<?php

namespace App\Form\DataTransformer;

use Doctrine\ORM\EntityManagerInterface;
use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\TransformationFailedException;

class EntityToIdTransformer implements DataTransformerInterface
{
    public function __construct(private readonly EntityManagerInterface $entityManager, private readonly string $class)
    {
    }

    public function transform($value)
    {
        if (null === $value) {
            return null;
        }

        return $value->getId();
    }

    public function reverseTransform($value)
    {
        if (empty($value)) {
            return null;
        }

        $entity = $this->entityManager->getRepository($this->class)->find($value);

        if (null === $entity) {
            throw new TransformationFailedException(sprintf('No %s with id %d found', $this->class, $value));
        }

        return $entity;
    }
}