<?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\Query\AST\Functions;

use Doctrine\ORM\Query\Lexer;

/**
 * "SUBSTRING" "(" StringPrimary "," SimpleArithmeticExpression "," SimpleArithmeticExpression ")"
 *
 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link    www.doctrine-project.org
 * @since   2.0
 * @version $Revision: 3938 $
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Jonathan Wage <jonwage@gmail.com>
 * @author  Roman Borschel <roman@code-factory.org>
 */
class SubstringFunction extends FunctionNode
{
    public $stringPrimary;
    public $firstSimpleArithmeticExpression;
    public $secondSimpleArithmeticExpression = null;

    /**
     * @override
     */
    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
    {
        $optionalSecondSimpleArithmeticExpression = null;
        if ($this->secondSimpleArithmeticExpression !== null) {
            $optionalSecondSimpleArithmeticExpression = $sqlWalker->walkSimpleArithmeticExpression($this->secondSimpleArithmeticExpression);
        }

        return $sqlWalker->getConnection()->getDatabasePlatform()->getSubstringExpression(
            $sqlWalker->walkStringPrimary($this->stringPrimary),
            $sqlWalker->walkSimpleArithmeticExpression($this->firstSimpleArithmeticExpression),
            $optionalSecondSimpleArithmeticExpression
        );
    }

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

        $this->stringPrimary = $parser->StringPrimary();
        
        $parser->match(Lexer::T_COMMA);
        
        $this->firstSimpleArithmeticExpression = $parser->SimpleArithmeticExpression();

        if ($lexer->isNextToken(Lexer::T_COMMA)) {
            $parser->match(Lexer::T_COMMA);
        
            $this->secondSimpleArithmeticExpression = $parser->SimpleArithmeticExpression();
        }

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