<?php
/*
 *  $Id$
 *
 * 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 LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\ORM\Persisters;

use Doctrine\ORM\PersistentCollection;

/**
 * Persister for one-to-many collections.
 * 
 * IMPORTANT:
 * This persister is only used for uni-directional one-to-many mappings on a foreign key
 * (which are not yet supported). So currently this persister is not used.
 *
 * @since 2.0
 * @author Roman Borschel <roman@code-factory.org>
 * @todo Complete implementation when the support for uni-directional one-to-many mappings
 *       on a foreign key gets added.
 */
class OneToManyPersister extends AbstractCollectionPersister
{
    /**
     * Generates the SQL UPDATE that updates a particular row's foreign
     * key to null.
     *
     * @param PersistentCollection $coll
     * @return string
     * @override
     */
    protected function _getDeleteRowSql(PersistentCollection $coll)
    {
        $mapping = $coll->getMapping();
        $targetClass = $this->_em->getClassMetadata($mapping->getTargetEntityName());
        $table = $targetClass->getTableName();

        $ownerMapping = $targetClass->getAssociationMapping($mapping->getMappedByFieldName());

        $setClause = '';
        foreach ($ownerMapping->getSourceToTargetKeyColumns() as $sourceCol => $targetCol) {
            if ($setClause != '') $setClause .= ', ';
            $setClause .= "$sourceCol = NULL";
        }

        $whereClause = '';
        foreach ($targetClass->getIdentifierColumnNames() as $idColumn) {
            if ($whereClause != '') $whereClause .= ' AND ';
            $whereClause .= "$idColumn = ?";
        }

        return array("UPDATE $table SET $setClause WHERE $whereClause", $this->_uow->getEntityIdentifier($element));
    }

    protected function _getInsertRowSql(PersistentCollection $coll)
    {
        return "UPDATE xxx SET foreign_key = yyy WHERE foreign_key = zzz";
    }

    /* Not used for OneToManyPersister */
    protected function _getUpdateRowSql(PersistentCollection $coll)
    {
        return;
    }
    
    /**
     * Generates the SQL UPDATE that updates all the foreign keys to null.
     *
     * @param PersistentCollection $coll
     */
    protected function _getDeleteSql(PersistentCollection $coll)
    {
        
    }
    
    /**
     * Gets the SQL parameters for the corresponding SQL statement to delete
     * the given collection.
     *
     * @param PersistentCollection $coll
     */
    protected function _getDeleteSqlParameters(PersistentCollection $coll)
    {}
    
    /**
     * Gets the SQL parameters for the corresponding SQL statement to insert the given
     * element of the given collection into the database.
     *
     * @param PersistentCollection $coll
     * @param mixed $element
     */
    protected function _getInsertRowSqlParameters(PersistentCollection $coll, $element)
    {}
    
    /**
     * Gets the SQL parameters for the corresponding SQL statement to delete the given
     * element from the given collection.
     *
     * @param PersistentCollection $coll
     * @param mixed $element
     */
    protected function _getDeleteRowSqlParameters(PersistentCollection $coll, $element)
    {}
}