<?php

declare(strict_types=1);

namespace Domain\Models\ValueObjects;

final readonly class ProductWeight
{
    public function __construct(
        /** Weight in grams */
        public int $value,
        public bool $isVariable,
    ) {
        if ($value < 1) {
            throw new \DomainException('weight shall be greater than 0');
        }
    }

    public function toGrams(): int
    {
        return $this->value;
    }

    public function forDisplay(): string
    {
        if ($this->value >= 1000) {
            $kg = $this->value / 1000;

            $formatted = fmod($kg, 1.0) === 0.0
                ? number_format($kg, 0, ',', ' ')
                : rtrim(rtrim(number_format($kg, 3, ',', ' '), '0'), ',');

            return "{$formatted} kg";
        }

        return "{$this->value} g";
    }
}