use super::Material;
use crate::core::color::LinearColor;
use crate::Point2D;

/// A material with the same characteristics on all points.
#[derive(Debug, PartialEq)]
pub struct UniformMaterial {
    diffuse: LinearColor,
    specular: LinearColor,
}

impl UniformMaterial {
    pub fn new(diffuse: LinearColor, specular: LinearColor) -> Self {
        UniformMaterial { diffuse, specular }
    }
}

impl Material for UniformMaterial {
    fn diffuse(&self, _: Point2D) -> LinearColor {
        self.diffuse.clone()
    }

    fn specular(&self, _: Point2D) -> LinearColor {
        self.specular.clone()
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn new_works() {
        let diffuse = LinearColor::new(0., 0.5, 0.);
        let specular = LinearColor::new(1., 1., 1.);
        let mat = UniformMaterial::new(diffuse.clone(), specular.clone());
        assert_eq!(mat, UniformMaterial { diffuse, specular })
    }

    fn simple_material() -> impl Material {
        UniformMaterial::new(
            LinearColor::new(0.5, 0.5, 0.5),
            LinearColor::new(1., 1., 1.),
        )
    }

    #[test]
    fn diffuse_works() {
        let mat = simple_material();
        assert_eq!(
            mat.diffuse(Point2D::origin()),
            LinearColor::new(0.5, 0.5, 0.5)
        )
    }

    #[test]
    fn specular_works() {
        let mat = simple_material();
        assert_eq!(
            mat.specular(Point2D::origin()),
            LinearColor::new(1., 1., 1.)
        )
    }
}