"""S1-T10: Excel parity gate for the Nagasamudra reference scenario.

HOW TO UNLOCK THIS TEST
───────────────────────
1. Open tests/fixtures/nagasamudra_inputs.json.
2. Replace the solar/wind config values with the actual project inputs.
3. Fill in _expected.solar_y1_mwh and _expected.wind_y1_mwh from the Excel model.
4. Remove the `pytest.skip` call below.

The test will then verify that year-1 generation matches Excel within 0.1 %
(the sprint parity gate from PROJECT.md).
"""

import json
from pathlib import Path

import pytest

FIXTURE = Path(__file__).parent.parent / "fixtures" / "nagasamudra_inputs.json"


@pytest.mark.skip(reason="Parity gate: awaiting real Nagasamudra data from user (S1-T10)")
def test_nagasamudra_solar_y1_parity() -> None:
    raw = json.loads(FIXTURE.read_text())
    expected_mwh = raw["_expected"]["solar_y1_mwh"]
    assert expected_mwh is not None, "Fill _expected.solar_y1_mwh in fixture"

    from remodel_engine.generation.solar import simulate_solar
    from remodel_engine.schemas.generation import SolarConfig

    cfg = SolarConfig(**raw["solar"])
    df = simulate_solar(cfg)
    actual_mwh = float(df[df["year"] == 1]["ac_power_mw"].sum())
    rel_error = abs(actual_mwh - expected_mwh) / expected_mwh
    assert rel_error <= 0.001, (
        f"Solar Y1 parity FAIL: engine={actual_mwh:.1f} MWh, "
        f"Excel={expected_mwh:.1f} MWh, error={rel_error:.4%}"
    )


@pytest.mark.skip(reason="Parity gate: awaiting real Nagasamudra data from user (S1-T10)")
def test_nagasamudra_wind_y1_parity() -> None:
    raw = json.loads(FIXTURE.read_text())
    expected_mwh = raw["_expected"]["wind_y1_mwh"]
    assert expected_mwh is not None, "Fill _expected.wind_y1_mwh in fixture"

    from remodel_engine.generation.wind import simulate_wind
    from remodel_engine.schemas.generation import WindConfig

    cfg = WindConfig(**raw["wind"])
    df = simulate_wind(cfg)
    actual_mwh = float(df[df["year"] == 1]["ac_power_mw"].sum())
    rel_error = abs(actual_mwh - expected_mwh) / expected_mwh
    assert rel_error <= 0.001, (
        f"Wind Y1 parity FAIL: engine={actual_mwh:.1f} MWh, "
        f"Excel={expected_mwh:.1f} MWh, error={rel_error:.4%}"
    )