Authentication.php

<?php
namespace Ninja;
class Authentication {
    private $users;
    private $usernameColumn;
    private $passwordColumn;

    public function __construct(DatabaseTable $users,
    $usernameColumn, $passwordColumn){
        session_start();
        $this->users = $users;
        $this->usernameColumn = $usernameColumn;
        $this->passwordColumn = $passwordColumn;
    }


    public function login($username, $password) {
        $user = $this->users->find($this->usernameColumn, strtolower($username));
        if (!empty($user) && password_verify($password,
            $user[0]->{$this->passwordColumn})) {
            session_regenerate_id();
            $_SESSION['username'] = $username;
            $_SESSION['password'] =
            $user[0]->{$this->passwordColumn};
            return true;
        }
        else {
            return false;
        }
    }



    public function isLoggedIn(){
        if (empty($_SESSION['username'])) {
            return false;
        }
        $user = $this->users->find($this->usernameColumn,
        strtolower($_SESSION['username']));
        if (!empty($user) &&
        $user[0]->{$this->passwordColumn}
        === $_SESSION['password']) {
            return true;
        } else {
            return false;
        }
    }

    public function getUser() {
        if ($this->isLoggedIn()) {
        return $this->users->find($this->usernameColumn,
        strtolower($_SESSION['username']))[0];
        }
        else {
        return false;
    }
}
}