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

  Program:   Visualization Toolkit

  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 "vtkOpenVROverlay.h"

#include "vtkCallbackCommand.h"
#include "vtkDataArray.h"
#include "vtkImageData.h"
#include "vtkInteractorStyle3D.h"
#include "vtkJPEGReader.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkOpenVRCamera.h"
#include "vtkOpenVRRenderWindow.h"
#include "vtkOpenVRRenderWindowInteractor.h"
#include "vtkPointData.h"
#include "vtkRenderer.h"
#include "vtkRendererCollection.h"
#include "vtkTextureObject.h"
#include "vtkXMLDataElement.h"
#include "vtkXMLUtilities.h"
#include "vtksys/SystemTools.hxx"

#include "vtkOpenVROverlayInternal.h"

#include <cmath>

vtkStandardNewMacro(vtkOpenVROverlay);

vtkOpenVROverlay::vtkOpenVROverlay()
{
  this->OverlayHandle = 0;
  this->OverlayThumbnailHandle = 0;
  this->OriginalTextureData = nullptr;
  this->CurrentTextureData = nullptr;
  this->LastSpot = nullptr;
  this->SessionName = "";
  this->SavedCameraPoses.resize(10);
  this->VRSystem = nullptr;
  this->DashboardImageFileName = "OpenVRDashboard.jpg";
  this->LastCameraPoseIndex = -1;
  this->LastSpotIntensity = 0.3;
  this->ActiveSpotIntensity = 0.3;
}

vtkOpenVROverlay::~vtkOpenVROverlay()
{
  if (this->OriginalTextureData)
  {
    delete [] this->OriginalTextureData;
    this->OriginalTextureData = 0;
  }
  if (this->CurrentTextureData)
  {
    delete [] this->CurrentTextureData;
    this->CurrentTextureData = 0;
  }
}

vtkOpenVRCameraPose *vtkOpenVROverlay::GetSavedCameraPose(size_t i)
{
  if (i < this->SavedCameraPoses.size())
  {
    return &(this->SavedCameraPoses[i]);
  }
  return nullptr;
}

void vtkOpenVROverlay::WriteCameraPoses(ostream& os)
{
  vtkNew<vtkXMLDataElement> topel;
  topel->SetName("CameraPoses");
  for (size_t i = 0; i < this->SavedCameraPoses.size(); ++i)
  {
    vtkOpenVRCameraPose &pose = this->SavedCameraPoses[i];
    if (pose.Loaded)
    {
      vtkNew<vtkXMLDataElement> el;
      el->SetName("CameraPose");
      el->SetIntAttribute("PoseNumber", static_cast<int>(i + 1));
      el->SetVectorAttribute("Position", 3, pose.Position);
      el->SetDoubleAttribute("Distance", pose.Distance);
      el->SetDoubleAttribute("MotionFactor", pose.MotionFactor);
      el->SetVectorAttribute("Translation", 3, pose.Translation);
      el->SetVectorAttribute("InitialViewUp", 3, pose.PhysicalViewUp);
      el->SetVectorAttribute("InitialViewDirection", 3, pose.PhysicalViewDirection);
      el->SetVectorAttribute("ViewDirection", 3, pose.ViewDirection);
      topel->AddNestedElement(el);
    }
  }

  vtkXMLUtilities::FlattenElement(topel, os);
}

void vtkOpenVROverlay::WriteCameraPoses()
{
  std::string fname = this->GetSessionName();
  fname += "VTKOpenVRCameraPoses.vovrcp";
  ofstream os(fname, ios::out);
  this->WriteCameraPoses(os);

  os.flush();
  if (os.fail())
  {
    os.close();
    unlink(fname.c_str());
  }
}

void vtkOpenVROverlay::ReadCameraPoses()
{
  std::string fname = this->GetSessionName();
  fname += "VTKOpenVRCameraPoses.vovrcp";

  if (!vtksys::SystemTools::FileExists(fname.c_str()))
  {
    return;
  }

  ifstream is(fname);
  this->ReadCameraPoses(is);
}

void vtkOpenVROverlay::ReadCameraPoses(istream &is)
{
  vtkXMLDataElement *topel =
    vtkXMLUtilities::ReadElementFromStream(is);

  if (topel)
  {
    int numPoses = topel->GetNumberOfNestedElements();
    this->SavedCameraPoses.resize(numPoses > 10 ? numPoses : 10);
    for (size_t i = 0; i < numPoses; i++)
    {
      vtkXMLDataElement *el = topel->GetNestedElement(static_cast<int>(i));
      int poseNum = 0;
      el->GetScalarAttribute("PoseNumber", poseNum);
      poseNum--;  // zero indexed
      el->GetVectorAttribute("Position", 3,
        this->SavedCameraPoses[poseNum].Position);
      el->GetVectorAttribute("InitialViewUp", 3,
        this->SavedCameraPoses[poseNum].PhysicalViewUp);
      el->GetVectorAttribute("InitialViewDirection", 3,
        this->SavedCameraPoses[poseNum].PhysicalViewDirection);
      el->GetVectorAttribute("ViewDirection", 3,
        this->SavedCameraPoses[poseNum].ViewDirection);
      el->GetVectorAttribute("Translation", 3,
        this->SavedCameraPoses[poseNum].Translation);
      el->GetScalarAttribute("Distance",
        this->SavedCameraPoses[poseNum].Distance);
      el->GetScalarAttribute("MotionFactor",
        this->SavedCameraPoses[poseNum].MotionFactor);
      this->SavedCameraPoses[poseNum].Loaded = true;
    }
    topel->Delete();
  }
}

void vtkOpenVROverlay::SaveCameraPose(int slot)
{
  vtkOpenVRCameraPose *pose = this->GetSavedCameraPose(slot);
  vtkRenderer *ren = static_cast<vtkRenderer *>(
    this->Window->GetRenderers()->GetItemAsObject(0));
  pose->Set(static_cast<vtkOpenVRCamera *>(ren->GetActiveCamera()), this->Window);
  // this->WriteCameraPoses();
}

void vtkOpenVROverlay::LoadCameraPose(int slot)
{
  this->LastCameraPoseIndex = slot;
  vtkOpenVRCameraPose *pose = this->GetSavedCameraPose(slot);
  if (pose && pose->Loaded)
  {
    vtkRenderer *ren = static_cast<vtkRenderer *>(
      this->Window->GetRenderers()->GetItemAsObject(0));
    pose->Apply(static_cast<vtkOpenVRCamera *>(ren->GetActiveCamera()), this->Window);
    ren->ResetCameraClippingRange();
  }
}

void vtkOpenVROverlay::LoadNextCameraPose()
{
  if (this->SavedCameraPoses.size() == 0)
  {
    return;
  }

  int newPose = (this->LastCameraPoseIndex + 1) % this->SavedCameraPoses.size();
  int count = 0;
  while (!this->SavedCameraPoses[newPose].Loaded && count < this->SavedCameraPoses.size())
  {
    newPose = (newPose + 1) % this->SavedCameraPoses.size();
    count++;
  }
  this->LoadCameraPose(newPose);
}

void vtkOpenVROverlay::Show()
{
  vr::VROverlay()->ShowOverlay(this->OverlayHandle);
  this->Render();
}

void vtkOpenVROverlay::Hide()
{
  vr::VROverlay()->HideOverlay(this->OverlayHandle);
}

void vtkOpenVROverlay::Create(vtkOpenVRRenderWindow *win)
{
  if( !vr::VROverlay() )
  {
    vtkErrorMacro("Error creating overlay");
    return;
  }

  if (this->OverlayHandle)
  {
    return;
  }

  this->Window = win;

  this->ReadCameraPoses();

  std::string sKey = std::string( "VTK OpenVR Settings");
  vr::VROverlayError overlayError =
    vr::VROverlay()->CreateDashboardOverlay(
      sKey.c_str(), "VTK",
      &this->OverlayHandle, &this->OverlayThumbnailHandle );
  if (overlayError != vr::VROverlayError_None)
  {
    vtkErrorMacro("Error creating overlay");
    return;
  }

  vr::VROverlay()->SetOverlayFlag(this->OverlayHandle, vr::VROverlayFlags_SortWithNonSceneOverlays, true);
  vr::VROverlay()->SetOverlayFlag(this->OverlayHandle, vr::VROverlayFlags_VisibleInDashboard, true);
  vr::VROverlay()->SetOverlayWidthInMeters( this->OverlayHandle, 2.5f );
  vr::VROverlay()->SetOverlayInputMethod( this->OverlayHandle, vr::VROverlayInputMethod_Mouse );

  win->MakeCurrent();

  this->OverlayTexture->SetContext(win);

  // delete any old texture data
  if (this->OriginalTextureData)
  {
    delete [] this->OriginalTextureData;
    this->OriginalTextureData = 0;
  }

  // if dashboard image exists use it
  vtkNew<vtkJPEGReader> imgReader;
  if (imgReader->CanReadFile(this->DashboardImageFileName.c_str()))
  {
    imgReader->SetFileName(this->DashboardImageFileName.c_str());
    imgReader->Update();
    vtkImageData *id = imgReader->GetOutput();
    int dims[3];
    id->GetDimensions(dims);
    int numC = id->GetPointData()->GetScalars()->GetNumberOfComponents();

    this->OriginalTextureData = new unsigned char[dims[0]*dims[1]*4];
    this->CurrentTextureData = new unsigned char[dims[0]*dims[1]*4];
    unsigned char *dataPtr = this->OriginalTextureData;
    unsigned char *inPtr = static_cast<unsigned char *>(
      id->GetPointData()->GetScalars()->GetVoidPointer(0));
    for (int j = 0; j < dims[1]; j++)
    {
      for (int i = 0; i < dims[0]; i++)
      {
        *(dataPtr++) = *(inPtr++);
        *(dataPtr++) = *(inPtr++);
        *(dataPtr++) = *(inPtr++);
        *(dataPtr++) = (numC == 4 ? *(inPtr++) : 255.0);
      }
    }
    memcpy(this->CurrentTextureData, this->OriginalTextureData, dims[0]*dims[1]*4);
    this->OverlayTexture->Create2DFromRaw(
      dims[0], dims[1],
      4,  VTK_UNSIGNED_CHAR,
      const_cast<void *>(static_cast<const void *const>(
        this->OriginalTextureData)));

    this->SetupSpots();
  }

  int width = this->OverlayTexture->GetWidth();
  int height = this->OverlayTexture->GetHeight();
  vr::HmdVector2_t vecWindowSize =
  {
    static_cast<float>(width),
    static_cast<float>(height)
  };
  vr::VROverlay()->SetOverlayMouseScale( this->OverlayHandle, &vecWindowSize );
}

void vtkOpenVROverlay::Render()
{
  // skip rendering if the overlay isn't visible
  if( !vr::VROverlay() ||
      ( !vr::VROverlay()->IsOverlayVisible( this->OverlayHandle ) &&
        !vr::VROverlay()->IsOverlayVisible( this->OverlayThumbnailHandle ) ) )
  {
    return;
  }

  this->Window->MakeCurrent();
  int dims[2];
  dims[0] = this->OverlayTexture->GetWidth();
  dims[1] = this->OverlayTexture->GetHeight();
  this->OverlayTexture->Create2DFromRaw(
    dims[0], dims[1],
    4,  VTK_UNSIGNED_CHAR,
    const_cast<void *>(static_cast<const void *const>(this->CurrentTextureData)));
  this->OverlayTexture->Bind();
  GLuint unTexture = this->OverlayTexture->GetHandle();
  if( unTexture != 0 )
  {
    vr::Texture_t texture = {(void*)(uintptr_t)unTexture, vr::TextureType_OpenGL, vr::ColorSpace_Auto };
    vr::VROverlay()->SetOverlayTexture( this->OverlayHandle, &texture );
  }
}

void vtkOpenVROverlay::MouseMoved(int x, int y)
{
  // did we leave the last active spot
  bool leftSpot = false;
  if (this->LastSpot && (
    x < this->LastSpot->xmin ||
    x > this->LastSpot->xmax ||
    y < this->LastSpot->ymin ||
    y > this->LastSpot->ymax))
  {
    leftSpot = true;
    vtkOpenVROverlaySpot *spot = this->LastSpot;
    this->LastSpot = nullptr;
    this->UpdateSpot(spot);
  }

  // if we are in a spot already and did not leave
  // just return
  if (this->LastSpot)
  {
    return;
  }

  // did we enter a new spot?
  bool enteredSpot = false;

  std::vector<vtkOpenVROverlaySpot>::iterator it = this->Spots.begin();
  for (; !enteredSpot && it != this->Spots.end(); ++it)
  {
    if (
      x >= it->xmin &&
      x <= it->xmax &&
      y >= it->ymin &&
      y <= it->ymax)
    {
      // if we are not already in this spot
      if (this->LastSpot != &(*it))
      {
        this->LastSpot = &(*it);
        enteredSpot = true;
        this->UpdateSpot(this->LastSpot);
      }
    }
  }

  if (!leftSpot && !enteredSpot)
  {
    return;
  }

  this->Render();
}

void vtkOpenVROverlay::UpdateSpot(vtkOpenVROverlaySpot *spot)
{
  int dims[2];
  dims[0] = this->OverlayTexture->GetWidth();
  dims[1] = this->OverlayTexture->GetHeight();
  unsigned char *currPtr = this->CurrentTextureData;
  unsigned char *origPtr = this->OriginalTextureData;

  float shift = 0.0;
  float scale = 1.0;
  if (spot->Active)
  {
    shift = this->ActiveSpotIntensity*255.0;
    scale = 1.0 - this->ActiveSpotIntensity;
  }
  if (spot == this->LastSpot)
  {
    shift = this->LastSpotIntensity*255.0;
    scale = 1.0 - this->LastSpotIntensity;
  }

  for (int j = spot->ymin; j <= spot->ymax; j++)
  {
    unsigned char *dataPtr = currPtr + (j*dims[0] + spot->xmin)*4;
    unsigned char *inPtr = origPtr + (j*dims[0] + spot->xmin)*4;
    for (int i = spot->xmin; i <= spot->xmax; i++)
    {
      *(dataPtr++) =  static_cast<unsigned char>(scale * *(inPtr++) + shift);
      *(dataPtr++) =  static_cast<unsigned char>(scale * *(inPtr++) + shift);
      *(dataPtr++) =  static_cast<unsigned char>(scale * *(inPtr++) + shift);
      dataPtr++;
      inPtr++;
    }
  }
}

void vtkOpenVROverlay::MouseButtonPress(int x, int y)
{
  this->MouseMoved(x, y);
  if (this->LastSpot && this->LastSpot->Callback)
  {
    this->LastSpot->Callback->Execute(this, vtkCommand::LeftButtonPressEvent,this->Window);
  }
}

void vtkOpenVROverlay::MouseButtonRelease(int, int)
{
  if (this->LastSpot && this->LastSpot->Callback)
  {
    this->LastSpot->Callback->Execute(this, vtkCommand::LeftButtonReleaseEvent,this->Window);
  }
}

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