/ManoWars/libs/Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php

<?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) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)

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

 * @version    $Id: Fuzzy.php 16971 2009-07-22 18:05:45Z mikaelkael $

 */





/** Zend_Search_Lucene_Search_Query_Processing */

require_once 'Zend/Search/Lucene/Search/Query/Preprocessing.php';



/** Zend_Search_Lucene_Search_Query_Phrase */

require_once 'Zend/Search/Lucene/Search/Query/Phrase.php';



/** Zend_Search_Lucene_Search_Query_Insignificant */

require_once 'Zend/Search/Lucene/Search/Query/Insignificant.php';



/** Zend_Search_Lucene_Search_Query_Empty */

require_once 'Zend/Search/Lucene/Search/Query/Empty.php';



/** Zend_Search_Lucene_Search_Query_Term */

require_once 'Zend/Search/Lucene/Search/Query/Term.php';



/** Zend_Search_Lucene_Index_Term */

require_once 'Zend/Search/Lucene/Index/Term.php';





/**

 * It's an internal abstract class intended to finalize ase a query processing after query parsing.

 * This type of query is not actually involved into query execution.

 *

 * @category   Zend

 * @package    Zend_Search_Lucene

 * @subpackage Search

 * @internal

 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)

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

 */

class Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy extends Zend_Search_Lucene_Search_Query_Preprocessing

{

    /**

     * word (query parser lexeme) to find.

     *

     * @var string

     */

    private $_word;



    /**

     * Word encoding (field name is always provided using UTF-8 encoding since it may be retrieved from index).

     *

     * @var string

     */

    private $_encoding;





    /**

     * Field name.

     *

     * @var string

     */

    private $_field;



    /**

     * A value between 0 and 1 to set the required similarity

     *  between the query term and the matching terms. For example, for a

     *  _minimumSimilarity of 0.5 a term of the same length

     *  as the query term is considered similar to the query term if the edit distance

     *  between both terms is less than length(term)*0.5

     *

     * @var float

     */

    private $_minimumSimilarity;



    /**

     * Class constructor.  Create a new preprocessing object for prase query.

     *

     * @param string $word       Non-tokenized word (query parser lexeme) to search.

     * @param string $encoding   Word encoding.

     * @param string $fieldName  Field name.

     * @param float  $minimumSimilarity minimum similarity

     */

    public function __construct($word, $encoding, $fieldName, $minimumSimilarity)

    {

        $this->_word     = $word;

        $this->_encoding = $encoding;

        $this->_field    = $fieldName;

        $this->_minimumSimilarity = $minimumSimilarity;

    }



    /**

     * Re-write query into primitive queries in the context of specified index

     *

     * @param Zend_Search_Lucene_Interface $index

     * @return Zend_Search_Lucene_Search_Query

     */

    public function rewrite(Zend_Search_Lucene_Interface $index)

    {

        if ($this->_field === null) {

            $query = new Zend_Search_Lucene_Search_Query_Boolean();



            $hasInsignificantSubqueries = false;



            if (Zend_Search_Lucene::getDefaultSearchField() === null) {

                $searchFields = $index->getFieldNames(true);

            } else {

                $searchFields = array(Zend_Search_Lucene::getDefaultSearchField());

            }



            foreach ($searchFields as $fieldName) {

                $subquery = new Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy($this->_word,

                                                                                    $this->_encoding,

                                                                                    $fieldName,

                                                                                    $this->_minimumSimilarity);



                $rewrittenSubquery = $subquery->rewrite($index);



                if ( !($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant  ||

                       $rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Empty) ) {

                    $query->addSubquery($rewrittenSubquery);

                }



                if ($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant) {

                	$hasInsignificantSubqueries = true;

                }

            }



            $subqueries = $query->getSubqueries();



            if (count($subqueries) == 0) {

            	$this->_matches = array();

                if ($hasInsignificantSubqueries) {

                    return new Zend_Search_Lucene_Search_Query_Insignificant();

                } else {

                    return new Zend_Search_Lucene_Search_Query_Empty();

                }

            }



            if (count($subqueries) == 1) {

            	$query = reset($subqueries);

            }



            $query->setBoost($this->getBoost());



            $this->_matches = $query->getQueryTerms();

            return $query;

        }



        // -------------------------------------

        // Recognize exact term matching (it corresponds to Keyword fields stored in the index)

        // encoding is not used since we expect binary matching

        $term = new Zend_Search_Lucene_Index_Term($this->_word, $this->_field);

        if ($index->hasTerm($term)) {

            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);

            $query->setBoost($this->getBoost());



            // Get rewritten query. Important! It also fills terms matching container.

            $rewrittenQuery = $query->rewrite($index);

            $this->_matches = $query->getQueryTerms();



            return $rewrittenQuery;

        }





        // -------------------------------------

        // Recognize wildcard queries



        /** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */

        if (@preg_match('/\pL/u', 'a') == 1) {

        	$subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));

        } else {

        	$subPatterns = preg_split('/[*?]/', $this->_word);

        }

        if (count($subPatterns) > 1) {

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

            throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search doesn\'t support wildcards (except within Keyword fields).');

        }





        // -------------------------------------

        // Recognize one-term multi-term and "insignificant" queries

        $tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);



        if (count($tokens) == 0) {

        	$this->_matches = array();

            return new Zend_Search_Lucene_Search_Query_Insignificant();

        }



        if (count($tokens) == 1) {

            $term  = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);

            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);

            $query->setBoost($this->getBoost());



            // Get rewritten query. Important! It also fills terms matching container.

            $rewrittenQuery = $query->rewrite($index);

            $this->_matches = $query->getQueryTerms();



            return $rewrittenQuery;

        }



        // Word is tokenized into several tokens

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

        throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search is supported only for non-multiple word terms');

    }



    /**

     * Query specific matches highlighting

     *

     * @param Zend_Search_Lucene_Search_Highlighter_Interface $highlighter  Highlighter object (also contains doc for highlighting)

     */

    protected function _highlightMatches(Zend_Search_Lucene_Search_Highlighter_Interface $highlighter)

    {

    	/** Skip fields detection. We don't need it, since we expect all fields presented in the HTML body and don't differentiate them */



    	/** Skip exact term matching recognition, keyword fields highlighting is not supported */



        // -------------------------------------

        // Recognize wildcard queries



        /** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */

        if (@preg_match('/\pL/u', 'a') == 1) {

            $subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));

        } else {

            $subPatterns = preg_split('/[*?]/', $this->_word);

        }

        if (count($subPatterns) > 1) {

            // Do nothing

            return;

        }



        // -------------------------------------

        // Recognize one-term multi-term and "insignificant" queries

        $tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);

        if (count($tokens) == 0) {

            // Do nothing

            return;

        }

        if (count($tokens) == 1) {

            $term  = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);

            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);



            $query->_highlightMatches($highlighter);

            return;

        }



        // Word is tokenized into several tokens

        // But fuzzy search is supported only for non-multiple word terms

        // Do nothing

    }



    /**

     * Print a query

     *

     * @return string

     */

    public function __toString()

    {

        // It's used only for query visualisation, so we don't care about characters escaping

        if ($this->_field !== null) {

            $query = $this->_field . ':';

        } else {

            $query = '';

        }



        $query .= $this->_word;



        if ($this->getBoost() != 1) {

            $query .= '^' . round($this->getBoost(), 4);

        }



        return $query;

    }

}