<?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.phpdoctrine.org>.
 */

/**
 * SelectClause = "SELECT" ["DISTINCT"] SelectExpression {"," SelectExpression}
 *
 * @package     Doctrine
 * @subpackage  Query
 * @author      Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author      Janne Vanhala <jpvanhal@cc.hut.fi>
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        http://www.phpdoctrine.org
 * @since       1.0
 * @version     $Revision$
 */
class Doctrine_Query_Production_SelectClause extends Doctrine_Query_Production
{
    protected $_isDistinct;

    protected $_selectExpressions = array();


    public function syntax($paramHolder)
    {
        // SelectClause = "SELECT" ["DISTINCT"] SelectExpression {"," SelectExpression}
        $this->_isDistinct = false;

        $this->_parser->match(Doctrine_Query_Token::T_SELECT);

        if ($this->_isNextToken(Doctrine_Query_Token::T_DISTINCT)) {
            $this->_parser->match(Doctrine_Query_Token::T_DISTINCT);
            $this->_isDistinct = true;
        }

        $this->_selectExpressions[] = $this->AST('SelectExpression', $paramHolder);

        while ($this->_isNextToken(',')) {
            $this->_parser->match(',');
            $this->_selectExpressions[] = $this->AST('SelectExpression', $paramHolder);
        }
    }


    public function semantical($paramHolder)
    {
        // We need to validate each SelectExpression
        for ($i = 0, $l = count($this->_selectExpressions); $i < $l; $i++) {
             $this->_selectExpressions[$i]->semantical($paramHolder);
        }
    }


    public function buildSql()
    {
        return 'SELECT ' . (($this->_isDistinct) ? 'DISTINCT ' : '')
             . implode(', ', $this->_mapSelectExpressions());
    }


    protected function _mapSelectExpressions()
    {
        return array_map(array(&$this, '_mapSelectExpression'), $this->_selectExpressions);
    }


    protected function _mapSelectExpression($value)
    {
        return $value->buildSql();
    }
}