from pathlib import Path
import importlib.util
import json
import subprocess
import sys

import pytest
import yaml

HERE = Path(__file__).resolve().parent
spec = importlib.util.spec_from_file_location("steel_beam_calc", HERE / "calc.py")
assert spec is not None and spec.loader is not None
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)


def result():
    with (HERE / "input.yaml").open(encoding="utf-8") as handle:
        return module.compute(yaml.safe_load(handle))


def test_typst_load_demands_match_checked_inputs():
    subprocess.run([sys.executable, str(HERE / "calc.py")], check=True, cwd=HERE.parents[1])
    query = subprocess.run(
        [
            "typst", "eval", "query(<load-demands>)", "--root", ".",
            "--in", "calcs/steel-beam/steel-beam.typ", "--format", "json",
        ],
        check=True,
        capture_output=True,
        text=True,
        cwd=HERE.parents[1],
    )
    published = json.loads(query.stdout)
    assert len(published) == 1
    derived = published[0]["value"]
    values = result()["values"]
    assert derived["Mu_kipft"] == pytest.approx(values["moment_kipft"], abs=0.001)
    assert derived["Vu_kip"] == pytest.approx(values["shear_kip"], abs=0.001)


def test_ground_truth_section_properties():
    values = result()["values"]
    assert values["section_d"] == pytest.approx(5.875)
    assert values["section_A"] == pytest.approx(2.52)
    assert values["section_Sx"] == pytest.approx(5.1)
    assert values["section_Zx"] == pytest.approx(5.73)
    assert values["section_rts"] == pytest.approx(1.05)


def test_ground_truth_demands_and_flexure():
    output = result()
    values = output["values"]
    assert values["point_load_lbf"] == pytest.approx(7500)
    assert values["moment_kipft"] == pytest.approx(9.375)
    assert values["shear_kip"] == pytest.approx(3.75)
    assert values["Lp_in"] == pytest.approx(37.7, abs=0.1)
    assert values["Lr_ft"] == pytest.approx(9.48, abs=0.01)
    assert values["Fcr_ksi"] == pytest.approx(99.57, abs=0.25)
    assert values["Mp_kipft"] == pytest.approx(23.875)
    assert values["MnLTB_kipft"] == pytest.approx(21.235, abs=0.01)
    assert values["phiMn_kipft"] == pytest.approx(19.1, abs=0.1)
    assert output["checks"]["flexure"]["ok"] is True


def test_ground_truth_shear_and_deflection():
    output = result()
    values = output["values"]
    assert values["Aw_in2"] == pytest.approx(1.102, abs=0.001)
    assert values["Cv1"] == pytest.approx(1)
    assert values["phiVn_kip"] == pytest.approx(33.047, abs=0.1)
    assert values["delta_limit_in"] == pytest.approx(0.25)
    assert values["delta_in"] == pytest.approx(0.078, abs=0.001)
    assert all(output["checks"][name]["ok"] for name in ("shear", "deflection"))


def test_invalid_section_is_rejected():
    with pytest.raises(ValueError, match="not found"):
        module.compute({**yaml.safe_load((HERE / "input.yaml").read_text()), "section": "W0X0"})


def test_cli_can_write_json_to_stdout():
    completed = subprocess.run(
        [sys.executable, str(HERE / "calc.py"), "--input", str(HERE / "input.yaml"), "--stdout"],
        check=True,
        capture_output=True,
        text=True,
    )
    output = json.loads(completed.stdout)
    assert output["section"] == "W6X8.5"
    assert output["values"]["moment_kipft"] == pytest.approx(9.375)
    assert completed.stderr == ""