#ifndef HITABLELISTH
#define HITABLELISTH

#include "hitable.h"

class hitable_list: public hitable  {
    public:
        hitable_list() {}
        hitable_list(hitable **l, int n) {list = l; list_size = n; }
        virtual bool hit(const ray& r, float tmin, float tmax, hit_record& rec) const;
        virtual bool bounding_box(float t0, float t1, aabb& box) const;
        virtual float  pdf_value(const vec3& o, const vec3& v) const;
        virtual vec3 random(const vec3& o) const;

        hitable **list;
        int list_size;
};

float hitable_list::pdf_value(const vec3& o, const vec3& v) const {
    float weight = 1.0/list_size;
    float sum = 0;
    for (int i = 0; i < list_size; i++)
        sum += weight*list[i]->pdf_value(o, v);
    return sum;
}

vec3 hitable_list::random(const vec3& o) const {
        int index = int(drand48() * list_size);
        return list[ index ]->random(o);
}


bool hitable_list::bounding_box(float t0, float t1, aabb& box) const {
    if (list_size < 1) return false;
    aabb temp_box;
    bool first_true = list[0]->bounding_box(t0, t1, temp_box);
    if (!first_true)
        return false;
    else 
        box = temp_box;
    for (int i = 1; i < list_size; i++) {
        if(list[0]->bounding_box(t0, t1, temp_box)) {
            box = surrounding_box(box, temp_box);
        }
        else
            return false;
    }
    return true;
}

bool hitable_list::hit(const ray& r, float t_min, float t_max, hit_record& rec) const {
        hit_record temp_rec;
        bool hit_anything = false;
        double closest_so_far = t_max;
        for (int i = 0; i < list_size; i++) {
            if (list[i]->hit(r, t_min, closest_so_far, temp_rec)) {
                hit_anything = true;
                closest_so_far = temp_rec.t;
                rec = temp_rec;
            }
        }
        return hit_anything;
}

#endif