl;
		exit(1);
	}

	return mViewCellsManager;
}


// use ascii format to store rays
#define USE_ASCII 0


inline bool ilt(Intersectable *obj1, Intersectable *obj2)
{
	return obj1->mId < obj2->mId;
}


bool Preprocessor::LoadSamples(VssRayContainer &samples, 
							   ObjectContainer &objects) const
{
	std::stable_sort(objects.begin(), objects.end(), ilt);
	char fileName[100];
	environment->GetStringValue("Preprocessor.samplesFilename", fileName);
	
    Vector3 origin, termination;
	// HACK: needed only for lower_bound algorithm to find the 
	// intersected objects
	MeshInstance sObj(NULL);
	MeshInstance tObj(NULL);

#if USE_ASCII
	ifstream samplesIn(fileName, ios::binary);
	if (!samplesIn.is_open())
		return false;

	string buf;
	while (!(getline(samplesIn, buf)).eof())
	{
		sscanf(buf.c_str(), "%f %f %f %f %f %f %d %d", 
			   &origin.x, &origin.y, &origin.z,
			   &termination.x, &termination.y, &termination.z, 
			   &(sObj.mId), &(tObj.mId));
		
		Intersectable *sourceObj = NULL;
		Intersectable *termObj = NULL;
		
		if (sObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &sObj, ilt);
			sourceObj = *oit;
		}
		
		if (tObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &tObj, ilt);
			termObj = *oit;
		}

		samples.push_back(new VssRay(origin, termination, sourceObj, termObj));
	}
#else
	ifstream samplesIn(fileName, ios::binary);
	if (!samplesIn.is_open())
		return false;

	while (1)
	{
		 samplesIn.read(reinterpret_cast<char *>(&origin), sizeof(Vector3));
		 samplesIn.read(reinterpret_cast<char *>(&termination), sizeof(Vector3));
		 samplesIn.read(reinterpret_cast<char *>(&(sObj.mId)), sizeof(int));
		 samplesIn.read(reinterpret_cast<char *>(&(tObj.mId)), sizeof(int));
		
		 if (samplesIn.eof())
			break;

		Intersectable *sourceObj = NULL;
		Intersectable *termObj = NULL;
		
		if (sObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &sObj, ilt);
			sourceObj = *oit;
		}
		
		if (tObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &tObj, ilt);
			termObj = *oit;
		}

		samples.push_back(new VssRay(origin, termination, sourceObj, termObj));
	}

#endif
	samplesIn.close();

	return true;
}


bool Preprocessor::ExportSamples(const VssRayContainer &samples) const
{
	char fileName[100];
	environment->GetStringValue("Preprocessor.samplesFilename", fileName);
	

	VssRayContainer::const_iterator it, it_end = samples.end();
	
#if USE_ASCII
	ofstream samplesOut(fileName);
	if (!samplesOut.is_open())
		return false;

	for (it = samples.begin(); it != it_end; ++ it)
	{
		VssRay *ray = *it;
		int sourceid = ray->mOriginObject ? ray->mOriginObject->mId : -1;		
		int termid = ray->mTerminationObject ? ray->mTerminationObject->mId : -1;	

		samplesOut << ray->GetOrigin().x << " " << ray->GetOrigin().y << " " << ray->GetOrigin().z << " " 
				   << ray->GetTermination().x << " " << ray->GetTermination().y << " " << ray->GetTermination().z << " " 
				   << sourceid << " " << termid << "\n";
	}
#else
	ofstream samplesOut(fileName, ios::binary);
	if (!samplesOut.is_open())
		return false;

	for (it = samples.begin(); it != it_end; ++ it)
	{	
		VssRay *ray = *it;
		Vector3 origin(ray->GetOrigin());
		Vector3 termination(ray->GetTermination());
		
		int sourceid = ray->mOriginObject ? ray->mOriginObject->mId : -1;		
		int termid = ray->mTerminationObject ? ray->mTerminationObject->mId : -1;		

		samplesOut.write(reinterpret_cast<char *>(&origin), sizeof(Vector3));
		samplesOut.write(reinterpret_cast<char *>(&termination), sizeof(Vector3));
		samplesOut.write(reinterpret_cast<char *>(&sourceid), sizeof(int));
		samplesOut.write(reinterpret_cast<char *>(&termid), sizeof(int));
    }
#endif
	samplesOut.close();
	return true;
}



bool
Preprocessor::GenerateRays(
						   const int number,
						   const int sampleType,
						   SimpleRayContainer &rays
						   )
{
  Vector3 origin, direction; 
  int startSize = rays.size();
  for (int i=0; rays.size() - startSize  < number; i++) {
	// now get the direction
	switch (sampleType) {
	case OBJECT_BASED_DISTRIBUTION: {
	  mViewCellsManager->GetViewPoint(origin);
	  Vector3 point;
	  Vector3 normal;
	  int i = RandomValue(0, mObjects.size() - 1);
	  Intersectable *object = mObjects[i];
	  object->GetRandomSurfacePoint(point, normal);
	  direction = point - origin;
	}
	  break;
	case OBJECT_DIRECTION_BASED_DISTRIBUTION: {
	  int i = RandomValue(0, mObjects.size() - 1);
	  Intersectable *object = mObjects[i];
	  Vector3 normal;
	  object->GetRandomSurfacePoint(origin, normal);
	  direction = UniformRandomVector(normal);
	  origin += 0.1f*direction;
	}
	  break;
	case DIRECTION_BASED_DISTRIBUTION:
	  mViewCellsManager->GetViewPoint(origin);
	  direction = UniformRandomVector();
	  break;
	case DIRECTION_BOX_BASED_DISTRIBUTION: {
	  mViewCellsManager->GetViewPoint(origin);
	  float alpha = RandomValue(0.0f, 2*M_PI);
	  float beta = RandomValue(-M_PI/2, M_PI/2);
	  direction = VssRay::GetDirection(alpha, beta);
	  break;
	}
	case SPATIAL_BOX_BASED_DISTRIBUTION:
	  mViewCellsManager->GetViewPoint(origin);
	  direction = mKdTree->GetBox().GetRandomPoint() - origin;
	  break;
	default:
	  // unsuported distribution type
	  return false;
	}
	// $$ jb the pdf is yet not correct for all sampling methods!
	float pdf = 1.0f;
	float c = Magnitude(direction);
	if (c > Limits::Small) {
	  direction*=1.0f/c;
	  rays.AddRay(SimpleRay(origin, direction, pdf));
	}
  }
  return true;
}