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

 Program:   Visualization Toolkit
 Module:    vtkAMRBaseReader.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 "vtkAMRBaseReader.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkDataObject.h"
#include "vtkMultiProcessController.h"
#include "vtkOverlappingAMR.h"
#include "vtkDataArraySelection.h"
#include "vtkCallbackCommand.h"
#include "vtkIndent.h"
#include "vtkSmartPointer.h"
#include "vtkCompositeDataPipeline.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkAMRDataSetCache.h"
#include "vtkUniformGrid.h"
#include "vtkDataArray.h"
#include "vtkCellData.h"
#include "vtkPointData.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkTimerLog.h"
#include "vtkAMRInformation.h"
#include "vtkParallelAMRUtilities.h"

#include <cassert>


vtkAMRBaseReader::vtkAMRBaseReader()
{
  this->LoadedMetaData     = false;
  this->NumBlocksFromCache = 0;
  this->NumBlocksFromFile  = 0;
  this->EnableCaching      = 0;
  this->Cache              = nullptr;
}

//------------------------------------------------------------------------------
vtkAMRBaseReader::~vtkAMRBaseReader()
{
  this->PointDataArraySelection->RemoveObserver( this->SelectionObserver );
  this->CellDataArraySelection->RemoveObserver( this->SelectionObserver );
  this->SelectionObserver->Delete( );
  this->CellDataArraySelection->Delete( );
  this->PointDataArraySelection->Delete( );

  if( this->Cache != nullptr )
  {
    this->Cache->Delete();
  }

  if( this->Metadata != nullptr )
  {
    this->Metadata->Delete();
  }
}

//------------------------------------------------------------------------------
int vtkAMRBaseReader::FillOutputPortInformation(
    int vtkNotUsed(port),vtkInformation *info )
{
  info->Set( vtkDataObject::DATA_TYPE_NAME(), "vtkOverlappingAMR" );
  return 1;
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::PrintSelf( std::ostream &os, vtkIndent indent )
{
  this->Superclass::PrintSelf( os, indent );
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::Initialize()
{
  vtkTimerLog::MarkStartEvent( "vtkAMRBaseReader::Initialize" );

  this->SetNumberOfInputPorts( 0 );
  this->FileName       = nullptr;
  this->MaxLevel       = 0;
  this->Metadata       = nullptr;
  this->Controller     = vtkMultiProcessController::GetGlobalController();
  this->InitialRequest = true;
  this->Cache          = vtkAMRDataSetCache::New();

  this->CellDataArraySelection  = vtkDataArraySelection::New();
  this->PointDataArraySelection = vtkDataArraySelection::New();
  this->SelectionObserver       = vtkCallbackCommand::New();
  this->SelectionObserver->SetCallback(
      &vtkAMRBaseReader::SelectionModifiedCallback);
  this->SelectionObserver->SetClientData( this );
  this->CellDataArraySelection->AddObserver(
     vtkCommand::ModifiedEvent,this->SelectionObserver );
  this->PointDataArraySelection->AddObserver(
     vtkCommand::ModifiedEvent, this->SelectionObserver );

  vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::Initialize" );
}

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

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

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

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

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

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

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

//------------------------------------------------------------------------------
void vtkAMRBaseReader::SetPointArrayStatus(const char* name, int status)
{

  if( status )
  {
    this->PointDataArraySelection->EnableArray(name);
  }
  else
  {
    this->PointDataArraySelection->DisableArray(name);
  }

}

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

//------------------------------------------------------------------------------
int vtkAMRBaseReader::GetBlockProcessId( const int blockIdx )
{
  // If this is reader instance is serial, return Process 0
  // as the Process ID for the corresponding block.
  if( !this->IsParallel() )
  {
    return 0;
  }

  int N = this->Controller->GetNumberOfProcesses();
  return( blockIdx%N );
}

//------------------------------------------------------------------------------
bool vtkAMRBaseReader::IsBlockMine( const int blockIdx )
{
  // If this reader instance does not run in parallel, then,
  // all blocks are owned by this reader.
  if( !this->IsParallel() )
  {
    return true;
  }

  int myRank = this->Controller->GetLocalProcessId();
  if( myRank == this->GetBlockProcessId( blockIdx ) )
  {
    return true;
  }
  return false;
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::InitializeArraySelections()
{
  if( this->InitialRequest )
  {
    this->PointDataArraySelection->DisableAllArrays();
    this->CellDataArraySelection->DisableAllArrays();
    this->InitialRequest=false;
  }
}

//------------------------------------------------------------------------------
bool vtkAMRBaseReader::IsParallel( )
{
  if( this->Controller == nullptr )
  {
    return false;
  }

  if( this->Controller->GetNumberOfProcesses() > 1 )
  {
    return true;
  }

  return false;
}


//------------------------------------------------------------------------------
int vtkAMRBaseReader::RequestInformation(
    vtkInformation *rqst,
    vtkInformationVector **inputVector,
    vtkInformationVector *outputVector )
{
  if( this->LoadedMetaData )
  {
    return( 1 );
  }

  this->Superclass::RequestInformation( rqst, inputVector, outputVector );

  this->Metadata = vtkOverlappingAMR::New();
  this->FillMetaData( );
  vtkInformation* info = outputVector->GetInformationObject(0);
  assert( "pre: output information object is nullptr" && (info != nullptr) );
  info->Set( vtkCompositeDataPipeline::COMPOSITE_DATA_META_DATA(),
             this->Metadata );
  if(this->Metadata && this->Metadata->GetInformation()->Has(vtkDataObject::DATA_TIME_STEP()))
  {
    double dataTime = this->Metadata->GetInformation()->Get(vtkDataObject::DATA_TIME_STEP());
    info->Set(vtkStreamingDemandDrivenPipeline::TIME_STEPS(), &dataTime, 1);
  }

  vtkTimerLog::MarkStartEvent("vtkAMRBaseReader::GenerateParentChildInformation");
  this->Metadata->GenerateParentChildInformation();
  vtkTimerLog::MarkEndEvent("vtkAMRBaseReader::GenerateParentChildInformation");

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

  // std::cout<<"Generate Meta Data: ";
  // for(int levelIdx=0 ; levelIdx < this->Metadata->GetNumberOfLevels(); ++levelIdx )
  //  {
  //  std::cout << " \tL(" << levelIdx << ") = " << this->Metadata->GetNumberOfDataSets( levelIdx ) << " ";
  //  std::cout.flush();
  //  } // END for levels
  // std::cout<<endl;
  this->LoadedMetaData = true;
  return 1;
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::SetupBlockRequest( vtkInformation *outInf )
{
  assert( "pre: output information is nullptr" && (outInf != nullptr) );

  if( outInf->Has(
      vtkCompositeDataPipeline::UPDATE_COMPOSITE_INDICES() ) )
  {
    assert( "Metadata should not be null" && (this->Metadata!=nullptr) );
    this->ReadMetaData();

    int size =
     outInf->Length(vtkCompositeDataPipeline::UPDATE_COMPOSITE_INDICES() );
    int *indices =
      outInf->Get(vtkCompositeDataPipeline::UPDATE_COMPOSITE_INDICES() );

    this->BlockMap.clear();
    this->BlockMap.resize( size );

    for( int i=0; i < size; ++i )
    {
      this->BlockMap[ i ] = indices[ i ];
    }
  }
  else
  {
    this->ReadMetaData();

    this->BlockMap.clear();
    int maxLevel = this->MaxLevel <  static_cast<int>(this->Metadata->GetNumberOfLevels())-1? this->MaxLevel : this->Metadata->GetNumberOfLevels()-1;
    for(int level=0; level<= maxLevel; level++)
    {
      for(unsigned int id=0; id<this->Metadata->GetNumberOfDataSets(level); id++)
      {
        int index = this->Metadata->GetCompositeIndex(static_cast<unsigned int>(level),id);
        this->BlockMap.push_back(index);
      }
    }
  }

}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::GetAMRData(
    const int blockIdx, vtkUniformGrid *block, const char *fieldName )
{
  assert( "pre: AMR block is nullptr" && (block != nullptr) );
  assert( "pre: field name is nullptr" && (fieldName != nullptr) );

  // If caching is disabled load the data from file
  if( !this->IsCachingEnabled() )
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridDataFromFile" );
    this->GetAMRGridData( blockIdx, block, fieldName );
    vtkTimerLog::MarkEndEvent( "GetAMRGridDataFromFile" );
    return;
  }

  // Caching is enabled.
  // Check the cache to see if the data has already been read.
  // Otherwise, read it and cache it.
  if( this->Cache->HasAMRBlockCellData( blockIdx, fieldName ) )
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridDataFromCache" );
    vtkDataArray *data =
       this->Cache->GetAMRBlockCellData( blockIdx, fieldName );
    assert( "pre: cached data is nullptr!" && (data != nullptr) );
    vtkTimerLog::MarkEndEvent( "GetAMRGridDataFromCache" );

    block->GetCellData()->AddArray( data );
  }
  else
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridDataFromFile" );
    this->GetAMRGridData( blockIdx, block, fieldName );
    vtkTimerLog::MarkEndEvent( "GetAMRGridDataFromFile" );

    vtkTimerLog::MarkStartEvent( "CacheAMRData" );
    this->Cache->InsertAMRBlockCellData(
        blockIdx, block->GetCellData()->GetArray( fieldName ) );
    vtkTimerLog::MarkEndEvent( "CacheAMRData" );
  }

}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::GetAMRPointData(
    const int blockIdx, vtkUniformGrid *block, const char *fieldName )
{
  assert( "pre: AMR block is nullptr" && (block != nullptr) );
  assert( "pre: field name is nullptr" && (fieldName != nullptr) );

  // If caching is disabled load the data from file
  if( !this->IsCachingEnabled() )
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridPointDataFromFile" );
    this->GetAMRGridPointData( blockIdx, block, fieldName );
    vtkTimerLog::MarkEndEvent( "GetAMRGridPointDataFromFile" );
    return;
  }

  // Caching is enabled.
  // Check the cache to see if the data has already been read.
  // Otherwise, read it and cache it.
  if( this->Cache->HasAMRBlockPointData( blockIdx, fieldName ) )
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridPointDataFromCache" );
    vtkDataArray *data =
       this->Cache->GetAMRBlockPointData( blockIdx, fieldName );
    assert( "pre: cached data is nullptr!" && (data != nullptr) );
    vtkTimerLog::MarkEndEvent( "GetAMRGridPointDataFromCache" );

    block->GetPointData()->AddArray( data );
  }
  else
  {
    vtkTimerLog::MarkStartEvent( "GetAMRGridPointDataFromFile" );
    this->GetAMRGridPointData( blockIdx, block, fieldName );
    vtkTimerLog::MarkEndEvent( "GetAMRGridPointDataFromFile" );

    vtkTimerLog::MarkStartEvent( "CacheAMRPointData" );
    this->Cache->InsertAMRBlockPointData(
        blockIdx, block->GetPointData()->GetArray( fieldName ) );
    vtkTimerLog::MarkEndEvent( "CacheAMRPointData" );
  }
}

//------------------------------------------------------------------------------
vtkUniformGrid* vtkAMRBaseReader::GetAMRBlock( const int blockIdx )
{

  // If caching is disabled load the data from file
  if( !this->IsCachingEnabled() )
  {
    ++this->NumBlocksFromFile;
    vtkTimerLog::MarkStartEvent( "ReadAMRBlockFromFile" );
    vtkUniformGrid *gridPtr = this->GetAMRGrid( blockIdx );
    vtkTimerLog::MarkEndEvent( "ReadAMRBlockFromFile" );
    assert( "pre: grid pointer is nullptr" && (gridPtr != nullptr) );
    return( gridPtr );
  }

  // Caching is enabled.
  // Check the cache to see if the block has already been read.
  // Otherwise, read it and cache it.
  if( this->Cache->HasAMRBlock( blockIdx ) )
  {
    ++this->NumBlocksFromCache;
    vtkTimerLog::MarkStartEvent("ReadAMRBlockFromCache");
    vtkUniformGrid *gridPtr    = vtkUniformGrid::New();
    vtkUniformGrid *cachedGrid = this->Cache->GetAMRBlock( blockIdx );
    gridPtr->CopyStructure( cachedGrid );
    vtkTimerLog::MarkEndEvent( "ReadAMRBlockFromCache" );
    return( gridPtr );
  }
  else
  {
    ++this->NumBlocksFromFile;
    vtkTimerLog::MarkStartEvent( "ReadAMRBlockFromFile" );
    vtkUniformGrid *cachedGrid = vtkUniformGrid::New();
    vtkUniformGrid *gridPtr    = this->GetAMRGrid( blockIdx );
    assert( "pre: grid pointer is nullptr" && (gridPtr != nullptr) );
    vtkTimerLog::MarkEndEvent( "ReadAMRBlockFromFile" );

    vtkTimerLog::MarkStartEvent( "CacheAMRBlock" );
    cachedGrid->CopyStructure( gridPtr );
    this->Cache->InsertAMRBlock( blockIdx, cachedGrid );
    vtkTimerLog::MarkEndEvent( "CacheAMRBlock" );

    return( gridPtr );
  }

//  assert( "Code should never reach here!" && (false) );
//  return nullptr;
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::LoadPointData(
    const int blockIdx, vtkUniformGrid* block )
{
  // Sanity check!
  assert( "pre: AMR block should not be nullptr" && (block != nullptr) );

  for( int i=0; i < this->GetNumberOfPointArrays(); ++i )
  {
    if( this->GetPointArrayStatus( this->GetPointArrayName( i ) ) )
    {
      this->GetAMRPointData( blockIdx, block, this->GetPointArrayName( i ) );
    }
  } // END for all point arrays
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::LoadCellData(
    const int blockIdx, vtkUniformGrid *block )
{
  // Sanity check!
  assert( "pre: AMR block should not be nullptr" && (block != nullptr) );

  for( int i=0; i < this->GetNumberOfCellArrays(); ++i )
  {
    if( this->GetCellArrayStatus( this->GetCellArrayName( i ) ) )
    {
      this->GetAMRData( blockIdx, block, this->GetCellArrayName( i ) );
    }
  } // END for all cell arrays
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::LoadRequestedBlocks( vtkOverlappingAMR *output )
{
  assert( "pre: AMR data-structure is nullptr" && (output != nullptr) );

  // Unlike AssignAndLoadBlocks, this code doesn't have to bother about
  // "distributing" blocks to load among processes when running in parallel.
  // Sinks should ensure that request appropriate blocks (similar to the way
  // requests for pieces or extents work).
  for (size_t block=0; block < this->BlockMap.size(); ++block)
  {
    // FIXME: this piece of code is very similar to the block in
    // AssignAndLoadBlocks. We should consolidate the two.
    int blockIndex =  this->BlockMap[ block ];
    int blockIdx = this->Metadata->GetAMRInfo()->GetAMRBlockSourceIndex(blockIndex);

    unsigned int metaLevel;
    unsigned int metaIdx;
    this->Metadata->GetAMRInfo()->ComputeIndexPair(blockIndex, metaLevel, metaIdx);
    unsigned int level    = this->GetBlockLevel( blockIdx );
    assert(level==metaLevel);

    // STEP 0: Get the AMR block
    vtkTimerLog::MarkStartEvent( "GetAMRBlock" );
    vtkUniformGrid *amrBlock = this->GetAMRBlock( blockIdx );
    vtkTimerLog::MarkEndEvent( "GetAMRBlock" );
    assert( "pre: AMR block is nullptr" && (amrBlock != nullptr) );

    // STEP 2: Load any point-data
    vtkTimerLog::MarkStartEvent( "vtkARMBaseReader::LoadPointData" );
    this->LoadPointData( blockIdx, amrBlock );
    vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::LoadPointData" );

    // STEP 3: Load any cell data
    vtkTimerLog::MarkStartEvent( "vtkAMRBaseReader::LoadCellData" );
    this->LoadCellData( blockIdx, amrBlock );
    vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::LoadCellData" );

    // STEP 4: Add dataset
    output->SetDataSet( level,metaIdx,amrBlock );
    amrBlock->FastDelete();
  } // END for all blocks
}

//------------------------------------------------------------------------------
void vtkAMRBaseReader::AssignAndLoadBlocks( vtkOverlappingAMR *output )
{
  assert( "pre: AMR data-structure is nullptr" && (output != nullptr) );

  // Initialize counter of the number of blocks at each level.
  // This counter is used to compute the block index w.r.t. the
  // hierarchical box data-structure. Note that then number of blocks
  // can change based on user constraints, e.g., the number of levels
  // visible.
  std::vector< int > idxcounter;
  idxcounter.resize(this->GetNumberOfLevels()+1, 0);

  // Find the number of blocks to be processed. BlockMap.size()
  // has all the blocks that are to be processesed and may be
  // less than or equal to this->GetNumberOfBlocks(), i.e., the
  // total number of blocks.
  int numBlocks = static_cast< int >( this->BlockMap.size() );
  for( int block=0; block < numBlocks; ++block )
  {
    int blockIndex =  this->BlockMap[ block ];
    int blockIdx = this->Metadata->GetAMRInfo()->GetAMRBlockSourceIndex(blockIndex);

    unsigned int metaLevel;
    unsigned int metaIdx;
    this->Metadata->GetAMRInfo()->ComputeIndexPair(blockIndex, metaLevel, metaIdx);
    unsigned int level    = this->GetBlockLevel( blockIdx );
    assert(level==metaLevel);

    if( this->IsBlockMine(block) )
    {
      // STEP 0: Get the AMR block
      vtkTimerLog::MarkStartEvent( "GetAMRBlock" );
      vtkUniformGrid *amrBlock = this->GetAMRBlock( blockIdx );
      vtkTimerLog::MarkEndEvent( "GetAMRBlock" );
      assert( "pre: AMR block is nullptr" && (amrBlock != nullptr) );

      // STEP 2: Load any point-data
      vtkTimerLog::MarkStartEvent( "vtkARMBaseReader::LoadPointData" );
      this->LoadPointData( blockIdx, amrBlock );
      vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::LoadPointData" );

      // STEP 3: Load any cell data
      vtkTimerLog::MarkStartEvent( "vtkAMRBaseReader::LoadCellData" );
      this->LoadCellData( blockIdx, amrBlock );
      vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::LoadCellData" );

      // STEP 4: Add dataset
      output->SetDataSet( level,metaIdx,amrBlock );
      amrBlock->Delete();
    } // END if the block belongs to this process
    else
    {
      output->SetDataSet( level, metaIdx, nullptr );
    }
  } // END for all blocks
}

//------------------------------------------------------------------------------
int vtkAMRBaseReader::RequestData(
        vtkInformation* vtkNotUsed(request),
        vtkInformationVector** vtkNotUsed(inputVector),
        vtkInformationVector* outputVector )
{
  vtkTimerLog::MarkStartEvent( "vtkAMRBaseReader::RqstData" );
  this->NumBlocksFromCache = 0;
  this->NumBlocksFromFile  = 0;

  vtkInformation    *outInf = outputVector->GetInformationObject( 0 );
  vtkOverlappingAMR *output =
    vtkOverlappingAMR::SafeDownCast(
     outInf->Get( vtkDataObject::DATA_OBJECT() ) );
  assert( "pre: output AMR dataset is nullptr" && ( output != nullptr ) );

  output->SetAMRInfo(this->Metadata->GetAMRInfo());

  // Setup the block request
  vtkTimerLog::MarkStartEvent( "vtkAMRBaseReader::SetupBlockRequest" );
  this->SetupBlockRequest( outInf );
  vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::SetupBlockRequest" );

  if( outInf->Has( vtkCompositeDataPipeline::LOAD_REQUESTED_BLOCKS() ) )
  {
    this->LoadRequestedBlocks( output );

    // Is blanking information generated when only a subset of blocks is
    // requested? Tricky question, since we need the blanking information when
    // requesting a fixed set of blocks and when when requesting one block at a
    // time in streaming fashion.
  }
  else
  {
#ifdef DEBUGME
    cout<<"load "<<this->BlockMap.size()<<" blocks"<<endl;
#endif
    this->AssignAndLoadBlocks( output );

    vtkTimerLog::MarkStartEvent( "AMR::Generate Blanking" );
    vtkParallelAMRUtilities::BlankCells(output, this->Controller);
    vtkTimerLog::MarkEndEvent( "AMR::Generate Blanking" );
  }

  // If this instance of the reader is not parallel, block until all processes
  // read their blocks.
  if( this->IsParallel() )
  {
    this->Controller->Barrier();
  }

  if(this->Metadata && this->Metadata->GetInformation()->Has(vtkDataObject::DATA_TIME_STEP()))
  {
    double dataTime = this->Metadata->GetInformation()->Get(vtkDataObject::DATA_TIME_STEP());
    output->GetInformation()->Set(vtkDataObject::DATA_TIME_STEP(),dataTime);
  }

  outInf = nullptr;
  output = nullptr;

  vtkTimerLog::MarkEndEvent( "vtkAMRBaseReader::RqstData" );

  return 1;
}