<?PHP
function session_check()
{
    if(!isset($_COOKIE['MYSID'])) {
        $token=md5(rand(0,1000000000));
        setcookie('MYSID',$token);
        $user=array('id'=>NULL,'username'=>"Visitor");
        redis_set_json($token,$user,0);
    }
    else
        $token=$_COOKIE['MYSID'];
    if(isset($_POST['username']) and isset($_POST['password']))
        return authorize($_POST['username'],$_POST['password'],$token);
    else
        return authorize(NULL,NULL,$token);
}
function authorize($username,$password,$token)
{
    if($user!=NULL and $password!=NULL)
    {
        if($username=="kalkos" and $password=="qwerty")
            $user=array('id'=>333,'username'=>$username);
        else
            $user=array('id'=>NULL,'username'=>"Visitor");
        redis_set_json($token,$user,"0");
        return $user;
    }
    else
        return redis_get_json($token);
}
function logout($user)
{
    $token=$_COOKIE['MYSID'];
    $user=array('id'=>NULL,'username'=>"Visitor");
    redis_set_json($token,$user,"0");
    return $user;
}
function redis_set_json($key, $val, $wxpire)
{
  $redisClient = new Redis();
  $redisClient->connect('127.0.0.1', 6379);
  $value=json_encode($val);
  if($expire > 0)
    $redisClient->setex($key, $expire, $value);
  else
    $redisClient->set($key, $value);
  $redisClient->close();
}

function redis_get_json($key)
{
  $redisClient = new Redis();
  $redisClient->connect('127.0.0.1', 6379);
  $red=json_decode($redisClient->get($key),true);
  $redisClient->close();
  return $ret;
}

function show_menu($user)
{
  echo '
  <nav class="uk-navbar">
    <ul class="uk-navbar-nav">';
      if($user==NULL or $user['id']==NULL)
        echo '<li class="uk-active"><a href="login.php">Login</a></li>';
      else
        echo '<li class="uk-active"><a href="logout.php">Logout</a></li>';
        echo '<li class="uk-parent"><a href="index.php">Home</a></li>
    </ul>
  </nav>';
}
?>