pub type Cluster<T> = Vec<T>;

pub trait Clusterable where Self: Sized + Clone + PartialEq {
    fn distance(&self, rhs: &Self) -> f64;
    fn get_centroid(elements: &Vec<Self>) -> Option<Self>;
}

macro_rules! impl_clusterable {
    ( $type: ty) => {
        impl Clusterable for $type {
            fn distance(&self, rhs: &Self) -> f64 {
                if self > rhs {
                    *self as f64 - *rhs as f64
                } else {
                    *rhs as f64 - *self as f64
                }
            }

            fn get_centroid(elements: &Vec<Self>) -> Option<Self> {

                if elements.len() == 0 {
                    return None;
                }

                let mut tmp = 0.0 as Self;
                for element in elements {
                    tmp += *element as Self;
                }
                Some(tmp / elements.len() as Self)

            }
        }
    }
}

impl_clusterable!(f32);
impl_clusterable!(f64);