<?php
/** 
 *  SeekQuarry/Yioop --
 *  Open Source Pure PHP Search Engine, Crawler, and Indexer
 *
 *  Copyright (C) 2009, 2010, 2011  Chris Pollett hide@address.com
 *
 *  LICENSE:
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  END LICENSE
 *
 * @author Chris Pollett hide@address.com
 * @package seek_quarry
 * @subpackage processor
 * @license http://www.gnu.org/licenses/ GPL3
 * @link http://www.seekquarry.com/
 * @copyright 2009, 2010, 2011
 * @filesource
 */

if(!defined('BASE_DIR')) {echo "BAD REQUEST"; exit();}

/**
 * Load base class, if needed
 */
require_once BASE_DIR."/lib/processors/text_processor.php";

/**
 * Used to create crawl summary information 
 * for RTF files
 *
 * @author Chris Pollett
 * @package seek_quarry
 * @subpackage processor
 */
class RtfProcessor extends TextProcessor
{

    /**
     * Computes a summary based on a rtf string of a document
     *
     * @param string $page rtf string of a document
     * @param string $url location the document came from, not used by 
     *      RTFProcessor at this point.
     *
     * @return array a summary of (title, description,links, and content) of 
     *      the information in $page
     */
    function process($page, $url)
    {
        $text = "";
        if(is_string($page)) {
            $text =  self::extractText($page);
        }

        if($text == "") {
            $text = $url;
        }

        $summary = parent::process($text, $url);

        return $summary;
    
    }

    /**
     * Gets plain text out of an rtf string
     *
     * Plain text is mainly extracted by getText(), this function does
     * some pre and post processing of escape braces and stuff
     *
     * @param string $rtf_string what to extract plain text out of
     * @return string plain texts
     */
    static function extractText($rtf_string) {
        $rtf_string = preg_replace('/\\\{/',"!ZZBL!", $rtf_string);
        $rtf_string = preg_replace('/\\\}/',"!ZZBR!", $rtf_string);
        $rtf_string = preg_replace('/\\\\\'d\d/',"'", $rtf_string);
        $rtf_string = preg_replace('/\\\\\'b\d/',"'", $rtf_string);

        $out = self::getText($rtf_string);

        $out = preg_replace("!ZZBL!",'/\\\{/', $out);
        $out = preg_replace("!ZZBR!", '/\\\}/', $out);


        return $out;
    }

    /**
     * Gets plain text out of an rtf string
     *
     * @param string $rtf_string what to extract plain text out of
     * @return string plain texts
     */
    static function getText($rtf_string) 
    {
        $len = strlen($rtf_string);
        $cur_pos = 0;
        $out = "";

        $i = 0;
        while($cur_pos < $len) {

        list($cur_pos, $object_string) = 
            self::getNextObject($rtf_string, $cur_pos);
        if(strpos($object_string, "{")) {
            $out .= self::getText($object_string);
        } else {
            if (preg_match('/\\\/',$object_string) == 0) {
                $out .=  $object_string;
            } else if(preg_match('/\\\(par)/', $object_string) > 0) {
                $text = preg_replace('/\\\(\w)+/', "", $object_string);
                $out .= $text."\n";
            } else if(preg_match(
                '/(\\\(title)|\\\(author)|\\\(operator)|\\\(company))/', 
                $object_string) > 0) {
                $text = preg_replace('/\\\(\w)+/', "", $object_string);
                $out .= $text."\n\n";
            }
        }

        }

        return $out;

    }

    /**
     * Gets the contents of the rtf group at the current position in the string
     *
     * @param string $rtf_string data to get rtf group from
     * @param int $cur_pos position in $rtf_string at which to get  group
     * @return string contents of rtf groups
     */
    static function getNextObject($rtf_string, $cur_pos) 
    {
        return self::getBetweenTags($rtf_string, $cur_pos, '{', '}'); 
    }


}

?>