<?php

namespace App\Yr\Forecast\Tabular\Time;

class WindSpeed extends AbstractUnit {
    const DEFAULT_VARIANCE = (4.9 / 3.5);

    const UNIT_MPS = 'mp/s';
    const UNIT_FTS = 'ft/s';
    const UNIT_KMH = 'km/h';
    const UNIT_KNOTS = 'knots';

    private $name;

    public function __construct(\SimpleXMLElement $xml){
        parent::__construct(
            (float)$xml['mps'], self::UNIT_MPS
        );

        $this->name = (string)$xml['name'];
    }

    public function convertTo(string $unit): int {
        switch ($unit) {
        case self::UNIT_KNOTS:
            return $this->getValue() * 1.9438445;
        case self::UNIT_FTS:
            return $this->getValue() * 3.28084;
        case self::UNIT_KMH:
            return $this->getValue() * 3.6;
        }
    }

    public function getName(): string {
        return $this->name;
    }

    public function __toString(): string {
        return sprintf(
            '%s (%s)', parent::__toString(), $this->name
        );
    }
}