#Gocha#

<?php

// This file is part of Moodle - http://moodle.org/
//
// Moodle 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.
//
// Moodle 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 Moodle. If not, see <http://www.gnu.org/licenses/>.

/**
 * @package filter
 * @subpackage multilang
 * @copyright Gaetan Frenoy <gaetan@frenoy.net>
 * @copyright 2004 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die();

// Given XML multilinguage text, return relevant text according to
// current language:
// - look for multilang blocks in the text.
// - if there exists texts in the currently active language, print them.
// - else, if there exists texts in the current parent language, print them.
// - else, print the first language in the text.
// Please note that English texts are not used as default anymore!
//
// This version is based on original multilang filter by Gaetan Frenoy,
// rewritten by Eloy and skodak.
//
// Following new syntax is not compatible with old one:
// one langanother language

class filter_multilang extends moodle_text_filter {
    function filter($text, array $options = array()) {
        global $CFG;

// [pj] I don't know about you but I find this new implementation funny :P
 // [skodak] I was laughing while rewriting it ;-)
 // [nicolasconnault] Should support inverted attributes: (Doesn't work curently)
 // [skodak] it supports it now, though it is slower - any better idea?

if (empty($text) or is_numeric($text)) {
            return $text;
        }

if (empty($CFG->filter_multilang_force_old) and !empty($CFG->filter_multilang_converted)) {
 // new syntax
 $search = '/(<span(\s+lang="[a-zA-Z0-9_-]+"|\s+class="multilang"){2}\s*>.*?<\/span>)(\s*<span(\s+lang="[a-zA-Z0-9_-]+"|\s+class="multilang"){2}\s*>.*?<\/span>)+/is';
 } else {
 // old syntax
 $search = '/(<(?:lang|span) lang="[a-zA-Z0-9_-]*".*?>.*?<\/(?:lang|span)>)(\s*<(?:lang|span) lang="[a-zA-Z0-9_-]*".*?>.*?<\/(?:lang|span)>)+/is';
 }

$result = preg_replace_callback($search, 'filter_multilang_impl', $text);

if (is_null($result)) {
            return $text; //error during regex processing (too many nested spans?)
        } else {
            return $result;
        }
    }
}

function filter_multilang_impl($langblock) {
    global $CFG;

$mylang = current_language();
    static $parentcache;
    if (!isset($parentcache)) {
        $parentcache = array();
    }
    if (!array_key_exists($mylang, $parentcache)) {
        $parentlang = get_parent_language($mylang);
        $parentcache[$mylang] = $parentlang;
    } else {
        $parentlang = $parentcache[$mylang];
    }

$searchtosplit = '/<(?:lang|span)[^>]+lang="([a-zA-Z0-9_-]+)"[^>]*>(.*?)<\/(?:lang|span)>/is';

if (!preg_match_all($searchtosplit, $langblock[0], $rawlanglist)) {
        //skip malformed blocks
        return $langblock[0];
    }

$langlist = array();
    foreach ($rawlanglist[1] as $index=>$lang) {
        $lang = str_replace('-','_',strtolower($lang)); // normalize languages
        $langlist[$lang] = $rawlanglist[2][$index];
    }

if (array_key_exists($mylang, $langlist)) {
        return $langlist[$mylang];
    } else if (array_key_exists($parentlang, $langlist)) {
        return $langlist[$parentlang];
    } else {
        $first = array_shift($langlist);
        return $first;
    }
}