PHP Verification Form - mySQLi - old - v2

// ------------------------------ //
// https://pastebin.com/996xp0kj  //
// ------------------------------ //

require '../php/session.php';
require '../php/config.php';
$token      = trim($_GET['auth_token']);
$invalid    = "login.php";
// CONFIRMATION FORM
if(isset($_POST['auth'])){
    // INPUTS
    $username = trim($_POST['auth_username']);
    $userpass = $_POST['auth_userpass'];

    // ERRORS ARRAY
    $errors = [];

    // Username Check
    if(!$username){
        $errors[] = "Empty Username";
    }elseif(!filter_var($username, FILTER_SANITIZE_STRING) || !preg_match("/^[\w]{4,16}$/", $username)){
        $errors[] = "Invalid Username";
        $username = "";
    }
    // Password Check
    if(!$userpass){
        $errors[] = "Empty Password";
    }

    // Verify Account Existence
    if($username && $userpass){
        $sql        = "SELECT user_id,user_name,user_pass,user_type FROM users WHERE user_name = ?";
        $verify = 1;
        $stmt   = prepareQuery($con, $sql, [$username]);
        $stmt   -> store_result();
        $num        = $stmt -> num_rows();
        // Check if account exists
        if($num === $verify){
            // Bind results to variables
            $stmt -> bind_result($uid, $uname, $uhash, $utype);
            while($stmt -> fetch()){
                $userid     = $uid;
                $username = $uname;
                $userhash = $uhash;
                $usertype = $utype;
            }

            // Finally check the password
            if(password_verify($userpass, $userhash)){
                $stmt -> close();
                // LOGIN ACCOUNT
                $_SESSION['uID']    = $userid;
                $_SESSION['pID']    = $username;
                $_SESSION['TYPE']   = $usertype;
                $_SESSION['LOGIN']  = $date;
                $errors[]   = "Successfully verified and logged in!";
                // LOG ACTIVITY
                $sql    = "UPDATE users SET user_status = ?, user_lastlogin = ?, user_verified = ? WHERE user_name = ?";
                $stmt = prepareQuery($con, $sql, [$verify, $date, $verify, $username]);
                redir("/dashboard/cpanel.php", $errors);
            }
        }
        $errors[] = "Username or password does not match our records";
        $con -> close();
    }
    // CHECK FOR ERRORS
    if($errors){
        $mins   = time() + 120;
        $path   = "confirmation.php?auth_token=".$token;
        setcookie("username", $username, $mins, $path);
        redir($path, $errors);
    }
// CONFIRMATION TOKEN
}elseif($token){
    $verify = 0;
    // Check token pattern [ONLY letters, numbers, and 16-char long]
    if(!filter_var($token, FILTER_SANITIZE_STRING) || !preg_match("/^[\w]{16}$/", $token)){
        redir($invalid, ["Invalid Token"]);
    }
    // Check token in Database
    $sql    = "SELECT user_name, user_token, user_verified FROM users WHERE user_token = ? AND user_verified = ?";
    $stmt = prepareQuery($con, $sql, [$token, $verify]);
    $stmt -> store_result();
    // If matches, allow access
    if($stmt -> num_rows()){
        $con -> close();
        $_SESSION['ERROR'] = ["Please enter your username and passsword"];
    }else{
        redir($invalid, ["Invalid Token"]);
    }
}else{
    redir($invalid, ["Page Unavailable"]);
}