<?php
namespace Shape;

use Codeception\Exception\ExtensionException;

class Circle{

    private static $radius;
    private static $area;
    private static $perimeter;

    public function __construct($num){
        if($num <0)
        {
            throw new \Exception('Cannot create circle with negative radius');
        }
        elseif(is_numeric($num)) {
            self::$radius = $num;
            self::$area = pi() * $num * $num;
            self::$perimeter = 2 * pi() * $num;
        }
        else{
            throw new \Exception('Cannot create circle with non-numeric radius');
        }
    }

    public function radius() {
        return self::$radius;
    }

    public function area(){
        return self::$area;
    }

    public function perimeter(){
        return self::$perimeter;
    }

}