"""Grass feature assembly (`landuse=grass`) with optional tuft scattering."""

from osmassets.geom import clip_polygon
from osmassets.mesh import MeshBatch


def assemble(ring, way_id, scene_xmin, scene_xmax, scene_ymin, scene_ymax,
             green_c, grass_mat, tuft_variants, add_grass_tufts_fn):
    ring = clip_polygon(ring, scene_xmin, scene_xmax, scene_ymin, scene_ymax)
    name = "Grass_" + str(way_id)
    focus = list(ring)
    if len(ring) < 3:
        return 0, 0, focus
    batch = MeshBatch(name, green_c, grass_mat)
    batch.add_polygon(ring, 0.015)
    obj = batch.finish()
    tufts = 0
    if tuft_variants:
        tufts = add_grass_tufts_fn(name, ring, tuft_variants, green_c)
        if obj:
            obj["grass_tufts"] = tufts
    return 1, tufts, focus