<?php

class User {

         public $userName;
         public $userPassword;
         public $userEmail;
         public $userID;

    function __construct(){

    }

        function registerUser(){

        }

        function verifyCredentials($results){
            if($this->userName == $results['userName'] &&
                $this->userPassword == $results['userPassword']){
                    //add other user data to class for input into session variables
                    $this->userEmail = $results['userEmail'];
                    $this->userID = $results['userID'];
                    //start the session for authenticated user
                    $this->setSession();
            }
            else{
                throw new Exception("Invalid username and/or password. [Error 1]");
            }
        }

        function changePassword($newPassword){

        }

        function setSession(){ //do I really need to explain this one?
            session_start();
            $_SESSION['userName'] = $this->userName;
            $_SESSION['userPassword'] = md5($this->userPassword);
            $_SESSION['userEmail'] = $this->userEmail;
            $_SESSION['userID'] = $this->userID;

        }

        function checkLogin(){
            if(isset($_SESSION['userName']) && isset($_SESSION['userID']) &&
                (mktime() - $_SESSION['userToken']) > 1800){
                    session_unset();
                    session_destroy();
                    return false;
            }
            elseif(isset($_SESSION['userName']) && isset($_SESSION['userID']) &&
                    (mktime() - $_SESSION['userToken']) < 1800){
                        $this->userName = $_SESSION['userName'];
                        $this->userPassword = $_SESSION['userPassword'];
                        $this->userEmail = $_SESSION['userEmail'];
                        $this->userID = $_SESSION['userID'];
                        $_SESSION['userToken'] = mktime(); //user is active so update the token with the new time!!
                        return true;
            }
        }

        function displayUserInfo(){
            echo "UserName: " .$this->userName. "<br>\n";
            echo "Password: " .$this->userPassword. "<br>\n";
        }

}

?>