from abc import ABCMeta, abstractmethod
from collections import namedtuple

from six import add_metaclass


class ServiceKey(namedtuple('ServiceKey', ['name', 'kid', 'service', 'jwk', 'metadata',
                                           'created_date', 'expiration_date', 'rotation_duration',
                                           'approval'])):
  """
  Service Key represents a public key (JWK) being used by an instance of a particular service to
  authenticate with other services.
  """
  pass


class ServiceKeyException(Exception):
  pass


class ServiceKeyDoesNotExist(ServiceKeyException):
  pass


@add_metaclass(ABCMeta)
class KeyServerDataInterface(object):
  """
  Interface that represents all data store interactions required by a JWT key service.
  """

  @abstractmethod
  def list_service_keys(self, service):
    """
    Returns a list of service keys or an empty list if the service does not exist.
    """
    pass

  @abstractmethod
  def get_service_key(self, signer_kid, service=None, alive_only=None, approved_only=None):
    """
    Returns a service kid with the given kid or raises ServiceKeyNotFound.
    """
    pass

  @abstractmethod
  def create_service_key(self, name, kid, service, jwk, metadata, expiration_date,
                         rotation_duration=None):
    """
    Stores a service key.
    """
    pass

  @abstractmethod
  def replace_service_key(self, old_kid, kid, jwk, metadata, expiration_date):
    """
    Replaces a service with a new key or raises ServiceKeyNotFound.
    """
    pass

  @abstractmethod
  def delete_service_key(self, kid):
    """
    Deletes and returns a service key with the given kid or raises ServiceKeyNotFound.
    """
    pass