class User {
    private $username;
    private $password;
    public  $ISLOGGEDIN = 'ISLOGGEDIN';

    ## Make a class function
    public function __construct() {
        $this->pdo = new PDO("mysql:host=localhost;dbname=login",'root','');
    }

    ## TJEK OM BRUGER EKSISTERE, return true, hvis ja
    private function userExists($username) {
        $this->username = $username;
        if ($stmt = $this->pdo->prepare("SELECT id FROM users WHERE username = :username")) {
            $stmt->bindParam(':username', $this->username);
            if ($stmt->execute()) {
                if ($stmt->rowCount() > 0) {
                    return true;
                } else {
                    return false;
                }
            } else {
                return true;
            }
        } else {
            return true;
        }
    }

    ## Opret ny bruger
    public function create($username, $password) {
        $this->username = $username;
        $this->password = $password;

        if (!$this->userExists($this->username)) {
            // Connect to database
            if ($stmt = $this->pdo->prepare("INSERT INTO users (username, password) VALUES (:username, :password)")) {
                $stmt->bindParam(':username', $this->username);
                $stmt->bindParam(':password', password_hash($this->password, PASSWORD_BCRYPT, ['cost' => 12]));
                if ($stmt->execute()) {
                    return true;
                } else {
                    return false;
                }
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    ## Get the latest userID
    public function getLastUserId() {
        $result = $this->pdo->query("SELECT id FROM users ORDER BY id DESC LIMIT 1");
        $row = $result->fetch(PDO::FETCH_ASSOC);
        return $row['id'];
    }

    ## Verify users
    public function verifyUser($username, $password) {
        $this->username = $username;
        $this->password = $password;

        if ($stmt = $this->pdo->prepare("SELECT id, password FROM users WHERE username = :username")) {
            $stmt->bindParam(':username', $this->username, PDO::PARAM_STR);
            if ($stmt->execute()) {
                $result = $stmt->fetch(PDO::FETCH_ASSOC);
                if (password_verify($this->password, $result['password'])) {
                    return true;
                } else {
                    return false;
                }
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    ## Get userID from users
    public function getUserId($username) {
        $this->username = $username;
        if ($stmt = $this->pdo->prepare("SELECT id FROM users WHERE username = :username")) {
            $stmt->bindParam(':username', $this->username, PDO::PARAM_STR);
            if ($stmt->execute()){
                $result = $stmt->fetch(PDO::FETCH_ASSOC);
                return $result['id'];
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    ## Login Method Filter Function
    public function methodCheck($method) {
        $requestMethod = filter_input(INPUT_SERVER, 'REQUEST_METHOD', FILTER_SANITIZE_SPECIAL_CHARS);
        if ($requestMethod === $method) {
            return TRUE;
        } else {
            return FALSE;
        }
    }

    ## Login Session
    public function doLogin($id) {
        if ($this->isSessionStarted() == false) {
            session_start();
        }
        $_SESSION[$this->ISLOGGEDIN] = TRUE;
        $_SESSION['userId'] = $id;
    }

    ## Token Generator
    private function generateToken() {
        if ($this->isSessionStarted() == false) {
            session_start();
        }
        $_SESSION['token'] = sha1(time()*rand(5,1000));
        $_SESSION['tokentime'] = time();
    }

    ## Get token
    public function getToken() {
        if ($this->isSessionStarted() == false) {
            session_start();
        }
        if(isset($_SESSION['token'])) {
            return $_SESSION['token'];
        } else {
            $this->generateToken();
            return $_SESSION['token'];
        }
    }

    ## Validate Token
    public function validateToken($token) {
        if ($this->isSessionStarted() == false) {
            session_start();
        }
        if ($token === $_SESSION['token']) {
            if ((time() - $_SESSION['tokentime']) > 120) {
                return FALSE;
            } else {
                return TRUE;
            }
        } else {
            return FALSE;
        }
    }

    ## Delete the token after use
    public function destroyToken(){
        if ($this->isSessionStarted() == false) {
            session_start();
        }
        if(isset($_SESSION['token']) && isset($_SESSION['tokentime'])) {
            unset($_SESSION['token']);
            unset($_SESSION['tokentime']);
        }
    }

    ## Is session started
    private function isSessionStarted() {
        if (php_sapi_name() !== 'cli') {
            if (version_compare(phpversion(), '5.4.0', '>=') ) {
                return session_status() === PHP_SESSION_ACTIVE ? true : false;
            } else {
                return session_id() === '' ? false : true;
            }
        }
        return true;
    }
}