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

   Library: iMSTK

   Copyright (c) Kitware, Inc. & Center for Modeling, Simulation,
   & Imaging in Medicine, Rensselaer Polytechnic Institute.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0.txt

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

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

#pragma once

#include "imstkVTKPolyDataRenderDelegate.h"

class vtkCellArray;
class vtkDataArray;
class vtkDoubleArray;
class vtkFloatArray;
class vtkPolyData;

namespace imstk
{
class AbstractDataArray;
class SurfaceMesh;
template<typename T, int N> class VecDataArray;

///
/// \class VTKSurfaceMeshRenderDelegate
///
/// \brief Surface mesh render delegate with VTK backend
///
class VTKSurfaceMeshRenderDelegate : public VTKPolyDataRenderDelegate
{
public:
    VTKSurfaceMeshRenderDelegate(std::shared_ptr<VisualModel> visualModel);
    virtual ~VTKSurfaceMeshRenderDelegate() override = default;

    ///
    /// \brief Event handler
    ///
    void processEvents() override;

    ///
    /// \brief Initialize textures
    ///
    void initializeTextures();

// Callbacks for modifications, when an element changes the user or API must post the modified event
// to inform that this happened, if the actual buffer on the geometry is swapped then geometry
// modified would instead be called
protected:
    ///
    /// \brief Callback for when vertex values are modified
    ///
    void vertexDataModified(Event* e);
    void indexDataModified(Event* e);
    void normalDataModified(Event* e);
    void vertexScalarsModified(Event* e);
    void cellScalarsModified(Event* e);
    void textureCoordinatesModified(Event* e);

    ///
    /// \brief Callback for when geometry is modified
    ///
    void geometryModified(Event* e);

    ///
    /// \brief Callback for when RenderMaterial textures are modified
    ///
    void texturesModified(Event* e);

protected:
    void setVertexBuffer(std::shared_ptr<VecDataArray<double, 3>> vertices);
    void setNormalBuffer(std::shared_ptr<VecDataArray<double, 3>> normals);
    void setIndexBuffer(std::shared_ptr<VecDataArray<int, 3>> indices);
    void setVertexScalarBuffer(std::shared_ptr<AbstractDataArray> scalars);
    void setCellScalarBuffer(std::shared_ptr<AbstractDataArray> scalars);
    void setTextureCoordinateBuffer(std::shared_ptr<AbstractDataArray> textureCoordinates);

protected:
    std::shared_ptr<SurfaceMesh> m_geometry;
    std::shared_ptr<VecDataArray<double, 3>> m_vertices;
    std::shared_ptr<VecDataArray<double, 3>> m_normals;
    std::shared_ptr<VecDataArray<int, 3>>    m_indices;
    std::shared_ptr<AbstractDataArray>       m_vertexScalars;
    std::shared_ptr<AbstractDataArray>       m_cellScalars;
    std::shared_ptr<AbstractDataArray>       m_textureCoordinates;

    vtkSmartPointer<vtkPolyData> m_polydata;

    vtkSmartPointer<vtkDoubleArray> m_mappedVertexArray;       ///> Mapped array of vertices
    vtkSmartPointer<vtkDoubleArray> m_mappedNormalArray;       ///> Mapped array of normals
    vtkSmartPointer<vtkFloatArray>  m_mappedTangentArray;      ///> Mapped array of tangents
    vtkSmartPointer<vtkFloatArray>  m_mappedTCoordsArray;      ///> Mapped array of tcoords
    vtkSmartPointer<vtkDataArray>   m_mappedVertexScalarArray; ///> Mapped array of scalars
    vtkSmartPointer<vtkDataArray>   m_mappedCellScalarArray;   ///> Mapped array of scalars
    vtkSmartPointer<vtkCellArray>   m_cellArray;               ///> Array of cells
};
}
