/*=========================================================================

  Program:   Visualization Toolkit
  Module:    TestParticleTracers.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkDoubleArray.h"
#include "vtkPolyData.h"
#include "vtkPoints.h"
#include "vtkPointData.h"
#include "vtkCellArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkImageData.h"
#include "vtkParticleTracer.h"
#include "vtkStreaklineFilter.h"
#include "vtkParticlePathFilter.h"
#include "vtkPointSource.h"
#include "vtkMath.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkSetGet.h"
#include "vtkFloatArray.h"
#include "vtkSmartPointer.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include <cassert>
#include <vector>
using namespace std;

class TestTimeSource : public vtkAlgorithm
{
public:
  static TestTimeSource *New();
  vtkTypeMacro(TestTimeSource,vtkAlgorithm);

  vtkGetMacro(NumRequestData,int);

  void SetBoundingBox(double x0, double x1, double y0,
                      double y1, double z0, double z1)
  {
    this->BoundingBox[0] = x0;
    this->BoundingBox[1] = x1;
    this->BoundingBox[2] = y0;
    this->BoundingBox[3] = y1;
    this->BoundingBox[4] = z0;
    this->BoundingBox[5] = z1;

  }
  int GetNumberOfTimeSteps()
  {
    return static_cast<int>(this->TimeSteps.size());
  }

protected:
  TestTimeSource()
  {
    this->NumRequestData=0;
    this->SetNumberOfInputPorts(0);
    this->SetNumberOfOutputPorts(1);
    for(int i=0; i<10 ;i++)
    {
      this->TimeSteps.push_back(i);
    }

    this->Extent[0] = 0;
    this->Extent[1] = 1;
    this->Extent[2] = 0;
    this->Extent[3] = 1;
    this->Extent[4] = 0;
    this->Extent[5] = 1;

    this->BoundingBox[0]=0;
    this->BoundingBox[1]=1;
    this->BoundingBox[2]=0;
    this->BoundingBox[3]=1;
    this->BoundingBox[4]=0;
    this->BoundingBox[5]=1;
  }
  void GetSpacing(double dx[3])
  {
    for(int i=0; i<3; i++)
    {
      dx[i] = (this->BoundingBox[2*i+1]- this->BoundingBox[2*i]) / (this->Extent[2*i+1] - this->Extent[2*i]);
    }
  }
  ~TestTimeSource() override = default;

  int ProcessRequest(vtkInformation* request,
                     vtkInformationVector** inputVector,
                     vtkInformationVector* outputVector) override
  {
    // generate the data
    if(request->Has(vtkDemandDrivenPipeline::REQUEST_DATA()))
    {
      return this->RequestData(request, inputVector, outputVector);
    }

    // execute information
    if(request->Has(vtkDemandDrivenPipeline::REQUEST_INFORMATION()))
    {
      return this->RequestInformation(request, inputVector, outputVector);
    }
    return this->Superclass::ProcessRequest(request, inputVector, outputVector);
  }

int FillOutputPortInformation(int, vtkInformation *info) override
  {
    info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkImageData");
    return 1;
  }

  virtual int RequestInformation(vtkInformation *,
                                 vtkInformationVector **,
                                 vtkInformationVector *outputInfoVector)
  {
    // get the info objects
    vtkInformation *outInfo = outputInfoVector->GetInformationObject(0);

    double range[2]= {0,9};
    outInfo->Set(vtkStreamingDemandDrivenPipeline::TIME_RANGE(),
                 range,2);

    outInfo->Set(vtkStreamingDemandDrivenPipeline::TIME_STEPS(),
                 &TimeSteps[0], static_cast<int>(TimeSteps.size()));


    outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), this->Extent,6);

    double spacing[3];
    this->GetSpacing(spacing);

    outInfo->Set(vtkDataObject::SPACING(), spacing[0], spacing[1], spacing[2]);

    double origin[3] = {this->BoundingBox[0],this->BoundingBox[2],this->BoundingBox[4]};
    outInfo->Set(vtkDataObject::ORIGIN(),origin,3);

    return 1;
  }

  int RequestData(
    vtkInformation* ,
    vtkInformationVector** vtkNotUsed( inputVector ),
    vtkInformationVector* outputVector)
  {
    NumRequestData++;
    vtkInformation *outInfo = outputVector->GetInformationObject(0);
    vtkDataObject* output = outInfo->Get(vtkDataObject::DATA_OBJECT());

    double timeStep = outInfo->Get( vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());

    output->GetInformation()->Set(vtkDataObject::DATA_TIME_STEP(),timeStep);

    // set the extent to be the update extent
    vtkImageData *outImage = vtkImageData::SafeDownCast(output);
    if (outImage)
    {
      int* uExtent = outInfo->Get(
        vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT());

      outImage->SetExtent(uExtent);
      int scalarType = vtkImageData::GetScalarType(outInfo);
      int numComponents = vtkImageData::GetNumberOfScalarComponents(outInfo);
      outImage->AllocateScalars(scalarType, numComponents);
    }
    else
    {
      return 0 ;
    }

    vtkDataArray* outArray = vtkArrayDownCast<vtkDataArray>(vtkAbstractArray::CreateArray(VTK_FLOAT));
    outArray->SetName("Gradients");
    outArray->SetNumberOfComponents(3);
    outArray->SetNumberOfTuples(outImage->GetNumberOfPoints());
    assert(outArray->GetNumberOfTuples()==outImage->GetNumberOfPoints());
    outImage->GetPointData()->AddArray(outArray);
    outArray->Delete();
    outImage->GetPointData()->SetActiveVectors("Gradients");

    int *extent = outImage->GetExtent(); //old style

    vtkIdType stepX,stepY,stepZ;
    outImage->GetContinuousIncrements(extent,stepX,stepY,stepZ);

    float * outPtr = static_cast<float*> (outImage->GetArrayPointerForExtent(outArray,extent));
 //   PRINT(stepY<<" "<<stepZ)

    int gridSize[3] = {Extent[1]-Extent[0],Extent[3]-Extent[2],Extent[5]-Extent[4]};

    double* origin = outImage->GetOrigin();

    double size[3];
    for(int i=0; i<3; i++)
    {
      size[i] = this->BoundingBox[2*i+1]- this->BoundingBox[2*i];
    }

    double speed =0.1*timeStep;
    for (int iz = extent[4]; iz<=extent[5]; iz++)
    {
      for (int iy = extent[2]; iy<=extent[3]; iy++)
      {
        for (int ix = extent[0]; ix<=extent[1]; ix++)
        {
          double x = size[0]*((double)ix)/gridSize[0] + origin[0];
          //double y = size[1]*((double)iy)/gridSize[1] + origin[1];
          double z = size[2]*((double)iz)/gridSize[2] + origin[2];
          *(outPtr++) = -z *speed;
          *(outPtr++) = 0;
          *(outPtr++) = x *speed;
        }
        outPtr += stepY;
      }
      outPtr += stepZ;
    }
    return 1;
  }


private:
  TestTimeSource(const TestTimeSource&) = delete;
  void operator=(const TestTimeSource&) = delete;

  vector<double> TimeSteps;
  int Extent[6];
  double BoundingBox[6];
  int NumRequestData;
};

vtkStandardNewMacro(TestTimeSource);

#define EXPECT(a,msg)\
  if(!(a)) {                                    \
  cerr<<"Line "<<__LINE__<<":"<<msg<<endl;\
  return EXIT_FAILURE;\
  }


int TestParticlePathFilter()
{
  vtkNew<TestTimeSource> imageSource;
  imageSource->SetBoundingBox(-1,1,-1,1,-1,1);

  vtkNew<vtkPoints> points;
  points->InsertNextPoint(0.5,0,0);
  points->InsertNextPoint(0.4,0,0);

  vtkNew<vtkPolyData> ps;
  ps->SetPoints(points);

  vtkNew<vtkParticlePathFilter> filter;

  filter->SetInputConnection(0,imageSource->GetOutputPort());
  filter->SetInputData(1,ps);

  filter->SetTerminationTime(3.3);
  filter->Update();

  vtkPolyData* out = filter->GetOutput();
  vtkCellArray* lines = out->GetLines();
  vtkNew<vtkIdList> polyLine;
//  vtkIntArray* particleIds = vtkArrayDownCast<vtkIntArray>(out->GetPointData()->GetArray("ParticleId"));



  double baseLines[2] = {0.271834, 0.217467};
  int lineIndex(0);

  lines->InitTraversal();
  while(lines->GetNextCell(polyLine))
  {
    double s = 0;
    for(int j=1; j<polyLine->GetNumberOfIds();j++)
    {
      int pIndex = polyLine->GetId(j-1);
      int qIndex = polyLine->GetId(j);
      double p[3],q[3];
      out->GetPoints()->GetPoint(pIndex,p);
      out->GetPoints()->GetPoint(qIndex,q);
      s+= sqrt( vtkMath::Distance2BetweenPoints(p,q));
    }
    EXPECT(fabs(s-baseLines[lineIndex++])<0.01,"Wrong particle path length "<<s);
  }

  int numRequestData = imageSource->GetNumRequestData();
  EXPECT(numRequestData == 5, "Wrong");

  filter->SetTerminationTime(4.0);
  filter->Update();

  numRequestData = imageSource->GetNumRequestData();
  EXPECT(imageSource->GetNumRequestData() == numRequestData, "Wrong # of requests");

  out = filter->GetOutput();
  EXPECT(out->GetNumberOfLines() == 2, "Wrong # of lines"<<out->GetNumberOfLines());


  double baseLines1[2] = {0.399236,0.319389};
  lines = out->GetLines();
  lines->InitTraversal();
  lineIndex = 0;
  while(lines->GetNextCell(polyLine))
  {
    double s = 0;
    for(int j=1; j<polyLine->GetNumberOfIds();j++)
    {
      int pIndex = polyLine->GetId(j-1);
      int qIndex = polyLine->GetId(j);
      double p[3],q[3];
      out->GetPoints()->GetPoint(pIndex,p);
      out->GetPoints()->GetPoint(qIndex,q);
      s+= sqrt( vtkMath::Distance2BetweenPoints(p,q));
    }
    EXPECT(fabs(s-baseLines1[lineIndex++])<0.01,"Wrong particle path length "<<s);
  }

  filter->SetTerminationTime(0);
  filter->Update();

  filter->SetTerminationTime(0.2);
  filter->Update();

  return EXIT_SUCCESS;
}

int TestParticlePathFilterStartTime()
{
  vtkNew<TestTimeSource> imageSource;
  imageSource->SetBoundingBox(-1,1,-1,1,-1,1);

  vtkNew<vtkPoints> points;
  points->InsertNextPoint(0.5,0,0);

  vtkNew<vtkPolyData> ps;
  ps->SetPoints(points);

  vtkNew<vtkParticlePathFilter> filter;
  filter->SetStartTime(2.0);
  filter->SetInputConnection(0,imageSource->GetOutputPort());
  filter->SetInputData(1,ps);

  filter->SetTerminationTime(5.3);
  filter->Update();

  vtkPolyData* out = filter->GetOutput();
  EXPECT(out->GetNumberOfCells() == 1, "Wrong number of particle paths for non-zero start time");

  vtkCell* cell = out->GetCell(0);
  EXPECT(cell->GetNumberOfPoints() == 6, "Wrong number of points for non-zero particle path start time");
  double pt[3];
  out->GetPoint(cell->GetPointId(5), pt);
  EXPECT(fabs(pt[0]-0.179085) < 0.01 && fabs(pt[1]) < 0.01 && fabs(pt[2]-0.466826) < 0.01,
         "Wrong end point for particle path with non-zero start time");

  return EXIT_SUCCESS;
}

int TestStreaklineFilter()
{
  vtkNew<TestTimeSource> imageSource;
  imageSource->SetBoundingBox(-1,1,-1,1,-1,1);

  //Test streak line filter
  vtkNew<vtkPoints> points;
  points->InsertNextPoint(0.5,0,0);
  points->InsertNextPoint(0.4,0,0);
  vtkNew<vtkPolyData> pointsSource;
  pointsSource->SetPoints(points);

  vtkNew<vtkStreaklineFilter> filter;
  filter->SetInputConnection(0,imageSource->GetOutputPort());
  filter->SetInputData(1,pointsSource);

  filter->SetStartTime(0.0);
  filter->SetTerminationTime(3.0);
  filter->Update();

  vtkPolyData* out = filter->GetOutput();
  EXPECT(out->GetNumberOfLines()==2,"Wrong number of streaks: "<<out->GetNumberOfLines());

  vtkCellArray* lines = out->GetLines();
  vtkNew<vtkIdList> polyLine;
  vtkFloatArray* particleAge = vtkArrayDownCast<vtkFloatArray>(out->GetPointData()->GetArray("ParticleAge"));

  lines->InitTraversal();
  while(lines->GetNextCell(polyLine))
  {
    for(int j=1; j<polyLine->GetNumberOfIds();j++)
    {
      int pIndex = polyLine->GetId(j-1);
      int qIndex = polyLine->GetId(j);
      EXPECT(particleAge->GetValue(pIndex)> particleAge->GetValue(qIndex), "Wrong point order");
    }
  }

  filter->SetTerminationTime(4.0);
  filter->Update();

  return EXIT_SUCCESS;
}


int TestParticleTracers(int, char*[])
{
  vtkPoints* pts(nullptr);
  double p[3];

  vtkNew<TestTimeSource> imageSource;
  imageSource->SetBoundingBox(-1,1,-1,1,-1,1);
  vtkNew<vtkPointSource> ps;
  ps->SetCenter(0.5,0.,0.);
  ps->SetRadius(0);
  ps->SetNumberOfPoints(1);

  vtkNew<vtkParticleTracer> filter;
  filter->SetInputConnection(0,imageSource->GetOutputPort());
  filter->SetInputConnection(1,ps->GetOutputPort());
  filter->SetComputeVorticity(0);

  filter->SetStartTime(0.1);
  filter->SetTerminationTime(4.5);
  filter->Update();
  double data_time = filter->GetOutputDataObject(0)->GetInformation()->Get(vtkDataObject::DATA_TIME_STEP());
  int numRequestData = imageSource->GetNumRequestData();
  EXPECT(data_time==4.5,"Wrong time");

  if(numRequestData!=6)
  {
    cerr<<"Wrong num requests\n";
    return EXIT_FAILURE;
  }

  pts = vtkPolyData::SafeDownCast(filter->GetOutputDataObject(0))->GetPoints();
  pts->GetPoint(0,p);
  EXPECT(fabs(p[2] - 0.424)<0.01,"Wrong termination point")

  filter->SetTerminationTime(5.5);
  filter->Update();
  pts = vtkPolyData::SafeDownCast(filter->GetOutputDataObject(0))->GetPoints();
  pts->GetPoint(0,p);
  EXPECT(fabs(p[2] - 0.499)<0.01,"Wrong termination point");
  EXPECT(imageSource->GetNumRequestData()-numRequestData==1," too many requests");

  numRequestData = imageSource->GetNumRequestData();

  filter->SetStartTime(0.10001);
  filter->Update();
  pts = vtkPolyData::SafeDownCast(filter->GetOutputDataObject(0))->GetPoints();

  double p1[3];
  pts->GetPoint(0,p1);

  EXPECT(fabs(p[2] - p1[2])<0.001, "Wrong termination point");
  EXPECT(imageSource->GetNumRequestData() - numRequestData == 7, "Wrong # of requests");
  numRequestData = imageSource->GetNumRequestData();


  ps->SetCenter(999,999,999);
  ps->SetCenter(0.5,0.,0.);

  filter->Update();
  EXPECT(imageSource->GetNumRequestData() - numRequestData == 7, "Wrong # of requests");
  numRequestData = imageSource->GetNumRequestData();

  filter->SetIgnorePipelineTime(1);
  filter->UpdateTimeStep(6.5);

  EXPECT(imageSource->GetNumRequestData()-numRequestData==0,"Pipeline Time should be ignored")
  numRequestData = imageSource->GetNumRequestData();

  filter->SetIgnorePipelineTime(0);
  filter->Update();
  EXPECT(imageSource->GetNumRequestData()-numRequestData==1,"Wrong");

  filter->UpdateTimeStep(0.0);
  pts = vtkPolyData::SafeDownCast(filter->GetOutputDataObject(0))->GetPoints();
  EXPECT(pts->GetNumberOfPoints()==1,"should have points even if start and stop time coincide");


  filter->UpdateTimeStep(100.0);
  filter->UpdateTimeStep(200.0);
  filter->SetIgnorePipelineTime(true);
  filter->SetTerminationTime(9.0); //make sure this doesn't crash
  filter->Update();


  EXPECT(TestParticlePathFilter()==EXIT_SUCCESS,"");
  EXPECT(TestParticlePathFilterStartTime()==EXIT_SUCCESS,"");
  EXPECT(TestStreaklineFilter()==EXIT_SUCCESS,"");

  return EXIT_SUCCESS;
}
