from uuid import uuid4

from src.aeros_simulation.ramp_engine import (
    _calc_result,
    _duration_to_hours,
    _filter_overrides_to_model,
    build_ramp_distribution_overrides_from_rbd_reliability,
    build_ramp_distribution_overrides,
    selected_simulation_engine,
)


def test_selected_simulation_engine_defaults_to_aeros():
    assert selected_simulation_engine({}) == "aeros"


def test_duration_to_hours_supports_aeros_units():
    assert _duration_to_hours(2, "UYear") == 17520
    assert _duration_to_hours(3, "UDay") == 72
    assert _duration_to_hours(5, "UHour") == 5


def test_build_ramp_distribution_overrides_from_ahm_custom_input():
    overrides = build_ramp_distribution_overrides(
        {
            "CustomInput": {
                "EQ001": {
                    "mttr": 10,
                    "failure_rate": 0.5,
                    "distribution": "Weibull",
                }
            }
        }
    )

    assert overrides["EQ001"]["repair_duration"] == 10
    assert overrides["EQ001"]["model"] == {
        "type": "NonRepairable",
        "distribution": {"type": "Weibull", "shape": 1.0, "scale": 2000000.0},
    }


def test_build_ramp_distribution_overrides_from_aeros_distribution_fields():
    overrides = build_ramp_distribution_overrides(
        {
            "DistributionOverrides": {
                "PUMP-A": {
                    "relDisType": "Weibull2",
                    "relDisP1": 1.7,
                    "relDisP2": 9000,
                    "cmDisType": "Normal",
                    "cmDisP1": 8,
                    "cmDisP2": 1.5,
                }
            }
        }
    )

    assert overrides["PUMP-A"]["model"]["distribution"] == {
        "type": "Weibull",
        "shape": 1.7,
        "scale": 9000.0,
    }
    assert overrides["PUMP-A"]["repair_duration"] == {
        "type": "Normal",
        "mean": 8.0,
        "std_dev": 1.5,
    }


def test_ramp_calc_result_uses_numeric_defaults_for_aeros_only_fields():
    calc = _calc_result(
        simulation_id=uuid4(),
        node_id=uuid4(),
        metrics={
            "system_availability": 0.95,
            "system_uptime": 95,
            "system_downtime": 5,
            "system_failures": 2,
        },
    )

    assert calc.stg_input == 0
    assert calc.stg_output == 0
    assert calc.average_level == 0
    assert calc.availability == 95.0


def test_build_ramp_distribution_overrides_from_rbd_reliability():
    overrides = build_ramp_distribution_overrides_from_rbd_reliability(
        {
            "PUMP-A": {
                "distribution": "NHPPTTFF",
                "beta": 1.4,
                "eta": 8000,
                "mttr": 12,
            },
            "PUMP-B": {
                "distribution": "Weibull2",
                "beta": 2,
                "eta": 9000,
                "mttr": 8,
            },
        }
    )

    assert overrides["PUMP-A"]["model"] == {
        "type": "RepairableNHPP",
        "beta": 1.4,
        "eta": 8000.0,
    }
    assert overrides["PUMP-A"]["repair_duration"] == 12.0
    assert overrides["PUMP-B"]["model"]["distribution"] == {
        "type": "Weibull",
        "shape": 2.0,
        "scale": 9000.0,
    }


def test_filter_overrides_keeps_only_assets_present_in_model():
    overrides = {
        "3AH-AU501A": {"repair_duration": 4},
        "3bad-m531": {"repair_duration": 6},
        "00CHA-CV804": {"repair_duration": 8},
    }
    kept, dropped = _filter_overrides_to_model(overrides, {"3AH-AU501A", "3BAD-M531"})

    assert set(kept) == {"3AH-AU501A", "3bad-m531"}
    assert dropped == ["00CHA-CV804"]


def test_filter_overrides_passes_through_when_model_assets_unknown():
    overrides = {"3AH-AU501A": {"repair_duration": 4}}
    kept, dropped = _filter_overrides_to_model(overrides, set())

    assert kept == overrides
    assert dropped == []