#ifndef MATERIAL_H
#define MATERIAL_H

#include "hittable.h"
#include "rtweekend.h"
#include "vec3.h"

struct hit_record;

class material {
	public:
		virtual bool scatter(const ray& r_in, const hit_record& rec, color& attenuation, ray& scattered) const = 0;
};


class lambertian : public material {
	public:
		lambertian(const color& a) : albedo(a) {}

		bool scatter(
			const ray &r_in, const hit_record &rec, color &attenuation, ray &scattered
		) const override {
			auto scatter_direction = rec.normal + random_in_hemisphere(rec.normal);

			// Catch degenerate scatter direction
			if (scatter_direction.near_zero())
				scatter_direction = rec.normal;

			scattered = ray(rec.p, scatter_direction);
			attenuation = albedo;
			return true;
		}

	public:
		color albedo;
};

class metal : public material {
	public:
		metal(const color& a, double f) : albedo(a), fuzz(f < 1 ? f : 1) {}

		bool scatter(
				const ray &r_in, const hit_record &rec, color &attenuation, ray &scattered
		) const override {
			vec3 reflected = reflect(unit_vector(r_in.direction()), rec.normal);
			scattered = ray(rec.p, reflected + fuzz*random_in_hemisphere(rec.normal));
			attenuation = albedo;
			return (dot(scattered.direction(), rec.normal) > 0);
		}

	public:
		color albedo;
		double fuzz;
};

#endif