<?php
/**
 * Class regrouping basic methods for download page.
 *
 * @copyright 2009-2011  Romain d'Alverny <rda>
 * @license GPL-3+
 *
*/
class Downloads
{
    /**
    */
    function __construct()
    {
    }
    /**
     * @param string $ua
     *
     * @return array
     *
     * @todo unit tests or use something else
     * Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_4_11; fr) AppleWebKit/533.18.1 (KHTML, like Gecko) Version/4.1.2 Safari/533.18.5
     * Mozilla/5.0 (X11; Linux i686; rv:2.0) Gecko/20110330 Firefox/4.0
     * other old ones
     *
     * @todo refactor this
    */
    public static function get_platform($ua = null)
    {
        if ($ua == '')
            return array(
                'arch'    => 'i586',
                'system'  => 'unknown',
                'locale'  => 'en',
                'browser' => null
            );

        $locale = null;

        if (preg_match_all('/([.^\(^\)]*) \((.*)\) (.*)/', $ua, $r))
        {
            $r = $r[2][0];
            $r = explode(';', $r);
            if (isset($r[3])) {
                $r = explode(')', trim($r[3]));
                if (strlen($r[0]) > 5)
                    $r = substr($r[0], 0, 5);
                else
                    $r = $r[0];
            }
            else
                $r = null;

            $locale = $r;
        }

        $arch = 'i586';
        if (strpos($ua, 'x86_64') !== false)
            $arch = 'x86_64';

        $sys = null;
        if (strpos($ua, 'Windows') !== false)
            $sys = 'win';
        elseif (strpos($ua, 'Macintosh') !== false
            || strpos($ua, 'Mac OS X') !== false)
            $sys = 'mac';
        elseif (strpos($ua, 'Linux') !== false)
            $sys = 'linux';

        $browser = null;
        if (strpos($ua, 'Firefox') !== false)
            $browser = 'firefox';
        elseif (strpos($ua, 'MSIE') !== false)
            $browser = 'msie';
        elseif (strpos($ua, 'Safari') !== false)
            $browser = 'safari';
        elseif (strpos($ua, 'Opera') !== false)
            $browser = 'opera';

        return array(
            'arch'    => $arch,
            'system'  => $sys,
            'locale'  => $locale, // FIXME (rda) use Accept-Language instead
            'browser' => $browser
        );
    }

    /**
     * Sort 2D array by multiple associative or numeric keys.
     * $sorted_array = self::sort_2d_array_by_multiple_keys($unsorted_array, 'first key', 'second', ...);
     *
     * based on SortArray http://php.net/manual/en/function.usort.php#42535
     *
     * @param array $unsorted_array
     *
     * @param string first key to order by
     *
     * @param string second key to order by
     *
     * @param string add as many keys to order by as needed
     *
     * @return array $sorted_array
    */
    public static function sort_2d_array_by_multiple_keys()
    {
        $arguments = func_get_args();
        $array = $arguments[0];
        $anonymous_function = '';
        $num_of_arguments = count($arguments);
        for ($cur_argument = 1; $cur_argument < $num_of_arguments; $cur_argument++) {
            $anonymous_function .= "if (\$first['$arguments[$cur_argument]'] != \$second['$arguments[$cur_argument]']) {";
            $anonymous_function .= "    \$compare_result = strcoll(\$first['$arguments[$cur_argument]'], \$second['$arguments[$cur_argument]']);";
            $anonymous_function .= "    if (0 == \$compare_result) { return 0; };";
            $anonymous_function .= "    return ((0 > \$compare_result) ? -1 : 1);";
            $anonymous_function .= "}";
        }
        $anonymous_function .= "return 0;";
        $compare_function = create_function("\$first, \$second", $anonymous_function);
        usort($array, $compare_function);
        return $array;
    }

    /**
     * Get mirrors list from mirrors.mageia.org,
     * store/cache it in a different key/value format
     * (keys are: "$country" and "_C:$continent"),
     * and return it.
     *
     * Note that the mirrors list doesn't change with versions, for now;
     * it's a full or nothing list.
     *
     * @param boolean $prod
     * @param boolean $documentation
     * @param boolean $mirrorlist
     *
     * @return array
    */
    public static function get_all_mirrors($prod = true, $documentation = false, $mirrorlist = false)
    {
        if ($documentation) {
            $cache_file = realpath(__DIR__ . '/cached.list_doc.php');
        } else if ($mirrorlist) {
            $cache_file = realpath(__DIR__ . '/cached.list_mirrorlist.php');
        } else {
            $cache_file = realpath(__DIR__ . '/cached.list.php');
        }

        if ($prod) {
            require $cache_file;

        } else {
            $data    = file('http://mirrors.mageia.org/api/mageia.7.i586.list');
            $mirrors = array();
            $num_up  = 0;
            $num_dn  = 0;
            foreach ($data as $line) {
                $line = explode(',', trim($line));
                $m    = array();
                foreach ($line as $val) {
                    $val        = explode('=', trim($val));
                    if (!empty($val[1])) {
                        $m[$val[0]] = $val[1];
                    }
                }
                $pu = parse_url($m['url']);
                if (in_array($pu['scheme'], array('http', 'https', 'ftp'))) {
                    $item = array(
                        'zone'      => isset($m['zone']) ? $m['zone'] : '?',
                        'country'   => isset($m['country']) ? $m['country'] : '?',
                        'city'      => isset($m['city']) ? utf8_encode($m['city']) : '-',
                        // BEWARE of the path substitution here. Must match.
                        'url'       => str_replace('/distrib/7/i586', '', $m['url'])
                    );

                    if ($documentation) {
                        $test_file = $item['url'].'/doc/mga7/date.txt';
                    } else if ($mirrorlist) {
                        $test_file = $item['url'].'/distrib/7/x86_64/media/core/updates/repodata/repomd.xml';
                    } else {
                        $test_file = $item['url'].'/iso/7.1/torrents/Mageia-7.1-x86_64.torrent';
                    }
                    if (false === @file_get_contents($test_file)) {
                        $num_dn++;
                        echo "Down ($num_dn) $test_file \n";
                    } else {
                        $num_up++;
                        echo "Up ($num_up) $test_file \n";
//                         $mirrors[$m['country']][]           = $item;
                        $mirrors['_C:' . $m['continent']][] = $item;
                    }
                }
            }
            ksort($mirrors);
            foreach ($mirrors as &$continent) {
                $continent = self::sort_2d_array_by_multiple_keys($continent, 'zone', 'country', 'city', 'url');
            }
            unset($continent);

            echo "\nThere are $num_up servers with the file and $num_dn with some kind of issue.\n";
            file_put_contents($cache_file,
                sprintf('<?php $mirrors = %s; ?>' . PHP_EOL, var_export($mirrors, true)));
        }
        return $mirrors;
    }

    /**
     * Get mirrors from stored dictionary and find best matching mirror:
     * - if it exists in the country otherwise
     * - on continent if it exists otherwise
     * - random mirror
     * It can also prepare a list of mirrors for mirrorlist page
     *
     * @param string $country
     * @param string $continent
     * @param boolean $prod
     * @param boolean $documentation
     * @param boolean $mirrorlist
     *
     * @return array
    */
    function get_mirror($country, $continent = null, $prod = true, $documentation = false, $mirrorlist = false)
    {
        $mirs      = self::get_all_mirrors($prod, $documentation, $mirrorlist);
        $continent = '_C:' . $continent;

        $mirrors       = array();
        $fr_mirr_asist = array();
        $list_of_mirrs = array(
            'country'                 => array(),
            'continent_minus_country' => array(),
            'other_continents'        => array()
        );
        foreach ($mirs as $curr_continent => $continent_mirrors) {
            if ($continent != $curr_continent)
            {
                if ($mirrorlist)
                {
                    foreach ($continent_mirrors as $mirror) {
                        $list_of_mirrs['other_continents'][] = $mirror['url'];
                    }
                }
                continue;
            }
            foreach ($continent_mirrors as $mirror) {
                if (strpos($mirror['url'], 'distrib-coffee.ipsl.jussieu.fr') !== false)
                {
                    // exclude source server to drop it's DL load
                    continue;
                }
                // keep assisting the french mirrors with german ones
                if ($mirror['country'] == 'DE')
                {
                    $fr_mirr_asist[] = $mirror;
                }
                // only add german mirrors when french are on turn
                // sorting of mirror db cache must be kept to work properly (DE before FR)
                if ($country == 'FR' && $mirror['country'] == 'FR' && count($fr_mirr_asist) > 0)
                {
                    $mirrors[$continent] = $fr_mirr_asist;
                    $fr_mirr_asist = array();
                }
                if ($mirrorlist)
                {
                    if ($mirror['country'] == $country)
                    {
                        $list_of_mirrs['country'][] = $mirror['url'];
                    }
                    else
                    {
                        $list_of_mirrs['continent_minus_country'][] = $mirror['url'];
                    }
                }
                else
                {
                    if ($mirror['country'] == $country)
                    {
                        $mirrors[$continent][] = $mirror;
                    }
                }
            }
            if (count($mirrors) == 0)
            {
                // add all continent mirrors if country doesn't have any
                $mirrors[$continent] = $continent_mirrors;
            }
        }
        if (count($mirrors) > 0)
        {
            $mirs = $mirrors;
        }

        shuffle($mirs);
        $mirr_continent = $mirs[0];
        $mirs = array_shift($mirs);
        shuffle($mirs);
        $one_mirror = array_shift($mirs);
        $one_mirror['continent'] = $mirr_continent;

        if ($mirrorlist)
        {
            shuffle($list_of_mirrs['country']);
            shuffle($list_of_mirrs['continent_minus_country']);
            shuffle($list_of_mirrs['other_continents']);
            $resulting_mirrs = array_merge(
                $list_of_mirrs['country'],
                $list_of_mirrs['continent_minus_country'],
                $list_of_mirrs['other_continents']
            );
            $one_mirror['mirrors_list'] = array_slice($resulting_mirrs, 0, 10);
        }

        return $one_mirror;
    }

    function prepare_download($force = false, $country = null, $prod = true, $documentation = false, $mirrorlist = false)
    {
        return $this->get_one_mirror($force, $country, $prod, $documentation, $mirrorlist);
    }

    /**
     * Setup session data about current visitor for downloads.
     *
     * @param boolean $force
     * @param string $country
     * @param boolean $prod
     * @param boolean $documentation
     * @param boolean $mirrorlist
     *
     * @return array
     *
     * TODO extract as much as possible $_SESSION(read) and $_SERVER and $_GET
    */
    function get_one_mirror($force = false, $country = null, $prod = true, $documentation = false, $mirrorlist = false)
    {
        $fuzzy_mirror = false;

        if (!is_null($country))
            $force = true;

        // FIXME break this into smaller parts and extract globals so we can test st
        if (!$force && isset($_SESSION['dl-data']))
        {
            //error_log(sprintf('Got session data: %s', print_r($_SESSION['dl-data'], true)));
            $system  = $_SESSION['dl-data']['system'];
            if (isset($_GET['mirror']))
            {
                $mirror                        = array('url' => $_GET['mirror']);
                $mirror['purl']                = parse_url($mirror['url']);
                $_SESSION['dl-data']['mirror'] = $mirror;
                $country                       = '';
            }
            else
            {
                $country = $_SESSION['dl-data']['country'];
                $mirror  = $_SESSION['dl-data']['mirror'];
            }
        }
        else
        {
            //error_log('getting platform');
            $system = self::get_platform($_SERVER['HTTP_USER_AGENT']);
            if (isset($_GET['mirror']))
            {
                $mirror         = array('url' => $_GET['mirror']);
                $mirror['purl'] = parse_url($mirror['url']);
                $country        = null;
            }
            else
            {
                //error_log('no mirror set yet');
                if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])
                    && $str = $_SERVER['HTTP_X_FORWARDED_FOR'])
                {
                    $arr = explode(', ', $str);
                    $ip  = $arr[0];
                }
                else
                    $ip = $_SERVER['REMOTE_ADDR'];

                $_SESSION['ip'] = $ip;
                if (is_null($country))
                {
                    require_once realpath(__DIR__ . '/mga_geoip.php');
                    $country      = MGA_Geoip::mga_geoip_country_by_ip($ip, false);
                    $continent    = MGA_Geoip::mga_geoip_continent_by_country($country);
                    $fuzzy_mirror = true;
                    $_SESSION['country']   = $country;
                    $_SESSION['continent'] = $continent;
                }
                if (!isset($continent))
                {
                    $continent = null;
                }

                $mirror         = $this->get_mirror($country, $continent, $prod, $documentation, $mirrorlist);
                $mirror['purl'] = parse_url($mirror['url']);

                // reassign country, as get_one_mirror() may have decided
                // to return a mirror from another country than the one
                // requested initially - @see get_one_mirror()
                $country   = $mirror['zone'];
                $continent = $mirror['continent'];

                if (is_null($mirror)) {
                    // @todo?
                }
            }

            // write to session
            $_SESSION['dl-data'] = array(
                'system'    => $system,
                'country'   => $country,
                'continent' => $continent,
                'mirror'    => $mirror
            );
        }
        if (!isset($mirror['mirrors_list']))
        {
            $mirror['mirrors_list'] = array();
        }
        return array(
            'arch'          => $system['arch'],
            'mirror_host'   => $mirror['purl']['host'],
            'mirror_scheme' => $mirror['purl']['scheme'],
            'mirror_url'    => $mirror['url'],
            'country'       => $country,
            'continent'     => $continent,
            'city'          => $mirror['city'],
            'fuzzy_mirror'  => $fuzzy_mirror,
            'mirrors_list'  => $mirror['mirrors_list'],
        );
    }
}