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

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

#include "vtkCallbackCommand.h"
#include "vtkDataArraySelection.h"
#include "vtkDataCompressor.h"
#include "vtkDataSet.h"
#include "vtkDataSetAttributes.h"
#include "vtkInstantiator.h"
#include "vtkObjectFactory.h"
#include "vtkXMLDataElement.h"
#include "vtkXMLDataParser.h"
#include "vtkXMLFileReadTester.h"
#include "vtkZLibDataCompressor.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkInformationQuadratureSchemeDefinitionVectorKey.h"
#include "vtkQuadratureSchemeDefinition.h"

#include <vtksys/ios/sstream>
#include <sys/stat.h>
#include <assert.h>
#include <locale> // C++ locale

//-----------------------------------------------------------------------------
static void ReadStringVersion(const char* version, int& major, int& minor)
{
  if (!version)
    {
    major = -1;
    minor = -1;
    return;
    }
  // Extract the major and minor version numbers.
  size_t length = strlen(version);
  const char* begin = version;
  const char* end = version + length;
  const char* s;

  for(s=begin; (s != end) && (*s != '.'); ++s)
    {
    ;
    }

  if(s > begin)
    {
    vtksys_ios::stringstream str;
    str.write(begin, s-begin);
    str >> major;
    if(!str)
      {
      major = 0;
      }
    }
  if(++s < end)
    {
    vtksys_ios::stringstream str;
    str.write(s, end-s);
    str >> minor;
    if(!str)
      {
      minor = 0;
      }
    }
}
//----------------------------------------------------------------------------
vtkXMLReader::vtkXMLReader()
{
  this->FileName = 0;
  this->Stream = 0;
  this->FileStream = 0;
  this->XMLParser = 0;
  this->FieldDataElement = 0;
  this->PointDataArraySelection = vtkDataArraySelection::New();
  this->CellDataArraySelection = vtkDataArraySelection::New();
  this->InformationError = 0;
  this->DataError = 0;
  this->ReadError = 0;
  this->ProgressRange[0] = 0;
  this->ProgressRange[1] = 1;
  
  // Setup the selection callback to modify this object when an array
  // selection is changed.
  this->SelectionObserver = vtkCallbackCommand::New();
  this->SelectionObserver->SetCallback(&vtkXMLReader::SelectionModifiedCallback);
  this->SelectionObserver->SetClientData(this);
  this->PointDataArraySelection->AddObserver(vtkCommand::ModifiedEvent,
                                             this->SelectionObserver);
  this->CellDataArraySelection->AddObserver(vtkCommand::ModifiedEvent,
                                            this->SelectionObserver); 
  this->SetNumberOfInputPorts(0);
  this->SetNumberOfOutputPorts(1);

  // Lower dimensional cell data support.
  this->AxesEmpty[0] = 0;
  this->AxesEmpty[1] = 0;
  this->AxesEmpty[2] = 0;

  // Time support:
  this->TimeStep = 0; // By default the file does not have timestep
  this->TimeStepRange[0] = 0;
  this->TimeStepRange[1] = 0;
  this->NumberOfTimeSteps = 0;
  this->TimeSteps = 0;
  this->CurrentTimeStep = 0;
  this->TimeStepWasReadOnce = 0;

  this->FileMinorVersion = -1;
  this->FileMajorVersion = -1;
  
  this->CurrentOutput = 0;
}

//----------------------------------------------------------------------------
vtkXMLReader::~vtkXMLReader()
{
  this->SetFileName(0);
  if(this->XMLParser)
    {
    this->DestroyXMLParser();
    }
  this->CellDataArraySelection->RemoveObserver(this->SelectionObserver);
  this->PointDataArraySelection->RemoveObserver(this->SelectionObserver);
  this->SelectionObserver->Delete();
  this->CellDataArraySelection->Delete();
  this->PointDataArraySelection->Delete();
  delete[] this->TimeSteps;
}

//----------------------------------------------------------------------------
void vtkXMLReader::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "FileName: "
     << (this->FileName? this->FileName:"(none)") << "\n";
  os << indent << "CellDataArraySelection: " << this->CellDataArraySelection 
     << "\n";
  os << indent << "PointDataArraySelection: " << this->PointDataArraySelection 
     << "\n";
  if(this->Stream)
    {
    os << indent << "Stream: " << this->Stream << "\n";
    }
  else
    {
    os << indent << "Stream: (none)\n";
    }
  os << indent << "TimeStep:" << this->TimeStep << "\n";
  os << indent << "NumberOfTimeSteps:" << this->NumberOfTimeSteps << "\n";
  os << indent << "TimeStepRange:(" << this->TimeStepRange[0] << "," 
                                    << this->TimeStepRange[1] << ")\n";
}

//----------------------------------------------------------------------------
vtkDataSet* vtkXMLReader::GetOutputAsDataSet()
{
  return this->GetOutputAsDataSet(0);
}

//----------------------------------------------------------------------------
vtkDataSet* vtkXMLReader::GetOutputAsDataSet(int index)
{
  return vtkDataSet::SafeDownCast( this->GetOutputDataObject(index) );
}

//----------------------------------------------------------------------------
// Major version should be incremented when older readers can no longer
// read files written for this reader. Minor versions are for added 
// functionality that can be safely ignored by older readers.
int vtkXMLReader::CanReadFileVersion(int major, int vtkNotUsed(minor))
{
  if (major > 0)
    {
    return 0;
    }
  return 1;
}

//----------------------------------------------------------------------------
int vtkXMLReader::OpenVTKFile()
{
  if(this->FileStream)
    {
    vtkErrorMacro("File already open.");
    return 1;
    }
  
  if(!this->Stream && !this->FileName)
    {
    vtkErrorMacro("File name not specified");
    return 0;
    }
  
  if(this->Stream)
    {
    // Use user-provided stream.
    return 1;
    }
  
  // Need to open a file.  First make sure it exists.  This prevents
  // an empty file from being created on older compilers.
  struct stat fs;
  if(stat(this->FileName, &fs) != 0)
    {
    vtkErrorMacro("Error opening file " << this->FileName);
    return 0;
    }
  
#ifdef _WIN32
  this->FileStream = new ifstream(this->FileName, ios::binary | ios::in);
#else
  this->FileStream = new ifstream(this->FileName, ios::in);
#endif
  
  if(!this->FileStream || !(*this->FileStream))
    {
    vtkErrorMacro("Error opening file " << this->FileName);
    if(this->FileStream)
      {
      delete this->FileStream;
      this->FileStream = 0;
      }
    return 0;
    }
  
  // Use the file stream.
  this->Stream = this->FileStream;
  
  return 1;
}

//----------------------------------------------------------------------------
void vtkXMLReader::CloseVTKFile()
{
  if(!this->Stream)
    {
    vtkErrorMacro("File not open.");
    return;
    }
  if(this->Stream == this->FileStream)
    {
    // We opened the file.  Close it.
    this->FileStream->close();
    delete this->FileStream;
    this->FileStream = 0;
    this->Stream = 0;
    }
}

//----------------------------------------------------------------------------
void vtkXMLReader::CreateXMLParser()
{
  if(this->XMLParser)
    {
    vtkErrorMacro("CreateXMLParser() called with existing XMLParser.");
    this->DestroyXMLParser();
    }
  this->XMLParser = vtkXMLDataParser::New();
}

//----------------------------------------------------------------------------
void vtkXMLReader::DestroyXMLParser()
{
  if(!this->XMLParser)
    {
    vtkErrorMacro("DestroyXMLParser() called with no current XMLParser.");
    return;
    }
  this->XMLParser->Delete();
  this->XMLParser = 0;
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetupCompressor(const char* type)
{
  // Instantiate a compressor of the given type.
  if(!type)
    {
    vtkErrorMacro("Compressor has no type.");
    return;
    }
  vtkObject* object = vtkInstantiator::CreateInstance(type);
  vtkDataCompressor* compressor = vtkDataCompressor::SafeDownCast(object);
  
  // In static builds, the vtkZLibDataCompressor may not have been
  // registered with the vtkInstantiator.  Check for it here.
  if(!compressor && (strcmp(type, "vtkZLibDataCompressor") == 0))
    {
    compressor = vtkZLibDataCompressor::New();
    }
  
  if(!compressor)
    {
    vtkErrorMacro("Error creating " << type);
    if(object)
      {
      object->Delete();
      }
    return;
    }
  this->XMLParser->SetCompressor(compressor);
  compressor->Delete();
}



//----------------------------------------------------------------------------
int vtkXMLReader::ReadXMLInformation()
{
  // only Parse if something has changed
  if(this->GetMTime() > this->ReadMTime)
    {
    // Destroy any old information that was parsed.
    if(this->XMLParser)
      {
      this->DestroyXMLParser();
      }

    // Open the input file.  If it fails, the error was already
    // reported by OpenVTKFile.
    if(!this->OpenVTKFile())
      {
      return 0;
      }

    // Create the vtkXMLParser instance used to parse the file.
    this->CreateXMLParser();

    // Configure the parser for this file.
    this->XMLParser->SetStream(this->Stream);

    // Parse the input file.
    if(this->XMLParser->Parse())
      {
      // Let the subclasses read the information they want.
      if(!this->ReadVTKFile(this->XMLParser->GetRootElement()))
        {
        // There was an error reading the file.
        this->ReadError = 1;
        }
      else
        {
        this->ReadError = 0;
        }
      }
    else
      {
      vtkErrorMacro("Error parsing input file.  ReadXMLInformation aborting.");
      // The output should be empty to prevent the rest of the pipeline
      // from executing.
      this->ReadError = 1;
      }

    // Close the file to prevent resource leaks.
    this->CloseVTKFile();

    this->ReadMTime.Modified();
    }
  return !this->ReadError;
}

//----------------------------------------------------------------------------
int vtkXMLReader
::RequestInformation(vtkInformation *request,
                     vtkInformationVector **vtkNotUsed(inputVector),
                     vtkInformationVector *outputVector)
{
  if (this->ReadXMLInformation())
    {
    this->InformationError = 0;
    // Let the subclasses read the information they want.
    int outputPort = 
      request->Get( vtkDemandDrivenPipeline::FROM_OUTPUT_PORT() );
    outputPort = outputPort >= 0 ? outputPort : 0;
    this->SetupOutputInformation
      (outputVector->GetInformationObject(outputPort) );

    // this->NumberOfTimeSteps has been set during the
    // this->ReadXMLInformation()
    int numTimesteps = this->GetNumberOfTimeSteps();
    this->TimeStepRange[0] = 0;
    this->TimeStepRange[1] = numTimesteps-1;
    if (numTimesteps != 0)
      {
      double* timeSteps = new double[numTimesteps];
      for (int i=0; i<numTimesteps; i++)
        {
        timeSteps[i] = i;
        }
      vtkInformation* outInfo = outputVector->GetInformationObject(0);
      outInfo->Set(vtkStreamingDemandDrivenPipeline::TIME_STEPS(), 
                   timeSteps, 
                   numTimesteps);
      double timeRange[2];
      timeRange[0] = timeSteps[0];
      timeRange[1] = timeSteps[numTimesteps-1];
      outInfo->Set(vtkStreamingDemandDrivenPipeline::TIME_RANGE(), 
                   timeRange, 2);
      }
    }
  else
    {
    this->InformationError = 1;
    }

  return !this->InformationError;
}

//----------------------------------------------------------------------------
int vtkXMLReader
::RequestUpdateExtentInformation
(vtkInformation *request,
 vtkInformationVector **vtkNotUsed(inputVector),
 vtkInformationVector *outputVector)
{
  int outputPort = 
    request->Get( vtkDemandDrivenPipeline::FROM_OUTPUT_PORT() );
  outputPort = outputPort >= 0 ? outputPort : 0;
  this->SetupUpdateExtentInformation
    (outputVector->GetInformationObject(outputPort) );

  return 1;
}

//----------------------------------------------------------------------------
int vtkXMLReader::RequestData(vtkInformation *vtkNotUsed(request),
                              vtkInformationVector **vtkNotUsed(inputVector),
                              vtkInformationVector *outputVector)
{
  this->CurrentTimeStep = this->TimeStep;

  // Get the output pipeline information and data object.
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  vtkDataObject* output = outInfo->Get(vtkDataObject::DATA_OBJECT());
  this->CurrentOutput = output;

  // Save the time value in the output data information.
  double* steps =
    outInfo->Get(vtkStreamingDemandDrivenPipeline::TIME_STEPS());
    
  // Check if a particular time was requested.
  if(steps &&
     outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEPS()))
    {
    // Get the requested time step. We only supprt requests of a single time
    // step in this reader right now
    double *requestedTimeSteps = 
      outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_TIME_STEPS());
    
    int length =
      outInfo->Length(vtkStreamingDemandDrivenPipeline::TIME_STEPS());
    
    // find the first time value larger than requested time value
    // this logic could be improved
    int cnt = 0;
    while (cnt < length-1 && steps[cnt] < requestedTimeSteps[0])
      {
      cnt++;
      }
    this->CurrentTimeStep = cnt;

    // Clamp the requested time step to be in bounds.
    if ( this->CurrentTimeStep < this->TimeStepRange[0] )
      {
      this->CurrentTimeStep = this->TimeStepRange[0];
      }
    else if ( this->CurrentTimeStep > this->TimeStepRange[1] )
      {
      this->CurrentTimeStep = this->TimeStepRange[1];
      }

    output->GetInformation()->Set(vtkDataObject::DATA_TIME_STEPS(),
                                  steps+this->CurrentTimeStep,1);
    }

  // Re-open the input file.  If it fails, the error was already
  // reported by OpenVTKFile.
  if(!this->OpenVTKFile())
    {
    this->SetupEmptyOutput();
    this->CurrentOutput = 0;
    return 0;
    }
  if(!this->XMLParser)
    {
    vtkErrorMacro("ExecuteData called with no current XMLParser.");
    }
  
  // Give the vtkXMLParser instance its file back so that data section
  // reads will work.
  
  (*this->Stream).imbue(vtkstd::locale::classic());
  this->XMLParser->SetStream(this->Stream);
  
  // We are just starting to read.  Do not call UpdateProgressDiscrete
  // because we want a 0 progress callback the first time.
  this->UpdateProgress(0);
  
  // Initialize progress range to entire 0..1 range.
  float wholeProgressRange[2] = {0,1};
  this->SetProgressRange(wholeProgressRange, 0, 1);
  
  if(!this->InformationError)
    {
    // We are just starting to execute.  No errors have yet occurred.
    this->XMLParser->SetAbort(0);
    this->DataError = 0;

    // Let the subclasses read the data they want.
    this->ReadXMLData();
    
    // If we aborted or there was an error, provide empty output.
    if(this->DataError || this->AbortExecute)
      {
      this->SetupEmptyOutput();
      }
    }
  else
    {
    // There was an error reading the file.  Provide empty output.
    this->SetupEmptyOutput();
    }
  
  // We have finished reading.
  this->UpdateProgressDiscrete(1);
  
  // Close the file to prevent resource leaks.
  this->CloseVTKFile();
  if( this->TimeSteps )
    {
    // The SetupOutput should not reallocate this should be done only in a TimeStep case
    this->TimeStepWasReadOnce = 1; 
    }

  this->CurrentOutput = 0;
  return 1;
}


//----------------------------------------------------------------------------
void vtkXMLReader::ReadXMLData()
{
  // Initialize the output's data.
  if( !this->TimeStepWasReadOnce )
    {
    this->SetupOutputData();
    }
}

//----------------------------------------------------------------------------
int vtkXMLReader::ReadVTKFile(vtkXMLDataElement* eVTKFile)
{
  // Check if the file version is one we support.
  const char* version = eVTKFile->GetAttribute("version");
  if(version && !this->CanReadFileVersionString(version))
    {
    vtkErrorMacro("File version: " << version << " is is higher than "
                  "this reader supports. Cannot read file.");
    return 0;
    }

  ::ReadStringVersion(version, this->FileMajorVersion, this->FileMinorVersion);

  // Setup the compressor if there is one.
  const char* compressor = eVTKFile->GetAttribute("compressor");
  if(compressor)
    {
    this->SetupCompressor(compressor);
    }
  
  // Get the primary element.
  const char* name = this->GetDataSetName();
  int i;
  vtkXMLDataElement* ePrimary = 0;
  for(i=0; i < eVTKFile->GetNumberOfNestedElements(); ++i)
    {
    vtkXMLDataElement* eNested = eVTKFile->GetNestedElement(i);
    if(strcmp(eNested->GetName(), name) == 0)
      {
      ePrimary = eNested;
      break;
      }
    }
  if(!ePrimary)
    {
    vtkErrorMacro("Cannot find " << name << " element in file.");
    return 0;
    }
  
  // Read the primary element.
  return this->ReadPrimaryElement(ePrimary);
}

//----------------------------------------------------------------------------
int vtkXMLReader::ReadPrimaryElement(vtkXMLDataElement* ePrimary)
{
  // We don't need any information from the primary element here.
  //
  //
  // Let check the "TimeValues" here
  const int tsMax = 4096;
  double timevalues[tsMax];
  int numTimeSteps = 
    ePrimary->GetVectorAttribute("TimeValues", tsMax, timevalues);
  assert( numTimeSteps <= tsMax);
  this->SetNumberOfTimeSteps( numTimeSteps );

  // See if there is a FieldData element
  int numNested = ePrimary->GetNumberOfNestedElements();
  for(int i=0; i < numNested; ++i)
    {
    vtkXMLDataElement* eNested = ePrimary->GetNestedElement(i);
    if(strcmp(eNested->GetName(), "FieldData") == 0) 
      {
      this->FieldDataElement = eNested;
      return 1;
      }
    }
  
  this->FieldDataElement = 0;

  return 1;
}


//----------------------------------------------------------------------------
void vtkXMLReader::SetupOutputData()
{
  // Initialize the output.
  this->CurrentOutput->Initialize();
}


//----------------------------------------------------------------------------
int vtkXMLReader::CreateInformationKey(
        vtkXMLDataElement *eInfoKey,
        vtkInformation *info)
{
  // Quick sanity check that, this is an InformationKey
  // and it is defined correctly.
  const char *name=eInfoKey->GetAttribute("name");
  const char *location=eInfoKey->GetAttribute("location");
  if ((strcmp(eInfoKey->GetName(),"InformationKey")!=0)
      || (location==NULL)
      || (name==NULL))
    {
    vtkWarningMacro("XML representation of Key: "
                    "\"InformationKey\" is expected to "
                    "have \"name\" and \"location\" "
                    "attributes.");
    return 0;
    }

  // Check that it's a recognized type, and restore.
  if ((strcmp(location, "vtkQuadratureSchemeDefinition")==0)
      &&(strcmp(name, "DICTIONARY")==0))
    {
    vtkInformationQuadratureSchemeDefinitionVectorKey *key=vtkQuadratureSchemeDefinition::DICTIONARY();
    key->RestoreState(info, eInfoKey);
    vtkIndent indent;
    }

  return 1;
}


//----------------------------------------------------------------------------
vtkAbstractArray* vtkXMLReader::CreateArray(vtkXMLDataElement* da)
{
  int dataType = 0;
  if(!da->GetWordTypeAttribute("type", dataType))
    {
    return 0;
    }

  vtkAbstractArray* array = vtkAbstractArray::CreateArray(dataType);

  array->SetName(da->GetAttribute("Name"));
  

  //if NumberOfComponents fails, we have 1 component
  int components = 1;

  if(da->GetScalarAttribute("NumberOfComponents", components))
    {
    array->SetNumberOfComponents(components);
    }

  //determine what component names have been saved in the file.  
  const char* compName = NULL;
  vtksys_ios::ostringstream buff;  
  for ( int i=0; i < components && i < 10; ++i )
    {
    //get the component names                    
    buff << "ComponentName" << i;        
    compName = da->GetAttribute( buff.str().c_str() );
    if ( compName )
      {      
      //detected a component name, add it
      array->SetComponentName( i ,compName );
      compName=NULL;
      }    
    buff.str("");
    buff.clear();
    }
    
    
  // Scan/load for vtkInformationKey data.  
  int nElements=da->GetNumberOfNestedElements();
  for (int i=0; i<nElements; ++i)
    {
    vtkXMLDataElement *eInfoKeyData=da->GetNestedElement(i);
    if(strcmp(eInfoKeyData->GetName(), "InformationKey") == 0)
      {
      vtkInformation *info=array->GetInformation();
      this->CreateInformationKey(eInfoKeyData, info);
      }
    }

  return array;
}

//----------------------------------------------------------------------------
int vtkXMLReader::CanReadFile(const char* name)
{
  // First make sure the file exists.  This prevents an empty file
  // from being created on older compilers.
  struct stat fs;
  if(stat(name, &fs) != 0) 
    { 
    return 0; 
    }
  
  // Test if the file with the given name is a VTKFile with the given
  // type.
  vtkXMLFileReadTester* tester = vtkXMLFileReadTester::New();
  tester->SetFileName(name);
  
  int result = 0;
  if(tester->TestReadFile() && tester->GetFileDataType())
    {
    if(strcmp(tester->GetFileDataType(), this->GetDataSetName()) == 0)
      {
      const char* version = tester->GetFileVersion();
      if(version)
        {
        if(this->CanReadFileVersionString(version))
          {
          result = 3;
          }
        }
      else
        {
        result = 3;
        }
      }
    }
  
  tester->Delete();
  return result;
}

//----------------------------------------------------------------------------
int vtkXMLReader::CanReadFileVersionString(const char* version)
{
  int major = 0;
  int minor = 0;
  ::ReadStringVersion(version, major, minor);
  return this->CanReadFileVersion(major, minor);
}

//----------------------------------------------------------------------------
int vtkXMLReader::IntersectExtents(int* extent1, int* extent2, int* result)
{
  if((extent1[0] > extent2[1]) || (extent1[2] > extent2[3]) ||
     (extent1[4] > extent2[5]) || (extent1[1] < extent2[0]) ||
     (extent1[3] < extent2[2]) || (extent1[5] < extent2[4]))
    {
    // No intersection of extents.
    return 0;
    }
  
  // Get the intersection of the extents.
  result[0] = this->Max(extent1[0], extent2[0]);
  result[1] = this->Min(extent1[1], extent2[1]);
  result[2] = this->Max(extent1[2], extent2[2]);
  result[3] = this->Min(extent1[3], extent2[3]);
  result[4] = this->Max(extent1[4], extent2[4]);
  result[5] = this->Min(extent1[5], extent2[5]);
  
  return 1;
}

//----------------------------------------------------------------------------
int vtkXMLReader::Min(int a, int b)
{
  return (a < b)? a : b;
}

//----------------------------------------------------------------------------
int vtkXMLReader::Max(int a, int b)
{
  return (a > b)? a : b;
}

//----------------------------------------------------------------------------
void vtkXMLReader::ComputePointDimensions(int* extent, int* dimensions)
{
  dimensions[0] = extent[1] - extent[0] + 1;
  dimensions[1] = extent[3] - extent[2] + 1;
  dimensions[2] = extent[5] - extent[4] + 1;
}

//----------------------------------------------------------------------------
void vtkXMLReader::ComputePointIncrements(int* extent, vtkIdType* increments)
{
  increments[0] = 1;
  increments[1] = increments[0] * (extent[1] - extent[0] + 1);
  increments[2] = increments[1] * (extent[3] - extent[2] + 1);
}

//----------------------------------------------------------------------------
void vtkXMLReader::ComputeCellDimensions(int* extent, int* dimensions)
{
  // For structured cells, axes that are empty of cells are treated as
  // having one cell when computing cell counts.  This allows cell
  // dimensions lower than 3.
  for(int a=0; a < 3; ++a)
    {
    if(this->AxesEmpty[a] && extent[2*a+1] == extent[2*a])
      {
      dimensions[a] = 1;
      }
    else
      {
      dimensions[a] = extent[2*a+1] - extent[2*a];
      }
    }
}

//----------------------------------------------------------------------------
void vtkXMLReader::ComputeCellIncrements(int* extent, vtkIdType* increments)
{
  // For structured cells, axes that are empty of cells do not
  // contribute to the memory layout of cell data.
  vtkIdType nextIncrement = 1;
  for(int a=0; a < 3; ++a)
    {
    if(this->AxesEmpty[a] && extent[2*a+1] == extent[2*a])
      {
      increments[a] = 0;
      }
    else
      {
      increments[a] = nextIncrement;
      nextIncrement *= extent[2*a+1] - extent[2*a];
      }
    }
}

//----------------------------------------------------------------------------
vtkIdType vtkXMLReader::GetStartTuple(int* extent, vtkIdType* increments,
                                      int i, int j, int k)
{
  vtkIdType offset = (i - extent[0]) * increments[0];
  offset += (j - extent[2]) * increments[1];
  offset += (k - extent[4]) * increments[2];
  return offset;
}

//----------------------------------------------------------------------------
void vtkXMLReader::ReadAttributeIndices(vtkXMLDataElement* eDSA,
                                        vtkDataSetAttributes* dsa)
{
  // Setup attribute indices.
  int i;
  for(i=0;i < vtkDataSetAttributes::NUM_ATTRIBUTES;++i)
    {
    const char* attrName = vtkDataSetAttributes::GetAttributeTypeAsString(i);
    if(eDSA && eDSA->GetAttribute(attrName))
      {
      dsa->SetActiveAttribute(eDSA->GetAttribute(attrName), i);
      }
    }
}

//----------------------------------------------------------------------------
char** vtkXMLReader::CreateStringArray(int numStrings)
{
  char** strings = new char*[numStrings];
  int i;
  for(i=0; i < numStrings; ++i)
    {
    strings[i] = 0;
    }
  return strings;
}

//----------------------------------------------------------------------------
void vtkXMLReader::DestroyStringArray(int numStrings, char** strings)
{
  int i;
  for(i=0; i < numStrings; ++i)
    {
    if(strings[i])
      {
      delete [] strings[i];
      }
    }
  delete [] strings;
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetDataArraySelections(vtkXMLDataElement* eDSA,
                                          vtkDataArraySelection* sel)
{
  if(!eDSA)
    {
    sel->SetArrays(0, 0);
    return;
    }

  int numArrays = eDSA->GetNumberOfNestedElements();
  if(!numArrays)
    {
    sel->SetArrays(0, 0);
    return;
    }
  
  for(int i=0;i < numArrays;++i)
    {
    vtkXMLDataElement* eNested = eDSA->GetNestedElement(i);
    const char* name = eNested->GetAttribute("Name");
    if(name)
      {
      sel->AddArray( name );
      }
    else
      {
      vtksys_ios::ostringstream ostr_with_warning_C4701;
      ostr_with_warning_C4701 << "Array " << i;
      sel->AddArray( ostr_with_warning_C4701.str().c_str() );
      }
    }
}


//----------------------------------------------------------------------------
int vtkXMLReader::SetFieldDataInfo(vtkXMLDataElement *eDSA, 
                                   int association, int numTuples,
                                   vtkInformationVector *(&infoVector))
{
  if (!eDSA)
    {
    return 1;
    }

  int i, j, components, dataType, activeFlag;
  const char *name;
  char *(attributeName[vtkDataSetAttributes::NUM_ATTRIBUTES]);
  vtkInformation *info = NULL;

  for(i = 0; i < vtkDataSetAttributes::NUM_ATTRIBUTES; i++)
    {
    const char* attrName = vtkDataSetAttributes::GetAttributeTypeAsString(i);
    name = eDSA->GetAttribute(attrName);
    if (name)
      {
      attributeName[i] = new char[strlen(name)+1];
      strcpy(attributeName[i], name);
      }
    else
      {
      attributeName[i] = NULL;
      }
    }

  if (!infoVector)
    {
    infoVector = vtkInformationVector::New();
    }

  // Cycle through each data array
  for(i = 0; i < eDSA->GetNumberOfNestedElements(); i++)
    {
    vtkXMLDataElement* eNested = eDSA->GetNestedElement(i);

    info = vtkInformation::New();
    activeFlag = 0;
    info->Set(vtkDataObject::FIELD_ASSOCIATION(), association);
    info->Set(vtkDataObject::FIELD_NUMBER_OF_TUPLES(), numTuples);

    name = eNested->GetAttribute( "Name" );
    if (!name)
      {
      this->InformationError = 1;
      break;
      }
    info->Set(vtkDataObject::FIELD_NAME(), name);

    // Search for matching attribute name
    for (j = 0; j < vtkDataSetAttributes::NUM_ATTRIBUTES; j++)
      {
      if (attributeName[j] && !strcmp(name, attributeName[j]))
        {
        // set appropriate bit to indicate an active attribute type
        activeFlag |= 1 << j;
        break;
        }
      }

    if (!eNested->GetWordTypeAttribute("type", dataType))
      {
      this->InformationError = 1;
      break;
      }
    info->Set(vtkDataObject::FIELD_ARRAY_TYPE(), dataType);

    if (eNested->GetScalarAttribute("NumberOfComponents", components))
      {
      info->Set(vtkDataObject::FIELD_NUMBER_OF_COMPONENTS(), components);
      }
    else
      {
      info->Set(vtkDataObject::FIELD_NUMBER_OF_COMPONENTS(), 1);
      }

    double range[2];
    if (eNested->GetScalarAttribute("RangeMin", range[0]) &&
        eNested->GetScalarAttribute("RangeMax", range[1]))
      {
      info->Set(vtkDataObject::FIELD_RANGE(), range, 2);
      }

    info->Set(vtkDataObject::FIELD_ACTIVE_ATTRIBUTE(), activeFlag);
    infoVector->Append( info );
    info->Delete();
    }

  for(i = 0; i < vtkDataSetAttributes::NUM_ATTRIBUTES; i++)
    {
    if (attributeName[i])
      {
      delete [] attributeName[i];
      }
    }

  if (this->InformationError)
    {
    info->Delete();
    infoVector->Delete();
    infoVector = NULL;
    return 0;
    }

  return 1;
  }


//----------------------------------------------------------------------------
int vtkXMLReader::PointDataArrayIsEnabled(vtkXMLDataElement* ePDA)
{
  const char* name = ePDA->GetAttribute("Name");
  return (name && this->PointDataArraySelection->ArrayIsEnabled(name));
}

//----------------------------------------------------------------------------
int vtkXMLReader::CellDataArrayIsEnabled(vtkXMLDataElement* eCDA)
{
  const char* name = eCDA->GetAttribute("Name");
  return (name && this->CellDataArraySelection->ArrayIsEnabled(name));
}

//----------------------------------------------------------------------------
void vtkXMLReader::SelectionModifiedCallback(vtkObject*, unsigned long,
                                             void* clientdata, void*)
{
  static_cast<vtkXMLReader*>(clientdata)->Modified();
}

//----------------------------------------------------------------------------
int vtkXMLReader::GetNumberOfPointArrays()
{
  return this->PointDataArraySelection->GetNumberOfArrays();
}

//----------------------------------------------------------------------------
const char* vtkXMLReader::GetPointArrayName(int index)
{
  return this->PointDataArraySelection->GetArrayName(index);
}

//----------------------------------------------------------------------------
int vtkXMLReader::GetPointArrayStatus(const char* name)
{
  return this->PointDataArraySelection->ArrayIsEnabled(name);
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetPointArrayStatus(const char* name, int status)
{
  if(status)
    {
    this->PointDataArraySelection->EnableArray(name);
    }
  else
    {
    this->PointDataArraySelection->DisableArray(name);
    }
}

//----------------------------------------------------------------------------
int vtkXMLReader::GetNumberOfCellArrays()
{
  return this->CellDataArraySelection->GetNumberOfArrays();
}

//----------------------------------------------------------------------------
const char* vtkXMLReader::GetCellArrayName(int index)
{
  return this->CellDataArraySelection->GetArrayName(index);
}

//----------------------------------------------------------------------------
int vtkXMLReader::GetCellArrayStatus(const char* name)
{
  return this->CellDataArraySelection->ArrayIsEnabled(name);
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetCellArrayStatus(const char* name, int status)
{
  if(status)
    {
    this->CellDataArraySelection->EnableArray(name);
    }
  else
    {
    this->CellDataArraySelection->DisableArray(name);
    }
}

//----------------------------------------------------------------------------
void vtkXMLReader::GetProgressRange(float* range)
{
  range[0] = this->ProgressRange[0];
  range[1] = this->ProgressRange[1];
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetProgressRange(float* range, int curStep, int numSteps)
{
  float stepSize = (range[1] - range[0])/numSteps;
  this->ProgressRange[0] = range[0] + stepSize*curStep;
  this->ProgressRange[1] = range[0] + stepSize*(curStep+1);
  this->UpdateProgressDiscrete(this->ProgressRange[0]);
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetProgressRange(float* range, int curStep,
                                    float* fractions)
{
  float width = range[1] - range[0];
  this->ProgressRange[0] = range[0] + fractions[curStep]*width;
  this->ProgressRange[1] = range[0] + fractions[curStep+1]*width;
  this->UpdateProgressDiscrete(this->ProgressRange[0]);
}

//----------------------------------------------------------------------------
void vtkXMLReader::UpdateProgressDiscrete(float progress)
{
  if(!this->AbortExecute)
    {
    // Round progress to nearest 100th.
    float rounded = float(int((progress*100)+0.5))/100;
    if(this->GetProgress() != rounded)
      {
      this->UpdateProgress(rounded);
      }
    }
}


//----------------------------------------------------------------------------
int vtkXMLReader::ProcessRequest(vtkInformation* request,
                                 vtkInformationVector** inputVector,
                                 vtkInformationVector* outputVector)
{
  this->CurrentOutputInformation =
    outputVector->GetInformationObject(0);
  // FIXME This piece of code should be rewritten to handle at the same
  // time Pieces and TimeSteps. The REQUEST_DATA_NOT_GENERATED should
  // ideally be changed during execution, so that allocation still
  // happen when needed but can be skipped in demand (when doing
  // timesteps)
  if(this->NumberOfTimeSteps &&
    request->Has(vtkDemandDrivenPipeline::REQUEST_DATA_NOT_GENERATED()))
    {
    vtkInformation* outInfo = outputVector->GetInformationObject(0);
    outInfo->Set(vtkDemandDrivenPipeline::DATA_NOT_GENERATED(), 1);
    this->CurrentOutputInformation = 0;
    return 1;
    }
  // END FIXME 

  // generate the data
  if(request->Has(vtkDemandDrivenPipeline::REQUEST_DATA()))
    {
    int retVal = this->RequestData(request, inputVector, outputVector);
    this->CurrentOutputInformation = 0;
    return retVal;
    }

  // create the output
  if(request->Has(vtkDemandDrivenPipeline::REQUEST_DATA_OBJECT()))
    {
    int retVal = this->RequestDataObject(request, inputVector, outputVector);
    this->CurrentOutputInformation = 0;
    return retVal;
    }

  // execute information
  if(request->Has(vtkDemandDrivenPipeline::REQUEST_INFORMATION()))
    {
    int retVal = this->RequestInformation(request, inputVector, outputVector);
    this->CurrentOutputInformation = 0;
    return retVal;
    }

  // return UE info
  if(request->Has
     (vtkStreamingDemandDrivenPipeline::REQUEST_UPDATE_EXTENT_INFORMATION()))
    {
    int retVal = this->RequestUpdateExtentInformation(request, 
        inputVector, outputVector);
    this->CurrentOutputInformation = 0;
    return retVal;
    }

  int retVal = 
    this->Superclass::ProcessRequest(request, inputVector, outputVector);
  this->CurrentOutputInformation = 0;
  return retVal;
}

//----------------------------------------------------------------------------
void vtkXMLReader::SetNumberOfTimeSteps(int num)
{
  if( num && (this->NumberOfTimeSteps != num) )
    {
    this->NumberOfTimeSteps = num;
    delete[] this->TimeSteps;
    // Reallocate a buffer large enough
    this->TimeSteps = new int[num];
    this->Modified();
    }
}

//----------------------------------------------------------------------------
int vtkXMLReader::IsTimeStepInArray(int timestep, int* timesteps, int length)
{
  for(int i=0; i<length; i++)
    {
    if (timesteps[i] == timestep)
      {
      return 1;
      }
    }
  return 0;
}

//----------------------------------------------------------------------------
vtkDataObject* vtkXMLReader::GetCurrentOutput()
{
  return this->CurrentOutput;
}

//----------------------------------------------------------------------------
vtkInformation* vtkXMLReader::GetCurrentOutputInformation()
{
  return this->CurrentOutputInformation;
}
