#pragma once
#ifndef _NB_DRAW
#define _NB_DRAW

#include <GLLoad.h>

#include <exception>
#include <map>
#include <string>
#include <vector>

#include "Buffers.h"
#include "Shader.h"
#include "VAOManager.hpp"

#define THROW_DRAW_ERROR(msg) throw DrawError(msg, __FILE__, __LINE__);

namespace NB{

class DrawError : public std::runtime_error {
public:
    DrawError(const std::string&, const std::string& file="", int line=-1);
};

uint8_t VerticesFromPrimitives(GLenum, unsigned int num_prims=1);

uint8_t PrimitivesFromVertices(GLenum, unsigned int);

void copyVertexAttribute(const VertexAttribute&, VertexAttribute&);

class DrawBuffer {
public:
typedef std::shared_ptr<Buffer> BufferManagerPointer;
    DrawBuffer(VertexAttributeList, GLenum prim_type=GL_TRIANGLES);
    //DrawBuffer(std::initializer_list<VertexAttribute>, std::initializer_list<VertexAttributePointer>);

    unsigned int vertSize() const;
    const std::shared_ptr<ShaderProgram> shader() const;
    unsigned int elementBufferID() const;
    unsigned int vertexBufferID() const;
    virtual void draw() const;
    RawVec vertAttrData(unsigned int);

    VertexAttributeList changeVertLayout(unsigned int, VertexAttributePointer);
    RawVec vertAttrData(unsigned int, const RawVec&);
    virtual void elementData(const std::vector<unsigned int>&);
    virtual void elementData(unsigned int);
    virtual void elementData(const std::vector<unsigned int>&, unsigned int offset);
    virtual void vertexData(const RawVec&);
    virtual void vertexData(unsigned int num_verts);
    virtual void vertexData(const RawVec&, unsigned int offset);

    BufferManagerPointer _vert_data;
    BufferManagerPointer _elmt_data;
    VAOManager _VAO;
    const GLenum _gl_primitive_type=0;
    virtual VertexAttributeList defaultVAO(VertexAttributeList);
    
    unsigned int _num_verts, _num_prims;
protected:
};

class DrawInstanceBuffer : public DrawBuffer {
public:
    DrawInstanceBuffer(VertexAttributeList, VertexAttributeList, GLenum primt_type=GL_TRIANGLES);

    unsigned int instSize() const;
    unsigned int instanceBufferID() const;
    virtual void draw() const override;

    VertexAttributeList changeInstanceLayout(unsigned int, VertexAttributePointer);
    virtual void instanceData(const RawVec&);
    virtual void instanceData(unsigned int);
    virtual void instanceData(const RawVec&, unsigned int offset);

    BufferManagerPointer _inst_data;
    virtual VertexAttributeList defaultVAO(VertexAttributeList);
    unsigned int _num_inst;
    
protected:
};

}
#endif