<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Search_Lucene

 * @subpackage Search

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Boolean.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/** Zend_Search_Lucene_Search_Weight */

require_once 'Zend/Search/Lucene/Search/Weight.php';

/**

 * @category   Zend

 * @package    Zend_Search_Lucene

 * @subpackage Search

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Search_Lucene_Search_Weight_Boolean extends Zend_Search_Lucene_Search_Weight

{

    /**

     * IndexReader.

     *

     * @var Zend_Search_Lucene_Interface

     */

    private $_reader;

    /**

     * The query that this concerns.

     *

     * @var Zend_Search_Lucene_Search_Query

     */

    private $_query;

    /**

     * Queries weights

     * Array of Zend_Search_Lucene_Search_Weight

     *

     * @var array

     */

    private $_weights;

    /**

     * Zend_Search_Lucene_Search_Weight_Boolean constructor

     * query - the query that this concerns.

     * reader - index reader

     *

     * @param Zend_Search_Lucene_Search_Query $query

     * @param Zend_Search_Lucene_Interface    $reader

     */

    public function __construct(Zend_Search_Lucene_Search_Query $query,

                                Zend_Search_Lucene_Interface    $reader)

    {

        $this->_query   = $query;

        $this->_reader  = $reader;

        $this->_weights = array();

        $signs = $query->getSigns();

        foreach ($query->getSubqueries() as $num => $subquery) {

            if ($signs === null || $signs[$num] === null || $signs[$num]) {

                $this->_weights[$num] = $subquery->createWeight($reader);

            }

        }

    }

    /**

     * The weight for this query

     * Standard Weight::$_value is not used for boolean queries

     *

     * @return float

     */

    public function getValue()

    {

        return $this->_query->getBoost();

    }

    /**

     * The sum of squared weights of contained query clauses.

     *

     * @return float

     */

    public function sumOfSquaredWeights()

    {

        $sum = 0;

        foreach ($this->_weights as $weight) {

            // sum sub weights

            $sum += $weight->sumOfSquaredWeights();

        }

        // boost each sub-weight

        $sum *= $this->_query->getBoost() * $this->_query->getBoost();

        // check for empty query (like '-something -another')

        if ($sum == 0) {

            $sum = 1.0;

        }

        return $sum;

    }

    /**

     * Assigns the query normalization factor to this.

     *

     * @param float $queryNorm

     */

    public function normalize($queryNorm)

    {

        // incorporate boost

        $queryNorm *= $this->_query->getBoost();

        foreach ($this->_weights as $weight) {

            $weight->normalize($queryNorm);

        }

    }

}