<?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

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

 */

/** Zend_Search_Lucene_Search_Weight */

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

/**

 * @category   Zend

 * @package    Zend_Search_Lucene

 * @subpackage Search

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

 */

class Zend_Search_Lucene_Search_Weight_Term extends Zend_Search_Lucene_Search_Weight

{

    /**

     * IndexReader.

     *

     * @var Zend_Search_Lucene_Interface

     */

    private $_reader;

    /**

     * Term

     *

     * @var Zend_Search_Lucene_Index_Term

     */

    private $_term;

    /**

     * The query that this concerns.

     *

     * @var Zend_Search_Lucene_Search_Query

     */

    private $_query;

    /**

     * Score factor

     *

     * @var float

     */

    private $_idf;

    /**

     * Query weight

     *

     * @var float

     */

    private $_queryWeight;

    /**

     * Zend_Search_Lucene_Search_Weight_Term constructor

     * reader - index reader

     *

     * @param Zend_Search_Lucene_Index_Term   $term

     * @param Zend_Search_Lucene_Search_Query $query

     * @param Zend_Search_Lucene_Interface    $reader

     */

    public function __construct(Zend_Search_Lucene_Index_Term   $term,

                                Zend_Search_Lucene_Search_Query $query,

                                Zend_Search_Lucene_Interface    $reader)

    {

        $this->_term   = $term;

        $this->_query  = $query;

        $this->_reader = $reader;

    }

    /**

     * The sum of squared weights of contained query clauses.

     *

     * @return float

     */

    public function sumOfSquaredWeights()

    {

        // compute idf

        $this->_idf = $this->_reader->getSimilarity()->idf($this->_term, $this->_reader);

        // compute query weight

        $this->_queryWeight = $this->_idf * $this->_query->getBoost();

        // square it

        return $this->_queryWeight * $this->_queryWeight;

    }

    /**

     * Assigns the query normalization factor to this.

     *

     * @param float $queryNorm

     */

    public function normalize($queryNorm)

    {

        $this->_queryNorm = $queryNorm;

        // normalize query weight

        $this->_queryWeight *= $queryNorm;

        // idf for documents

        $this->_value = $this->_queryWeight * $this->_idf;

    }

}