<?php

namespace App\Yr\Forecast\Tabular\Time;

/**
 * Time-object entity should inherit this
 */
abstract class AbstractUnit implements DiffInterface {
    const DEFAULT_VARIANCE = 2;

    private $value;
    private $unit;

    /**
     * @param float The value
     * @param float The unit
     */
    public function __construct(float $value, string $unit) {
        $this->value = $value;
        $this->unit = $unit;
    }

    /**
     * Get the value
     *
     * @return float
     */
    public function getValue(): float {
        return $this->value;
    }

    /**
     * Return the unit (e.g «degree»)
     *
     * @return string
     */
    public function getUnit(): string {
        return $this->unit;
    }

    /**
     * {@inheritDoc}
     */
    public function diff(DiffInterface $d): int {
        if ($d instanceof $this)
            return $this->value - $d->getValue();

        return 0;
    }

    public function __toString(): string {
        return sprintf(
            "%s: %f %s", basename(str_replace(
                '\\', DIRECTORY_SEPARATOR, get_class($this)
            )), $this->value, $this->unit);
    }
}