#ifndef MATHS_RAYS_HPP_
#define MATHS_RAYS_HPP_

#include "aabb.hpp"
#include "glm/glm.hpp"
#define GLM_ENABLE_EXPERIMENTAL
#include "glm/gtx/hash.hpp"

#include <array>

using rayvec3 = glm::highp_dvec3;
using rayvec2 = glm::highp_dvec2;
using scalar_t = double;

enum class RayRelation {
    Embed=2, Intersect=1, Parallel=0, None=0
};

class AABBFaces {
    static const unsigned char AABBFACES_COUNT = 6;
public:
    std::array<std::pair<rayvec3, rayvec2>, AABBFACES_COUNT> faces; // every face is min-point and opposite corner point

    AABBFaces(){};
    AABBFaces(const rayvec3& parentBoxPos, const AABB& parentBox);
};

class Ray {
public:
    rayvec3 origin;
    rayvec3 dir;

    Ray(const rayvec3& rayOrigin,
        const rayvec3& rayDir);

    RayRelation isIntersectsYZFace(
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner);	
    RayRelation isIntersectsXZFace(
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner);	
    RayRelation isIntersectsXYFace(
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner);

///returns normal and distance
    RayRelation intersectYZFace( 
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner,
        glm::ivec3& normal_ret,
        scalar_t& distance_ret);
    RayRelation intersectXZFace(
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner,
        glm::ivec3& normal_ret,
        scalar_t& distance_ret);
    RayRelation intersectXYFace(
        const rayvec3& faceMin,
        const rayvec2& faceOppositeCorner,
        glm::ivec3& normal_ret,
        scalar_t& distance_ret);

    RayRelation intersectAABB(
        const rayvec3& boxPos,
        const AABB& box,
        float maxDist,
        glm::ivec3& normal_ret,
        scalar_t& distance_ret);

    RayRelation intersectAABBFaces( // calculates only normal and distance
        const AABBFaces& boxFaces,
        float maxDist,
        glm::ivec3& normal_ret,
        scalar_t& distance_ret);
};

#endif // SRC_VOXNATHS_HPP_