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

  Program:   Visualization Toolkit
  Module:    vtkTimeSourceExample.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 "vtkTimeSourceExample.h"

#include "vtkObjectFactory.h"
#include "vtkAlgorithm.h"
#include "vtkAlgorithmOutput.h"
#include "vtkCellData.h"
#include "vtkCellTypes.h"
#include "vtkDoubleArray.h"
#include "vtkIdTypeArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMath.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkUnstructuredGrid.h"
#include <vector>

vtkStandardNewMacro(vtkTimeSourceExample);

//----------------------------------------------------------------------------
double vtkTimeSourceExample::ValueFunction(double t)
{
  return sin(2*vtkMath::Pi()*t);
}

//----------------------------------------------------------------------------
double vtkTimeSourceExample::XFunction(double t)
{
  return sin(2*vtkMath::Pi()*t)*this->XAmplitude;
}

//----------------------------------------------------------------------------
double vtkTimeSourceExample::YFunction(double t)
{
  return sin(2*vtkMath::Pi()*t)*this->YAmplitude;
}

//----------------------------------------------------------------------------
void vtkTimeSourceExample::LookupTimeAndValue(double &time, double &value)
{
  double t = time;
  if (this->Analytic)
    {
    time = t;
    //clamp within range
    if (time < this->Steps[0])
      {
      time = this->Steps[0];
      }
    if (time > this->Steps[this->NumSteps-1])
      {
      time = this->Steps[this->NumSteps-1];
      }
    value = this->ValueFunction(time);
    }
  else
    {
    int index = -2;
    for (int i = 0; i < this->NumSteps; i++)
      {
      if (this->Steps[i] == t)
        {
        index = i;
        break;
        }
      if (this->Steps[i] > t)
        {
        index = i-1;
        break;
        }
      }
    if (index == -1)
      {
      index = 0;
      }
    if (index == -2)
      {
      index = this->NumSteps-1;
      }
    time = this->Steps[index];
    value = this->Values[index];
    }
}

//----------------------------------------------------------------------------
int vtkTimeSourceExample::NumCellsFunction(double t)
{
  int numCells = 1;
  if (this->Growing)
    {
    //goes from 1 to NumSteps/2+1, adding one cell each step, and returns
    double halfSteps = this->NumSteps/2.0;
    numCells = (int)(halfSteps - (fabs(2.0*(t-0.5)*halfSteps)));
    numCells+=1;
    }
  return numCells;
}

//----------------------------------------------------------------------------
vtkTimeSourceExample::vtkTimeSourceExample()
{
  this->SetNumberOfInputPorts(0);

  this->Analytic = 0;
  this->XAmplitude = 0.0;
  this->YAmplitude = 0.0;
  this->Growing = 0;

  this->NumSteps = 10;

  //times are regularly sampled from 0.0 to 1.0
  this->Steps = new double[this->NumSteps];
  for (int i = 0; i < this->NumSteps; i++)
    {
    this->Steps[i] = (double)i/(double)(this->NumSteps-1);
    }

  //create the table of values at those times for usee when acting as discrete
  this->Values = new double[this->NumSteps];
  for (int i = 0; i < this->NumSteps; i++)
    {
    this->Values[i] =
      this->ValueFunction((double)i/(double)(this->NumSteps-1));
    }
}

//----------------------------------------------------------------------------
vtkTimeSourceExample::~vtkTimeSourceExample()
{
  delete[] this->Steps;
  delete[] this->Values;
}


//----------------------------------------------------------------------------
int vtkTimeSourceExample::RequestInformation(
  vtkInformation* reqInfo,
  vtkInformationVector** inVector,
  vtkInformationVector* outVector
  )
{
  if(!this->Superclass::RequestInformation(reqInfo,inVector,outVector))
    {
    return 0;
    }

  vtkInformation *info=outVector->GetInformationObject(0);

  //tell the caller that I can provide time varying data and
  //tell it what range of times I can deal with
  double tRange[2];
  tRange[0] = this->Steps[0];
  tRange[1] = this->Steps[this->NumSteps-1];
  info->Set(
    vtkStreamingDemandDrivenPipeline::TIME_RANGE(),
    tRange,
    2);

  //tell the caller if this filter can provide values ONLY at discrete times
  //or anywhere within the time range
  if (!this->Analytic)
    {
    info->Set(
      vtkStreamingDemandDrivenPipeline::TIME_STEPS(),
      this->Steps,
      this->NumSteps);
    }
  else
    {
    info->Remove(
      vtkStreamingDemandDrivenPipeline::TIME_STEPS()
      );
    }

  info->Set(CAN_HANDLE_PIECE_REQUEST(), 1);

  return 1;
}

//----------------------------------------------------------------------------
int vtkTimeSourceExample::RequestData(
  vtkInformation* vtkNotUsed(reqInfo),
  vtkInformationVector** vtkNotUsed(inVector),
  vtkInformationVector* outVector
  )
{
  vtkInformation *outInfo = outVector->GetInformationObject(0);
  vtkUnstructuredGrid *output= vtkUnstructuredGrid::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));
  if (!output)
    {
    return 0;
    }

  //determine what time is being asked for
  double reqTime = 0.0;
  //int reqNTS = 0;
  double reqTS(0);
  if (outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP()))
    {
    //reqNTS = outInfo->Length
    //  (vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());
    reqTS = outInfo->Get
      (vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEP());

    //TODO: produce multiblock output when multiple time steps are asked for
    //for now just answer the first one
    reqTime = reqTS;
    }

  //if analytic compute the value at that time
  //if discrete look up the nearest time and value from the table
  double time = reqTime;
  double value = 0.0;
  this->LookupTimeAndValue(time, value);

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

  //figure out the world space position of the output
  double x = this->XFunction(time);
  double y = this->YFunction(time);

  //figure out the number of cells in the output
  int numCells = this->NumCellsFunction(time);

  //compute values for each point and cell to test with
  vtkDoubleArray *pd = vtkDoubleArray::New();
  pd->SetNumberOfComponents(1);
  pd->SetName("Point Value");
  output->GetPointData()->AddArray(pd);
  vtkIdTypeArray *id = vtkIdTypeArray::New();
  id->SetNumberOfComponents(1);
  id->SetName("Point Label");
  output->GetPointData()->AddArray(id);
  output->GetPointData()->SetGlobalIds(id);
  vtkDoubleArray *xd = vtkDoubleArray::New();
  xd->SetNumberOfComponents(1);
  xd->SetName("Point X");
  output->GetPointData()->AddArray(xd);
  vtkDoubleArray *yd = vtkDoubleArray::New();
  yd->SetNumberOfComponents(1);
  yd->SetName("Point Y");
  output->GetPointData()->AddArray(yd);
  vtkDoubleArray *zd = vtkDoubleArray::New();
  zd->SetNumberOfComponents(1);
  zd->SetName("Point Z");
  output->GetPointData()->AddArray(zd);


  vtkPoints *points = vtkPoints::New();
  vtkIdType pid = 0;
  for (int i = 0; i < 2; i++)
    {
    for (int j = 0; j < numCells+1; j++)
      {
      for (int k = 0; k < 2; k++)
        {
        pd->InsertNextValue(value);
        id->InsertNextValue(pid);
        pid++;
        xd->InsertNextValue(x+k);
        yd->InsertNextValue(y+j);
        zd->InsertNextValue(i);
        points->InsertNextPoint(x+k,y+j,i);
        }
      }
    }
  output->SetPoints(points);
  points->Delete();
  id->Delete();
  xd->Delete();
  yd->Delete();
  zd->Delete();
  pd->Delete();


  vtkDoubleArray *cd = vtkDoubleArray::New();
  cd->SetNumberOfComponents(1);
  cd->SetName("Cell Value");
  output->GetCellData()->AddArray(cd);
  id = vtkIdTypeArray::New();
  id->SetNumberOfComponents(1);
  id->SetName("Cell Label");
  output->GetCellData()->AddArray(id);
  output->GetCellData()->SetGlobalIds(id);
  xd = vtkDoubleArray::New();
  xd->SetNumberOfComponents(1);
  xd->SetName("Cell X");
  output->GetCellData()->AddArray(xd);
  yd = vtkDoubleArray::New();
  yd->SetNumberOfComponents(1);
  yd->SetName("Cell Y");
  output->GetCellData()->AddArray(yd);
  zd = vtkDoubleArray::New();
  zd->SetNumberOfComponents(1);
  zd->SetName("Cell Z");
  output->GetCellData()->AddArray(zd);
  output->Allocate();

  vtkIdType ptcells[8];
  vtkIdType cid = 0;
  for (int i = 0; i < 1; i++)
    {
    for (int j = 0; j < numCells; j++)
      {
      for (int k = 0; k < 1; k++)
        {
        cd->InsertNextValue(value);
        id->InsertNextValue(cid);
        cid++;
        xd->InsertNextValue(x+k+0.5); //center of the cell
        yd->InsertNextValue(y+j+0.5);
        zd->InsertNextValue(i+0.5);

        ptcells[0] = (i+0)*((numCells+1)*2) + (j+0)*2 + (k+0);
        ptcells[1] = (i+0)*((numCells+1)*2) + (j+0)*2 + (k+1);
        ptcells[2] = (i+0)*((numCells+1)*2) + (j+1)*2 + (k+0);
        ptcells[3] = (i+0)*((numCells+1)*2) + (j+1)*2 + (k+1);
        ptcells[4] = (i+1)*((numCells+1)*2) + (j+0)*2 + (k+0);
        ptcells[5] = (i+1)*((numCells+1)*2) + (j+0)*2 + (k+1);
        ptcells[6] = (i+1)*((numCells+1)*2) + (j+1)*2 + (k+0);
        ptcells[7] = (i+1)*((numCells+1)*2) + (j+1)*2 + (k+1);
        output->InsertNextCell(VTK_VOXEL, 8, ptcells);
        }
      }
    }
  id->Delete();
  xd->Delete();
  yd->Delete();
  zd->Delete();
  cd->Delete();

  return 1;
}

//----------------------------------------------------------------------------
void vtkTimeSourceExample::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "Analytic: " << (this->Analytic?"ON":"OFF") << endl;
  os << indent << "XAmplitude: " << this->XAmplitude << endl;
  os << indent << "YAmplitude: " << this->YAmplitude << endl;
  os << indent << "Growing: " << this->Growing << endl;

}
