<?php
  
  /**
   * Copyright (c) 2013 Robin Appelman <icewind@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  namespace OC\User;
  
  use OC\Hooks\Emitter;

  use OCP\IUserSession;

  
  /**
   * Class Session
   *
   * Hooks available in scope \OC\User:
   * - preSetPassword(\OC\User\User $user, string $password, string $recoverPassword)
   * - postSetPassword(\OC\User\User $user, string $password, string $recoverPassword)
   * - preDelete(\OC\User\User $user)
   * - postDelete(\OC\User\User $user)
   * - preCreateUser(string $uid, string $password)
   * - postCreateUser(\OC\User\User $user)
   * - preLogin(string $user, string $password)

   * - postLogin(\OC\User\User $user, string $password)
   * - preRememberedLogin(string $uid)
   * - postRememberedLogin(\OC\User\User $user)

   * - logout()
   *
   * @package OC\User
   */

  class Session implements IUserSession, Emitter {

  	/**
  	 * @var \OC\User\Manager $manager
  	 */
  	private $manager;
  
  	/**
  	 * @var \OC\Session\Session $session
  	 */
  	private $session;
  
  	/**
  	 * @var \OC\User\User $activeUser
  	 */
  	protected $activeUser;
  
  	/**
  	 * @param \OC\User\Manager $manager
  	 * @param \OC\Session\Session $session
  	 */
  	public function __construct($manager, $session) {
  		$this->manager = $manager;
  		$this->session = $session;
  	}
  
  	/**
  	 * @param string $scope
  	 * @param string $method
  	 * @param callable $callback
  	 */
  	public function listen($scope, $method, $callback) {
  		$this->manager->listen($scope, $method, $callback);
  	}
  
  	/**
  	 * @param string $scope optional
  	 * @param string $method optional
  	 * @param callable $callback optional
  	 */
  	public function removeListener($scope = null, $method = null, $callback = null) {
  		$this->manager->removeListener($scope, $method, $callback);
  	}
  
  	/**
  	 * get the manager object
  	 *
  	 * @return \OC\User\Manager
  	 */
  	public function getManager() {
  		return $this->manager;
  	}
  
  	/**
  	 * set the currently active user
  	 *

  	 * @param \OC\User\User|null $user

  	 */
  	public function setUser($user) {
  		if (is_null($user)) {

  			$this->getSession()->remove('user_id');

  		} else {

  			$this->getSession()->set('user_id', $user->getUID());

  		}
  		$this->activeUser = $user;
  	}
  
  	/**
  	 * get the current active user
  	 *
  	 * @return \OC\User\User
  	 */
  	public function getUser() {
  		if ($this->activeUser) {
  			return $this->activeUser;
  		} else {

  			$uid = $this->getSession()->get('user_id');

  			if ($uid !== null) {

  				$this->activeUser = $this->manager->get($uid);
  				return $this->activeUser;
  			} else {
  				return null;
  			}
  		}
  	}
  
  	/**

  	 * set the login name
  	 *

  	 * @param string|null $loginName for the logged in user

  	 */
  	public function setLoginName($loginName) {
  		if (is_null($loginName)) {

  			$this->getSession()->remove('loginname');

  		} else {

  			$this->getSession()->set('loginname', $loginName);

  		}
  	}
  
  	/**
  	 * get the login name of the current user
  	 *
  	 * @return string
  	 */
  	public function getLoginName() {
  		if ($this->activeUser) {

  			return $this->getSession()->get('loginname');

  		} else {

  			$uid = $this->getSession()->get('user_id');

  			if ($uid) {
  				$this->activeUser = $this->manager->get($uid);

  				return $this->getSession()->get('loginname');

  			} else {
  				return null;
  			}
  		}
  	}
  
  	/**

  	 * try to login with the provided credentials
  	 *
  	 * @param string $uid
  	 * @param string $password

  	 * @return boolean|null

  	 */
  	public function login($uid, $password) {
  		$this->manager->emit('\OC\User', 'preLogin', array($uid, $password));
  		$user = $this->manager->checkPassword($uid, $password);
  		if($user !== false) {
  			if (!is_null($user)) {
  				if ($user->isEnabled()) {
  					$this->setUser($user);

  					$this->setLoginName($uid);

  					$this->manager->emit('\OC\User', 'postLogin', array($user, $password));
  					return true;
  				} else {
  					return false;
  				}
  			}
  		} else {
  			return false;
  		}
  	}
  
  	/**

  	 * perform login using the magic cookie (remember login)
  	 *
  	 * @param string $uid the username
  	 * @param string $currentToken
  	 * @return bool
  	 */
  	public function loginWithCookie($uid, $currentToken) {
  		$this->manager->emit('\OC\User', 'preRememberedLogin', array($uid));
  		$user = $this->manager->get($uid);
  		if(is_null($user)) {
  			// user does not exist
  			return false;
  		}
  
  		// get stored tokens
  		$tokens = \OC_Preferences::getKeys($uid, 'login_token');
  		// test cookies token against stored tokens
  		if(!in_array($currentToken, $tokens, true)) {
  			return false;
  		}
  		// replace successfully used token with a new one
  		\OC_Preferences::deleteKey($uid, 'login_token', $currentToken);
  		$newToken = \OC_Util::generateRandomBytes(32);
  		\OC_Preferences::setValue($uid, 'login_token', $newToken, time());
  		$this->setMagicInCookie($user->getUID(), $newToken);
  
  		//login
  		$this->setUser($user);
  		$this->manager->emit('\OC\User', 'postRememberedLogin', array($user));
  		return true;
  	}
  
  	/**

  	 * logout the user from the session
  	 */
  	public function logout() {
  		$this->manager->emit('\OC\User', 'logout');
  		$this->setUser(null);

  		$this->setLoginName(null);

  		$this->unsetMagicInCookie();
  	}
  
  	/**
  	 * Set cookie value to use in next page load
  	 *
  	 * @param string $username username to be set
  	 * @param string $token
  	 */
  	public function setMagicInCookie($username, $token) {
  		$secure_cookie = \OC_Config::getValue("forcessl", false); //TODO: DI for cookies and OC_Config
  		$expires = time() + \OC_Config::getValue('remember_login_cookie_lifetime', 60 * 60 * 24 * 15);
  		setcookie("oc_username", $username, $expires, \OC::$WEBROOT, '', $secure_cookie);
  		setcookie("oc_token", $token, $expires, \OC::$WEBROOT, '', $secure_cookie, true);

  		setcookie("oc_remember_login", "1", $expires, \OC::$WEBROOT, '', $secure_cookie);

  	}
  
  	/**
  	 * Remove cookie for "remember username"
  	 */
  	public function unsetMagicInCookie() {
  		unset($_COOKIE["oc_username"]); //TODO: DI
  		unset($_COOKIE["oc_token"]);
  		unset($_COOKIE["oc_remember_login"]);
  		setcookie('oc_username', '', time()-3600, \OC::$WEBROOT);
  		setcookie('oc_token', '', time()-3600, \OC::$WEBROOT);
  		setcookie('oc_remember_login', '', time()-3600, \OC::$WEBROOT);
  		// old cookies might be stored under /webroot/ instead of /webroot
  		// and Firefox doesn't like it!
  		setcookie('oc_username', '', time()-3600, \OC::$WEBROOT . '/');
  		setcookie('oc_token', '', time()-3600, \OC::$WEBROOT . '/');
  		setcookie('oc_remember_login', '', time()-3600, \OC::$WEBROOT . '/');
  	}

  
  	/**
  	 * will keep the session instance in sync with \OC::$session
  	 * @return \OC\Session\Session
  	 */
  	private function getSession() {
  		//keep $this->session in sync with \OC::$session
  		if ($this->session !== \OC::$session) {
  			\OC::$server->getLogger()->debug(
  				'\OC::$session has been replaced with a new instance. '.
  				'Closing and replacing session in UserSession instance.'
  			);
  			$this->session->close();
  			$this->session = \OC::$session;
  		}
  		return $this->session;
  	}

  }