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

#include "vtkCamera.h"
#include "vtkDisplayConfiguration.h"
#include "vtkMath.h"
#include "vtkMultiProcessController.h"
#include "vtkObjectFactory.h"
#include "vtkPerspectiveTransform.h"
#include "vtkProcessModule.h"
#include "vtkRemotingCoreConfiguration.h"
#include "vtkRenderer.h"
#include "vtkTimerLog.h"
#include "vtkTransform.h"
#include "vtkUnsignedCharArray.h"

#include <cassert>
#include <cmath>
#include <vtksys/SystemTools.hxx>

vtkStandardNewMacro(vtkCaveSynchronizedRenderers);
//----------------------------------------------------------------------------
vtkCaveSynchronizedRenderers::vtkCaveSynchronizedRenderers()
{
  this->NumberOfDisplays = 0;
  this->Displays = nullptr;
  this->SetNumberOfDisplays(1);
  this->SetEyeSeparation(0.065);
  this->DisplayOrigin[0] = -0.5;
  this->DisplayOrigin[1] = -0.5;
  this->DisplayOrigin[2] = -0.5;
  this->DisplayX[0] = 0.5;
  this->DisplayX[1] = -0.5;
  this->DisplayX[2] = -0.5;
  this->DisplayY[0] = 0.5;
  this->DisplayY[1] = 0.5;
  this->DisplayY[2] = -0.5;

  once = 1;
  this->SetParallelController(vtkMultiProcessController::GetGlobalController());

  // Initialize using pvx file specified on the command line options.
  auto config = vtkRemotingCoreConfiguration::GetInstance();
  auto displayConfig = vtkRemotingCoreConfiguration::GetInstance()->GetDisplayConfiguration();
  if (!displayConfig)
  {
    vtkErrorMacro("Are you sure vtkCaveSynchronizedRenderers is created on "
                  "an appropriate processes?");
  }
  else
  {
    this->SetNumberOfDisplays(displayConfig->GetNumberOfDisplays());
    const auto rank = this->ParallelController ? this->ParallelController->GetLocalProcessId() : -1;
    if (rank >= 0 && rank < this->NumberOfDisplays)
    {
      if (auto env = displayConfig->GetEnvironment(rank))
      {
        // PutEnv() avoids memory leak.
        vtksys::SystemTools::PutEnv(env);
      }
      if (displayConfig->GetHasCorners(rank))
      {
        this->DefineDisplay(rank, displayConfig->GetLowerLeft(rank).GetData(),
          displayConfig->GetLowerRight(rank).GetData(),
          displayConfig->GetUpperRight(rank).GetData());
      }
    }
    this->SetEyeSeparation(config->GetEyeSeparation());
  }
}

//----------------------------------------------------------------------------
vtkCaveSynchronizedRenderers::~vtkCaveSynchronizedRenderers()
{
  this->SetNumberOfDisplays(0);
}

//----------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::HandleStartRender()
{
  this->ImageReductionFactor = 1;
  this->Superclass::HandleStartRender();
  this->ComputeCamera(this->GetRenderer()->GetActiveCamera());
  this->GetRenderer()->ResetCameraClippingRange();
}

//-----------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::SetEyeSeparation(double eyeSeparation)
{
  this->EyeSeparation = eyeSeparation;
}
//-----------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::SetNumberOfDisplays(int numberOfDisplays)
{
  if (numberOfDisplays == this->NumberOfDisplays)
  {
    return;
  }
  double** newDisplays = nullptr;
  if (numberOfDisplays > 0)
  {
    newDisplays = new double*[numberOfDisplays];
    for (int i = 0; i < numberOfDisplays; ++i)
    {
      newDisplays[i] = new double[12];
      if (i < this->NumberOfDisplays)
      {

        memcpy(newDisplays[i], this->Displays[i], 12 * sizeof(double));
      }
      else
      {
        newDisplays[i][0] = -0.5;
        newDisplays[i][1] = -0.5;
        newDisplays[i][2] = -0.5;
        newDisplays[i][3] = 1.0;

        newDisplays[i][4] = 0.5;
        newDisplays[i][5] = -0.5;
        newDisplays[i][6] = -0.5;
        newDisplays[i][7] = 1.0;

        newDisplays[i][8] = 0.5;
        newDisplays[i][9] = 0.5;
        newDisplays[i][10] = -0.5;
        newDisplays[i][11] = 1.0;
      }
    }
  }
  for (int i = 0; i < this->NumberOfDisplays; ++i)
  {
    delete[] this->Displays[i];
  }
  delete[] this->Displays;
  this->Displays = newDisplays;

  this->NumberOfDisplays = numberOfDisplays;
  this->Modified();
}

//-------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::DefineDisplay(
  int idx, double origin[3], double x[3], double y[3])
{
  if (idx >= this->NumberOfDisplays)
  {
    vtkErrorMacro("idx is too high !");
    return;
  }
  memcpy(&this->Displays[idx][0], origin, 3 * sizeof(double));
  memcpy(&this->Displays[idx][4], x, 3 * sizeof(double));
  memcpy(&this->Displays[idx][8], y, 3 * sizeof(double));
  if (idx == this->GetParallelController()->GetLocalProcessId())
  {
    memcpy(this->DisplayOrigin, origin, 3 * sizeof(double));
    memcpy(this->DisplayX, x, 3 * sizeof(double));
    memcpy(this->DisplayY, y, 3 * sizeof(double));
  }
  this->Modified();
}

//-------------------------------------------------------------------------
// Room camera is a camera in room coordinates that points at the display.
// Client camera is the camera on the client.  The out camera is the
// combination of the two used for the final cave display.
// It is the room camera transformed by the world camera.
void vtkCaveSynchronizedRenderers::ComputeCamera(vtkCamera* camera)
{
  if (once)
  {
    double eyePosition[3] = { 0.0, 0.0, 0.5 };
    camera->SetScreenBottomLeft(this->DisplayOrigin);
    camera->SetScreenBottomRight(this->DisplayX);
    camera->SetScreenTopRight(this->DisplayY);
    camera->SetUseOffAxisProjection(true);
    camera->SetEyePosition(eyePosition);
    camera->SetEyeSeparation(this->EyeSeparation);

    // cam->SetHeadTracked( true );
    // cam->SetScreenConfig( this->DisplayOrigin,
    //                       this->DisplayX,
    //                       this->DisplayY ,0.065, 1.0);
    once = 0;
  }
}

//----------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "NumberOfDisplays: " << this->NumberOfDisplays << endl;
  vtkIndent rankIndent = indent.GetNextIndent();
  for (int i = 0; i < this->NumberOfDisplays; ++i)
  {
    os << rankIndent;
    for (int j = 0; j < 12; ++j)
    {
      os << this->Displays[i][j] << " ";
    }
    os << endl;
  }
  os << indent << "Origin: " << this->DisplayOrigin[0] << " " << this->DisplayOrigin[1] << " "
     << this->DisplayOrigin[2] << endl;
  os << indent << "X: " << this->DisplayX[0] << " " << this->DisplayX[1] << " " << this->DisplayX[2]
     << endl;
  os << indent << "Y: " << this->DisplayY[0] << " " << this->DisplayY[1] << " " << this->DisplayY[2]
     << endl;
}

//----------------------------------------------------------------------------
void vtkCaveSynchronizedRenderers::SetRenderer(vtkRenderer* renderer)
{
  this->Superclass::SetRenderer(renderer);
  if (this->NumberOfDisplays != 1)
  {
    return;
  }

  auto displayConfig = vtkRemotingCoreConfiguration::GetInstance()->GetDisplayConfiguration();
  if (displayConfig->GetNumberOfDisplays() != 1)
  {
    return;
  }

  const auto geometry = displayConfig->GetGeometry(0);
  if (!displayConfig->GetHasCorners(0) && geometry[2] != 0)
  {
    vtkCamera* camera = this->GetRenderer() ? this->GetRenderer()->GetActiveCamera() : nullptr;
    double angle = camera ? camera->GetViewAngle() / 2. : 15.;
    double ratio = static_cast<double>(geometry[3]) / geometry[2];
    double z = ratio / tan(vtkMath::RadiansFromDegrees(angle));
    double lowerLeft[3] = { 1., ratio, z };
    double lowerRight[3] = { -1., ratio, z };
    double upperRight[3] = { -1., -ratio, z };
    this->DefineDisplay(0, lowerLeft, lowerRight, upperRight);
  }
}
