"""The gzip file-like object."""

from dfvfs.file_io import file_object_io
from dfvfs.lib import errors
from dfvfs.lib import gzipfile
from dfvfs.resolver import resolver


class GzipFile(file_object_io.FileObjectIO):
    """File input/output (IO) object of a gzip file."""

    @property
    def comments(self):
        """Retrieves the comments.

        Returns:
          list[str]: comments of the members.
        """
        return [member.comment for member in self._file_object.members]

    @property
    def modification_times(self):
        """Retrieves the modification times.

        Returns:
          list[str]: modification times of the members.
        """
        return [member.modification_time for member in self._file_object.members]

    @property
    def original_filenames(self):
        """Retrieves the original filenames.

        Returns:
          list[str]: original filenames of the members.
        """
        return [member.original_filename for member in self._file_object.members]

    @property
    def operating_systems(self):
        """Retrieves the operating system values.

        Returns:
          list[str]: operating system values of the members.
        """
        return [member.operating_system for member in self._file_object.members]

    @property
    def uncompressed_data_size(self):
        """Retrieves the uncompressed data size.

        Returns:
          int: uncompressed data size.
        """
        return self._file_object.uncompressed_data_size

    def _OpenFileObject(self, path_spec):
        """Opens the file-like object defined by path specification.

        Args:
          path_spec (PathSpec): path specification.

        Returns:
          pyvde.volume: gzip file-like object.

        Raises:
          PathSpecError: if the path specification is incorrect.
        """
        if not path_spec.HasParent():
            raise errors.PathSpecError("Unsupported path specification without parent.")

        file_object = resolver.Resolver.OpenFileObject(
            path_spec.parent, resolver_context=self._resolver_context
        )

        gzip_compressed_stream = gzipfile.GzipCompressedStream()
        gzip_compressed_stream.Open(file_object)

        return gzip_compressed_stream

    # Note: that the following functions do not follow the style guide
    # because they are part of the file-like object interface.
    # pylint: disable=invalid-name

    def get_size(self):
        """Retrieves the size of the file-like object.

        Returns:
          int: size of the file-like object data.

        Raises:
          OSError: if the file-like object has not been opened.
        """
        if not self._is_open:
            raise OSError("Not opened.")

        return self._file_object.uncompressed_data_size
