import numpy as np
from leonida.classify import CLASSES
from leonida.vectors import land_polygons, mask_polygons, road_polygons

def test_square_becomes_one_polygon_with_right_area():
    mask = np.zeros((100, 100), dtype=bool)
    mask[20:60, 30:80] = True                       # 40 x 50 Pixel = 2000 m²
    polys = mask_polygons(mask, min_area=10, simplify=1.0)
    assert len(polys) == 1
    assert abs(polys[0].area - 2000) < 60           # Vereinfachung darf etwas abweichen

def test_island_keeps_its_lagoon():
    labels = np.full((80, 80), CLASSES["wasser"], dtype=np.uint8)
    labels[10:70, 10:70] = CLASSES["land"]
    labels[30:50, 30:50] = CLASSES["wasser"]        # Lagune
    polys = land_polygons(labels)
    assert len(polys) == 1
    assert len(polys[0].interiors) == 1

def test_road_over_water_is_flagged_as_bridge():
    labels = np.full((60, 60), CLASSES["wasser"], dtype=np.uint8)
    labels[0:10, :] = CLASSES["land"]
    labels[25:31, :] = CLASSES["strasse"]           # Damm quer durchs Wasser
    roads = road_polygons(labels)
    assert len(roads) == 1
    assert roads[0][1] is True

def test_crossing_roads_form_a_single_polygon():
    labels = np.full((60, 60), CLASSES["land"], dtype=np.uint8)
    labels[28:32, :] = CLASSES["strasse"]
    labels[:, 28:32] = CLASSES["strasse"]
    roads = road_polygons(labels)
    assert len(roads) == 1                          # Kreuzung, kein Zerfall in vier Arme