skqr/hateoas

<?php
/**
 * @copyright 2014 Integ S.A.
 * @license http://opensource.org/licenses/MIT The MIT License (MIT)
 * @author Javier Lorenzana <javier.lorenzana@gointegro.com>
 */

namespace GoIntegro\Hateoas\Metadata\Entity;

// ORM.
use Doctrine\ORM\EntityManagerInterface;

/**
 * A cache for the entity metadata - its reflection and ORM mapping.
 *
 * The ReflectionClass cannot be serialized, and thus, cannot be cached other
 * than in runtime memory. The ORM mapping can be cached by Doctrine 2. Given
 * this, it's unlikely an alternative implementation will be needed.
 * @pattern multiton
 */
class ArrayMetadataCache implements MetadataCache
{
    const ERROR_REFLECTION_EXPECTED_VALUE = "Sólo puede obtenerse la reflexión de una clase por su nombre o una instancia.",
        ERROR_MAPPING_EXPECTED_VALUE = "Sólo puede obtenerse la metadata de mapeo de una entidad por su clase o una instancia.";

    /**
     * @var EntityManagerInterface
     */
    protected $entityManager;
    /**
     * @var array
     */
    protected static $metadata = [];

    /**
     * @param EntityManagerInterface $entityManager
     */
    public function __construct(EntityManagerInterface $entityManager) {
        $this->entityManager = $entityManager;
    }

    /**
     * @param string $className
     * @return EntityMetadata
     */
    protected function getMetadata($className)
    {
        if (!isset(self::$metadata[$className])) {
            self::$metadata[$className] = new EntityMetadata($className);
        }

        return self::$metadata[$className];
    }

    /**
     * @see MetadataCache::getReflection
     */
    public function getReflection($className)
    {
        if (
            (!is_string($className) || !class_exists($className))
            && !is_object($className)
        ) {
            throw new \Exception(self::ERROR_REFLECTION_EXPECTED_VALUE);
        }

        $this->stringify($className);
        $metadata = $this->getMetadata($className);

        if (empty($metadata->reflection)) {
            $metadata->reflection = new \ReflectionClass($className);
        }

        return $metadata->reflection;
    }

    /**
     * @see MetadataCache::getMapping
     */
    public function getMapping($className)
    {
        if (!is_string($className) && !is_object($className)) {
            throw new \Exception(self::ERROR_MAPPING_EXPECTED_VALUE);
        }

        $this->stringify($className);
        $metadata = $this->getMetadata($className);

        if (empty($metadata->mapping)) {
            $metadata->mapping
                = $this->entityManager->getClassMetadata($className);
        }

        return $metadata->mapping;
    }

    /**
     * @param &$value mixed
     * @return $string
     * @throws \Exception
     */
    protected function stringify(&$value)
    {
        if (
            !is_string($value)
            and !$value = get_class($value)
        ) {
            $message = "El parámetro no es una cadena de caracteres ni una instancia.";
            throw new \Exception($message);
        }

        return $value;
    }
}