ldc-boutique-cnc-sable/domain/Enums/TaxRate.php

<?php

declare(strict_types=1);

namespace Domain\Enums;

use Domain\Models\Entities\Product;
use Money\Money;
use Shared\Enums\BaseEnum;

enum TaxRate: int
{
    /** @use \Shared\Enums\BaseEnum<int> */
    use BaseEnum;

    case TVA_20  = 1;
    case TVA_5_5 = 2;

    /**
     * Optional labels definition
     *
     * @phpstan-ignore-next-line classConstant.unused (Base enum usage)
     */
    private const LABELS = [
        self::TVA_20->name  => 'TVA 20%',
        self::TVA_5_5->name => 'TVA 5.5%',
    ];

    public function percent(): float
    {
        return match ($this) {
            self::TVA_20  => 20.0,
            self::TVA_5_5 => 5.5,
        };
    }

    public static function fromPercent(float $percent): self
    {
        return match ($percent) {
            self::TVA_20->percent()  => self::TVA_20,
            self::TVA_5_5->percent() => self::TVA_5_5,
            default                  => self::tryFrom((int) $percent) ?? throw new \UnexpectedValueException(
                sprintf('Unhandled tax rate: %s', $percent)
            ),
        };
    }

    public function rate(): float
    {
        return $this->percent() / 100;
    }

    /**
     * Exact decimal multiplier (1 + rate), as a string to avoid any float rounding.
     *
     * @return numeric-string
     */
    public function multiplier(): string
    {
        return match ($this) {
            self::TVA_20  => '1.2',
            self::TVA_5_5 => '1.055',
        };
    }

    public function applyTo(Money $price): Money
    {
        return $price->multiply($this->multiplier(), Product::ROUNDING);
    }
}