"""The gzip file path specification implementation."""

from dfvfs.lib import definitions
from dfvfs.path import factory
from dfvfs.path import path_spec


class GzipPathSpec(path_spec.PathSpec):
    """Gzip file path specification."""

    TYPE_INDICATOR = definitions.TYPE_INDICATOR_GZIP

    def __init__(self, parent=None, **kwargs):
        """Initializes a path specification.

        Note that the gzip file path specification must have a parent.

        Args:
          parent (Optional[PathSpec]): parent path specification.

        Raises:
          ValueError: when parent is not set.
        """
        if not parent:
            raise ValueError("Missing parent value.")

        super().__init__(parent=parent, **kwargs)


factory.Factory.RegisterPathSpec(GzipPathSpec)
