<?php
/*
* Auth_Simple.inc
* Code by Strangecode :: www.strangecode.com :: This document contains copyrighted information.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    04 Mar 2009 21:59:03
*/

class Auth_Simple {

    // Namespace of this auth object.
    protected $_ns;

    // Parameters to be configured by setParam.
    protected $_params = array();
    protected $_default_params = array(

        // The URL to the login script.
        'login_url' => '/',

        // The maximum amount of time a user is allowed to be logged in. They will be forced to login again if they expire.
        // In seconds. 21600 seconds = 6 hours.
        'login_timeout' => 21600,

        // The maximum amount of time a user is allowed to be idle before their session expires. They will be forced to login again if they expire.
        // In seconds. 3600 seconds = 1 hour.
        'idle_timeout' => 3600,
    );

    /**
     * Constructs a new authentication object.
     *
     * @access public
     * @param optional array $params  A hash containing parameters.
     */
    public function __construct($namespace='')
    {
    	$app =& App::getInstance();

        $this->_ns = $namespace;

        // Initialize default parameters.
        $this->setParam($this->_default_params);

        // Get create tables config from global context.
        if (!is_null($app->getParam('db_create_tables'))) {
            $this->setParam(array('create_table' => $app->getParam('db_create_tables')));
        }

        if (!isset($_SESSION['_auth_simple'][$this->_ns])) {
            $this->clear();
        }
    }

    /**
     * Set the params of an auth object.
     *
     * @param  array $params   Array of parameter keys and value to set.
     * @return bool true on success, false on failure
     */
    public function setParam($params)
    {
        if (isset($params) && is_array($params)) {
            // Merge new parameters with old overriding only those passed.
            $this->_params = array_merge($this->_params, $params);
        }
    }

    /**
     * Return the value of a parameter, if it exists.
     *
     * @access public
     * @param string $param        Which parameter to return.
     * @return mixed               Configured parameter value.
     */
    public function getParam($param)
    {
		$app =& App::getInstance();

        if (isset($this->_params[$param])) {
            return $this->_params[$param];
        } else {
            $app->logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__);
            return null;
        }
    }

    /**
     * Sets a variable into a registered auth session.
     *
     * @access public
     * @param mixed $key      Which value to set.
     * @param mixed $val      Value to set variable to.
     */
    public function set($key, $val)
    {
        if (!isset($_SESSION['_auth_simple'][$this->_ns]['user_data'])) {
            $_SESSION['_auth_simple'][$this->_ns]['user_data'] = array();
        }
        $_SESSION['_auth_simple'][$this->_ns]['user_data'][$key] = $val;
    }

    /**
     * Returns a specified value from a registered auth session.
     *
     * @access public
     * @param mixed $key      Which value to return.
     * @param mixed $default  Value to return if key not found in user_data.
     * @return mixed          Value stored in session.
     */
    public function get($key, $default='')
    {
        if (isset($_SESSION['_auth_simple'][$this->_ns][$key])) {
            return $_SESSION['_auth_simple'][$this->_ns][$key];
        } else if (isset($_SESSION['_auth_simple'][$this->_ns]['user_data'][$key])) {
            return $_SESSION['_auth_simple'][$this->_ns]['user_data'][$key];
        } else {
            return $default;
        }
    }

    /**
     * Clear any authentication tokens in the current session. A.K.A. logout.
     *
     * @access public
     */
    public function clear()
    {
        $_SESSION['_auth_simple'][$this->_ns] = array('authenticated' => false);
    }

    /*
    * Runs a full login sequence: clear old session, validate auth, create session.
    *
    * @access   public
    * @param    int     $user_id     User ID.
    * @return   mixed                   False on failure, true on success.
    * @author   Quinn Comendant <quinn@strangecode.com>
    * @version  1.0
    * @since    04 Mar 2009 21:07:33
    */
    public function login($user_id, $password, $callback)
    {
        global $acct;

		$app =& App::getInstance();

        $this->clear();

        if (!is_callable($callback)) {
            $app->logMsg(sprintf('Not callable: %s', getDump($callable)), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        if (!call_user_func($callback, $user_id, $password)) {
            $app->logMsg(sprintf('Authentication failed for user_id: %s', $user_id), LOG_NOTICE, __FILE__, __LINE__);
            return false;
        }

        $app->logMsg(sprintf('Authentication successful for user_id: %s', $user_id), LOG_INFO, __FILE__, __LINE__);
        return $this->createSession($user_id);
    }


    /*
    *
    *
    * @access   public
    * @param
    * @return
    * @author   Quinn Comendant <quinn@strangecode.com>
    * @version  1.0
    * @since    04 Mar 2009 21:07:33
    */
    public function createSession($user_id)
    {
		$app =& App::getInstance();

        // Register authenticated session.
        $_SESSION['_auth_simple'][$this->_ns] = array(
            'authenticated'         => true,
            'user_id'               => $user_id,
            'login_datetime'        => date('Y-m-d H:i:s'),
            'last_access_datetime'  => date('Y-m-d H:i:s'),
            'remote_ip'             => getRemoteAddr(),
        );

        return true;
    }

    /*
    *
    *
    * @access   public
    * @param
    * @return
    * @author   Quinn Comendant <quinn@strangecode.com>
    * @version  1.0
    * @since    04 Mar 2009 21:10:41
    */
    public function isLoggedIn($update_last_access_datetime=true)
    {
        $app =& App::getInstance();

        // Test login with information stored in session. Skip IP matching for users from trusted networks.
        if (isset($_SESSION['_auth_simple'][$this->_ns]['authenticated'])
            && true === $_SESSION['_auth_simple'][$this->_ns]['authenticated']
            && !empty($_SESSION['_auth_simple'][$this->_ns]['user_id'])
            && strtotime($_SESSION['_auth_simple'][$this->_ns]['login_datetime']) > time() - $this->_params['login_timeout']
            && strtotime($_SESSION['_auth_simple'][$this->_ns]['last_access_datetime']) > time() - $this->_params['idle_timeout']
        ) {
            // User is authenticated!
            if ($update_last_access_datetime) {
                $_SESSION['_auth_simple'][$this->_ns]['last_access_datetime'] = date('Y-m-d H:i:s');
            }
            $seconds_until_login_timeout = max(0, $this->_params['login_timeout'] - $result['seconds_since_last_login']);
            $seconds_until_idle_timeout = max(0, $this->_params['idle_timeout'] - $result['seconds_since_last_access']);
            $session_expiry_seconds = min($seconds_until_login_timeout, $seconds_until_idle_timeout);
            $app->logMsg(sprintf('Returning true login status for user_id %s (session expires in %s seconds)', $_SESSION['_auth_simple'][$this->_ns]['user_id'], $session_expiry_seconds), LOG_DEBUG, __FILE__, __LINE__);
            return $session_expiry_seconds;
        } else if (isset($_SESSION['_auth_simple'][$this->_ns]['authenticated']) && true === $_SESSION['_auth_simple'][$this->_ns]['authenticated']) {
            // User is authenticated, but login has expired.
            if (strtotime($_SESSION['_auth_simple'][$this->_ns]['last_access_datetime']) > time() - 43200) {
                // Only raise message if last session is less than 12 hours old.
                // TODO: Can we move this message to requireLogin() so it doesn't display unless the user expects it to?
                // $app->raiseMsg(_("Your session has expired. You need to log-in again."), MSG_NOTICE, __FILE__, __LINE__);
            }
            // Log the reason for login expiration.
            $expire_reasons = array();
            if (empty($_SESSION['_auth_simple'][$this->_ns]['user_id'])) {
                $expire_reasons[] = 'user_id not found';
            }
            if (strtotime($_SESSION['_auth_simple'][$this->_ns]['login_datetime']) <= time() - $this->_params['login_timeout']) {
                $expire_reasons[] = 'login_timeout expired';
            }
            if (strtotime($_SESSION['_auth_simple'][$this->_ns]['last_access_datetime']) <= time() - $this->_params['idle_timeout']) {
                $expire_reasons[] = 'idle_timeout expired';
            }
            $app->logMsg(sprintf('user_id %s session expired: %s', $this->get('user_id'), join(', ', $expire_reasons)), LOG_INFO, __FILE__, __LINE__);
        }

        // User is not authenticated.
        $this->clear();
        return false;
    }

    /**
     * Redirect user to login page if they are not logged in.
     *
     * @param string $message The text description of a message to raise.
     * @param int    $type    The type of message: MSG_NOTICE,
     *                        MSG_SUCCESS, MSG_WARNING, or MSG_ERR.
     * @param string $file    __FILE__.
     * @param string $line    __LINE__.
     * @access public
     */
    public function requireLogin($message='', $type=MSG_NOTICE, $file=null, $line=null)
    {
		$app =& App::getInstance();

        if (!$this->isLoggedIn()) {
            // Display message for requiring login. (RaiseMsg will ignore empty strings.)
            if ('' != $message) {
                $app->raiseMsg($message, $type, $file, $line);
            }

            // Login scripts must have the same 'login' tag for boomerangURL verification/manipulation.
            $app->setBoomerangURL(getenv('REQUEST_URI'), 'login');
            $app->dieURL($this->_params['login_url']);
        }
    }

    /**
     * Stub method to fulfill requirements by Version()
     *
     * @param  string   $null
     * @return string   Empty string
     */
    public function getUsername($null=null)
    {
        return '';
    }
}