class.ilLinkChecker.php

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<?php
/* Copyright (c) 1998-2009 ILIAS open source, Extended GPL, see docs/LICENSE */

class ilLinkChecker
{
    public $db = null;
    public $log_messages = array();
    public $invalid_links = array();

    public $validate_all = true;
    public $mail_status = false;
    public $page_id = 0;


    public function __construct($db, $a_validate_all = true)
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];

        define('DEBUG', 1);
        define('SOCKET_TIMEOUT', 5);
        define('MAX_REDIRECTS', 5);

        $this->db = $db;

        // SET GLOBAL DB HANDLER FOR STATIC METHODS OTHER CLASSES
        $ilDB = $db;

        $this->validate_all = $a_validate_all;
    }

    public function setCheckPeriod($a_period)
    {
        $this->period = $a_period;
    }
    public function getCheckPeriod()
    {
        return $this->period;
    }

    public function setMailStatus($a_status)
    {
        $this->mail_status = (bool) $a_status;
    }
    public function getMailStatus()
    {
        return (bool) $this->mail_status;
    }

    public function __setType($a_type)
    {
        $this->type = $a_type;
    }
    public function __getType()
    {
        return $this->type;
    }

    public function setObjId($a_page_id)
    {
        return $this->page_id = $a_page_id;
    }
    public function getObjId()
    {
        return $this->page_id;
    }

    public function getValidateAll()
    {
        return $this->validate_all ? true : false;
    }

    public function getLogMessages()
    {
        return $this->log_messages ? $this->log_messages : array();
    }

    public function getInvalidLinks()
    {
        return $this->invalid_links ? $this->invalid_links : array();
    }

    public function getInvalidLinksFromDB()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        $query = "SELECT * FROM link_check " .
            "WHERE obj_id = " . $ilDB->quote($this->getObjId(), 'integer') . " ";

        $res = $this->db->query($query);
        while ($row = $res->fetchRow(ilDBConstants::FETCHMODE_OBJECT)) {
            $invalid[] = array('page_id' => $row->page_id,
                               'url' => $row->url);
        }

        return $invalid ? $invalid : array();
    }

    public function getLastCheckTimestamp()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        if ($this->getValidateAll()) {
            $query = "SELECT MAX(last_check) last_check FROM link_check ";
        } else {
            $query = "SELECT MAX(last_check) last_check FROM link_check " .
                "WHERE obj_id = " . $ilDB->quote($this->getObjId(), 'integer') . " ";
        }
        $res = $ilDB->query($query);
        $row = $ilDB->fetchObject($res);

        return $row->last_check ? $row->last_check : 0;
    }

    public function checkWebResourceLinks()
    {
        $pages = array();

        $this->__setType('webr');
        $this->__clearLogMessages();
        $this->__clearInvalidLinks();
        $this->__appendLogMessage('LinkChecker: Start checkLinks()');

        if (count($invalid = $this->__validateLinks($this->__getWebResourceLinks()))) {
            foreach ($invalid as $invalid_item) {
                $this->__appendLogMessage('LinkChecker: found invalid link: ' . $invalid_item['complete']);
                $this->__appendInvalidLink($invalid_item);
            }
        }
        
        $this->__appendLogMessage('LinkChecker: End checkLinks()');
        $this->__saveInDB();
        
        $this->__sendMail();
        
        return $this->getInvalidLinks();
    }
    
    public function checkLinks()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        $pages = array();

        $this->__setType('lm');
        $this->__clearLogMessages();
        $this->__clearInvalidLinks();
        $this->__appendLogMessage('LinkChecker: Start checkLinks()');

        if (!$this->getValidateAll() and !$this->getObjId()) {
            echo "ilLinkChecker::checkLinks() No Page id given";

            return false;
        } elseif (!$this->getValidateAll() and $this->getObjId()) {
            $query = "SELECT * FROM page_object " .
                "WHERE parent_id = " . $ilDB->quote($this->getObjId()) . " " .
                "AND parent_type = 'lm'";

            $res = $this->db->query($query);
            while ($row = $res->fetchRow(ilDBConstants::FETCHMODE_OBJECT)) {
                $pages[] = array('page_id' => $row->page_id,
                                 'content' => $row->content,
                                 'type' => $row->parent_type);
            }
        } elseif ($this->getValidateAll()) {
            $query = "SELECT * FROM page_object " .
                "WHERE parent_type = 'lm'";

            $res = $this->db->query($query);
            while ($row = $res->fetchRow(ilDBConstants::FETCHMODE_OBJECT)) {
                $pages[] = array('page_id' => $row->page_id,
                                 'content' => $row->content,
                                 'type' => $row->parent_type);
            }
        }

        // VALIDATE
        foreach ($pages as $page) {
            if (count($invalid = $this->__validateLinks($this->__getLinks($page)))) {
                foreach ($invalid as $invalid_item) {
                    $this->__appendLogMessage('LinkChecker: found invalid link: ' . $invalid_item['complete']);
                    $this->__appendInvalidLink($invalid_item);
                }
            }
        }
        
        $this->__appendLogMessage('LinkChecker: End checkLinks()');
        $this->__saveInDB();

        $this->__sendMail();

        return $this->getInvalidLinks();
    }

    // PRIVATE
    public function __txt($language, $key, $module = 'common')
    {
        return ilLanguage::_lookupEntry($language, $module, $key);
    }

    public function __fetchUserData($a_usr_id)
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];

        $r = $this->db->query("SELECT email FROM usr_data WHERE usr_id = " . $ilDB->quote($a_usr_id));

        $row = $r->fetchRow(ilDBConstants::FETCHMODE_OBJECT);

        $data['email'] = $row->email;

        $set = $ilDB->query("SELECT * FROM usr_pref " .
            "WHERE usr_id = " . $ilDB->quote($a_usr_id, "integer") . " " .
            "AND keyword = " . $ilDB->quote('language', "text"));

        $row = $ilDB->fetchObject($set);

        $data['lang'] = $row->value;

        return $data;
    }

    public function __getTitle($a_lm_obj_id)
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];

        $r = $this->db->query("SELECT title FROM object_data " .
            "WHERE obj_id = " . $ilDB->quote($a_lm_obj_id, 'integer') . " ");

        $row = $r->fetchRow(ilDBConstants::FETCHMODE_OBJECT);

        return $row->title;
    }

    public function __sendMail()
    {
        global $DIC;

        $ilUser = $DIC['ilUser'];


        if (!count($notify = $this->__getNotifyLinks())) {
            // Nothing to do
            return true;
        }
        if (!$this->getMailStatus()) {
            return true;
        }


        $body = "";
        $obj_name = "";

        foreach (ilLinkCheckNotify::_getAllNotifiers($this->db) as $usr_id => $obj_ids) {
            if (!is_object($tmp_user = &ilObjectFactory::getInstanceByObjId($usr_id, false))) {
                $this->__appendLogMessage('LinkChecker: Cannot find user with id: ' . $usr_id);
                continue;
            }

            $counter = 0;
            foreach ($obj_ids as $obj_id) {
                if (!isset($notify[$obj_id])) {
                    continue;
                }
                ++$counter;

                switch ($this->__getType()) {
                    case 'webr':
                        $obj_name = $this->__txt($tmp_user->getLanguage(), 'obj_webr');
                        break;
                    case 'lm':
                    default:
                        $obj_name = $this->__txt($tmp_user->getLanguage(), 'lo');
                        break;
                }
                $body .= $obj_name . ': ' . $this->__getTitle($obj_id) . "\r\n";
                $body .= $this->__txt($tmp_user->getLanguage(), 'link_check_perma_link', "mail") . ": " .
                    $this->createPermanentLink($obj_id, $usr_id, $this->__getType()) . " \r\n";
                $body .= $this->__txt($tmp_user->getLanguage(), "link_check_affected_links", "mail") . ":\r\n";

                // Print all invalid
                foreach ($notify[$obj_id] as $data) {
                    $body .= $data['url'] . "\r\n";
                }
                $body .= "\r\n";
            }
            if ($counter) {
                $ntf = new ilSystemNotification();
                $ntf->setLangModules(array("mail", "common"));
                $ntf->setSubjectLangId("link_check_subject");
                $ntf->setIntroductionLangId("link_check_introduction");
                $ntf->setReasonLangId("link_check_reason");
                $ntf->addAdditionalInfo("additional_info", $body, true);
                $ntf->sendMail(array($tmp_user->getId()));

                $this->__appendLogMessage('LinkChecker: Sent mail to ' . $tmp_user->getEmail());
            }
            $body = "";
        }
    }

    protected function createPermanentLink($a_obj_id, $a_usr_id, $a_obj_type)
    {
        global $DIC;

        $ilAccess = $DIC['ilAccess'];
        $ref_ids = ilObject::_getAllReferences($a_obj_id);
        $ref_id = null;

        foreach ((array) $ref_ids as $id) {
            if ($ilAccess->checkAccessOfUser($a_usr_id, "read", "", $id, $a_obj_type, $a_obj_id)) {
                $ref_id = $id;
            }
        }

        if ($ref_id === null) {
            return false;
        }


        return ilLink::_getLink($ref_id, $a_obj_type);
    }

    public function __getNotifyLinks()
    {
        return $this->notify ? $this->notify : array();
    }


    public function __clearInvalidLinks()
    {
        $this->invalid_links = array();
    }
    public function __appendInvalidLink($a_link)
    {
        $this->invalid_links[] = $a_link;
    }
                    

    public function __appendLogMessage($a_string)
    {
        $this->log_messages[] = $a_string;
    }
    public function __clearLogMessages()
    {
        return $this->log_messages = array();
    }

    public function __getLinks($a_page)
    {
        $matches = array();

        $pattern_complete = '/<ExtLink Href="([^"]*)">/';
        if (preg_match_all($pattern_complete, $a_page['content'], $matches)) {
            for ($i = 0;$i < count($matches[0]); ++$i) {
                $url_data = @parse_url($matches[1][$i]);
                // continue if mailto link
                if ($url_data['scheme'] == 'mailto') {
                    continue;
                }
                
                // PUH, HTTP_REQUEST needs a beginning http://
                if (!$url_data['scheme']) {
                    $matches[1][$i] = 'http://' . $matches[1][$i];
                }

                $lm_id = $this->__getObjIdByPageId($a_page['page_id']);
                $link[] = array('page_id' => $a_page['page_id'],
                                'obj_id' => $lm_id,
                                'type' => $a_page['type'],
                                'complete' => $matches[1][$i],
                                'scheme' => isset($url_data['scheme']) ? $url_data['scheme'] : 'http',
                                'host' => isset($url_data['host']) ? $url_data['host'] : $url_data['path']);
            }
        }

        return $link ? $link : array();
    }

    public function __getWebResourceLinks()
    {
        global $DIC;

        $objDefinition = $DIC['objDefinition'];
        


        $link_res_obj = new ilLinkResourceItems($this->getObjId());

        foreach ($check_links = $link_res_obj->getCheckItems($this->getCheckPeriod()) as $item_data) {
            // #10091 - internal
            if (strpos($item_data['target'], '|')) {
                $parts = explode('|', $item_data['target']);
                if (sizeof($parts) == 2 &&
                    is_numeric($parts[1]) &&
                    $objDefinition->isAllowedInRepository($parts[0])) {
                    $link[] = array('page_id' => $item_data['link_id'],
                                'obj_id' => $this->getObjId(),
                                'type' => 'webr',
                                'complete' => $item_data['target'],
                                'scheme' => 'internal',
                                'obj_type' => $parts[0],
                                'ref_id' => $parts[1]);
                    continue;
                }
            }
            
            // external
            $url_data = @parse_url($item_data['target']);

            // PUH, HTTP_REQUEST needs a beginning http://
            if (!$url_data['scheme']) {
                $item_data['target'] = 'http://' . $item_data['target'];
            }

            $link[] = array('page_id' => $item_data['link_id'],
                        'obj_id' => $this->getObjId(),
                        'type' => 'webr',
                        'complete' => $item_data['target'],
                        'scheme' => isset($url_data['scheme']) ? $url_data['scheme'] : 'http',
                        'host' => isset($url_data['host']) ? $url_data['host'] : $url_data['path']);
        }
        return $link ? $link : array();
    }


    public function __validateLinks($a_links)
    {
        global $DIC;

        $tree = $DIC['tree'];
        if (!ilCurlConnection::_isCurlExtensionLoaded()) {
            $this->__appendLogMessage('LinkChecker: Pear HTTP_Request is not installed. Aborting');
            ilLoggerFactory::getLogger('lchk')->error('LinkChecker: Curl extension is not loeaded. Aborting');
            return array();
        }
        $invalid = array();

        foreach ($a_links as $link) {
            // #10091 - internal
            if ($link['scheme'] == 'internal') {
                $obj_id = ilObject::_lookupObjId($link['ref_id']);
                if (!$obj_id ||
                    ilObject::_lookupType($obj_id) != $link['obj_type'] ||
                    $tree->isDeleted($link['ref_id'])) {
                    $invalid[] = $link;
                }
            }
            // external
            else {
                //ilLoggerFactory::getLogger('lchk')->debug('Check: '.$link['complete']);

                if ($link['scheme'] !== 'http' and $link['scheme'] !== 'https') {
                    ilLoggerFactory::getLogger('lchk')->error('LinkChecker: Unkown link sheme "' . $link['scheme'] . '". Continue check');
                    continue;
                }

                $curl = null;
                $http_code = 0;
                $c_error_no = 0;
                try {
                    $curl = new ilCurlConnection($link['complete']);
                    $curl->init();

                    if (ilProxySettings::_getInstance()->isActive()) {
                        $curl->setOpt(CURLOPT_HTTPPROXYTUNNEL, true);
                        $curl->setOpt(CURLOPT_PROXY, ilProxySettings::_getInstance()->getHost());
                        $curl->setOpt(CURLOPT_PROXYPORT, ilProxySettings::_getInstance()->getPort());
                    }

                    $curl->setOpt(CURLOPT_HEADER, 1);
                    $curl->setOpt(CURLOPT_RETURNTRANSFER, 1);
                    $curl->setOpt(CURLOPT_CONNECTTIMEOUT, SOCKET_TIMEOUT);
                    $curl->setOpt(CURLOPT_FOLLOWLOCATION, 1);
                    $curl->setOpt(CURLOPT_MAXREDIRS, MAX_REDIRECTS);
                    $curl->exec();
                    $headers = $curl->getInfo();
                    $http_code = $headers['http_code'];
                } catch (ilCurlConnectionException $e) {
                    $c_error_no = $e->getCode();
                    ilLoggerFactory::getLogger('lchk')->error('LinkChecker: No valid http code received. Curl error (' . $e->getCode() . '): ' . $e->getMessage());
                } finally {
                    if ($curl != null) {
                        $curl->close();
                    }
                }

                switch ($http_code) {
                    // EVERYTHING OK
                    case '200':
                        // In the moment 301 will be handled as ok
                    case '301':
                    case '302':
                        break;
                    default:
                        $link['http_status_code'] = $http_code;
                        if ($http_code == 0 && $c_error_no != 0) {
                            $link['curl_errno'] = $c_error_no;
                        }
                        $invalid[] = $link;
                        break;
                }
            }
        }
        return $invalid;
    }

    public function __getObjIdByPageId($a_page_id)
    {
        $res = $this->db->query("SELECT lm_id FROM lm_data " .
            "WHERE obj_id = '" . $a_page_id . "'");

        $row = $res->fetchRow(ilDBConstants::FETCHMODE_OBJECT);

        return $row->lm_id ? $row->lm_id : 0;
    }

    public function __isInvalid($a_page_id, $a_url)
    {
        foreach ($this->getInvalidLinks() as $link) {
            if ($link['page_id'] == $a_page_id and
               substr($link['complete'], 0, 255) == $a_url) {
                return true;
            }
        }
        return false;
    }

    public function __saveInDB()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        if ($this->getMailStatus()) {
            $this->__checkNotify();
        }
        $this->__clearDBData();


        foreach ($this->getInvalidLinks() as $link) {
            $id = $ilDB->nextId('link_check');

            $query = "INSERT INTO link_check (id, obj_id,page_id,url,parent_type,http_status_code,last_check) " .
                "VALUES ( " .
                $ilDB->quote($id, "integer") . "," .
                $ilDB->quote($link['obj_id'], 'integer') . ", " .
                $ilDB->quote($link['page_id'], 'integer') . ", " .
                $ilDB->quote(substr($link['complete'], 0, 255), 'text') . ", " .
                $ilDB->quote($link['type'], 'text') . ", " .
                $ilDB->quote($link['http_status_code'] ? $link['http_status_code'] : 0, 'integer') . ", " .
                $ilDB->quote(time(), 'integer') . " " .
                ")";
            $res = $ilDB->manipulate($query);
        }
    }

    public function __checkNotify()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        foreach ($this->getInvalidLinks() as $link) {
            $query = "SELECT * FROM link_check " .
                "WHERE page_id = " . $ilDB->quote($link['page_id'], 'integer') . " " .
                "AND url = " . $ilDB->quote(substr($link['complete'], 0, 255), 'text') . " ";
            $res = $ilDB->query($query);
                        
            if (!$res->numRows()) {
                $this->notify[$link["obj_id"]][] = array('page_id' => $link['page_id'],
                                                         'url' => $link['complete']);
            }
        }
    }


    public function __clearDBData()
    {
        global $DIC;

        $ilDB = $DIC['ilDB'];
        
        if ($this->getValidateAll()) {
            $query = "DELETE FROM link_check";
        } else {
            $query = "DELETE FROM link_check " .
                "WHERE obj_id = " . $ilDB->quote($this->getObjId(), 'integer');
        }
        $res = $ilDB->manipulate($query);

        return true;
    }
}