<?php

namespace Doctrine\ORM\Event;

use Doctrine\Common\EventArgs,

    Doctrine\ORM\EntityManager;

/**

 * Class that holds event arguments for a preInsert/preUpdate event.

 *

 * @author Roman Borschel <roman@code-factory.org>

 * @author Benjamin Eberlei <kontakt@beberlei.de>

 * @since 2.0

 */

class PreUpdateEventArgs extends LifecycleEventArgs

{

    /**

     * @var array

     */

    private $_entityChangeSet;

    /**

     *

     * @param object $entity

     * @param EntityManager $em

     * @param array $changeSet

     */

    public function __construct($entity, $em, array &$changeSet)

    {

        parent::__construct($entity, $em);

        $this->_entityChangeSet = &$changeSet;

    }

    public function getEntityChangeSet()

    {

        return $this->_entityChangeSet;

    }

    /**

     * Field has a changeset?

     *

     * @return bool

     */

    public function hasChangedField($field)

    {

        return isset($this->_entityChangeSet[$field]);

    }

    /**

     * Get the old value of the changeset of the changed field.

     * 

     * @param  string $field

     * @return mixed

     */

    public function getOldValue($field)

    {

    	$this->_assertValidField($field);

        return $this->_entityChangeSet[$field][0];

    }

    /**

     * Get the new value of the changeset of the changed field.

     *

     * @param  string $field

     * @return mixed

     */

    public function getNewValue($field)

    {

        $this->_assertValidField($field);

        return $this->_entityChangeSet[$field][1];

    }

    /**

     * Set the new value of this field.

     * 

     * @param string $field

     * @param mixed $value

     */

    public function setNewValue($field, $value)

    {

        $this->_assertValidField($field);

        $this->_entityChangeSet[$field][1] = $value;

    }

    private function _assertValidField($field)

    {

    	if (!isset($this->_entityChangeSet[$field])) {

            throw new \InvalidArgumentException(

                "Field '".$field."' is not a valid field of the entity ".

                "'".get_class($this->getEntity())."' in PreInsertUpdateEventArgs."

            );

        }

    }

}