<?php

/**

 * Library Class for handling OpenID authentication.

 *

 * $Id: auth.php 2008-09-25 17:28:07 BST Atomless $

 *

 * Instantiation of this class initiates a chain of extension down to the Openid base class:

 * Openid_Auth <- Openid_Relyingparty <- Openid_Response <-

 * Openid_Association <- Openid_Discovery <- Openid_Request <- Openid

 *

 * @package    Openid

 * @author     Kohana Team

 * @copyright  (c) 2007-2008 Kohana Team

 * @license    http://kohanaphp.com/license.html

 */

class Openid_Auth extends Openid_Relyingparty {



	/**

	 * Singleton instance of Openid_Auth.

	 */

	public static function instance()

	{

		static $instance;



		// Create the instance if it does not exist

		($instance === NULL) AND $instance = new Openid_Auth;



		return $instance;

	}



	/**

	 * Create an instance of Openid_Auth.

	 *

	 * @param   array - openid fields contained in parent Openid class

	 * @return  object

	 */

	public static function factory($fields = array())

	{

		return new Openid_Auth($fields);

	}



	/**

	 * Constructor.

	 *

	 * @param   array - openid fields to be set in the base Openid.php class

	 * @return  void

	 */

	public function __construct($fields = array())

	{

		// See the set_authentication_fields method of the parent Openid library class

		// and the Openid_identifier helper for the steps taken when

		// the claimed_id is set to a param passed to the Openid constructor

		parent::__construct($fields);

	}



	/**

	 * Check if there's a user session

	 *

	 * @return boolean

	 */

	public function logged_in()

	{

		$logged_in_user = $this->session->get('user', FALSE);



		// Checks if a user is logged in and valid

		return ( ! empty($logged_in_user)

				 AND is_object($logged_in_user)

				 AND ($logged_in_user instanceof Model_User)

				 AND $logged_in_user->loaded);

	}



	/**

	 * Logs a user in.

	 *

	 * @param   String   username

	 * @param   boolean  enable auto-login

	 * @return  boolean

	 */

	public function login($user, $remember)

	{

		if ($remember)

		{

			// Create a new autologin token

			$token = new Model_User_Token;



			// Set token data

			$token->user_id = $user->id;

			$token->expires = time() + KOHANA::config('openid.login_token_lifetime');

			$token->save();



			// Set the autologin cookie - links to user_token in the db

			cookie::set('openidautologin', $token->token, KOHANA::config('openid.login_token_lifetime'));

		}



		// Finish the login

		$this->complete_login($user);



		return TRUE;

	}



	/**

	 * Logs a user in, based on stored credentials in authautologin cookie.

	 *

	 * @return  boolean

	 */

	public function auto_login()

	{

		if ($token = cookie::get('openidautologin'))

		{

			// Load the token and user

			$token = new Model_User_token($token);



			if ($token->id > 0 AND $token->user->id > 0)

			{

				if ($token->user_agent === sha1(Kohana::$user_agent))

				{

					// Save the token to create a new unique token

					$token->save();



					// Set the new token

					cookie::set('openidautologin', $token->token, $token->expires - time());



					// Complete the login with the found data

					$this->complete_login($token->user);



					// Automatic login was successful

					return TRUE;

				}



				// Token is invalid

				$token->delete();

			}

		}



		return FALSE;

	}



	/**

	 * Complete the login for an openid user by incrementing the logins and setting

	 * session data: user_id, username, roles

	 *

	 * @param   object   user model object

	 * @return  void

	 */

	protected function complete_login(Model_User $user)

	{

		// Update the number of logins

		$user->logins += 1;



		// Set the last login date

		$user->last_login = time();



		// Save the user

		$user->save();



		// Regenerate session_id

		$this->session->regenerate();



		// Store session data

		$this->session->set('user', $user);

	}



	/**

	 * Log a user out.

	 *

	 * @param   boolean   completely destroy the session - also delete authautologin cookie

	 * @return  boolean

	 */

	public function logout($destroy)

	{

		// Delete the autologin cookie if it exists

		cookie::get('openidautologin') and cookie::delete('openidautologin');



		if ($destroy === TRUE)

		{

			// Destroy the session completely

			$this->session->destroy();

		}

		else

		{

			// Remove the user object from the session

			$this->session->delete('user');



			// Regenerate session_id

			$this->session->regenerate();

		}



		// Double check

		return ! $this->session->get('user', FALSE);

	}

}