<?php
    if (isset($_SESSION["email"])) {
        /* special nav class ($navClass) used for repositioning the navbar when the user is logged in or not */
        $navClass = "nav-logged-in"; 
        $links = [
            "timeline" => "Timeline",
            "cms" => "CMS",
        ];
    } 
    else {
        $navClass = "nav-logged-out"; 
        $links = [
            // "login" => "Login",
        ];
    }
?>

<nav class="<?php echo $navClass; ?>">
 
    <?php
        //-----------LOGIN----------------------------------------------------------
        if(isset($_SESSION["email"]))
        {
            echo '<form method="post" id="form-logout">
                <p><label for="logoff">User: ' . "<span id = 'username'>" . $_SESSION["email"] . "</span>" . '</label>
                    <input type="submit" name="BUTTON_logout" value="Logout" class="btn logout"></p>
                </form>';
        }

        if(isset($_POST["BUTTON_logout"]))
        {
            unset($_SESSION["email"]);
            header("location: index.php?page=timeline");  
        }
        //---------------------------------------------------------------------------
    ?>
    <ul>
        <?php
            $currentPage = "timeline";   // default page
        
            if (isset($_GET["page"])) {
                $currentPage = $_GET["page"];
            }

            foreach ($links as $link => $name) {
                $isActive = "";

                if ($currentPage == $link) {
                    $isActive = "active";
                }
                echo "<li><a href='index.php?page=$link' class='$isActive'>$name</a></li>";
            }
        ?>
    </ul>
</nav>