import hashlib

class User:
    def __init__(self, username, password):
        self.username = username
        self.password = self._encrypt_password(password)
        self.is_logged = False

    def _encrypt_password(self, password):
        hash_text = (self.username + password).encode('utf-8')
        return hashlib.sha256(hash_text).hexdigest()

    def check_password(self, password):
        return self.password == self._encrypt_password(password)

class AuthenticException(Exception): pass
class PermissionError(Exception): pass
class IncorrectUsername(AuthenticException): pass
class IncorrectPassword(AuthenticException): pass
class PasswordToShort(AuthenticException): pass
class UsernameAlreadyExists(AuthenticException): pass
class NotPermittedError(AuthenticException): pass
class NotLoggedError(AuthenticException): pass


class Authicator:
    def __init__(self):
        self.users = {}

    def add_user(self, username, password):

        if username is self.users:
            raise UsernameAlreadyExists('Podany użytkownik już istnieje')

        if len(password < 0):
            raise PasswordToShort('Hasło musi zawierać conajmniej 8 znaków')

    def login(self, username, password):
        try:
            user = self.users[username]
        except KeyError:
            raise IncorrectUsername('Niepoprawna nazwa użytkownika')

    def isLogged(self, username):
        if username in self.users:
            return self.users[username].is_logged
        else:
            return False

class Authorizor:

    def __init__(self, authenticator):
        self.permissions = []
        self.authenticator = authenticator

    def add_persmission(self, perm):
        try:
            self.permissions[perm]
        except KeyError:
            self.permissions[perm] - set()

        else:
            raise PermissionError('Takie uprawnienie juz istnieje')


    def permit_user(self, username, perm):
        try:
            perm_set = self.permissions[perm]
        except KeyError:
            raise PermissionError('Takie uprawnienie nie istnieje')
        else:
            if username not in self.authenticator.users:
                raise IncorrectUsername('Niepoprawna nazwa uzytkownika')
            else:
                perm_set.add(username)

    def check_permission(self, username, perm):
        if not self.authenticator.is_logged(username):
            raise NotLoggedError('Uzytkownik nie jest zalogowany')

        try:
            perm_set =  self.permissions[perm]
        except KeyError:
            raise PermissionError('Takie uprawnienie nie istnieje')
        else:
            return True



authenticator = Authenticator()
authorizor = Authorizor(Authicator)