<?php
  /**
   * ownCloud
   *
   * @author Bjoern Schiessle
   * @copyright 2013 Bjoern Schiessle schiessle@owncloud.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\Files\Share;
  
  class Api {
  
  	/**
  	 * @brief get all shares
  	 *
  	 * @param array $params option 'file' to limit the result to a specific file/folder
  	 * @return \OC_OCS_Result share information
  	 */
  	public static function getAllShares($params) {
  		// if a file is specified, get the share for this file
  		if (isset($_GET['path'])) {
  			$params['itemSource'] = self::getFileId($_GET['path']);
  			$params['path'] = $_GET['path'];
  			$params['itemType'] = self::getItemType($_GET['path']);
  
  			if ( isset($_GET['reshares']) && $_GET['reshares'] !== 'false' ) {
  				$params['reshares'] = true;
  			} else {
  				$params['reshares'] = false;
  			}
  
  			if (isset($_GET['subfiles']) && $_GET['subfiles'] !== 'false') {
  				return self::getSharesFromFolder($params);
  			}
  			return self::collectShares($params);
  		}
  
  		$share = \OCP\Share::getItemShared('file', null);
  
  		if ($share === false) {
  			return new \OC_OCS_Result(null, 404, 'could not get shares');
  		} else {
  			return new \OC_OCS_Result($share);
  		}
  
  	}
  
  	/**
  	 * @brief get share information for a given share
  	 *
  	 * @param array $params which contains a 'id'
  	 * @return \OC_OCS_Result share information
  	 */
  	public static function getShare($params) {
  
  		$s = self::getShareFromId($params['id']);

  		$params['itemSource'] = $s['file_source'];

  		$params['itemType'] = $s['item_type'];
  		$params['specificShare'] = true;
  
  		return self::collectShares($params);
  	}
  
  	/**
  	 * @brief collect all share information, either of a specific share or all
  	 *        shares for a given path
  	 * @param array $params
  	 * @return \OC_OCS_Result
  	 */
  	private static function collectShares($params) {
  
  		$itemSource = $params['itemSource'];
  		$itemType = $params['itemType'];
  		$getSpecificShare = isset($params['specificShare']) ? $params['specificShare'] : false;
  
  		if ($itemSource !== null) {
  			$shares = \OCP\Share::getItemShared($itemType, $itemSource);
  			$receivedFrom = \OCP\Share::getItemSharedWithBySource($itemType, $itemSource);
  			// if a specific share was specified only return this one
  			if ($getSpecificShare === true) {
  				foreach ($shares as $share) {
  					if ($share['id'] === (int) $params['id']) {
  						$shares = array('element' => $share);
  						break;
  					}
  				}

  			} else {
  				$path = $params['path'];
  				foreach ($shares as $key => $share) {
  					$shares[$key]['path'] = $path;
  				}

  			}

  			// include also reshares in the lists. This means that the result
  			// will contain every user with access to the file.
  			if (isset($params['reshares']) && $params['reshares'] === true) {
  				$shares = self::addReshares($shares, $itemSource);
  			}
  
  			if ($receivedFrom) {

  				foreach ($shares as $key => $share) {
  					$shares[$key]['received_from'] = $receivedFrom['uid_owner'];
  					$shares[$key]['received_from_displayname'] = \OCP\User::getDisplayName($receivedFrom['uid_owner']);
  				}

  			}
  		} else {
  			$shares = null;
  		}
  
  		if ($shares === null || empty($shares)) {
  			return new \OC_OCS_Result(null, 404, 'share doesn\'t exist');
  		} else {
  			return new \OC_OCS_Result($shares);
  		}
  	}
  
  	/**
  	 * @brief add reshares to a array of shares
  	 * @param array $shares array of shares
  	 * @param int $itemSource item source ID
  	 * @return array new shares array which includes reshares
  	 */
  	private static function addReshares($shares, $itemSource) {
  
  		// if there are no shares than there are also no reshares
  		$firstShare = reset($shares);
  		if ($firstShare) {
  			$path = $firstShare['path'];
  		} else {
  			return $shares;
  		}

  		$select = '`*PREFIX*share`.`id`, `item_type`, `*PREFIX*share`.`parent`, `share_type`, `share_with`, `file_source`, `path` , `permissions`, `stime`, `expiration`, `token`, `storage`, `mail_send`, `mail_send`';

  		$getReshares = \OC_DB::prepare('SELECT ' . $select . ' FROM `*PREFIX*share` INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` WHERE `*PREFIX*share`.`file_source` = ? AND `*PREFIX*share`.`item_type` IN (\'file\', \'folder\') AND `uid_owner` != ?');
  		$reshares = $getReshares->execute(array($itemSource, \OCP\User::getUser()))->fetchAll();
  
  		foreach ($reshares as $key => $reshare) {
  			if (isset($reshare['share_with']) && $reshare['share_with'] !== '') {
  				$reshares[$key]['share_with_displayname'] = \OCP\User::getDisplayName($reshare['share_with']);
  			}
  			// add correct path to the result
  			$reshares[$key]['path'] = $path;
  		}
  
  		return array_merge($shares, $reshares);
  	}
  
  	/**
  	 * @brief get share from all files in a given folder (non-recursive)
  	 * @param array $params contains 'path' to the folder
  	 * @return \OC_OCS_Result
  	 */
  	private static function getSharesFromFolder($params) {
  		$path = $params['path'];
  		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
  
  		if(!$view->is_dir($path)) {

  			return new \OC_OCS_Result(null, 400, "not a directory");

  		}
  
  		$content = $view->getDirectoryContent($path);
  
  		$result = array();
  		foreach ($content as $file) {
  			// workaround because folders are named 'dir' in this context
  			$itemType = $file['type'] === 'file' ? 'file' : 'folder';
  			$share = \OCP\Share::getItemShared($itemType, $file['fileid']);

  			if($share) {
  				$receivedFrom =  \OCP\Share::getItemSharedWithBySource($itemType, $file['fileid']);

  				reset($share);
  				$key = key($share);
  				$share[$key]['path'] = self::correctPath($share[$key]['path'], $path);

  				if ($receivedFrom) {

  					$share[$key]['received_from'] = $receivedFrom['uid_owner'];
  					$share[$key]['received_from_displayname'] = \OCP\User::getDisplayName($receivedFrom['uid_owner']);

  				}
  				$result = array_merge($result, $share);

  			}
  		}
  
  		return new \OC_OCS_Result($result);
  	}
  
  	/**
  	 * @breif create a new share
  	 * @param array $params
  	 * @return \OC_OCS_Result
  	 */
  	public static function createShare($params) {
  
  		$path = isset($_POST['path']) ? $_POST['path'] : null;
  
  		if($path === null) {
  			return new \OC_OCS_Result(null, 400, "please specify a file or folder path");
  		}
  		$itemSource = self::getFileId($path);
  		$itemType = self::getItemType($path);
  
  		if($itemSource === null) {
  			return new \OC_OCS_Result(null, 404, "wrong path, file/folder doesn't exist.");
  		}
  
  		$shareWith = isset($_POST['shareWith']) ? $_POST['shareWith'] : null;
  		$shareType = isset($_POST['shareType']) ? (int)$_POST['shareType'] : null;
  
  		switch($shareType) {
  			case \OCP\Share::SHARE_TYPE_USER:
  				$permissions = isset($_POST['permissions']) ? (int)$_POST['permissions'] : 31;
  				break;
  			case \OCP\Share::SHARE_TYPE_GROUP:
  				$permissions = isset($_POST['permissions']) ? (int)$_POST['permissions'] : 31;
  				break;
  			case \OCP\Share::SHARE_TYPE_LINK:
  				//allow password protection
  				$shareWith = isset($_POST['password']) ? $_POST['password'] : null;
  				//check public link share
  				$publicUploadEnabled = \OC_Appconfig::getValue('core', 'shareapi_allow_public_upload', 'yes');

  				if(isset($_POST['publicUpload']) && $publicUploadEnabled !== 'yes') {
  					return new \OC_OCS_Result(null, 403, "public upload disabled by the administrator");

  				}
  				$publicUpload = isset($_POST['publicUpload']) ? $_POST['publicUpload'] : 'false';
  				// read, create, update (7) if public upload is enabled or
  				// read (1) if public upload is disabled
  				$permissions = $publicUpload === 'true' ? 7 : 1;
  				break;
  			default:

  				return new \OC_OCS_Result(null, 400, "unknown share type");

  		}
  
  		try	{
  			$token = \OCP\Share::shareItem(
  					$itemType,
  					$itemSource,
  					$shareType,
  					$shareWith,
  					$permissions
  					);
  		} catch (\Exception $e) {

  			return new \OC_OCS_Result(null, 403, $e->getMessage());

  		}
  
  		if ($token) {
  			$data = array();
  			$data['id'] = 'unknown';
  			$shares = \OCP\Share::getItemShared($itemType, $itemSource);
  			if(is_string($token)) { //public link share
  				foreach ($shares as $share) {
  					if ($share['token'] === $token) {
  						$data['id'] = $share['id'];
  						break;
  					}
  				}
  				$url = \OCP\Util::linkToPublic('files&t='.$token);
  				$data['url'] = $url; // '&' gets encoded to $amp;
  				$data['token'] = $token;
  
  			} else {
  				foreach ($shares as $share) {
  					if ($share['share_with'] === $shareWith && $share['share_type'] === $shareType) {
  						$data['id'] = $share['id'];
  						break;
  					}
  				}
  			}
  			return new \OC_OCS_Result($data);
  		} else {
  			return new \OC_OCS_Result(null, 404, "couldn't share file");
  		}
  	}
  
  	/**
  	 * update shares, e.g. password, permissions, etc
  	 * @param array $params shareId 'id' and the parameter we want to update
  	 *                      currently supported: permissions, password, publicUpload
  	 * @return \OC_OCS_Result
  	 */
  	public static function updateShare($params) {
  
  		$share = self::getShareFromId($params['id']);

  		if(!isset($share['file_source'])) {

  			return new \OC_OCS_Result(null, 404, "wrong share Id, share doesn't exist.");
  		}
  
  		try {
  			if(isset($params['_put']['permissions'])) {
  				return self::updatePermissions($share, $params);
  			} elseif (isset($params['_put']['password'])) {
  				return self::updatePassword($share, $params);
  			} elseif (isset($params['_put']['publicUpload'])) {
  				return self::updatePublicUpload($share, $params);
  			}
  		} catch (\Exception $e) {
  			return new \OC_OCS_Result(null, 400, $e->getMessage());
  		}
  
  		return new \OC_OCS_Result(null, 400, "Wrong or no update parameter given");
  
  	}
  
  	/**
  	 * @brief update permissions for a share
  	 * @param array $share information about the share
  	 * @param array $params contains 'permissions'
  	 * @return \OC_OCS_Result
  	 */
  	private static function updatePermissions($share, $params) {
  
  		$itemSource = $share['item_source'];
  		$itemType = $share['item_type'];
  		$shareWith = $share['share_with'];
  		$shareType = $share['share_type'];
  		$permissions = isset($params['_put']['permissions']) ? (int)$params['_put']['permissions'] : null;
  
  		$publicUploadStatus = \OC_Appconfig::getValue('core', 'shareapi_allow_public_upload', 'yes');

  		$publicUploadEnabled = ($publicUploadStatus === 'yes') ? true : false;

  
  		// only change permissions for public shares if public upload is enabled
  		// and we want to set permissions to 1 (read only) or 7 (allow upload)
  		if ( (int)$shareType === \OCP\Share::SHARE_TYPE_LINK ) {
  			if ($publicUploadEnabled === false || ($permissions !== 7 && $permissions !== 1)) {
  				return new \OC_OCS_Result(null, 400, "can't change permission for public link share");
  			}
  		}
  
  		try {
  			$return = \OCP\Share::setPermissions(
  					$itemType,
  					$itemSource,
  					$shareType,
  					$shareWith,
  					$permissions
  					);
  		} catch (\Exception $e) {
  			return new \OC_OCS_Result(null, 404, $e->getMessage());
  		}
  
  		if ($return) {
  			return new \OC_OCS_Result();
  		} else {
  			return new \OC_OCS_Result(null, 404, "couldn't set permissions");
  		}
  	}
  
  	/**
  	 * @brief enable/disable public upload
  	 * @param array $share information about the share
  	 * @param array $params contains 'publicUpload' which can be 'yes' or 'no'
  	 * @return \OC_OCS_Result
  	 */
  	private static function updatePublicUpload($share, $params) {
  
  		$publicUploadEnabled = \OC_Appconfig::getValue('core', 'shareapi_allow_public_upload', 'yes');

  		if($publicUploadEnabled !== 'yes') {
  			return new \OC_OCS_Result(null, 403, "public upload disabled by the administrator");

  		}
  
  		if ($share['item_type'] !== 'folder' ||
  				(int)$share['share_type'] !== \OCP\Share::SHARE_TYPE_LINK ) {
  			return new \OC_OCS_Result(null, 404, "public upload is only possible for public shared folders");
  		}
  
  		// read, create, update (7) if public upload is enabled or
  		// read (1) if public upload is disabled
  		$params['_put']['permissions'] = $params['_put']['publicUpload'] === 'true' ? 7 : 1;
  
  		return self::updatePermissions($share, $params);
  
  	}
  
  	/**
  	 * @brief update password for public link share
  	 * @param array $share information about the share
  	 * @param type $params 'password'
  	 * @return \OC_OCS_Result
  	 */
  	private static function updatePassword($share, $params) {
  
  		$itemSource = $share['item_source'];
  		$itemType = $share['item_type'];
  
  		if( (int)$share['share_type'] !== \OCP\Share::SHARE_TYPE_LINK) {
  			return  new \OC_OCS_Result(null, 400, "password protection is only supported for public shares");
  		}
  
  		$shareWith = isset($params['_put']['password']) ? $params['_put']['password'] : null;
  
  		if($shareWith === '') {
  			$shareWith = null;
  		}
  
  		$items = \OCP\Share::getItemShared($itemType, $itemSource);
  
  		$checkExists = false;
  		foreach ($items as $item) {
  			if($item['share_type'] === \OCP\Share::SHARE_TYPE_LINK) {
  				$checkExists = true;
  				$permissions = $item['permissions'];
  			}
  		}
  
  		if (!$checkExists) {
  			return  new \OC_OCS_Result(null, 404, "share doesn't exists, can't change password");
  		}
  
  		$result = \OCP\Share::shareItem(
  				$itemType,
  				$itemSource,
  				\OCP\Share::SHARE_TYPE_LINK,
  				$shareWith,
  				$permissions
  				);
  		if($result) {
  			return new \OC_OCS_Result();
  		}
  
  		return new \OC_OCS_Result(null, 404, "couldn't set password");
  	}
  
  	/**
  	 * @brief unshare a file/folder
  	 * @param array $params contains the shareID 'id' which should be unshared
  	 * @return \OC_OCS_Result
  	 */
  	public static function deleteShare($params) {
  
  		$share = self::getShareFromId($params['id']);

  		$fileSource = isset($share['file_source']) ? $share['file_source'] : null;

  		$itemType = isset($share['item_type']) ? $share['item_type'] : null;;

  		if($fileSource === null) {

  			return new \OC_OCS_Result(null, 404, "wrong share ID, share doesn't exist.");
  		}
  
  		$shareWith = isset($share['share_with']) ? $share['share_with'] : null;
  		$shareType = isset($share['share_type']) ? (int)$share['share_type'] : null;
  
  		if( $shareType === \OCP\Share::SHARE_TYPE_LINK) {
  			$shareWith = null;
  		}
  
  		try {
  			$return = \OCP\Share::unshare(
  					$itemType,

  					$fileSource,

  					$shareType,
  					$shareWith);
  		} catch (\Exception $e) {
  			return new \OC_OCS_Result(null, 404, $e->getMessage());
  		}
  
  		if ($return) {
  			return new \OC_OCS_Result();
  		} else {
  			$msg = "Unshare Failed";
  			return new \OC_OCS_Result(null, 404, $msg);
  		}
  	}
  
  	/**
  	 * @brief get file ID from a given path
  	 * @param string $path
  	 * @return string fileID or null
  	 */
  	private static function getFileId($path) {
  
  		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
  		$fileId = null;
  		$fileInfo = $view->getFileInfo($path);
  		if ($fileInfo) {
  			$fileId = $fileInfo['fileid'];
  		}
  
  		return $fileId;
  	}
  
  	/**
  	 * @brief get itemType
  	 * @param string $path
  	 * @return string type 'file', 'folder' or null of file/folder doesn't exists
  	 */
  	private static function getItemType($path) {
  		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
  		$itemType = null;
  
  		if ($view->is_dir($path)) {
  			$itemType = "folder";
  		} elseif ($view->is_file($path)) {
  			$itemType = "file";
  		}
  
  		return $itemType;
  	}
  
  	/**
  	 * @brief get some information from a given share
  	 * @param int $shareID
  	 * @return array with: item_source, share_type, share_with, item_type, permissions
  	 */
  	private static function getShareFromId($shareID) {

  		$sql = 'SELECT `file_source`, `item_source`, `share_type`, `share_with`, `item_type`, `permissions` FROM `*PREFIX*share` WHERE `id` = ?';

  		$args = array($shareID);
  		$query = \OCP\DB::prepare($sql);
  		$result = $query->execute($args);
  
  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('files_sharing', \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
  			return null;
  		}
  		if ($share = $result->fetchRow()) {
  			return $share;
  		}
  
  		return null;
  
  	}

  	/**
  	 * @brief make sure that the path has the correct root
  	 *
  	 * @param string $path path returned from the share API
  	 * @param string $folder current root folder
  	 * @return string the correct path
  	 */
  	protected static function correctPath($path, $folder) {
  		return \OC_Filesystem::normalizePath('/' . $folder . '/' . basename($path));
  	}

  }