from pathlib import Path

import pytest

from femsurrogate.fea.io import read_beam_example, read_expected_displacements

ROOT = Path(__file__).resolve().parents[1]


def test_read_beam_example_parses_cantilever_fixture():
    model = read_beam_example(ROOT / "BeamExamples" / "CantileverBeam.txt")

    assert model.metadata["Area"] == pytest.approx(1.0)
    assert model.metadata["Izz"] == pytest.approx(0.0833333)
    assert model.metadata["ElasticModulus"] == pytest.approx(2.05e11)
    assert model.metadata["Poisson'sRatio"] == pytest.approx(0.3)

    assert len(model.nodes) == 6
    assert model.nodes[1].x == pytest.approx(0.0)
    assert model.nodes[6].x == pytest.approx(5.0)
    assert model.nodes[6].y == pytest.approx(0.0)

    assert len(model.beams) == 5
    assert model.beams[0].id == 1
    assert model.beams[0].node_i == 1
    assert model.beams[0].node_j == 2
    assert model.beams[-1].node_i == 5
    assert model.beams[-1].node_j == 6

    assert model.fixed_nodes == (1,)
    assert model.nodal_loads[6].fx == pytest.approx(0.0)
    assert model.nodal_loads[6].fy == pytest.approx(-100000.0)
    assert model.nodal_loads[6].mz == pytest.approx(0.0)


def test_read_expected_displacements_parses_reference_values():
    displacements = read_expected_displacements(
        ROOT / "BeamExamples" / "CantileverBeam_Displacements.txt"
    )

    assert len(displacements) == 6
    assert displacements[1].ux == pytest.approx(0.0)
    assert displacements[1].uy == pytest.approx(0.0)
    assert displacements[1].rz == pytest.approx(0.0)
    assert displacements[6].ux == pytest.approx(0.0)
    assert displacements[6].uy == pytest.approx(-0.000244)
    assert displacements[6].rz == pytest.approx(0.000073)