use crate::{Color, Vec3};
use crate::hittable::{HitRecord, HittableList};
use crate::material::Scatterable;
use crate::vec3::Point3;

#[derive(Debug)]
pub struct Ray {
    origin: Point3,
    direction: Vec3,
    time: f64
}
impl Default for Ray {
    fn default() -> Self {
        Ray::new(Vec3::default(), Vec3::default(), 0.0)
    }
}

impl Ray {
    pub fn new(origin: Point3, direction: Point3, time: f64) -> Ray {
        Ray { origin, direction, time }
    }
    pub fn at(&self, t: f64) -> Point3 {
        self.origin + self.direction * t
    }
    pub fn direction(&self) -> Vec3 { self.direction }
    pub fn origin(&self) -> Point3 { self.origin }
    pub fn time(&self) -> f64 { self.time }
    pub fn pixel_color(&self, world: &HittableList, depth: i32) -> Color {
        if depth <= 0 {
            return Color::default();
        }
        if let Some(rect) = self.hit_world(world, 0.001, f64::INFINITY) {
           let scattered = rect.material.scatter(self, &rect);
            return match scattered {
                Some((scattered_ray, albedo)) => {
                    match scattered_ray {
                        Some(sr) => {
                            albedo * sr.pixel_color(world, depth-1)
                        },
                        None => albedo
                    }
                },
                None => { return Color::default() }
            };

        }

        //Hot nothing, display sky color
        let unit_direction = self.direction().unit_vector();
        let t = 0.5 * (unit_direction.y() + 1.0);
        (1.0 - t) * Color::new(1.0, 1.0, 1.0) + t * Color::new(0.5, 0.7, 1.0)
    }
    fn hit_world<'material>(
        &self,
        world: &'material HittableList,
        t_min: f64,
        t_max: f64,
    ) -> Option<HitRecord<'material>> {
        let mut closest_so_far = t_max;
        let mut hit_record = None;
        for sphere in world {
            if let Some(hit) = sphere.hit(self, t_min, closest_so_far) {
                closest_so_far = hit.t;
                hit_record = Some(hit);
            }
        }
        hit_record
    }
}