<?php
/** 
 * @brief Guest Manager
 * @version $Id: Guest.php 2517 2014-09-25 09:47:45Z elena $
 *   
 */
 
class Guest {

    private $guestXmlFile;
    public  $Id, $Start, $Ip, $email;

    function __construct($Ip_, $email_ = null){
        if($email_) {
            $this->Start = getdate();
            $this->Ip = $Ip_;
            $this->email = $email_;  
        }
        else {
            $this->Id = substr($Ip_,strlen("guest"));
        }

        $this->guestXmlFile = DATAPATH."guests.xml";
    }

    public function checkGuestTimes() {
        return $this->concurrentAccessGuestFile(array($this,'_checkGuestTimes'));
    }

    public function deleteGuest() {
        return $this->concurrentAccessGuestFile(array($this,'_deleteGuest'));
    }

    public function addGuest(){
        return $this->concurrentAccessGuestFile(array($this,'_addGuest'));
    }

    public function registerGuest(){
        return $this->concurrentAccessGuestFile(array($this,'_registerGuest'));
    }

    private function concurrentAccessGuestFile($callback) {
        $lockFile =  $this->guestXmlFile.".lockfile";

        $fp = fopen($lockFile, "w+");

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

        $res = true;

        if (flock($fp, LOCK_EX))
        {
            if (!file_exists($this->guestXmlFile)) {
                $res = $this->_generateXML();
            }

            if ($res) {
                $dom = new DomDocument("1.0","UTF-8");
                $dom->preserveWhiteSpace = false;
                $dom->formatOutput = true;
                $res = $dom->load($this->guestXmlFile);
                if ($res) {
                    $func_res = call_user_func($callback,$dom);
                }
            }
        }
        else
            $res = false;

        fclose($fp);

        if ($res)
            return $func_res;

        return false;
    }

    private function _generateXML() {
        $dom = new DOMDocument("1.0","UTF-8");
        $dom->preserveWhiteSpace = false;
        $dom->formatOutput = true;
        $rootNode = $dom->createElement('guests'); 
        $dom->appendChild($rootNode);
        return $dom->save($this->guestXmlFile);
    } 

    private function _getId($dom){
        $xp = new DOMXpath($dom); 
        $elements = $xp->query("//@xml:id"); 
// Now find New Valid ID        
        if ($elements->length > 0) {
            $idList = array();
            for ($i = 0; $i < $elements->length; $i++) 
                $idList[$i] = $elements->item($i)->nodeValue; 
                      
            sort($idList);
            for ($i = 0; $i < $elements->length; $i++) {
                if ($idList[$i] > $i) { 
                    $newID = $i;
                    break;
                }  
                $newID = $i+1;  
            }                 
        } else { $newID = 0;}

        return $newID;
    }

    private function _checkGuestTimes($dom){
        $xp = new DOMXpath($dom);
        $Start_0 = time() - GuestSessionDuration*60; // in secs
        $startTimes = $xp->query("//guest[@start<".$Start_0."]/@xml:id"); 

        if ($startTimes->length > 0) {
            for ($i = 0; $i < $startTimes->length; $i++) {                
                $user = "guest".$startTimes->item($i)->value;
                $this->_deltree(USERPATH.$user);
                $dom->documentElement->removeChild($startTimes->item($i)->parentNode);
            }

            return $dom->save($this->guestXmlFile);
        }
        return true;
    }

    private function _deleteGuest($dom){
        $user = "guest".$this->Id;
        $this->_deltree(USERPATH.$user);
        $theGuest = $dom->getElementById($this->Id);
        $dom->documentElement->removeChild($theGuest);
        return $dom->save($this->guestXmlFile);
    }

    private function _addGuest($dom){ 
        if (($this->Id = $this->_getId($dom)) < MaxGuests) {
            $guest = $dom->createElement("guest");        
            $guest->setAttribute('xml:id',$this->Id );         
            $guest->setAttribute('start',time());
            $guest->appendChild($dom->createElement("IP", $this->Ip));
            $guest->appendChild($dom->createElement("email", $this->email));
            $dom->documentElement->appendChild($guest);
            $dom->save($this->guestXmlFile);
            return "guest".$this->Id;
        }
        else  {  
            return "allGuestLoginsInUse";
        }
    }

    private function _registerGuest($dom){
        $guest_file = fopen(DATAPATH.'guest.login','a'); 
        fwrite($guest_file, $this->email." ".$this->Ip." ".$this->Start['mday']."/".$this->Start['mon']."/".$this->Start['year']."\n"); 
        fclose($guest_file);
        return true; 
    }

    private function _deltree($f) {
 
        if (is_dir($f)) {

            $files = array_diff(scandir($f), array('.','..'));

            foreach($files as $sf) {
                if (is_dir("$f/$sf") && !is_link("$f/$sf")) {
                    $this->_deltree("$f/$sf");
                } else {
                    unlink("$f/$sf");
                } 
            } 
        }

        if (is_dir($f)) rmdir($f);
    }
    
} 
?>