"""Behaviour of the roof Recommendation Generator: detecting an uninsulated
loft and emitting a Recommendation whose Measure Option carries the loft-
insulation Simulation Overlay and a priced Cost. Mirrors the wall generator.
"""

from datatypes.epc.domain.epc_property_data import (
    BuildingPartIdentifier,
    EpcPropertyData,
    SapBuildingPart,
    SapRoomInRoof,
)
from domain.modelling.scoring.overlay_applicator import apply_simulations
from domain.modelling.product import Product
from domain.modelling.recommendation import Recommendation
from domain.modelling.generators.roof_recommendation import recommend_roof_insulation
from repositories.product.product_repository import ProductRepository
from tests.domain.sap10_calculator.worksheet._elmhurst_worksheet_000490 import (
    build_epc,
)


class _StubProducts(ProductRepository):
    def get(self, measure_type: str) -> Product:
        return Product(
            measure_type=measure_type, unit_cost_per_m2=30.0, contingency_rate=0.10
        )


def _part(epc: EpcPropertyData, identifier: BuildingPartIdentifier) -> SapBuildingPart:
    return next(p for p in epc.sap_building_parts if p.identifier is identifier)


def test_uninsulated_loft_yields_a_loft_insulation_recommendation() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    _part(baseline, BuildingPartIdentifier.MAIN).roof_insulation_thickness = 0

    # Act
    recommendation: Recommendation | None = recommend_roof_insulation(
        baseline, _StubProducts()
    )

    # Assert
    assert recommendation is not None
    assert recommendation.surface == "Roof"
    assert len(recommendation.options) == 1
    option = recommendation.options[0]
    assert option.measure_type == "loft_insulation"
    simulated: EpcPropertyData = apply_simulations(baseline, [option.overlay])
    assert _part(simulated, BuildingPartIdentifier.MAIN).roof_insulation_thickness == 300


def test_already_insulated_loft_yields_no_recommendation() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()  # MAIN roof already 300 mm
    _part(baseline, BuildingPartIdentifier.MAIN).roof_insulation_thickness = 300

    # Act
    recommendation: Recommendation | None = recommend_roof_insulation(
        baseline, _StubProducts()
    )

    # Assert
    assert recommendation is None


def test_room_in_roof_yields_no_recommendation_pending_a_dedicated_branch() -> None:
    # Arrange — an uninsulated loft the fallback would otherwise top up, but the
    # part is a room-in-roof. The simple loft/sloping overlay can't model RR
    # insulation (its sloping/stud/gable surfaces carry their own U-values via
    # Table 17/18), so the generator must defer rather than mis-fire loft.
    baseline: EpcPropertyData = build_epc()
    main: SapBuildingPart = _part(baseline, BuildingPartIdentifier.MAIN)
    main.roof_insulation_thickness = 0
    main.sap_room_in_roof = SapRoomInRoof(floor_area=9.0, construction_age_band="D")

    # Act
    recommendation: Recommendation | None = recommend_roof_insulation(
        baseline, _StubProducts()
    )

    # Assert
    assert recommendation is None


def test_loft_option_carries_cost_from_roof_area_and_product() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()  # MAIN roof area 14.85 m^2
    _part(baseline, BuildingPartIdentifier.MAIN).roof_insulation_thickness = 0

    # Act
    recommendation: Recommendation | None = recommend_roof_insulation(
        baseline, _StubProducts()
    )

    # Assert
    assert recommendation is not None
    cost = recommendation.options[0].cost
    assert cost is not None
    assert abs(cost.total - 14.85 * 30.0) <= 0.01
    assert abs(cost.contingency_rate - 0.10) <= 1e-9