extern crate num_complex;

use num_complex::Complex;
use crate::shapes::*;

/// An iterator containing the shapes to display
pub struct CircleShapes {
    modulo: u32,
    factor: u32,
    position: u32,
    circle: Circle,
}

impl CircleShapes {
    pub fn new(modulo: u32, factor: u32, circle: Circle) -> CircleShapes {
        CircleShapes {
            modulo,
            factor,
            position: 0,
            circle,
        }
    }
}

impl Iterator for CircleShapes {
    type Item = Shape;

    fn next(&mut self) -> Option<Self::Item> {
        if self.position == 0 {
            self.position += 1;
            Some(Shape::Circle(self.circle))
        } else if self.position < self.modulo {
            let center = Complex::new(self.circle.center.x, self.circle.center.y);
            let pi = std::f64::consts::PI;
            let radius = self.circle.radius;
            let azimuth_1 = (self.position as f64) * 2. * pi / (self.modulo as f64);
            let azimuth_2 = (self.position * self.factor) as f64 * 2. * pi / self.modulo as f64;
            let complex_point_1 = Complex::from_polar(radius, azimuth_1) + center;
            let complex_point_2 = Complex::from_polar(radius, azimuth_2) + center;
            let p1 = Point { x: complex_point_1.re, y: complex_point_1.im };
            let p2 = Point { x: complex_point_2.re, y: complex_point_2.im };
            self.position += 1;
            Some(Shape::Line(Line {p1, p2}))
        } else {
            None
        }
    }
}