<?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\Query\AST\Functions;

use Doctrine\ORM\Query\Lexer;

/**
 * "IDENTITY" "(" SingleValuedAssociationPathExpression ")"
 *
 * 
 * @link    www.doctrine-project.org
 * @since   2.2
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Benjamin Eberlei <kontakt@beberlei.de>
 */
class IdentityFunction extends FunctionNode
{
    public $pathExpression;

    /**
     * @override
     */
    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
    {
        $dqlAlias   = $this->pathExpression->identificationVariable;
        $assocField = $this->pathExpression->field;

        $qComp = $sqlWalker->getQueryComponent($dqlAlias);
        $class = $qComp['metadata'];
        $assoc = $class->associationMappings[$assocField];

        $tableAlias = $sqlWalker->getSQLTableAlias($class->getTableName(), $dqlAlias);

        return $tableAlias . '.' . reset($assoc['targetToSourceKeyColumns']);;
    }

    /**
     * @override
     */
    public function parse(\Doctrine\ORM\Query\Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);

        $this->pathExpression = $parser->SingleValuedAssociationPathExpression();

        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }
}