<?php

/*
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the MIT license. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\ORM\Cache;

use Doctrine\ORM\Query;
use Doctrine\ORM\PersistentCollection;
use Doctrine\ORM\Mapping\ClassMetadata;
use Doctrine\ORM\EntityManagerInterface;

/**
 * Collection hydrator that expects a target region to be instance of {Doctrine\ORM\Cache\MultiGetRegion},
 * to enable loading the entire collection with one cache request.
 *
 * @since   2.5
 * @author  Asmir Mustafic <goetas@gmail.com>
 */
class MultiGetCollectionHydrator implements CollectionHydrator
{
    /**
     * @var \Doctrine\ORM\EntityManagerInterface
     */
    private $em;

    /**
     * @var \Doctrine\ORM\UnitOfWork
     */
    private $uow;

    /**
     * @var MultiGetRegion
     */
    private $targetRegion;

    /**
     * @var array
     */
    private static $hints = array(Query::HINT_CACHE_ENABLED => true);

    /**
     * @param \Doctrine\ORM\EntityManagerInterface $em The entity manager.
     */
    public function __construct(EntityManagerInterface $em, MultiGetRegion $targetRegion)
    {
        $this->em  = $em;
        $this->uow = $em->getUnitOfWork();
        $this->targetRegion = $targetRegion;
    }

    /**
     * {@inheritdoc}
     */
    public function buildCacheEntry(ClassMetadata $metadata, CollectionCacheKey $key, $collection)
    {
        $data = array();

        foreach ($collection as $index => $entity) {
            $data[$index] = $this->uow->getEntityIdentifier($entity);
        }

        return new CollectionCacheEntry($data);
    }

    /**
     * {@inheritdoc}
     */
    public function loadCacheEntry(ClassMetadata $metadata, CollectionCacheKey $key, CollectionCacheEntry $entry, PersistentCollection $collection)
    {
        $assoc           = $metadata->associationMappings[$key->association];
        $list            = array();

        $keys = array();
        foreach ($entry->identifiers as $index => $identifier) {
            $keys[$index] = new EntityCacheKey($assoc['targetEntity'], $identifier);
        }

        $entityEntries = $this->targetRegion->getMulti($keys);

        if ($entityEntries === null) {
            return null;
        }

        foreach ($entityEntries as $index => $entityEntry) {
            $list[$index] = $this->uow->createEntity($entityEntry->class, $entityEntry->data, self::$hints);
        }

        array_walk($list, function ($entity, $index) use ($collection) {
            $collection->hydrateSet($index, $entity);
        });

        return $list;
    }
}