<?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 LGPL. For more information, see

 * <http://www.doctrine-project.org>.

 */

namespace Doctrine\ORM\Query\AST\Functions;

use Doctrine\ORM\Query\Lexer;

use Doctrine\ORM\Query\SqlWalker;

use Doctrine\ORM\Query\Parser;

use Doctrine\ORM\Query\QueryException;

/**

 * "DATE_ADD(date1, interval, unit)"

 *

 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL

 * @link    www.doctrine-project.org

 * @since   2.0

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

 */

class DateSubFunction extends DateAddFunction

{

    public $firstDateExpression = null;

    public $intervalExpression = null;

    public $unit = null;

    public function getSql(SqlWalker $sqlWalker)

    {

        $unit = strtolower($this->unit);

        if ($unit == "day") {

            return $sqlWalker->getConnection()->getDatabasePlatform()->getDateSubDaysExpression(

                $this->firstDateExpression->dispatch($sqlWalker),

                $this->intervalExpression->dispatch($sqlWalker)

            );

        } else if ($unit == "month") {

            return $sqlWalker->getConnection()->getDatabasePlatform()->getDateSubMonthExpression(

                $this->firstDateExpression->dispatch($sqlWalker),

                $this->intervalExpression->dispatch($sqlWalker)

            );

        } else {

            throw QueryException::semanticalError('DATE_SUB() only supports units of type day and month.');

        }

    }

}