// SPDX-FileCopyrightText: Copyright (c) Kitware Inc.
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkStreamingParticlesRepresentation.h"

#include "vtkAlgorithmOutput.h"
#include "vtkAppendCompositeDataLeaves.h"
#include "vtkCompositeDataIterator.h"
#include "vtkCompositeDataPipeline.h"
#include "vtkCompositePolyDataMapper.h"
#include "vtkFieldData.h"
#include "vtkGeometryRepresentation.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkMultiProcessController.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkPVGeometryFilter.h"
#include "vtkPVLODActor.h"
#include "vtkPVRenderView.h"
#include "vtkPVStreamingMacros.h"
#include "vtkPVTrivialProducer.h"
#include "vtkPolyData.h"
#include "vtkProperty.h"
#include "vtkRenderer.h"
#include "vtkStreamingParticlesPriorityQueue.h"
#include "vtkUnsignedIntArray.h"

#include <algorithm>
#include <cassert>

static char const BLOCKS_TO_PURGE_ARRAY_NAME[] = "__blocks_to_purge";

static inline void purge_blocks(
  vtkMultiBlockDataSet* data, const std::set<unsigned int>& blocksToPurge)
{
  unsigned int block_index = 0;
  unsigned int num_levels = data->GetNumberOfBlocks();
  for (unsigned int level = 0; level < num_levels; level++)
  {
    vtkMultiBlockDataSet* mb = vtkMultiBlockDataSet::SafeDownCast(data->GetBlock(level));
    assert(mb != nullptr);

    unsigned int num_blocks = mb->GetNumberOfBlocks();
    for (unsigned int cc = 0; cc < num_blocks; cc++, block_index++)
    {
      if (blocksToPurge.find(block_index) != blocksToPurge.end())
      {
        mb->SetBlock(cc, nullptr);
      }
    }
  }
}

vtkStandardNewMacro(vtkStreamingParticlesRepresentation);
//----------------------------------------------------------------------------
vtkStreamingParticlesRepresentation::vtkStreamingParticlesRepresentation()
{
  this->StreamingCapablePipeline = false;
  this->InStreamingUpdate = false;
  this->UseOutline = false;
  this->StreamingRequestSize = 1;

  this->PriorityQueue = vtkSmartPointer<vtkStreamingParticlesPriorityQueue>::New();
  this->PriorityQueue->UseBlockDetailInformationOn();
  this->Mapper = vtkSmartPointer<vtkCompositePolyDataMapper>::New();

  this->Actor = vtkSmartPointer<vtkPVLODActor>::New();
  this->Actor->SetMapper(this->Mapper);
  this->Actor->GetProperty()->SetRepresentationToPoints();
  this->Actor->GetProperty()->SetAmbient(1.0);
  this->Actor->GetProperty()->SetDiffuse(0.0);
  this->Actor->GetProperty()->SetSpecular(0.0);
  this->Actor->SetPickable(0);
}

//----------------------------------------------------------------------------
vtkStreamingParticlesRepresentation::~vtkStreamingParticlesRepresentation() = default;

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetVisibility(bool val)
{
  this->Actor->SetVisibility(val);
  this->Superclass::SetVisibility(val);
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetOpacity(double val)
{
  this->Actor->GetProperty()->SetOpacity(val);
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetUseBlockDetailInformation(bool newVal)
{
  if (newVal != this->PriorityQueue->GetUseBlockDetailInformation())
  {
    this->PriorityQueue->SetUseBlockDetailInformation(newVal);
    this->Modified();
  }
}
//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::GetUseBlockDetailInformation() const
{
  return this->PriorityQueue->GetUseBlockDetailInformation();
}
//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetProcessesCanLoadAnyBlock(bool newVal)
{
  if (newVal != this->PriorityQueue->GetAnyProcessCanLoadAnyBlock())
  {
    this->PriorityQueue->SetAnyProcessCanLoadAnyBlock(newVal);
    this->Modified();
  }
}
//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::GetProcessesCanLoadAnyBlock() const
{
  return this->PriorityQueue->GetAnyProcessCanLoadAnyBlock();
}
//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetDetailLevelToLoad(double level)
{
  if (level != this->PriorityQueue->GetDetailLevelToLoad())
  {
    this->PriorityQueue->SetDetailLevelToLoad(level);
    this->Modified();
  }
}

//----------------------------------------------------------------------------
double vtkStreamingParticlesRepresentation::GetDetailLevelToLoad()
{
  return this->PriorityQueue->GetDetailLevelToLoad();
}

//----------------------------------------------------------------------------
int vtkStreamingParticlesRepresentation::ProcessViewRequest(
  vtkInformationRequestKey* request_type, vtkInformation* inInfo, vtkInformation* outInfo)
{
  // always forward to superclass first. Superclass returns 0 if the
  // representation is not visible (among other things). In which case there's
  // nothing to do.
  if (!this->Superclass::ProcessViewRequest(request_type, inInfo, outInfo))
  {
    return 0;
  }

  if (request_type == vtkPVView::REQUEST_UPDATE())
  {
    // Standard representation stuff, first.
    // 1. Provide the data being rendered.
    vtkPVRenderView::SetPiece(inInfo, this, this->ProcessedData);
    // 2. Provide the bounds.
    double bounds[6];
    this->DataBounds.GetBounds(bounds);
    vtkPVRenderView::SetGeometryBounds(inInfo, this, bounds);

    // The only thing extra we need to do here is that we need to let the view
    // know that this representation is streaming capable (or not).
    vtkPVRenderView::SetStreamable(inInfo, this, this->GetStreamingCapablePipeline());
  }
  else if (request_type == vtkPVView::REQUEST_RENDER())
  {
    if (this->RenderedData == nullptr)
    {
      vtkStreamingStatusMacro(<< this << ": cloning delivered data.");
      vtkAlgorithmOutput* producerPort = vtkPVRenderView::GetPieceProducer(inInfo, this);
      vtkAlgorithm* producer = producerPort->GetProducer();

      this->RenderedData = producer->GetOutputDataObject(producerPort->GetIndex());
      this->Mapper->SetInputDataObject(this->RenderedData);
    }
  }
  else if (request_type == vtkPVRenderView::REQUEST_STREAMING_UPDATE())
  {
    if (this->GetStreamingCapablePipeline())
    {
      // This is a streaming update request, request next piece.
      double view_planes[24];
      inInfo->Get(vtkPVRenderView::VIEW_PLANES(), view_planes);
      if (this->StreamingUpdate(view_planes))
      {
        // since we indeed "had" a next piece to produce, give it to the view
        // so it can deliver it to the rendering nodes.
        vtkPVRenderView::SetNextStreamedPiece(inInfo, this, this->ProcessedPiece);
      }
    }
  }
  else if (request_type == vtkPVRenderView::REQUEST_PROCESS_STREAMED_PIECE())
  {
    vtkDataObject* piece = vtkPVRenderView::GetCurrentStreamedPiece(inInfo, this);
    if (piece && piece->IsA("vtkMultiBlockDataSet"))
    {
      assert(this->RenderedData != nullptr);
      vtkStreamingStatusMacro(<< this << ": received new piece.");

      vtkSmartPointer<vtkUnsignedIntArray> array = vtkUnsignedIntArray::SafeDownCast(
        piece->GetFieldData()->GetArray(BLOCKS_TO_PURGE_ARRAY_NAME));
      if (array != nullptr)
      {
        piece->GetFieldData()->RemoveArray(BLOCKS_TO_PURGE_ARRAY_NAME);
        vtkMultiBlockDataSet* data = vtkMultiBlockDataSet::SafeDownCast(this->RenderedData);
        std::set<unsigned int> blocksToPurge;
        for (int i = 0; i < array->GetNumberOfTuples(); ++i)
        {
          blocksToPurge.insert(array->GetValue(i));
        }
        purge_blocks(data, blocksToPurge);
      }

      // merge with what we are already rendering.
      vtkNew<vtkAppendCompositeDataLeaves> appender;
      appender->AddInputDataObject(piece);
      appender->AddInputDataObject(this->RenderedData);
      appender->Update();

      this->RenderedData = appender->GetOutputDataObject(0);
      this->Mapper->SetInputDataObject(this->RenderedData);
    }
  }

  return 1;
}

//----------------------------------------------------------------------------
int vtkStreamingParticlesRepresentation::RequestInformation(
  vtkInformation* rqst, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  // Determine if the input is streaming capable. A pipeline is streaming
  // capable if it provides us with COMPOSITE_DATA_META_DATA() in the
  // RequestInformation() pass. It implies that we can request arbitrary blocks
  // from the input pipeline which implies stream-ability.

  this->StreamingCapablePipeline = false;
  if (inputVector[0]->GetNumberOfInformationObjects() == 1)
  {
    vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
    if (inInfo->Has(vtkCompositeDataPipeline::COMPOSITE_DATA_META_DATA()) &&
      vtkPVView::GetEnableStreaming())
    {
      this->StreamingCapablePipeline = true;
    }
  }

  vtkStreamingStatusMacro(<< this << ": streaming capable input pipeline? "
                          << (this->StreamingCapablePipeline ? "yes" : "no"));
  return this->Superclass::RequestInformation(rqst, inputVector, outputVector);
}

//----------------------------------------------------------------------------
int vtkStreamingParticlesRepresentation::RequestUpdateExtent(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (!this->Superclass::RequestUpdateExtent(request, inputVector, outputVector))
  {
    return 0;
  }

  for (int cc = 0; cc < this->GetNumberOfInputPorts(); cc++)
  {
    for (int kk = 0; kk < inputVector[cc]->GetNumberOfInformationObjects(); kk++)
    {
      vtkInformation* info = inputVector[cc]->GetInformationObject(kk);
      if (this->InStreamingUpdate)
      {
        assert(this->StreamingRequestSize > 0);
        assert(this->StreamingRequest.size() > 0);

        // Request the next "group of blocks" to stream.
        info->Set(vtkCompositeDataPipeline::LOAD_REQUESTED_BLOCKS(), 1);
        info->Set(vtkCompositeDataPipeline::UPDATE_COMPOSITE_INDICES(), &this->StreamingRequest[0],
          static_cast<int>(this->StreamingRequest.size()));
      }
      else
      {
        // let the source deliver whatever is the default. What the reader does
        // when the downstream doesn't request any particular blocks in poorly
        // defined right now. I am assuming the reader will only read the root
        // block or down to some user-specified level.
        info->Remove(vtkCompositeDataPipeline::LOAD_REQUESTED_BLOCKS());
        info->Remove(vtkCompositeDataPipeline::UPDATE_COMPOSITE_INDICES());
      }
    }
  }
  return 1;
}

//----------------------------------------------------------------------------
int vtkStreamingParticlesRepresentation::RequestData(
  vtkInformation* rqst, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (inputVector[0]->GetNumberOfInformationObjects() == 1)
  {
    vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
    if (inInfo->Has(vtkCompositeDataPipeline::COMPOSITE_DATA_META_DATA()) &&
      this->GetStreamingCapablePipeline() && !this->GetInStreamingUpdate())
    {
      // Since the representation reexecuted, it means that the input changed
      // and we should initialize our streaming.
      vtkMultiBlockDataSet* metadata = vtkMultiBlockDataSet::SafeDownCast(
        inInfo->Get(vtkCompositeDataPipeline::COMPOSITE_DATA_META_DATA()));
      this->PriorityQueue->Initialize(metadata);
    }
  }

  this->ProcessedPiece = nullptr;
  if (inputVector[0]->GetNumberOfInformationObjects() == 1)
  {
    // Do the streaming independent "transformation" of the data here, in our
    // case, generate the polydata from the input.

    // Streaming and "flip-book" caching don't make much sense together. Hence
    // we don't complicate the logic with adding support for caching for
    // animation playback.

    vtkNew<vtkPVGeometryFilter> geomFilter;
    geomFilter->SetUseOutline(this->UseOutline ? 1 : 0);
    geomFilter->SetController(nullptr);

    vtkDataObject* input = vtkDataObject::GetData(inputVector[0], 0);
    geomFilter->SetInputData(input);
    geomFilter->Update();
    if (!this->GetInStreamingUpdate())
    {
      vtkDataObject* output = geomFilter->GetOutputDataObject(0);
      if (!output->IsA("vtkMultiBlockDataSet"))
      {
        vtkNew<vtkMultiBlockDataSet> mb;
        mb->SetBlock(0, output);
        this->ProcessedData = mb.GetPointer();
      }
      else
      {
        this->ProcessedData = vtkMultiBlockDataSet::SafeDownCast(output);
      }
      assert(this->ProcessedData.GetPointer());

      // Collect data bounds.
      this->DataBounds.Reset();
      vtkCompositeDataIterator* iter = this->ProcessedData->NewIterator();
      for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
      {
        vtkDataSet* ds = vtkDataSet::SafeDownCast(iter->GetCurrentDataObject());
        if (ds)
        {
          this->DataBounds.AddBounds(ds->GetBounds());
        }
      }
      iter->Delete();
    }
    else
    {
      this->ProcessedPiece = geomFilter->GetOutputDataObject(0);
    }
  }
  else
  {
    // create an empty dataset. This is needed so that view knows what dataset
    // to expect from the other processes on this node.
    this->ProcessedData = vtkSmartPointer<vtkMultiBlockDataSet>::New();
    this->DataBounds.Reset();
  }

  if (!this->GetInStreamingUpdate())
  {
    this->RenderedData = nullptr;

    // provide the mapper with an empty input. This is needed only because
    // mappers die when input is nullptr, currently.
    vtkNew<vtkMultiBlockDataSet> tmp;
    this->Mapper->SetInputDataObject(tmp.GetPointer());
  }

  return this->Superclass::RequestData(rqst, inputVector, outputVector);
}

//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::StreamingUpdate(const double view_planes[24])
{
  assert(this->InStreamingUpdate == false);

  // update the priority queue, if needed.
  this->PriorityQueue->Update(view_planes);

  // FIXME: This will not work in client-server mode.
  // For this demo, we'll just use the local data object.
  if (this->RenderedData && !this->PriorityQueue->GetBlocksToPurge().empty())
  {
    // purge blocks that no longer have sufficient coverage in the new
    // view-frustum.
    const std::set<unsigned int>& blocksToPurge = this->PriorityQueue->GetBlocksToPurge();

    vtkMultiBlockDataSet* data = vtkMultiBlockDataSet::SafeDownCast(this->RenderedData);

    purge_blocks(data, blocksToPurge);

    this->RenderedData->Modified();
    if (this->PriorityQueue->IsEmpty())
    {
      vtkNew<vtkMultiBlockDataSet> clone;
      clone->CopyStructure(vtkMultiBlockDataSet::SafeDownCast(this->ProcessedPiece));
      this->ProcessedPiece = clone.GetPointer();
      return true;
    }
  }

  const std::set<unsigned int>& toPurge = this->PriorityQueue->GetBlocksToPurge();
  vtkSmartPointer<vtkUnsignedIntArray> localPurgeArray =
    vtkSmartPointer<vtkUnsignedIntArray>::New();
  localPurgeArray->SetNumberOfTuples(toPurge.size());
  int i = 0;
  for (std::set<unsigned int>::const_iterator itr = toPurge.begin(); itr != toPurge.end();
       ++itr, ++i)
  {
    localPurgeArray->SetValue(i, *itr);
  }
  vtkMultiProcessController* controller = vtkMultiProcessController::GetGlobalController();
  vtkSmartPointer<vtkUnsignedIntArray> globalPurgeArray =
    vtkSmartPointer<vtkUnsignedIntArray>::New();
  controller->GatherV(localPurgeArray, globalPurgeArray, 0);
  globalPurgeArray->SetName(BLOCKS_TO_PURGE_ARRAY_NAME);

  int needsToStream = !this->PriorityQueue->IsEmpty();
  int allNeedToStream;
  controller->AllReduce(&needsToStream, &allNeedToStream, 1, vtkCommunicator::LOGICAL_OR_OP);
  // If this process doesn't need to fetch another block, return without executing the pipeline
  // The return value should be true if ANY process needs to fetch another block
  if (!needsToStream)
  {
    if (controller->GetLocalProcessId() == 0 && globalPurgeArray->GetNumberOfTuples() > 0)
    {
      this->ProcessedPiece->GetFieldData()->AddArray(globalPurgeArray);
    }
    return (allNeedToStream == 0) ? false : true;
  }

  // determine if we need to stream any blocks.
  if (!this->DetermineBlocksToStream())
  {
    // nothing to stream at the moment.
    return false;
  }

  // We've determined we need to request something. Do it.
  this->InStreamingUpdate = true;
  vtkStreamingStatusMacro(<< this << ": doing streaming-update.");

  // This ensure that the representation re-executes.
  this->MarkModified();

  // Execute the pipeline.
  this->Update();

  if (controller->GetLocalProcessId() == 0 && globalPurgeArray->GetNumberOfTuples() > 0)
  {
    this->ProcessedPiece->GetFieldData()->AddArray(globalPurgeArray);
  }

  this->InStreamingUpdate = false;
  return true;
}

//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::DetermineBlocksToStream()
{
  assert(this->PriorityQueue->IsEmpty() == false);
  assert(this->StreamingRequestSize > 0);
  this->StreamingRequest.clear();

  for (int jj = 0; jj < this->StreamingRequestSize; jj++)
  {
    unsigned int cid = this->PriorityQueue->Pop();
    if (cid != VTK_UNSIGNED_INT_MAX)
    {
      vtkStreamingStatusMacro(<< this << ": requesting blocks: " << cid);
      this->StreamingRequest.push_back(static_cast<int>(cid));
    }
  }
  return !this->StreamingRequest.empty();
}

//----------------------------------------------------------------------------
int vtkStreamingParticlesRepresentation::FillInputPortInformation(
  int vtkNotUsed(port), vtkInformation* info)
{
  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkCompositeDataSet");
  info->Append(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkDataSet");

  // Saying INPUT_IS_OPTIONAL() is essential, since representations don't have
  // any inputs on client-side (in client-server, client-render-server mode) and
  // render-server-side (in client-render-server mode).
  info->Set(vtkAlgorithm::INPUT_IS_OPTIONAL(), 1);

  return 1;
}

//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::AddToView(vtkView* view)
{
  vtkPVRenderView* rview = vtkPVRenderView::SafeDownCast(view);
  if (rview)
  {
    rview->GetRenderer()->AddActor(this->Actor);
    return this->Superclass::AddToView(view);
  }
  return false;
}

//----------------------------------------------------------------------------
bool vtkStreamingParticlesRepresentation::RemoveFromView(vtkView* view)
{
  vtkPVRenderView* rview = vtkPVRenderView::SafeDownCast(view);
  if (rview)
  {
    rview->GetRenderer()->RemoveActor(this->Actor);
    return this->Superclass::RemoveFromView(view);
  }
  return false;
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "StreamingCapablePipeline: " << this->StreamingCapablePipeline << endl;
  os << indent << "UseOutline: " << this->UseOutline << endl;
  os << indent << "StreamingRequestSize: " << this->StreamingRequestSize << endl;
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetInputArrayToProcess(
  int idx, int port, int connection, int fieldAssociation, const char* name)
{
  this->Superclass::SetInputArrayToProcess(idx, port, connection, fieldAssociation, name);

  if (name && name[0])
  {
    this->Mapper->SetScalarVisibility(1);
    this->Mapper->SelectColorArray(name);
    this->Mapper->SetUseLookupTableScalarRange(1);
  }
  else
  {
    this->Mapper->SetScalarVisibility(0);
    this->Mapper->SelectColorArray(static_cast<const char*>(nullptr));
  }

  switch (fieldAssociation)
  {
    case vtkDataObject::FIELD_ASSOCIATION_CELLS:
      this->Mapper->SetScalarMode(VTK_SCALAR_MODE_USE_CELL_FIELD_DATA);
      break;

    case vtkDataObject::FIELD_ASSOCIATION_POINTS:
    default:
      this->Mapper->SetScalarMode(VTK_SCALAR_MODE_USE_POINT_FIELD_DATA);
      break;
  }
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetLookupTable(vtkScalarsToColors* lut)
{
  this->Mapper->SetLookupTable(lut);
}

//----------------------------------------------------------------------------
void vtkStreamingParticlesRepresentation::SetPointSize(double val)
{
  this->Actor->GetProperty()->SetPointSize(val);
}
