<?php
/*
 * 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; under version 2
 * of the License (non-upgradable).
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2002-2008 (original work) Public Research Centre Henri Tudor & University of Luxembourg (under the project TAO & TAO2);
 *               2008-2010 (update and modification) Deutsche Institut für Internationale Pädagogische Forschung (under the project TAO-TRANSFER);
 *               2009-2012 (update and modification) Public Research Centre Henri Tudor (under the project TAO-SUSTAIN & TAO-DEV);
 *
 */
?>
<?php
/**
 * This class aims at providing utilities about the current installation from
 * the host system and its filesystem, including the tao platform directory.
 *
 * @author Somsack Sipasseuth <somsack.sipasseuth@tudor.lu>
 * @author Jerome Bogaerts <jerome.bogaerts@tudor.lu>
 * @package tao

 */
class tao_install_utils_System
{

    /**
     * Checks if system is installed in Debug mode.
     *
     * @return bool
     */
    public static function isTAOInDebugMode()
    {
        return defined('DEBUG_MODE') && DEBUG_MODE;
    }

    /**
     * Get informations on the host system.
     *
     * @return array where key/values are 'folder' as string, 'host' as string, 'https' as boolean.
     */
    public static function getInfos()
    {
                
                
        //subfolder shall be detected as /SUBFLODERS/tao/install/index.php so we remove the "/extension/module/action" part:
        $subfolder = $_SERVER['REQUEST_URI'];
        $subfolder = preg_replace('/\/(([^\/]*)\/){2}([^\/]*)$/', '', $subfolder);
        $subfolder = preg_replace('/^\//', '', $subfolder);
        
        return [
            'folder'    => $subfolder,
            'host'      => $_SERVER['HTTP_HOST'],
            'https'     => ($_SERVER['SERVER_PORT'] == 443)
        ];
    }
    
    /**
     * Check if TAO is already installed.
     *
     * @return boolean
     */
    public static function isTAOInstalled($path = '')
    {
        $path = (empty($path)) ? __DIR__ . '/../../../config' : rtrim($path, '/\\');
        $config = "${path}/generis.conf.php";
        return file_exists($config);
    }

    /**
     * Check if TAO is already up to date.
     *
     * @return boolean
     */
    public static function isTAOUpToDate($path = '')
    {
        $path = (empty($path)) ? __DIR__ . '/../../../config' : rtrim($path, '/\\');
        $generisConf = "${path}/generis.conf.php";

        if (!is_readable($generisConf)) {
            return false;
        }

        include_once($generisConf);
        $installationConf = "${path}/generis/installation.conf.php";

        if (!is_readable($installationConf)) {
            return false;
        }

        $conf = include_once($installationConf);
        $extIterator = is_array($conf) ? $conf : $conf->getConfig();

        foreach ($extIterator as $extName => $ext) {
            $manifestPath = __DIR__ . "/../../../${extName}/manifest.php";

            if (!is_readable($manifestPath)) {
                return false;
            } else {
                $manifest = include_once($manifestPath);

                if ((!isset($ext["installed"])) || (!isset($manifest["version"])) || ($ext["installed"] !== $manifest["version"])) {
                    return false;
                }
            }
        }

        return true;
    }
    
    /**
     * Returns the availables locales (languages or cultures) of the tao platform
     * on the basis of a particular locale folder e.g.  the /locales folder of the tao
     * meta-extension.
     *
     * A locale will be included in the resulting array only if a valid 'lang.rdf'
     * file is found.
     *
     * @param string $path The location of the /locales folder to inspect.
     * @return array An array of strings where keys are the language code and values the language label.
     * @throws UnexpectedValueException
     */
    public static function getAvailableLocales($path)
    {
        $locales = @scandir($path);
        $returnValue = [];
        
        if ($locales !== false) {
            foreach ($locales as $l) {
                if ($l[0] !== '.') {
                    // We found a locale folder. Does it contain a valid lang.rdf file?
                    $langFilePath = $path . '/' . $l . '/lang.rdf';
                    if (is_file($langFilePath) && is_readable($langFilePath)) {
                        try {
                            $doc = new DOMDocument('1.0', 'UTF-8');
                            $doc->load($langFilePath);
                            $xpath = new DOMXPath($doc);
                            $xpath->registerNamespace('rdf', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#');
                            $xpath->registerNamespace('rdfs', 'http://www.w3.org/2000/01/rdf-schema#');
                            $expectedUri = 'http://www.tao.lu/Ontologies/TAO.rdf#Lang' . $l;
                            
                            // Look for an rdf:value equals to the folder name.
                            $rdfValues = $xpath->query("//rdf:Description[@rdf:about='${expectedUri}']/rdf:value");
                            if ($rdfValues->length == 1 && $rdfValues->item(0)->nodeValue == $l) {
                                $key = $l;
                                
                                $rdfsLabels = $xpath->query("//rdf:Description[@rdf:about='${expectedUri}']/rdfs:label[@xml:lang='en-US']");
                                if ($rdfsLabels->length == 1) {
                                    $value = $rdfsLabels->item(0)->nodeValue;
                                    $returnValue[$l] = $value;
                                }
                            }
                        } catch (DOMException $e) {
                            // Invalid lang.rdf file, we continue to look for other ones.
                            continue;
                        }
                    }
                }
            }

            return $returnValue;
        } else {
            throw new UnexpectedValueException("Unable to list locales in '${path}'.");
        }
    }
}