import numpy as np
from tests.node_tests._shared import make_field


def test_height_histogram():
    from backend.nodes.histogram import Histogram
    node = Histogram()

    data = np.linspace(0, 1, 1000).reshape(25, 40)
    field = make_field(data=data)

    overlays = []
    Histogram._broadcast_overlay_fn = lambda nid, data: overlays.append(data)
    Histogram._current_node_id = "test"

    table, coord_pair = node.process(field, n_bins=10, y_scale="linear", x1=0.2, y1=0.5, x2=0.8, y2=0.5)
    assert isinstance(coord_pair, tuple) and len(coord_pair) == 2
    measurements = {row["quantity"]: row for row in table}
    assert "A position" in measurements
    assert "A count" in measurements
    assert "B position" in measurements
    assert "B count" in measurements
    assert "delta X" in measurements
    assert "delta Y" in measurements
    assert measurements["A count"]["unit"] == "count"
    assert measurements["B count"]["unit"] == "count"
    assert measurements["B position"]["value"] > measurements["A position"]["value"]
    assert len(overlays) == 1
    assert overlays[0]["kind"] == "line_plot"
    assert overlays[0]["section_title"] == "Histogram"
    assert len(overlays[0]["line"]) == 10
    assert len(overlays[0]["x_axis"]) == 10
    assert np.isclose(overlays[0]["x1"], 0.2)
    assert np.isclose(overlays[0]["x2"], 0.8)
    assert np.isclose(
        measurements["delta Y"]["value"],
        measurements["B count"]["value"] - measurements["A count"]["value"],
    )

    Histogram._broadcast_overlay_fn = None