XRDS.php

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<?php

require_once 'Auth/Yadis/XML.php';

define('SERVICES_YADIS_MATCH_ALL', 101);

define('SERVICES_YADIS_MATCH_ANY', 102);

define('SERVICES_YADIS_MAX_PRIORITY', pow(2, 30));

define('Auth_Yadis_XMLNS_XRD_2_0', 'xri://$xrd*($v*2.0)');

define('Auth_Yadis_XMLNS_XRDS', 'xri://$xrds');

function Auth_Yadis_getNSMap()
{
    return array('xrds' => Auth_Yadis_XMLNS_XRDS,
                 'xrd' => Auth_Yadis_XMLNS_XRD_2_0);
}

function Auth_Yadis_array_scramble($arr)
{
    $result = array();

    while (count($arr)) {
        $index = array_rand($arr, 1);
        $result[] = $arr[$index];
        unset($arr[$index]);
    }

    return $result;
}

class Auth_Yadis_Service {

    function Auth_Yadis_Service()
    {
        $this->element = null;
        $this->parser = null;
    }

    function getTypes()
    {
        $t = array();
        foreach ($this->getElements('xrd:Type') as $elem) {
            $c = $this->parser->content($elem);
            if ($c) {
                $t[] = $c;
            }
        }
        return $t;
    }

    function matchTypes($type_uris)
    {
        $result = array();

        foreach ($this->getTypes() as $typ) {
            if (in_array($typ, $type_uris)) {
                $result[] = $typ;
            }
        }

        return $result;
    }

    function getURIs()
    {
        $uris = array();
        $last = array();

        foreach ($this->getElements('xrd:URI') as $elem) {
            $uri_string = $this->parser->content($elem);
            $attrs = $this->parser->attributes($elem);
            if ($attrs &&
                array_key_exists('priority', $attrs)) {
                $priority = intval($attrs['priority']);
                if (!array_key_exists($priority, $uris)) {
                    $uris[$priority] = array();
                }

                $uris[$priority][] = $uri_string;
            } else {
                $last[] = $uri_string;
            }
        }

        $keys = array_keys($uris);
        sort($keys);

        // Rebuild array of URIs.
        $result = array();
        foreach ($keys as $k) {
            $new_uris = Auth_Yadis_array_scramble($uris[$k]);
            $result = array_merge($result, $new_uris);
        }

        $result = array_merge($result,
                              Auth_Yadis_array_scramble($last));

        return $result;
    }

    function getPriority()
    {
        $attributes = $this->parser->attributes($this->element);

        if (array_key_exists('priority', $attributes)) {
            return intval($attributes['priority']);
        }

        return null;
    }

    function getElements($name)
    {
        return $this->parser->evalXPath($name, $this->element);
    }
}

/*
 * Return the expiration date of this XRD element, or None if no
 * expiration was specified.
 *
 * @param $default The value to use as the expiration if no expiration
 * was specified in the XRD.
 */
function Auth_Yadis_getXRDExpiration($xrd_element, $default=null)
{
    $expires_element = $xrd_element->$parser->evalXPath('/xrd:Expires');
    if ($expires_element === null) {
        return $default;
    } else {
        $expires_string = $expires_element->text;

        // Will raise ValueError if the string is not the expected
        // format
        $t = strptime($expires_string, "%Y-%m-%dT%H:%M:%SZ");

        if ($t === false) {
            return false;
        }

        // [int $hour [, int $minute [, int $second [,
        //  int $month [, int $day [, int $year ]]]]]]
        return mktime($t['tm_hour'], $t['tm_min'], $t['tm_sec'],
                      $t['tm_mon'], $t['tm_day'], $t['tm_year']);
    }
}

class Auth_Yadis_XRDS {

    function Auth_Yadis_XRDS($xmlParser, $xrdNodes)
    {
        $this->parser = $xmlParser;
        $this->xrdNode = $xrdNodes[count($xrdNodes) - 1];
        $this->allXrdNodes = $xrdNodes;
        $this->serviceList = array();
        $this->_parse();
    }

    static function parseXRDS($xml_string, $extra_ns_map = null)
    {
        $_null = null;

        if (!$xml_string) {
            return $_null;
        }

        $parser = Auth_Yadis_getXMLParser();

        $ns_map = Auth_Yadis_getNSMap();

        if ($extra_ns_map && is_array($extra_ns_map)) {
            $ns_map = array_merge($ns_map, $extra_ns_map);
        }

        if (!($parser && $parser->init($xml_string, $ns_map))) {
            return $_null;
        }

        // Try to get root element.
        $root = $parser->evalXPath('/xrds:XRDS[1]');
        if (!$root) {
            return $_null;
        }

        if (is_array($root)) {
            $root = $root[0];
        }

        $attrs = $parser->attributes($root);

        if (array_key_exists('xmlns:xrd', $attrs) &&
            $attrs['xmlns:xrd'] != Auth_Yadis_XMLNS_XRDS) {
            return $_null;
        } else if (array_key_exists('xmlns', $attrs) &&
                   preg_match('/xri/', $attrs['xmlns']) &&
                   $attrs['xmlns'] != Auth_Yadis_XMLNS_XRD_2_0) {
            return $_null;
        }

        // Get the last XRD node.
        $xrd_nodes = $parser->evalXPath('/xrds:XRDS[1]/xrd:XRD');

        if (!$xrd_nodes) {
            return $_null;
        }

        $xrds = new Auth_Yadis_XRDS($parser, $xrd_nodes);
        return $xrds;
    }

    function _addService($priority, $service)
    {
        $priority = intval($priority);

        if (!array_key_exists($priority, $this->serviceList)) {
            $this->serviceList[$priority] = array();
        }

        $this->serviceList[$priority][] = $service;
    }

    function _parse()
    {
        $this->serviceList = array();

        $services = $this->parser->evalXPath('xrd:Service', $this->xrdNode);

        foreach ($services as $node) {
            $s = new Auth_Yadis_Service();
            $s->element = $node;
            $s->parser = $this->parser;

            $priority = $s->getPriority();

            if ($priority === null) {
                $priority = SERVICES_YADIS_MAX_PRIORITY;
            }

            $this->_addService($priority, $s);
        }
    }

    function services($filters = null,
                      $filter_mode = SERVICES_YADIS_MATCH_ANY)
    {

        $pri_keys = array_keys($this->serviceList);
        sort($pri_keys, SORT_NUMERIC);

        // If no filters are specified, return the entire service
        // list, ordered by priority.
        if (!$filters ||
            (!is_array($filters))) {

            $result = array();
            foreach ($pri_keys as $pri) {
                $result = array_merge($result, $this->serviceList[$pri]);
            }

            return $result;
        }

        // If a bad filter mode is specified, return null.
        if (!in_array($filter_mode, array(SERVICES_YADIS_MATCH_ANY,
                                          SERVICES_YADIS_MATCH_ALL))) {
            return null;
        }

        // Otherwise, use the callbacks in the filter list to
        // determine which services are returned.
        $filtered = array();

        foreach ($pri_keys as $priority_value) {
            $service_obj_list = $this->serviceList[$priority_value];

            foreach ($service_obj_list as $service) {

                $matches = 0;

                foreach ($filters as $filter) {

                    if (call_user_func_array($filter, array($service))) {
                        $matches++;

                        if ($filter_mode == SERVICES_YADIS_MATCH_ANY) {
                            $pri = $service->getPriority();
                            if ($pri === null) {
                                $pri = SERVICES_YADIS_MAX_PRIORITY;
                            }

                            if (!array_key_exists($pri, $filtered)) {
                                $filtered[$pri] = array();
                            }

                            $filtered[$pri][] = $service;
                            break;
                        }
                    }
                }

                if (($filter_mode == SERVICES_YADIS_MATCH_ALL) &&
                    ($matches == count($filters))) {

                    $pri = $service->getPriority();
                    if ($pri === null) {
                        $pri = SERVICES_YADIS_MAX_PRIORITY;
                    }

                    if (!array_key_exists($pri, $filtered)) {
                        $filtered[$pri] = array();
                    }
                    $filtered[$pri][] = $service;
                }
            }
        }

        $pri_keys = array_keys($filtered);
        sort($pri_keys, SORT_NUMERIC);

        $result = array();
        foreach ($pri_keys as $pri) {
            $result = array_merge($result, $filtered[$pri]);
        }

        return $result;
    }
}