#pragma once

#if !defined(MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED)
#define MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED 1

#include <mikktspace.h>
#include "./geometry_traits.hpp"

namespace mijin
{
namespace impl
{
template<FullMesh3D TMesh>
struct MikktData
{
    Mesh3DTraits<TMesh> traits;
    Vector2Traits<typename TMesh::vector2_t> vec2Traits;
    Vector3Traits<typename TMesh::vector3_t> vec3Traits;
    Vector4Traits<typename TMesh::vector4_t> vec4Traits;
    TMesh* mesh;
};

template<FullMesh3D TMesh>
int mikktGetNumFaces(const SMikkTSpaceContext* context)
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    return static_cast<int>(data.traits.getNumFaces(*data.mesh));
}

template<FullMesh3D TMesh>
int mikktGetNumVerticesOfFace(const SMikkTSpaceContext* context, const int face)
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    return static_cast<int>(data.traits.getFaceNumVertices(*data.mesh, face));
}

template<FullMesh3D TMesh>
void mikktGetPosition(const SMikkTSpaceContext* context, float posOut[], const int face, const int vert) // NOLINT
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    const auto position = data.traits.getPosition(*data.mesh, face, vert);
    posOut[0] = data.vec3Traits.getX(position);
    posOut[1] = data.vec3Traits.getY(position);
    posOut[2] = data.vec3Traits.getZ(position);
}

template<FullMesh3D TMesh>
void mikktGetNormal(const SMikkTSpaceContext* context, float normOut[], const int face, const int vert) // NOLINT
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    const auto normal = data.traits.getNormal(*data.mesh, face, vert);
    normOut[0] = data.vec3Traits.getX(normal);
    normOut[1] = data.vec3Traits.getY(normal);
    normOut[2] = data.vec3Traits.getZ(normal);
}

template<FullMesh3D TMesh>
void mikktGetTexCoord(const SMikkTSpaceContext* context, float texcOut[], const int face, const int vert) // NOLINT
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    const auto texCoord = data.traits.getTexCoord(*data.mesh, face, vert);
    texcOut[0] = data.vec2Traits.getX(texCoord);
    texcOut[1] = data.vec2Traits.getY(texCoord);
}

template<FullMesh3D TMesh>
void mikktSetTSpaceBasic(const SMikkTSpaceContext* context, const float resultTangent[], const float sign, const int face, const int vert) // NOLINT
{
    const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
    typename Mesh3DTraits<TMesh>::vector4_t tangent;
    data.vec4Traits.setX(tangent, resultTangent[0]);
    data.vec4Traits.setY(tangent, resultTangent[1]);
    data.vec4Traits.setZ(tangent, resultTangent[2]);
    data.vec4Traits.setW(tangent, sign);
    data.traits.setTangent(*data.mesh, face, vert, tangent);
}
}
template<FullMesh3D TMesh>
bool generateTangentsMikkt(TMesh& mesh)
{
    SMikkTSpaceInterface mikktInterface = {
        .m_getNumFaces = &impl::mikktGetNumFaces<TMesh>,
        .m_getNumVerticesOfFace = &impl::mikktGetNumVerticesOfFace<TMesh>,
        .m_getPosition = &impl::mikktGetPosition<TMesh>,
        .m_getNormal = &impl::mikktGetNormal<TMesh>,
        .m_getTexCoord = &impl::mikktGetTexCoord<TMesh>,
        .m_setTSpaceBasic = &impl::mikktSetTSpaceBasic<TMesh>
    };
    impl::MikktData<TMesh> data = {
        .mesh = &mesh
    };
    const SMikkTSpaceContext context = {
        .m_pInterface = &mikktInterface,
        .m_pUserData = &data
    };
    return genTangSpaceDefault(&context);
}
}

#endif // MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED