use std::ops::{Add, Mul};

#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct Vec3<T = f64> {
  pub x: T,
  pub y: T,
  pub z: T,
}

impl<T> Vec3<T> {
  pub fn new(x: T, y: T, z: T) -> Self {
    Vec3 { x, y, z }
  }
}

/// Vector addition
impl<T> Add<Vec3<T>> for Vec3<T>
where
  T: Add<T>,
{
  type Output = Vec3<T::Output>;

  fn add(self, rhs: Vec3<T>) -> Self::Output {
    Vec3::new(self.x + rhs.x, self.y + rhs.y, self.z + rhs.z)
  }
}

/// Scalar multiplication
impl<T, U> Mul<U> for Vec3<T>
where
  T: Mul<U, Output = U>,
  U: Copy,
{
  type Output = Vec3<U>;

  fn mul(self, rhs: U) -> Self::Output {
    Vec3::new(self.x * rhs, self.y * rhs, self.z * rhs)
  }
}

pub struct Sphere {
  pub center: Vec3,
  pub radius: f64,
}

pub enum Object {
  Sphere(Sphere),
  Cylinder {
    center: Vec3,
    direction: Vec3,
    radius: f64,
    length: f64,
  },
}

pub struct Scene {
  pub eye_pos: Vec3,
  pub view_dir: Vec3,
  pub up_dir: Vec3,

  /// Horizontal field of view (in degrees)
  pub hfov: f64,

  pub image_width: usize,
  pub image_height: usize,

  /// Background color
  pub bkg_color: Vec3,

  /// Material color
  pub mtl_color: Vec3,

  pub objects: Vec<Object>,
}