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#pragma once
#ifndef QT3DS_RENDER_BACKEND_SHADER_PROGRAM_GL_H
#define QT3DS_RENDER_BACKEND_SHADER_PROGRAM_GL_H

#include "foundation/Qt3DSFoundation.h"
#include "foundation/Utils.h"
#include "render/Qt3DSRenderBaseTypes.h"

namespace qt3ds {
namespace render {

    struct NVRenderBackendShaderInputEntryGL
    {
        CRegisteredString m_AttribName; ///< must be the same name as used in the vertex shader
        QT3DSU32 m_AttribLocation; ///< attribute index
        QT3DSU32 m_Type; ///< GL vertex format type @sa GL_FLOAT, GL_INT
        QT3DSU32 m_NumComponents; ///< component count. max 4
    };

    ///< this class handles the shader input variables
    class NVRenderBackendShaderInputGL
    {
    public:
        ///< constructor
        NVRenderBackendShaderInputGL(NVDataRef<NVRenderBackendShaderInputEntryGL> entries)
            : m_ShaderInputEntries(entries)
        {
        }
        ///< destructor
        ~NVRenderBackendShaderInputGL(){}

        NVRenderBackendShaderInputEntryGL *getEntryByName(CRegisteredString entryName) const
        {
            QT3DS_FOREACH(idx, m_ShaderInputEntries.size())
            {
                if (m_ShaderInputEntries[idx].m_AttribName == entryName)
                    return &m_ShaderInputEntries.mData[idx];
            }
            return NULL;
        }

        Option<NVRenderBackendShaderInputEntryGL>
        getEntryByAttribLocation(QT3DSU32 attribLocation) const
        {
            QT3DS_FOREACH(idx, m_ShaderInputEntries.size())
            {
                if (m_ShaderInputEntries[idx].m_AttribLocation == attribLocation)
                    return m_ShaderInputEntries[idx];
            }
            return Empty();
        }

        NVDataRef<NVRenderBackendShaderInputEntryGL> m_ShaderInputEntries; ///< shader input entries
    };

    ///< this class represents the internals of a GL program
    class NVRenderBackendShaderProgramGL
    {
    public:
        ///< constructor
        NVRenderBackendShaderProgramGL(QT3DSU32 programID)
            : m_ProgramID(programID)
            , m_shaderInput(NULL)
        {
        }

        ///< destructor
        ~NVRenderBackendShaderProgramGL(){}

        QT3DSU32 m_ProgramID; ///< this is the OpenGL object ID
        NVRenderBackendShaderInputGL *m_shaderInput; ///< pointer to shader input object
    };
}
}

#endif