Model/tests/domain/modelling/test_wall_recommendation.py

"""Behaviour of the wall Recommendation Generator: detecting a treatable
wall and emitting a Recommendation whose Measure Option carries the
Simulation Overlay for the intervention. See CONTEXT.md / ADR-0016.
"""

from datatypes.epc.domain.epc_property_data import (
    BuildingPartIdentifier,
    EpcPropertyData,
    SapBuildingPart,
)
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.wall_recommendation import recommend_cavity_wall
from domain.modelling.generators.solid_wall_recommendation import recommend_solid_wall
from repositories.product.product_repository import ProductRepository
from tests.domain.sap10_calculator.worksheet._elmhurst_worksheet_000490 import (
    build_epc,
)


class _StubProducts(ProductRepository):
    """In-memory ProductRepository returning a fixed cavity Product."""

    def get(self, measure_type: str) -> Product:
        return Product(
            measure_type=measure_type, unit_cost_per_m2=18.5, 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_main_cavity_wall_yields_a_cavity_fill_recommendation() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()  # MAIN: cavity (4), uninsulated (4)

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

    # Assert
    assert recommendation is not None
    assert recommendation.surface == "Main wall"
    assert len(recommendation.options) == 1
    option = recommendation.options[0]
    assert option.measure_type == "cavity_wall_insulation"
    simulated: EpcPropertyData = apply_simulations(baseline, [option.overlay])
    assert _part(simulated, BuildingPartIdentifier.MAIN).wall_insulation_type == 2


def test_already_insulated_main_wall_yields_no_recommendation() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    _part(baseline, BuildingPartIdentifier.MAIN).wall_insulation_type = 2  # filled

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

    # Assert
    assert recommendation is None


def test_cavity_option_carries_fully_loaded_cost_from_area_and_product() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()  # MAIN gross heat-loss area 45.93 m^2
    products = _StubProducts()  # cavity 18.5 GBP/m^2, contingency 0.10

    # Act
    recommendation: Recommendation | None = recommend_cavity_wall(baseline, products)

    # Assert
    assert recommendation is not None
    cost = recommendation.options[0].cost
    assert cost is not None
    assert abs(cost.total - 45.93 * 18.5) <= 0.01
    assert abs(cost.contingency_rate - 0.10) <= 1e-9


def test_non_cavity_main_wall_yields_no_recommendation() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    main: SapBuildingPart = _part(baseline, BuildingPartIdentifier.MAIN)
    main.wall_construction = 2  # solid (not cavity); still uninsulated

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

    # Assert
    assert recommendation is None


def test_at_regs_age_band_cavity_yields_no_cavity_fill_recommendation() -> None:
    # Arrange — a cavity wall lodged as-built at construction age band L
    # (2012-2022): the as-built cascade already assigns the at-regs U-value, so
    # filling the cavity cannot lower it. The Wall U-Value Gate withholds the
    # Option (ADR-0051); the legacy insulation-state trigger alone would offer
    # a paid no-op.
    baseline: EpcPropertyData = build_epc()  # MAIN: cavity (4), uninsulated (4)
    _part(baseline, BuildingPartIdentifier.MAIN).construction_age_band = "L"

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

    # Assert
    assert recommendation is None


def test_at_regs_age_band_wall_yields_no_solid_wall_recommendation() -> None:
    # Arrange — a timber-frame wall lodged as-built at construction age band L
    # (2012-2022). RdSAP's cascade assigns it the at-regs U-value (0.28), and
    # 100 mm IWI resolves to the SAME value — the measure cannot change the
    # modelled wall, so offering it sells £4k of insulation for +0.00 SAP
    # (property 711795, PRD #1435 WS2). The Wall U-Value Gate withholds it
    # (ADR-0051).
    baseline: EpcPropertyData = build_epc()
    main: SapBuildingPart = _part(baseline, BuildingPartIdentifier.MAIN)
    main.wall_construction = 5  # timber frame — IWI-only construction
    main.wall_insulation_type = 4  # as-built / uninsulated — the legacy trigger
    main.construction_age_band = "L"

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

    # Assert
    assert recommendation is None


def test_treatable_old_band_solid_wall_keeps_its_insulation_options() -> None:
    # Arrange — solid brick as-built at age band B: the cascade U (~2.1) far
    # exceeds what 100 mm EWI/IWI achieves, so the Wall U-Value Gate must let
    # both Options through unchanged (the gate is physical possibility only —
    # ADR-0051).
    baseline: EpcPropertyData = build_epc()  # age band B
    main: SapBuildingPart = _part(baseline, BuildingPartIdentifier.MAIN)
    main.wall_construction = 3  # solid brick — EWI + IWI constructable
    main.wall_insulation_type = 4

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

    # Assert
    assert recommendation is not None
    assert {option.measure_type for option in recommendation.options} == {
        "external_wall_insulation",
        "internal_wall_insulation",
    }


def test_park_home_wall_yields_no_solid_wall_recommendation() -> None:
    # Arrange — a park home (wall_construction code 8) with an uninsulated
    # as-built wall. Code 8 is NOT system-built (ADR-0019); a park home's
    # proprietary panel is never EWI/IWI-suitable, so the generator excludes it.
    baseline: EpcPropertyData = build_epc()
    main: SapBuildingPart = _part(baseline, BuildingPartIdentifier.MAIN)
    main.wall_construction = 8
    main.wall_insulation_type = 4  # as-built / uninsulated — the trigger

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

    # Assert
    assert recommendation is None