use crate::calculus::calculus::Point3;
use crate::interval::Interval;

// "Ideal" aspect ratio, allowing fraction
pub const ASPECT_RATIO: f32 = 16.0f32 / 9.0f32;
pub const IMG_WIDTH: usize = 1000;
pub const IMG_HEIGHT: usize = get_image_height(IMG_WIDTH, ASPECT_RATIO);

pub const VIEWPORT_HEIGHT: f32 = 2.0;
pub const FOCAL_LENGTH: f32 = 1.0;
pub const CAMERA_CENTER: Point3 = Point3 { x: 0f32, y: 0f32, z: 0f32 };

pub const SAMPLES_PER_PIXEL: usize = 100;

pub const fn get_image_height(image_width: usize, aspect_ratio: f32) -> usize {
    let image_height = (image_width as f32 / aspect_ratio) as usize;
    if image_width < 1 { 1 } else { image_height }
}

pub struct Color {
    pub r: f32,
    pub g: f32,
    pub b: f32,
}

impl Color {
    pub fn new(r: f32, g: f32, b: f32) -> Self {
        Self { r, g, b }
    }

    pub fn mul_scalar(&self, scalar: f32) -> Color {
        Self {
            r: self.r * scalar,
            g: self.g * scalar,
            b: self.b * scalar,
        }
    }

    pub fn add(&self, other: &Self) -> Color {
        Self {
            r: self.r + other.r,
            g: self.g + other.g,
            b: self.b + other.b
        }
    }
}


#[derive(Debug, Copy, Clone)]
pub struct Pixel {
    pub r: u8,
    pub g: u8,
    pub b: u8,
}

impl Pixel {
    pub fn from_frac(r: f32, g: f32, b: f32) -> Self {
        let intensity = Interval::new(0.0, 0.999);
        Self {
            r: (256.0 * intensity.clamp(r)) as u8,
            g: (256.0 * intensity.clamp(g)) as u8,
            b: (256.0 * intensity.clamp(b)) as u8,
        }
    }

    pub fn from_color(color: &Color) -> Self {
        let (r, g, b) = (color.r, color.g, color.b);
        Self::from_frac(r, g, b)
    }
}

impl Default for Pixel {
    fn default() -> Self {
        Pixel { r:0, g:0, b:0 }
    }
}

pub type DisplayBuffer = [[Pixel; IMG_WIDTH]; IMG_HEIGHT];