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)