from fontTools.misc.textTools import Tag, bytesjoin, strjoin
try:
	import xattr
except ImportError:
	xattr = None


def _reverseString(s):
	s = list(s)
	s.reverse()
	return strjoin(s)


def getMacCreatorAndType(path):
	"""Returns file creator and file type codes for a path.

	Args:
		path (str): A file path.

	Returns:
		A tuple of two :py:class:`fontTools.textTools.Tag` objects, the first
		representing the file creator and the second representing the
		file type.
	"""
	if xattr is not None:
		try:
			finderInfo = xattr.getxattr(path, 'com.apple.FinderInfo')
		except (KeyError, IOError):
			pass
		else:
			fileType = Tag(finderInfo[:4])
			fileCreator = Tag(finderInfo[4:8])
			return fileCreator, fileType
	return None, None


def setMacCreatorAndType(path, fileCreator, fileType):
	"""Set file creator and file type codes for a path.

	Note that if the ``xattr`` module is not installed, no action is
	taken but no error is raised.

	Args:
		path (str): A file path.
		fileCreator: A four-character file creator tag.
		fileType: A four-character file type tag.

	"""
	if xattr is not None:
		from fontTools.misc.textTools import pad
		if not all(len(s) == 4 for s in (fileCreator, fileType)):
			raise TypeError('arg must be string of 4 chars')
		finderInfo = pad(bytesjoin([fileType, fileCreator]), 32)
		xattr.setxattr(path, 'com.apple.FinderInfo', finderInfo)
