<?php

// initialise ktapi instance
KT_cmis_atom_service_helper::$ktapi = KT_cmis_atom_service_helper::getKt();

class KT_cmis_atom_service_helper {

    public static $ktapi = null;
    public static $repositoryId = null;
    
    /**
     * Helper function to set internal repository id
     *
     * @param object $RepositoryService
     */
    static public function setRepositoryId(&$RepositoryService = null)
    {
        if (is_null($RepositoryService)) {
            $RepositoryService = new RepositoryService();
        }
        
        $repositories = $RepositoryService->getRepositories();
        
        // TODO handle multiple repositories
        self::$repositoryId = $repositories[0]['repositoryId'];         
    }
    
    /**
     * Helper function to fetch internal repository id
     * 
     * Calls set function automatically, use $set = false to prevent this and return the current setting, if any
     * 
     * NOTE the function will automatically call the setRepositoryId function if no previous repository id was set
     *
     * @param object $RepositoryService
     * @param boolean $RepositoryService
     * @return string
     */
    static public function getRepositoryId(&$RepositoryService = null, $set = true)
    {        
        if (empty(self::$repositoryId) || $set) {
            self::setRepositoryId($RepositoryService);
        }
        
        return self::$repositoryId;
    }

    /**
     * Retrieves data about a specific folder OR document within a folder
     *
     * @param object $ObjectService The CMIS service
     * @param string $repositoryId
     * @param string $folderId
     * @return string CMIS AtomPub feed
     */
    static public function getObjectFeed(&$service, $ObjectService, $repositoryId, $objectId, $method = 'GET')
    {
        self::$repositoryId = $repositoryId;
        
        $serviceType = $service->getServiceType();
        $response = $ObjectService->getProperties($repositoryId, $objectId, false, false);

        if (PEAR::isError($response)) {
            return KT_cmis_atom_service_helper::getErrorFeed($service, KT_cmis_atom_service::STATUS_SERVER_ERROR, $response->getMessage());
        }
        
        $cmisEntry = $response;
        $response = null;
        
        // POST/PWC responses only send back an entry, not a feed
        if (($serviceType == 'PWC') || ($method == 'POST')) {
            if ($method == 'POST') {
                $response = new KT_cmis_atom_response_POST(CMIS_APP_BASE_URI);
            }
            else {
                $response = new KT_cmis_atom_response_GET(CMIS_APP_BASE_URI);
            }
        }
        else if ($method == 'GET') {
            $response = new KT_cmis_atom_responseFeed_GET(CMIS_APP_BASE_URI);
            $response->newField('title', $cmisEntry['properties']['ObjectTypeId']['value'], $response);
            $response->newField('id', 'urn:uuid:' . $cmisEntry['properties']['ObjectId']['value'], $response);
        }

        if ($serviceType == 'PWC') $pwc = true; else $pwc = false;
        KT_cmis_atom_service_helper::createObjectEntry($response, $cmisEntry, $cmisEntry['properties']['ParentId']['value'], $pwc, $method);

        // Don't think this should be here...only one item so why would we need to say there are no more?
        /*if ($method == 'GET') {
            $response->newField('cmis:hasMoreItems', 'false', $response);
        }*/
        
        return $response;
    }

    /**
     * Creates an AtomPub entry for a CMIS entry and adds it to the supplied feed
     *
     * @param object $feed The feed to which we add the entry
     * @param array $cmisEntry The entry data
     * @param string $parent The parent folder
     */
    static public function createObjectEntry(&$response, $cmisEntry, $parent, $pwc = false, $method = 'GET')
    {        
        $workspace = $response->getWorkspace();
        $type = strtolower($cmisEntry['properties']['ObjectTypeId']['value']);

    	// create entry
        $entry = $response->newEntry();

        // FIXME this maybe belongs in the response feed class only how?
        if (($method == 'POST') || $pwc)
        {
            // append attributes
            $entry->appendChild($response->newAttr('xmlns', 'http://www.w3.org/2005/Atom'));
            $entry->appendChild($response->newAttr('xmlns:app', 'http://www.w3.org/2007/app'));
            $entry->appendChild($response->newAttr('xmlns:cmis', 'http://docs.oasis-open.org/ns/cmis/core/200901'));
        }
		
        // TODO dynamic actual creator name
        $responseElement = $response->newField('author');
        $element = $response->newField('name', 'admin', $responseElement);
        $entry->appendChild($responseElement);
        
        if (!empty($cmisEntry['properties']['ContentStreamLength']['value']))
        {
            $field = $response->newElement('content');
            $field->appendChild($response->newAttr('type', $cmisEntry['properties']['ContentStreamMimeType']['value']));
            $field->appendChild($response->newAttr('src', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                          . '/' . $cmisEntry['properties']['ObjectId']['value'] 
                                                          . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
            $entry->appendChild($field);
        }
		
		// content & id tags
        $id = $cmisEntry['properties']['ObjectId']['value'];
        
        $response->newField('id', 'urn:uuid:' . $id, $entry);

        // links
        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'self'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . (!$pwc ? $type : 'pwc') . '/' 
                                                    . $cmisEntry['properties']['ObjectId']['value']));
        $entry->appendChild($link);

        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'edit'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                  . '/' . $cmisEntry['properties']['ObjectId']['value']));
        $entry->appendChild($link);
        
        if ((strtolower($cmisEntry['properties']['ObjectTypeId']['value']) == 'document') 
            && (!empty($cmisEntry['properties']['ContentStreamLength']['value'])))
        {
            $link = $response->newElement('link');
            $link->appendChild($response->newAttr('rel', 'edit-media'));
            $link->appendChild($response->newAttr('type', $cmisEntry['properties']['ContentStreamMimeType']['value']));
            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                          . '/' . $cmisEntry['properties']['ObjectId']['value'] 
                                                          . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
            $entry->appendChild($link);

            $link = $response->newElement('link');
            $link->appendChild($response->newAttr('rel', 'enclosure'));
            $link->appendChild($response->newAttr('type', $cmisEntry['properties']['ContentStreamMimeType']['value']));
            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                          . '/' . $cmisEntry['properties']['ObjectId']['value'] 
                                                          . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
            $entry->appendChild($link);
        }

        // according to spec this MUST be present, but spec says that links for function which are not supported
        // do not need to be present, so unsure for the moment
        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'allowableactions'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type . '/'
                                                . $cmisEntry['properties']['ObjectId']['value'] . '/permissions'));
        $entry->appendChild($link);

        // according to spec this MUST be present, but spec says that links for function which are not supported
        // do not need to be present, so unsure for the moment
        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'relationships'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type . '/'
                                                . $cmisEntry['properties']['ObjectId']['value'] . '/rels'));
        $entry->appendChild($link);
        
        // if there is no parent or parent is 0, do not add the parent link
        // also if this is specifically the root folder, do not add the parent link
//        if (!empty($cmisEntry['properties']['ParentId']['value']) && !CMISUtil::isRootFolder(self::$repositoryId, $cmisEntry['properties']['ObjectId']['value']))

        if (!CMISUtil::isRootFolder(self::$repositoryId, $cmisEntry['properties']['ObjectId']['value'], self::$ktapi))
        {
            // TODO check parent link is correct, fix if needed
            $link = $response->newElement('link');
            $link->appendChild($response->newAttr('rel', 'parents'));
            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/folder/'
                                                    . $cmisEntry['properties']['ObjectId']['value'] . '/parent'));
            $entry->appendChild($link);
        }

        // Folder/Document specific links
        if (strtolower($cmisEntry['properties']['ObjectTypeId']['value']) == 'folder')
        {
            $link = $response->newElement('link');
            $link->appendChild($response->newAttr('rel', 'children'));
            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/'
                                                    . $type
                                                    . '/' . $cmisEntry['properties']['ObjectId']['value']
                                                    . '/children'));
            $entry->appendChild($link);
            $link = $response->newElement('link');
            $link->appendChild($response->newAttr('rel', 'descendants'));
            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/'
                                                    . $type
                                                    . '/' . $cmisEntry['properties']['ObjectId']['value']
                                                    . '/descendants'));
            $entry->appendChild($link);
        }
        else if (strtolower($cmisEntry['properties']['ObjectTypeId']['value']) == 'document')
        {
            // according to spec this MUST be present, but spec says that links for function which are not supported
            // do not need to be present, so unsure for the moment
//            $link = $response->newElement('link');
//            $link->appendChild($response->newAttr('rel', 'allversions'));
//            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type . '/' . $cmisEntry['properties']['ParentId']['value']));
//            $entry->appendChild($link);

            // according to spec this MUST be present, but spec says that links for function which are not supported
            // do not need to be present, so unsure for the moment
//            $link = $response->newElement('link');
//            $link->appendChild($response->newAttr('rel', 'latestversion'));
//            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type . '/' . $cmisEntry['properties']['ParentId']['value']));
//            $entry->appendChild($link);

            // if there is a content stream, this link MUST be present
            // not sure yet where it must point...
            if (!empty($cmisEntry['properties']['ContentStreamLength']['value']))
            {
                $link = $response->newElement('link');
                $link->appendChild($response->newAttr('rel', 'stream'));
                $link->appendChild($response->newAttr('type', $cmisEntry['properties']['ContentStreamMimeType']['value']));
                $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                        . '/' . $cmisEntry['properties']['ObjectId']['value']
                                                        . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
                $entry->appendChild($link);
            }

            // if the document is checked out and this is NOT the PWC, this link MUST be present
            // NOTE at the moment the document and the PWC are the same object, so we always show it for a checked out document
            // TODO separated code for PWC and actual document object
            if (!empty($cmisEntry['properties']['VersionSeriesCheckedOutId']['value']))
            {
                $link = $response->newElement('link');
                $link->appendChild($response->newAttr('rel', 'pwc'));
                $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                                                . '/' . $cmisEntry['properties']['ObjectId']['value'] 
                                                                                . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
                $entry->appendChild($link);
                $link = $response->newElement('link');
                $link->appendChild($response->newAttr('rel', 'source'));
                $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
                                                                                . '/' . $cmisEntry['properties']['ObjectId']['value'] 
                                                                                . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
                $entry->appendChild($link);
            }

//            $link = $response->newElement('link');
//            $link->appendChild($response->newAttr('rel', 'stream'));
//            $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type 
//                                                          . '/' . $cmisEntry['properties']['ObjectId']['value'] 
//                                                          . '/' . $cmisEntry['properties']['ContentStreamFilename']['value']));
        }        

        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'type'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/type/' . $type));
        $entry->appendChild($link);

        $link = $response->newElement('link');
        $link->appendChild($response->newAttr('rel', 'repository'));
        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . '/servicedocument'));
        $entry->appendChild($link);

        // according to spec this MUST be present, but spec says that links for function which are not supported
        // do not need to be present, so unsure for the moment - policies are being abandoned, or so I thought...
//        $link = $response->newElement('link');
//        $link->appendChild($response->newAttr('rel', 'policies'));
//        $link->appendChild($response->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/' . $type . '/' . $cmisEntry['properties']['ParentId']['value']));
//        $entry->appendChild($link);
        // end links

        // TODO proper date
        $entry->appendChild($response->newField('published', self::formatDatestamp()));
        $entry->appendChild($response->newElement('summary', $cmisEntry['properties']['Name']['value']));
        $entry->appendChild($response->newElement('title', $cmisEntry['properties']['Name']['value']));
        $entry->appendChild($response->newField('updated', self::formatDatestamp()));

        // main CMIS entry
        $objectElement = $response->newElement('cmis:object');
        $propertiesElement = $response->newElement('cmis:properties');

        foreach($cmisEntry['properties'] as $propertyName => $property)
        {
            $propElement = $response->newElement('cmis:' . $property['type']);
            $propElement->appendChild($response->newAttr('cmis:name', $propertyName));
            if (!empty($property['value']))
            {
                if ($propertyName == 'ContentStreamUri') {
                    $property['value'] = CMIS_APP_BASE_URI . $workspace . '/' . $type . '/' .$property['value'];
                }
                $response->newField('cmis:value', CMISUtil::boolToString($property['value']), $propElement);
            }
            $propertiesElement->appendChild($propElement);
        }

        $objectElement->appendChild($propertiesElement);
        $entry->appendChild($objectElement);
        
        // after every entry, append a cmis:terminator tag
        $entry->appendChild($response->newElement('cmis:terminator'));
        
        // TODO check determination of when to add app:edited tag
//        if ($method == 'POST') {
            $entry->appendChild($response->newElement('app:edited', self::formatDatestamp()));
//        }
    }

    /**
     * Retrieves the list of types|type definition as a CMIS AtomPub feed
     *
     * @param string $typeDef Type requested - 'All Types' indicates a listing, else only a specific type
     * @param array $types The types found
     * @return string CMIS AtomPub feed
     */
    static public function getTypeFeed($typeDef, $types)
    {
        $typesString = '';
        $typesHeading = '';
        switch($typeDef)
        {
            case 'all':
            case 'children':
            case 'descendants':
                $typesString = 'types-' . $typeDef;
                $typesHeading = 'All Types';
                break;
            default:
                $typesString = 'type-' . $typeDef;
                $typesHeading = $typeDef;
                break;
        }

        //Create a new response feed
        $feed = new KT_cmis_atom_responseFeed_GET(CMIS_APP_BASE_URI);
        $workspace = $feed->getWorkspace();
        
        $feed->newField('title', $typesHeading, $feed);
        $feed->newField('id', 'urn:uuid:' . $typesString, $feed);

        // TODO set page number correctly - to be done when we support paging the the API
        
        // author
        // TODO generate this dynamically (based on???)\
        $feedElement = $feed->newField('author');
        $element = $feed->newField('name', 'admin', $feedElement);
        $feed->appendChild($feedElement);

        // NOTE spec says this link MUST be present but is vague on where it points
        //      as of 0.61c:
        //      "The source link relation points to the underlying CMIS Type Definition as Atom Entry"
        //      so what is the underlying CMIS Type Definition for a collection of base types?
        //      suspect that it only applies when not listing all types, i.e. a base type is asked for
        /*
        $link = $feed->newElement('link');
        $link->appendChild($feed->newAttr('rel','source'));
        $link->appendChild($feed->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/type/' . strtolower($type['typeId'])));
        $feed->appendChild($link);
         */

        // current time: format = 2009-07-13T14:49:27.659+02:00
        $feed->appendChild($feed->newElement('updated', self::formatDatestamp()));

        foreach($types as $type)
        {
            $entry = $feed->newEntry();
            
            $feedElement = $feed->newField('author');
            $element = $feed->newField('name', 'admin', $feedElement);
            $entry->appendChild($feedElement);
            $feedElement = $feed->newField('content', $type['typeId']);
            $entry->appendChild($feedElement);

            $feed->newField('id', 'urn:uuid:type-' . $type['typeId'], $feed);

            // TODO add parents link when not selecting a base type.
            // TODO add children link when type has children
            // TODO add descendants link when type has children
            // NOTE KnowledgeTree currently only supports base types so these are not important at the present time.

            // links
            $link = $feed->newElement('link');
            $link->appendChild($feed->newAttr('rel','self'));
            $link->appendChild($feed->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/type/' . strtolower($type['typeId'])));
            $entry->appendChild($link);
            // TODO type link MUST point to base type
            //      KnowledgeTree currently only supports base types so this is not important
            //      at the present time as it will always point at the base type.
            $link = $feed->newElement('link');
            $link->appendChild($feed->newAttr('rel','type'));
            $link->appendChild($feed->newAttr('href', CMIS_APP_BASE_URI . $workspace . '/type/' . strtolower($type['typeId'])));
            $entry->appendChild($link);
            $link = $feed->newElement('link');
            $link->appendChild($feed->newAttr('rel','repository'));
            $link->appendChild($feed->newAttr('href', CMIS_APP_BASE_URI . '/servicedocument'));
            $entry->appendChild($link);

            $entry->appendChild($feed->newElement('summary', $type['typeId'] . ' Type'));
            $entry->appendChild($feed->newElement('title', $type['typeId']));
            $entry->appendChild($feed->newElement('updated', self::formatDatestamp()));

            // main CMIS entry
            $feedElement = $feed->newElement('cmis:' . strtolower($type['typeId']) . 'Type');
            foreach($type as $property => $value)
            {
                $feed->newField('cmis:' . $property, CMISUtil::boolToString($value), $feedElement);
            }

            $entry->appendChild($feedElement);
            
            // after every entry, append a cmis:terminator tag
            $entry->appendChild($feed->newElement('cmis:terminator'));
        }

        return $feed;
    }

    static public function getErrorFeed(&$service, $status, $message)
    {
        $service->setStatus($status);
        $feed = new KT_cmis_atom_responseFeed_GET(CMIS_APP_BASE_URI);
        
        $feed->newField('title', 'Error: ' . $status, $feed);
        $entry = $feed->newEntry();
        $feed->newField('error', $message, $entry);

        return $feed;
    }

    /**
     * Fetches the CMIS objectId based on the path
     *
     * @param array $path
     * @param object $ktapi KTAPI instance
     */
    // TODO make this much more efficient than this method
    static public function getFolderId($path, &$ktapi)
    {
        // lose first item
        array_shift($path);

        $numQ = count($path);
        $numFolders = $numQ;
        $folderId = 1;

        $start = 0;
        while($start < $numFolders)
        {
            $name = $path[$numQ-$numFolders+$start];
            // fix for possible url encoding issue
            $name = str_replace('%2520', '%20', $name);

            $folderName = urldecode($name);
            $folder = $ktapi->get_folder_by_name($folderName, $folderId);
            $folderId = $folder->get_folderid();
            ++$start;
        }
        
        return CMISUtil::encodeObjectId('Folder', $folderId);
    }

    static public function getCmisProperties($xmlArray)
    {
        $properties = array();
        
        // find cmis:object tag
        $baseCmisObject = KT_cmis_atom_service_helper::findTag('cmis:object', $xmlArray, null, false);
        if(count($baseCmisObject) <= 0)
        {
            $entryObject = KT_cmis_atom_service_helper::findTag('entry', $xmlArray, null, false);
            $baseCmisObject = KT_cmis_atom_service_helper::findTag('cmis:object', $entryObject['@children'], null, true);
        }
        
        if(count($baseCmisObject)>0)
        {
            foreach($baseCmisObject['@children'] as $key => $childElement)
            {
                if ($key == 'cmis:properties')
                {
                    foreach($childElement[0]['@children'] as $cmisPropertyDefinition)
                    {
                        foreach($cmisPropertyDefinition as $propertyType => $propertyDefinition)
                        {
                            $properties[$propertyDefinition['@attributes']['cmis:name']] = $propertyDefinition['@children']['cmis:value'][0]['@value'];
                        }
                    }
                }
            }
        }

        return $properties;
    }

    static public function getAtomValues($xmlArray, $tag)
    {
        if (!is_null($xmlArray['atom:'.$tag]))
            return $xmlArray['atom:'.$tag][0]['@value'];
        else if (!is_null($xmlArray[$tag]))
            return $xmlArray[$tag][0]['@value'];

        return null;
    }

    /**
	 * Get the KT singleton instance
	 *
	 * @return object
	 */
	public static function getKt()
    {
		if(!isset(self::$ktapi))
        {
        	self::$ktapi = new KTAPI();
			$active = self::$ktapi->get_active_session(session_id());
			
			if (PEAR::isError($active))
			{
				// invoke auth code, session must be restarted
				if(!KT_atom_HTTPauth::isLoggedIn()) {
					KT_atom_HTTPauth::login('KnowledgeTree DMS', 'You must authenticate to enter this realm');
				}
			}
		}
		return self::$ktapi;
	}

    // TODO adjust for time zones?
    static public function formatDatestamp($time = null)
    {
        if (is_null($time)) $time = time();
        return date('Y-m-d H:i:s', $time);
    }
    
    /**
     * Fetches the document content stream for internal use
     * 
     * @param object $ObjectService
     * @param string $repositoryId
     * @return null | string $contentStream
     */
    static public function getContentStream(&$service, &$ObjectService, $repositoryId)
    {
        $response = $ObjectService->getProperties($repositoryId, $service->params[0], false, false);
        if (PEAR::isError($response)) {
            return null;
        }
        
        $contentStream = $ObjectService->getContentStream($repositoryId, $service->params[0]);
        
        return $contentStream;
    }
    /**
     * Fetches and prepares the document content stream for download/viewing
     * 
     * @param object $ObjectService
     * @param string $repositoryId
     * @return null | nothing
     */
    static public function downloadContentStream(&$service, &$ObjectService, $repositoryId)
    {
        $response = $ObjectService->getProperties($repositoryId, $service->params[0], false, false);
        if (PEAR::isError($response)) {
            $feed = KT_cmis_atom_service_helper::getErrorFeed($service, KT_cmis_atom_service::STATUS_SERVER_ERROR, $response->getMessage());
            $service->responseFeed = $feed;
            return null;
        }
        
        // TODO also check If-Modified-Since?
//        $service->headers['If-Modified-Since'] => 2009-07-24 17:16:54

        $service->setContentDownload(true);
        $eTag = md5($response['properties']['LastModificationDate']['value'] . $response['properties']['ContentStreamLength']['value']);
        
        if ($service->headers['If-None-Match'] == $eTag)
        {
            $service->setStatus(KT_cmis_atom_service::STATUS_NOT_MODIFIED);
            $service->setContentDownload(false);
            return null;
        }
        
        $contentStream = $ObjectService->getContentStream($repositoryId, $service->params[0]);
        
        // headers specific to output
        $service->setEtag($eTag);
        $service->setHeader('Last-Modified', $response['properties']['LastModificationDate']['value']);

        if (!empty($response['properties']['ContentStreamMimeType']['value'])) {
    		$service->setHeader('Content-type', $response['properties']['ContentStreamMimeType']['value'] . ';charset=utf-8');
        }
        else {
    		$service->setHeader('Content-type', 'text/plain;charset=utf-8');
        }
        
        $service->setHeader('Content-Disposition', 'attachment;filename="' . $response['properties']['ContentStreamFilename']['value'] . '"');
		$service->setHeader('Content-Length', $response['properties']['ContentStreamLength']['value']);
        $service->setOutput($contentStream);
    }
    
    //TODO: Add key information to be able to find the same tag in the original struct (MarkH)
    static public function findTag($tagName=NULL,$xml=array(),$tagArray=NULL,$deep=false){
        $tagArray=is_array($tagArray)?$tagArray:array();
        foreach($xml as $xmlTag=>$content){
            if($xmlTag===$tagName){
                $tagArray[]=$content;
            }
            if($deep){
                foreach($content as $contentTags){
                    if(is_array($contentTags['@children'])) {
                        if(count($contentTags['@children'])>0) $tagArray=self::findTag($tagName,$contentTags['@children'],$tagArray);
                    }
                }
            }
        }
        //TODO: this is very ugly. Change it. (MarkH)
        return self::rebaseArray($tagArray);
    }
    
    static public function rebaseArray($arr=array()){
        //Force Array
        $arr=is_array($arr)?$arr:array();
        
        //Rebase recursively
        if(count($arr)===1)$arr=self::rebaseArray($arr[0]);
        return $arr;
    }

}

?>