<?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 Index

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

 */

/**

 * A Term represents a word from text.  This is the unit of search.  It is

 * composed of two elements, the text of the word, as a string, and the name of

 * the field that the text occured in, an interned string.

 *

 * Note that terms may represent more than words from text fields, but also

 * things like dates, email addresses, urls, etc.

 *

 * @category   Zend

 * @package    Zend_Search_Lucene

 * @subpackage Index

 * @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_Index_Term

{

    /**

     * Field name or field number (depending from context)

     *

     * @var mixed

     */

    public $field;

    /**

     * Term value

     *

     * @var string

     */

    public $text;

    /**

     * Object constructor

     */

    public function __construct($text, $field = null)

    {

        $this->field = ($field === null)?  Zend_Search_Lucene::getDefaultSearchField() : $field;

        $this->text  = $text;

    }

    /**

     * Returns term key

     *

     * @return string

     */

    public function key()

    {

        return $this->field . chr(0) . $this->text;

    }

    /**

     * Get term prefix

     *

     * @param string $str

     * @param integer $length

     * @return string

     */

    public static function getPrefix($str, $length)

    {

        $prefixBytes = 0;

        $prefixChars = 0;

        while ($prefixBytes < strlen($str)  &&  $prefixChars < $length) {

            $charBytes = 1;

            if ((ord($str[$prefixBytes]) & 0xC0) == 0xC0) {

                $charBytes++;

                if (ord($str[$prefixBytes]) & 0x20 ) {

                    $charBytes++;

                    if (ord($str[$prefixBytes]) & 0x10 ) {

                        $charBytes++;

                    }

                }

            }

            if ($prefixBytes + $charBytes > strlen($str)) {

                // wrong character

                break;

            }

            $prefixChars++;

            $prefixBytes += $charBytes;

        }

        return substr($str, 0, $prefixBytes);

    }

    /**

     * Get UTF-8 string length

     *

     * @param string $str

     * @return string

     */

    public static function getLength($str)

    {

        $bytes = 0;

        $chars = 0;

        while ($bytes < strlen($str)) {

            $charBytes = 1;

            if ((ord($str[$bytes]) & 0xC0) == 0xC0) {

                $charBytes++;

                if (ord($str[$bytes]) & 0x20 ) {

                    $charBytes++;

                    if (ord($str[$bytes]) & 0x10 ) {

                        $charBytes++;

                    }

                }

            }

            if ($bytes + $charBytes > strlen($str)) {

                // wrong character

                break;

            }

            $chars++;

            $bytes += $charBytes;

        }

        return $chars;

    }

}