from app.analysis.spc import SPCResult, calculate_spc
from app.parsers.models import MeasurementRecord


def _make_records(name: str, nominal: float, tol: float, actuals: list[float]):
    return [
        MeasurementRecord(
            feature_name=name,
            nominal=nominal,
            tolerance_plus=tol,
            tolerance_minus=-tol,
            actual=a,
            deviation=a - nominal,
        )
        for a in actuals
    ]


def test_single_measurement_returns_none_indices():
    records = _make_records("D1", 10.0, 0.05, [10.01])
    results = calculate_spc(records)
    assert len(results) == 1
    r = results[0]
    assert r.cp is None
    assert r.cpk is None
    assert r.pp is None
    assert r.ppk is None


def test_basic_spc_calculation():
    actuals = [10.01, 10.02, 9.99, 10.00, 10.03, 9.98, 10.01, 10.02, 9.99, 10.00]
    records = _make_records("D1", 10.0, 0.05, actuals)
    results = calculate_spc(records)

    assert len(results) == 1
    r = results[0]
    assert r.n == 10
    assert r.pp is not None
    assert r.ppk is not None
    assert r.cp is not None
    assert r.cpk is not None
    assert r.pp > 0
    assert r.cpk > 0
    assert r.out_of_spec_count == 0


def test_out_of_spec_count():
    actuals = [10.0, 10.06, 9.94, 10.0, 10.0]  # 10.06 and 9.94 outside ±0.05
    records = _make_records("D1", 10.0, 0.05, actuals)
    results = calculate_spc(records)
    assert results[0].out_of_spec_count == 2


def test_multiple_features():
    records = (
        _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99])
        + _make_records("D2", 20.0, 0.10, [20.05, 19.95, 20.01])
    )
    results = calculate_spc(records)
    assert len(results) == 2
    names = {r.feature_name for r in results}
    assert names == {"D1", "D2"}


def test_shapiro_not_computed_for_small_n():
    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02])
    results = calculate_spc(records)
    assert results[0].shapiro_p is None


def test_shapiro_computed_for_n_ge_3():
    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99])
    results = calculate_spc(records)
    assert results[0].shapiro_p is not None


def test_to_dict():
    records = _make_records("D1", 10.0, 0.05, [10.01, 10.02, 9.99, 10.00, 10.03])
    results = calculate_spc(records)
    d = results[0].to_dict()
    assert "feature_name" in d
    assert "cpk" in d
    assert "values" in d
    assert isinstance(d["values"], list)