use geometry::*;

pub enum Hitbox {
    Circle(CircleHitbox),
    Point(PointHitbox)
}

pub struct CircleHitbox {
    pub pos: Vec2d,
    pub radius: f64
}

pub struct PointHitbox {
    pub pos: Vec2d
}

impl Hitbox {
    pub fn intersect(a: &Hitbox, b: &Hitbox) -> bool {
        use self::Hitbox::*;

        match (a, b) {
            (Circle(x), Circle(y)) => circles_intersect(x, y),
            (Circle(x), Point(y)) => circle_point_intersect(x, y),
            (Point(x), Circle(y)) => circle_point_intersect(y, x),
            (Point(x), Point(y)) => points_intersect(x, y)
        }
    }
}

fn circles_intersect(x: &CircleHitbox, y: &CircleHitbox) -> bool {
    x.pos.distance_squared(y.pos) <= (x.radius + y.radius).powi(2)
}

fn circle_point_intersect(x: &CircleHitbox, y: &PointHitbox) -> bool {
    x.pos.distance_squared(y.pos) <= x.radius.powi(2)
}

fn points_intersect(x: &PointHitbox, y: &PointHitbox) -> bool {
    x.pos == y.pos
}