use palette::encoding::srgb::Srgb;

use rgb::RGB8;

pub trait Rgb8Blend {
    fn saturating_add(&self, b: Self) -> Self;
}

impl Rgb8Blend for RGB8 {
    fn saturating_add(&self, b: Self) -> Self {
        RGB8::new(self.r.saturating_add(b.r), self.g.saturating_add(b.g), self.b.saturating_add(b.b))
    }
}

pub trait IntoRgb8 {
    fn into_rgb8(self) -> RGB8;
}

impl IntoRgb8 for RGB8 {
    fn into_rgb8(self) -> RGB8 {
        self
    }
}

impl IntoRgb8 for palette::Hsv<Srgb, u8> {
    fn into_rgb8(self) -> RGB8 {
        if self.saturation == 0 {
            return RGB8::new(self.value, self.value, self.value);
        }

        let region = self.hue.into_inner() / 43;
        let remainder = (self.hue.into_inner() - (region * 43)) * 6;

        let p = self.value.wrapping_mul(255 - self.saturation).wrapping_shr(8);
        let q = (self.value.wrapping_mul(255 - ((self.saturation.wrapping_mul(remainder)).wrapping_shr(8)))).wrapping_shr(8);
        let t = (self.value.wrapping_mul(255 - ((self.saturation.wrapping_mul(255 - remainder)).wrapping_shr(8)))).wrapping_shr(8);

        match region {
            0 => RGB8::new(self.value, t, p),
            1 => RGB8::new(q, self.value, p),
            2 => RGB8::new(p, self.value, t),
            3 => RGB8::new(p, q, self.value),
            4 => RGB8::new(t, p, self.value),
            _ => RGB8::new(self.value, p, q)
        }
    }
}