import pytest
import h06_web_mercator_utils as H06

class TestH06WebMercatorUtils:
    
    def test_latlon_to_tile(self):
        # Ukraine typical coords
        x, y = H06.latlon_to_tile(50.4501, 30.5234, 19)
        assert x > 0
        assert y > 0
        
    def test_tile_to_latlon(self):
        x, y, zoom = 305000, 175000, 19
        lat, lon = H06.tile_to_latlon(x, y, zoom)
        assert -90 <= lat <= 90
        assert -180 <= lon <= 180
        
    def test_compute_tile_bounds(self):
        bounds = H06.compute_tile_bounds(305000, 175000, 19)
        assert "nw" in bounds
        assert "se" in bounds
        assert "gsd" in bounds
        # GSD at zoom 19 in mid-latitudes should be roughly 0.15 to 0.4 m/px
        assert 0.15 < bounds["gsd"] < 0.4