<?php

/**
 *
 * $Id$
 *
 * KTDownloadManager manages files in the download_files table.
 *
 * KnowledgeTree Community Edition
 * Document Management Made Simple
 * Copyright (C) 2008, 2009 KnowledgeTree Inc.
 * 
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 3 as published by the
 * Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * You can contact KnowledgeTree Inc., PO Box 7775 #87847, San Francisco,
 * California 94120-7775, or email info@knowledgetree.com.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "Powered by
 * KnowledgeTree" logo and retain the original copyright notice. If the display of the
 * logo is not reasonably feasible for technical reasons, the Appropriate Legal Notices
 * must display the words "Powered by KnowledgeTree" and retain the original
 * copyright notice.
 * Contributor( s): ______________________________________
 *
 */

class KTDownloadManager
{
	var $session;
	var $age;
	var $download_url;
	var $random;

	/**
	 * Constructor for the download manager.
	 *
	 * @param KTAPI_Session $session
	 * @return KTDownloadManager
	 */
	function KTDownloadManager()
	{
		$config = &KTConfig::getSingleton();

		$this->age = $config->get('webservice/downloadExpiry',5);

		$protocol = $config->get('KnowledgeTree/sslEnabled')?'https':'http';

		$this->download_url = $protocol . '://' . $_SERVER['HTTP_HOST'] . $config->get('webservice/downloadUrl');
		//FIXME: store multipart download url in db config
		$this->multipart_download_url = $protocol . '://' . $_SERVER['HTTP_HOST'] . '/webservice/clienttools/services/mdownload.php';
		$this->random=$config->get('webservice/randomKeyText','jhsdf8q1jkjpoiudfs7sd3ds1');
	}

	/**
	 * Sets the current session.
	 *
	 * @param string $session
	 */
	function set_session($session)
	{
		$this->session = $session;
	}
	
	/**
	 * This returns
	 *
	 * @access public
	 * @param KTAPI_Document $document
	 * @return string
	 */
	function allow_download($document, $content_version = null, $multipart = false) {
		assert ( ! is_null ( $document ) );
		
		$content_version = 0;
		$filesize = 0;
		
		if ($document instanceof KTAPI_Document) {
			$doc_id = $document->documentid;
			$content_version = $document->document->getContentVersionId ();
			$filesize = $document->document->getFileSize ();
		} else if ($document instanceof Document || $document instanceof DocumentProxy) {
			$doc_id = $document->getId ();
			$content_version = $document->getContentVersionId ();
			$filesize = $document->getFileSize ();
		} else if (is_numeric ( $document )) {
			$doc_id = $document;
		} else
			die ( 'gracefully' );
			
		//assert(is_a($document, 'KTAPI_Document'));
		

		$hash = sha1 ( "$doc_id $this->session $this->random" );
		
		$id = DBUtil::autoInsert ( 'download_files', array ('document_id' => $doc_id, 'session' => $this->session, 'download_date' => date ( 'Y-m-d H:i:s' ), 'content_version' => $content_version, 'filesize' => $filesize, 'hash' => $hash ), array ('noid' => true ) );
		
		return $multipart?$this->build_multipart_url( $hash, $doc_id ):$this->build_url ( $hash, $doc_id );
	}
	
	
	/**
	 * This returns the url used to download a document.
	 *
	 * @param string $hash
	 * @param int $documentid
	 * @param int $userid
	 * @return string
	 */
	function build_url($hash, $documentid) {
		return $this->download_url . "?code=$hash&d=$documentid&u=$this->session";
	}
	
	function build_multipart_url($hash, $documentId) {
//		return '@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@';
		return $this->multipart_download_url . "?code=$hash&d=$documentId&u=$this->session";
	}


	/**
	 * This starts a download.
	 *
	 * @access public
	 */
	function download($document_id, $hash, $version = null, $apptype = 'ws')
	{
		$sql = "SELECT 1 FROM download_files WHERE hash=? AND session=? AND document_id=?";
		$rows = DBUtil::getResultArray(array($sql, array($hash, $this->session, $document_id)));
		if (PEAR::isError($rows))
		{
			return $rows;
		}

		if (count($rows) == 0)
		{
			return new PEAR_Error('Invalid session.');
		}

		// If document is being downloaded by an external user bypass the session checking
		$check = strstr($this->session, 'ktext_'.$document_id);
		if($check == 0 && $check !== false){
		    // Use external download function
		    return $this->download_ext($document_id, $hash, $version = null);
		}

		$storage =& KTStorageManagerUtil::getSingleton();

        $ktapi = &new KTAPI();
        $res = $ktapi->get_active_session($this->session, null, $apptype);
        if (PEAR::isError($res))
        {
        	return $res;
        }

        $document = $ktapi->get_document_by_id($document_id);
        if (PEAR::isError($document))
        {
        	return $document;
        }

        if (!empty($version))
        {
            $version = KTDocumentContentVersion::get($version);

            $res = $storage->downloadVersion($document->document, $version);
        }
        else
        {
            $res = $storage->download($document->document);
        }
        if (PEAR::isError($res))
        {
        	return $res;
        }

        $sql = "DELETE FROM download_files WHERE hash='$hash' AND session='$this->session' AND document_id=$document_id";
        $result = DBUtil::runQuery($sql);

        return true;
	}
	
	function download_ext($document_id, $hash, $version = null)
	{
	    $storage =& KTStorageManagerUtil::getSingleton();
	    $document = Document::get($document_id);
	    if (PEAR::isError($document))
	    {
	        return $document;
	    }

	    if (!empty($version))
	    {
	        $version = KTDocumentContentVersion::get($version);

	        $res = $storage->downloadVersion($document, $version);
	    }
	    else
	    {
	        $res = $storage->download($document);
	    }
	    if (PEAR::isError($res))
	    {
	        return $res;
	    }

	    $sql = "DELETE FROM download_files WHERE hash='$hash' AND session='$this->session' AND document_id=$document_id";
	    $result = DBUtil::runQuery($sql);

	    return true;
	}

	/**
	 * This will remove any temporary files that have not been dealt with in the correct timeframe.
	 *
	 * @access public
	 */
	function cleanup()
	{
		list($year,$mon,$day,$hour, $min) = explode(':', date('Y:m:d:H:i'));
		$expirydate = date('Y-m-d H:i:s', mktime($hour, $min - $this->age, 0, $mon, $day, $year));
		$sql = "DELETE FROM download_files WHERE download_date<'$expirydate'";
		DBUtil::runQuery($sql);
	}
}
?>