<?php
  /**
   * ownCloud - Documents App
   *
   * @author Victor Dubiniuk
   * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either 
   * version 3 of the License, or any later version.
   * 
   * This library 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 AFFERO GENERAL PUBLIC LICENSE for more details.
   *  

   * You should have received a copy of the GNU Affero General Public

   * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
   * 
   */
  
  
  namespace OCA\Documents;
  
  class File {
  	protected $fileId;
  	protected $owner;
  	protected $path;
  	protected $sharing;
  	protected $token ='';
  	protected $passwordProtected = false;
  
  
  	public function __construct($fileId, $shareOps = null){
  		if (!$fileId){
  			throw new \Exception('No valid file has been passed');
  		}
  
  		$this->fileId = $fileId;
  		
  		//if you know how to get sharing info by fileId via API, 
  		//please send me a link to video tutorial :/
  		if (!is_null($shareOps)){
  			$this->sharing = $shareOps;
  		} else {
  			$this->sharing = $this->getSharingOps();
  		}
  	}
  	
  	
  	public static function getByShareToken($token){
  		$linkItem = \OCP\Share::getShareByToken($token, false);
  		if (is_array($linkItem) && isset($linkItem['uid_owner'])) {
  			// seems to be a valid share
  			$rootLinkItem = \OCP\Share::resolveReShare($linkItem);
  		} else {
  			throw new \Exception('This file was probably unshared');
  		}
  		
  		$file = new File($rootLinkItem['file_source'], array($rootLinkItem));
  		$file->setToken($token);
  		
  		if (isset($linkItem['share_with']) && !empty($linkItem['share_with'])){
  			$file->setPasswordProtected(true);
  		}
  		
  		return $file;
  	}
  
  	public function getToken(){
  		return $this->token;
  	}
  	
  	public function getFileId(){
  		return $this->fileId;
  	}
  	
  	public function setOwner($owner){
  		$this->owner = $owner;
  	}
  	
  	public function setPath($path){
  		$this->path = $path;
  	}
  	
  	public function setToken($token){
  		$this->token = $token;
  	}
  	
  	public function isPublicShare(){
  		return  !empty($this->token);
  	}
  	
  	public function isPasswordProtected(){
  		return $this->passwordProtected;
  	}
  	
  	public function checkPassword($password){
  		$shareId  = $this->getShareId();
  		if (!$this->isPasswordProtected()

  			|| (\OC::$server->getSession()->exists('public_link_authenticated')
  				&& \OC::$server->getSession()->get('public_link_authenticated') === $shareId
  			)
  		){

  				return true;
  		}
  		
  		// Check Password
  		$forcePortable = (CRYPT_BLOWFISH != 1);
  		$hasher = new \PasswordHash(8, $forcePortable);
  		if ($hasher->CheckPassword($password.\OC_Config::getValue('passwordsalt', ''),
  									 $this->getPassword())) {
  			// Save item id in session for future request

  			\OC::$server->getSession()->set('public_link_authenticated', $shareId);

  			return true;
  		}
  		return false;
  	}
  	
  	public function setPasswordProtected($value){
  		$this->passwordProtected = $value;
  	}
  	
  	public function getPermissions(){
  		if (count($this->sharing)){
  			if ($this->isPublicShare()){
  				$permissions = \OCP\PERMISSION_READ | \OCP\PERMISSION_UPDATE;
  			} else {
  				$permissions = $this->sharing[0]['permissions'];
  			}
  		} else {
  			list($owner, $path) = $this->getOwnerViewAndPath();
  			$permissions = 0;
  			if (\OC\Files\Filesystem::isReadable($path)){
  				$permissions |= \OCP\PERMISSION_READ;
  			}
  			if (\OC\Files\Filesystem::isUpdatable($path)){
  				$permissions |= \OCP\PERMISSION_UPDATE;
  			}
  				
  		}
  		return $permissions;
  	}
  
  
  	/**
  	 * 
  	 * @return string owner of the current file item
  	 * @throws \Exception
  	 */

  	public function getOwnerViewAndPath($useDefaultRoot = false){

  		if ($this->isPublicShare()){
  			$rootLinkItem = \OCP\Share::resolveReShare($this->sharing[0]);
  			if (isset($rootLinkItem['uid_owner'])){
  				$owner = $rootLinkItem['uid_owner'];

  				\OCP\JSON::checkUserExists($rootLinkItem['uid_owner']);
  				\OC_Util::tearDownFS();
  				\OC_Util::setupFS($rootLinkItem['uid_owner']);

  			} else {
  				throw new \Exception($this->fileId . ' is a broken share');
  			}
  			$view = new View('/' . $owner . '/files');

  		} else {
  			$owner = \OCP\User::getUser();

  			$root = '/' . $owner;
  			if ($useDefaultRoot){
  				$root .= '/' . 'files';
  			}
  			$view = new View($root);

  		}
  			

  		$path = $view->getPath($this->fileId);

  		if (!$path){
  			throw new \Exception($this->fileId . ' can not be resolved');
  		}
  		$this->path = $path;
  		$this->owner = $owner;
  		
  		if (!$view->file_exists($this->path)){
  			throw new \Exception($this->path . ' doesn\'t exist');
  		}
  
  		return array($view, $this->path);
  	}
  	
  
  	public function getOwner(){
  		if (!$this->owner){
  			$this->getOwnerViewAndPath();
  		}
  		return $this->owner;
  	}
  	
  	
  	protected function getPassword(){
  		return $this->sharing[0]['share_with'];
  	}
  	
  	protected function getShareId(){
  		return $this->sharing[0]['id'];
  	}
  
  	protected function getSharingOps(){
  		
  		$where  = 'AND `file_source`=?';
  		$values = array($this->fileId);
  		
  		if (\OCP\User::isLoggedIn()){
  			$where .= ' AND ((`share_type`=' . \OCP\Share::SHARE_TYPE_USER . ' AND `share_with`=?) OR  `share_type`=' . \OCP\Share::SHARE_TYPE_LINK . ')';
  			$values[] = \OCP\User::getUser();
  		} else {
  			$where .= ' AND (`share_type`=' . \OCP\Share::SHARE_TYPE_LINK . ')';
  		}
  		
  		$query = \OC_DB::prepare('SELECT `*PREFIX*share`.`id`, `item_type`, `*PREFIX*share`.`parent`, `uid_owner`, '
  							.'`share_type`, `share_with`, `file_source`, `path`, `file_target`, '

  							.'`*PREFIX*share`.`permissions`, `expiration`, `storage`, `*PREFIX*filecache`.`parent` as `file_parent`, '

  							.'`name`, `mtime`, `mimetype`, `mimepart`, `size`, `encrypted`, `etag`' 
  							.'FROM `*PREFIX*share` INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` WHERE `item_type` = \'file\' ' . $where);
  		$result = $query->execute($values);
  		$shares = $result->fetchAll();
  		
  		$origins = array();
  		if (is_array($shares)){
  			foreach ($shares as $share){
  				$origin = \OCP\Share::resolveReShare($share);
  				if (!isset($origin['path']) && isset($origin['file_target'])){
  					$origin['path'] = 'files/' . $origin['file_target'];
  				}
  				$origins[] = $origin;
  			}
  		}
  		return $origins;
  	}
  }