from abc import ABCMeta, abstractmethod
from six import add_metaclass

@add_metaclass(ABCMeta)
class RegistryDataInterface(object):
  """ Interface for code to work with the registry data model. The registry data model consists
      of all tables that store registry-specific information, such as Manifests, Blobs, Images,
      and Labels.
  """

  @abstractmethod
  def find_matching_tag(self, repository_ref, tag_names):
    """ Finds an alive tag in the repository matching one of the given tag names and returns it
        or None if none.
    """

  @abstractmethod
  def get_most_recent_tag(self, repository_ref):
    """ Returns the most recently pushed alive tag in the repository, if any. If none, returns
        None.
    """