use crate::tuples::{color, Color};

pub struct Canvas {
    pub height: usize,
    pub width: usize,
    pub pixels: Vec<Color>,
}

fn canvas(width: usize, height: usize) -> Canvas {
    let pixels = vec![color(0., 0., 0.); width * height];
    Canvas {
        width,
        height,
        pixels,
    }
}

impl Canvas {
    pub fn set(&mut self, x: usize, y: usize, c: Color) {
        self.pixels[x + y * self.width] = c;
    }
    pub fn get(&mut self, x: usize, y: usize) -> Color {
        self.pixels[x + y * self.width]
    }
}
#[cfg(test)]
mod tests {
    use super::canvas;

    use crate::tuples::color;

    #[test]
    fn create_canvas() {
        let c = canvas(10, 20);
        assert_eq!(c.width, 10);
        assert_eq!(c.height, 20);
        let black = color(0., 0., 0.);
        for (i, p) in c.pixels.iter().enumerate() {
            assert_eq!(p, &black, "pixel {} not {:?}: {:?}", i, &black, p);
        }
    }

    #[test]
    fn write_to_canvas() {
        let mut c = canvas(10, 20);
        let red = color(1., 0., 0.);
        c.set(2, 3, red);
        assert_eq!(c.get(2, 3), red);
    }
}