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

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

#include "vtkDataSetAttributes.h" // for vtkDataSetAttributes::VECTORS
#include "vtkGenericAdaptorCell.h"
#include "vtkGenericAttribute.h"
#include "vtkGenericAttributeCollection.h"
#include "vtkGenericCellIterator.h"
#include "vtkGenericDataSet.h"
#include "vtkObjectFactory.h"

#include <vector>

vtkStandardNewMacro(vtkGenericInterpolatedVelocityField);

typedef std::vector<vtkGenericDataSet*> DataSetsTypeBase;
class vtkGenericInterpolatedVelocityFieldDataSetsType : public DataSetsTypeBase
{
};

vtkGenericInterpolatedVelocityField::vtkGenericInterpolatedVelocityField()
{
  this->NumFuncs = 3;     // u, v, w
  this->NumIndepVars = 4; // x, y, z, t
  this->GenCell = nullptr;
  this->CacheHit = 0;
  this->CacheMiss = 0;
  this->Caching = 1; // Caching on by default

  this->VectorsSelection = nullptr;

  this->DataSets = new vtkGenericInterpolatedVelocityFieldDataSetsType;
  this->LastDataSet = nullptr;
}

vtkGenericInterpolatedVelocityField::~vtkGenericInterpolatedVelocityField()
{
  this->NumFuncs = 0;
  this->NumIndepVars = 0;
  if (this->GenCell != nullptr)
  {
    this->GenCell->Delete();
  }

  this->SetVectorsSelection(nullptr);

  delete this->DataSets;
}

static int tmp_count = 0;
// Evaluate u,v,w at x,y,z,t
int vtkGenericInterpolatedVelocityField::FunctionValues(double* x, double* f)
{
  vtkGenericDataSet* ds;
  if (!this->LastDataSet && !this->DataSets->empty())
  {
    ds = (*this->DataSets)[0];
    this->LastDataSet = ds;
  }
  else
  {
    ds = this->LastDataSet;
  }
  int retVal = this->FunctionValues(ds, x, f);
  if (!retVal)
  {
    tmp_count = 0;
    for (DataSetsTypeBase::iterator i = this->DataSets->begin(); i != this->DataSets->end(); ++i)
    {
      ds = *i;
      if (ds && ds != this->LastDataSet)
      {
        this->ClearLastCell();
        retVal = this->FunctionValues(ds, x, f);
        if (retVal)
        {
          this->LastDataSet = ds;
          return retVal;
        }
      }
    }
    this->ClearLastCell();
    return 0;
  }
  tmp_count++;
  return retVal;
}

const double vtkGenericInterpolatedVelocityField::TOLERANCE_SCALE = 1.0E-8;

// Evaluate u,v,w at x,y,z,t
int vtkGenericInterpolatedVelocityField::FunctionValues(
  vtkGenericDataSet* dataset, double* x, double* f)
{
  int i, subId;
  vtkGenericAttribute* vectors = nullptr;
  double dist2;
  int ret;
  int attrib;

  for (i = 0; i < 3; i++)
  {
    f[i] = 0;
  }

  // See if a dataset has been specified and if there are input vectors
  int validState = dataset != nullptr;
  if (validState)
  {
    if (this->VectorsSelection != nullptr)
    {
      attrib = dataset->GetAttributes()->FindAttribute(this->VectorsSelection);
      validState = attrib >= 0;
      if (validState)
      {
        vectors = dataset->GetAttributes()->GetAttribute(attrib);
        validState = (vectors->GetType() == vtkDataSetAttributes::VECTORS) ||
          (vectors->GetCentering() == vtkPointCentered);
      }
    }
    else
    {
      // Find the first attribute, point centered and with vector type.
      attrib = 0;
      validState = 0;
      int c = dataset->GetAttributes()->GetNumberOfAttributes();
      while (attrib < c && !validState)
      {
        validState = (dataset->GetAttributes()->GetAttribute(attrib)->GetType() ==
                       vtkDataSetAttributes::VECTORS) &&
          (dataset->GetAttributes()->GetAttribute(attrib)->GetCentering() == vtkPointCentered);
        ++attrib;
      }
      if (validState)
      {
        vectors = dataset->GetAttributes()->GetAttribute(attrib - 1);
      }
    }
  }

  if (!validState)
  {
    vtkErrorMacro(<< "Can't evaluate dataset!");
    return 0;
  }

  double tol2 = dataset->GetLength() * vtkGenericInterpolatedVelocityField::TOLERANCE_SCALE;

  int found = 0;

  if (this->Caching)
  {
    // See if the point is in the cached cell
    if (this->GenCell == nullptr || this->GenCell->IsAtEnd() ||
      !(ret = this->GenCell->GetCell()->EvaluatePosition(
          x, nullptr, subId, this->LastPCoords, dist2)) ||
      ret == -1)
    {
      // if not, find and get it
      if (this->GenCell != nullptr && !this->GenCell->IsAtEnd())
      {
        this->CacheMiss++;
        found = dataset->FindCell(x, this->GenCell, tol2, subId, this->LastPCoords);
      }
    }
    else
    {
      this->CacheHit++;
      found = 1;
    }
  }

  if (!found)
  {
    // if the cell is not found, do a global search (ignore initial
    // cell if there is one)
    if (this->GenCell == nullptr)
    {
      this->GenCell = dataset->NewCellIterator();
    }
    found = dataset->FindCell(x, this->GenCell, tol2, subId, this->LastPCoords);
    if (!found)
    {
      return 0;
    }
  }

  this->GenCell->GetCell()->InterpolateTuple(vectors, this->LastPCoords, f);

  return 1;
}

//------------------------------------------------------------------------------
void vtkGenericInterpolatedVelocityField::AddDataSet(vtkGenericDataSet* dataset)
{
  if (!dataset)
  {
    return;
  }

  this->DataSets->push_back(dataset);
}

//------------------------------------------------------------------------------
// Description:
// Set the last cell id to -1 so that the next search does not
// start from the previous cell
void vtkGenericInterpolatedVelocityField::ClearLastCell()
{
  if (this->GenCell != nullptr)
  {
    if (!this->GenCell->IsAtEnd())
    {
      this->GenCell->Next();
    }
  }
}
//------------------------------------------------------------------------------
// Description:
// Return the cell cached from last evaluation.
vtkGenericAdaptorCell* vtkGenericInterpolatedVelocityField::GetLastCell()
{
  vtkGenericAdaptorCell* result;
  if (this->GenCell != nullptr && !this->GenCell->IsAtEnd())
  {
    result = this->GenCell->GetCell();
  }
  else
  {
    result = nullptr;
  }
  return result;
}

//------------------------------------------------------------------------------
int vtkGenericInterpolatedVelocityField::GetLastLocalCoordinates(double pcoords[3])
{
  int j;

  // If last cell is valid, fill p with the local coordinates
  // and return true
  if (this->GenCell != nullptr && !this->GenCell->IsAtEnd())
  {
    for (j = 0; j < 3; j++)
    {
      pcoords[j] = this->LastPCoords[j];
    }
    return 1;
  }
  // otherwise, return false
  else
  {
    return 0;
  }
}

void vtkGenericInterpolatedVelocityField::CopyParameters(vtkGenericInterpolatedVelocityField* from)
{
  this->Caching = from->Caching;
}

void vtkGenericInterpolatedVelocityField::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  if (this->VectorsSelection)
  {
    os << indent << "VectorsSelection: " << this->VectorsSelection << endl;
  }
  else
  {
    os << indent << "VectorsSelection: (none)" << endl;
  }
  if (this->GenCell)
  {
    os << indent << "Last cell: " << this->GenCell << endl;
  }
  else
  {
    os << indent << "Last cell: (none)" << endl;
  }
  os << indent << "Cache hit: " << this->CacheHit << endl;
  os << indent << "Cache miss: " << this->CacheMiss << endl;
  os << indent << "Caching: ";
  if (this->Caching)
  {
    os << "on." << endl;
  }
  else
  {
    os << "off." << endl;
  }

  os << indent
     << "VectorsSelection: " << (this->VectorsSelection ? this->VectorsSelection : "(none)")
     << endl;
  os << indent << "LastDataSet : " << this->LastDataSet << endl;
}