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

pub struct Rainbow;
impl Sample for Rainbow {
    fn sample(&mut self, x: f64, _y: f64) -> Color {
        static PI: f64 = 3.14;
        let x = x * PI * 2.0;
        return Color {
            r: (x + PI / 3.0 * 0.0).sin() * 0.5 + 0.5,
            g: (x + PI / 3.0 * 2.0).sin() * 0.5 + 0.5,
            b: (x + PI / 3.0 * 4.0).sin() * 0.5 + 0.5,
        };
    }
}

pub struct Sequence(pub Vec<Color>);
impl Sample for Sequence {
    fn sample(&mut self, x: f64, _y: f64) -> Color {
        self.0[(x * self.0.len() as f64).floor() as usize % self.0.len()]
    }
}

pub struct Gradient(pub Vec<Color>);
impl Sample for Gradient {
    fn sample(&mut self, x: f64, _y: f64) -> Color {
        let index = x * self.0.len() as f64;
        let index_int = index.floor() as usize;
        let index_error = index % 1.0;
        let a = self.0[index_int % self.0.len()];
        let b = self.0[(index_int + 1) % self.0.len()];
        Color::mix(a, b, index_error)
    }
}

pub struct Solid(pub Color);
impl Sample for Solid {
    fn sample(&mut self, _x: f64, _y: f64) -> Color {
        self.0
    }
}