from engine.camera import OrthoCamera


def test_zoom_defaults_target_to_initial_tiles_visible_y():
    camera = OrthoCamera(800, 600, tiles_visible_y=12.0)
    assert camera.target_tiles_visible_y == 12.0


def test_set_zoom_target_does_not_snap_immediately():
    camera = OrthoCamera(800, 600, tiles_visible_y=12.0)
    camera.set_zoom_target(20.0)
    assert camera.tiles_visible_y == 12.0
    assert camera.target_tiles_visible_y == 20.0


def test_update_zoom_moves_toward_the_target_over_time():
    camera = OrthoCamera(800, 600, tiles_visible_y=12.0)
    camera.set_zoom_target(20.0)
    camera.update_zoom(dt=0.1)
    assert 12.0 < camera.tiles_visible_y < 20.0


def test_update_zoom_snaps_once_close_enough():
    camera = OrthoCamera(800, 600, tiles_visible_y=12.0)
    camera.set_zoom_target(20.0)
    for _ in range(100):
        camera.update_zoom(dt=0.1)
    assert camera.tiles_visible_y == 20.0


def test_update_zoom_can_zoom_back_in():
    camera = OrthoCamera(800, 600, tiles_visible_y=20.0)
    camera.set_zoom_target(12.0)
    camera.update_zoom(dt=0.1)
    assert 12.0 < camera.tiles_visible_y < 20.0