"""Validation tests for the study JSON protocol (v1)."""

import json

import pytest

from fem_solver.errors import FemSolverError
from fem_solver.study import parse_study


def valid_study() -> dict:
    return {
        "version": 1,
        "material": {"name": "Steel", "youngModulus": 210000, "poissonRatio": 0.3, "density": 7.85e-9},
        "mesh": {"targetSize": 2.5},
        "fixtures": [{"type": "fixed", "patch": {"vertices": [[0, 0, 0], [0, 10, 10]]}}],
        "loads": [
            {"type": "force", "value": [0, -1000, 0], "patch": {"vertices": [[100, 0, 0], [100, 10, 10]]}}
        ],
    }


def test_valid_study_is_normalized():
    parsed = parse_study(__import__("json").dumps(valid_study()))

    assert parsed["material"]["youngModulus"] == 210000
    assert parsed["mesh"]["targetSize"] == 2.5
    assert parsed["fixtures"][0]["type"] == "fixed"
    assert parsed["loads"][0]["type"] == "force"


def test_defaults_are_applied():
    study = valid_study()
    del study["mesh"]
    study["material"].pop("density")

    parsed = parse_study(__import__("json").dumps(study))

    assert parsed["mesh"]["targetSize"] == 2.5
    assert parsed["material"]["density"] == 7.85e-9


@pytest.mark.parametrize(
    "mutation,stage",
    [
        (lambda s: s.update(material=None), "study"),
        (lambda s: s["material"].update(youngModulus=-1), "study"),
        (lambda s: s["material"].update(poissonRatio=0.5), "study"),
        (lambda s: s.update(fixtures=[]), "study"),
        (lambda s: s.update(loads=[]), "study"),
        (lambda s: s["loads"][0].update(value=[0, None, 0]), "study"),
        (lambda s: s["fixtures"][0].update(patch={"vertices": []}), "study"),
        (lambda s: s.update(version=99), "study"),
    ],
)
def test_invalid_studies_are_rejected(mutation, stage):
    study = valid_study()
    mutation(study)

    with pytest.raises(FemSolverError) as excinfo:
        parse_study(__import__("json").dumps(study))

    assert excinfo.value.stage == stage


def test_pressure_load_requires_area_and_normal():
    study = valid_study()
    study["loads"] = [{"type": "pressure", "value": 0.1, "patch": {"vertices": [[0, 0, 0]]}}]

    with pytest.raises(FemSolverError):
        parse_study(__import__("json").dumps(study))

    study["loads"][0]["patch"].update(area=120.0, normal=[0, 1, 0])
    parsed = parse_study(__import__("json").dumps(study))

    assert parsed["loads"][0]["patch"]["area"] == 120.0


def test_malformed_json_is_rejected():
    with pytest.raises(FemSolverError) as excinfo:
        parse_study("{not json")

    assert excinfo.value.stage == "study"