"""ttLib.Attachment: Converting Attachment rules to TrueType."""

from fontFeatures.utils import categorize_glyph


def lookup_type(self):
    """Mixin to determine the GPOS lookup type of a fontFeatures.Attachment object

    Returns: integer GPOS lookup type."""
    if self.is_cursive:
        return 3
    # Terrible hacks
    firstbase = list(self.bases.keys())[0]
    if (
        hasattr(self, "fontfeatures")
        and self.fontfeatures.glyphclasses.get(firstbase) == "mark"
    ):
        return 6
    if self.font and categorize_glyph(self.font, firstbase)[0] == "mark":
        return 6
    return 4