Model/tests/domain/modelling/test_elmhurst_cascade_pins.py

"""Elmhurst before/after cascade pins for the Recommendation Generators.

Each measure has an Elmhurst `before` Summary (baseline cert) and an `after`
Summary (the same cert re-lodged with the measure applied). The pin drives the
matching generator on the parsed `before`, scores its Option's overlay through
the `PackageScorer`, and asserts the result equals the calculator's score on
the parsed `after` at `abs(diff) <= 1e-4` for SAP / CO2 / primary energy.

This is the real cert→generator→overlay→calculator cascade, not a per-section
isolation test (see `[[feedback-cascade-pin-methodology]]`): a non-zero delta
is a named generator/overlay/calculator gap to fix, never a tolerance to widen
(`[[feedback-zero-error-strict]]`).
"""

from __future__ import annotations

import copy
from dataclasses import replace
from typing import Final

import pytest

from datatypes.epc.domain.epc_property_data import (
    BuildingPartIdentifier,
    EpcPropertyData,
    PhotovoltaicArray,
    PvBatteries,
    PvBattery,
)
from domain.modelling.scoring.package_scorer import PackageScorer, Score
from domain.modelling.product import Product
from domain.modelling.recommendation import Recommendation
from domain.modelling.generators.floor_recommendation import recommend_floor_insulation
from domain.modelling.generators.roof_recommendation import (
    recommend_roof_insulation,
)
from domain.modelling.simulation import (
    BuildingPartOverlay,
    EpcSimulation,
    SolarOverlay,
)
from domain.modelling.generators.wall_recommendation import recommend_cavity_wall
from domain.geospatial.planning_restrictions import PlanningRestrictions
from domain.modelling.generators.solid_wall_recommendation import (
    recommend_solid_wall,
)
from domain.modelling.generators.glazing_recommendation import recommend_glazing
from domain.modelling.generators.lighting_recommendation import recommend_lighting
from domain.modelling.generators.heating_recommendation import recommend_heating
from domain.modelling.generators.secondary_heating_recommendation import (
    recommend_secondary_heating_removal,
)
from domain.modelling.scoring.overlay_applicator import apply_simulations
from domain.modelling.recommendation import MeasureOption
from domain.sap10_calculator.calculator import Sap10Calculator, SapResult
from repositories.product.product_repository import ProductRepository
from tests.domain.modelling._elmhurst_recommendation import (
    parse_recommendation_summary,
)
from tests.domain.sap10_calculator.worksheet._elmhurst_worksheet_001431 import (
    build_epc as build_001431_epc,
)

# RdSAP §A.2.2 forces a secondary system for electric-storage mains; SAP code
# 402 (slimline storage) is in that set. Code 104 (a gas combi boiler) is not.
_ELECTRIC_STORAGE_MAIN_CODE: Final[int] = 402
_STANDARD_ELECTRICITY_FUEL: Final[int] = 30
# SAP 10.2 Table 4a code 691 — electric panel/convector/radiant heaters, the
# fixed secondary the user's example cert lodges.
_SECONDARY_ELECTRIC_PANEL_CODE: Final[int] = 691

# Pin tolerance: the Summary PDFs are deterministic test vectors, so the
# overlay must reproduce the re-lodged cert exactly. Matches the worksheet
# e2e tolerance.
_PIN_ABS: Final[float] = 1e-4

# RdSAP wall_insulation_type codes for solid-wall insulation (Elmhurst
# Summary "E External" / "I Internal"); cf. domain/sap10_ml/rdsap_uvalues.py.
_WALL_INSULATION_EXTERNAL: Final[int] = 1
_WALL_INSULATION_INTERNAL: Final[int] = 3
# Recommended solid-wall insulation depth (mm); the calculator's λ default
# (0.04 W/m·K) matches Elmhurst's lodged thermal conductivity.
_SOLID_WALL_INSULATION_MM: Final[int] = 100


class _AnyProduct(ProductRepository):
    """In-memory ProductRepository returning a fixed Product for any Measure
    Type. The pins assert the SAP cascade, not Cost, so the unit cost is
    immaterial — only the generator's overlay is exercised."""

    def get(self, measure_type: str) -> Product:
        return Product(
            measure_type=measure_type, unit_cost_per_m2=1.0, contingency_rate=0.0
        )


def _assert_overlay_reproduces_after(
    before: EpcPropertyData, after: EpcPropertyData, overlay: EpcSimulation
) -> None:
    """Score ``overlay`` on ``before`` and assert it matches the calculator's
    score on the re-lodged ``after`` across all three metrics."""
    calculator = Sap10Calculator()
    relodged: SapResult = calculator.calculate(after)
    scored: Score = PackageScorer(calculator).score(before, [overlay])

    assert abs(scored.sap_continuous - relodged.sap_score_continuous) <= _PIN_ABS
    assert abs(scored.co2_kg_per_yr - relodged.co2_kg_per_yr) <= _PIN_ABS
    assert (
        abs(scored.primary_energy_kwh_per_yr - relodged.primary_energy_kwh_per_yr)
        <= _PIN_ABS
    )


def _assert_overlay_scores(
    before: EpcPropertyData,
    overlay: EpcSimulation,
    *,
    sap: float,
    co2: float,
    pe: float,
) -> None:
    """Score ``overlay`` on ``before`` and assert it matches the given snapshot
    of SAP / CO2 / primary energy. Used where the relodged after-cert predates
    the Vaillant product swap (it lodges the old heat-pump index): the snapshot
    is taken as correct because the same overlay reproduces the corrected
    Vaillant cert at delta 0 in the boiler-3 pin (ADR-0025)."""
    scored: Score = PackageScorer(Sap10Calculator()).score(before, [overlay])
    assert abs(scored.sap_continuous - sap) <= _PIN_ABS
    assert abs(scored.co2_kg_per_yr - co2) <= _PIN_ABS
    assert abs(scored.primary_energy_kwh_per_yr - pe) <= _PIN_ABS


def test_cavity_wall_overlay_reproduces_the_relodged_after() -> None:
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "cavity_wall_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "cavity_wall_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_cavity_wall(
        before, _AnyProduct()
    )
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_solid_brick_ewi_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — 100 mm external wall insulation on a solid-brick main wall.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_after.pdf"
    )
    overlay = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(
                wall_insulation_type=_WALL_INSULATION_EXTERNAL,
                wall_insulation_thickness=_SOLID_WALL_INSULATION_MM,
            )
        }
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_solid_brick_iwi_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — 100 mm internal wall insulation on a solid-brick main wall
    # (also lowers the thermal-mass parameter, unlike EWI).
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_iwi_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_iwi_001431_after.pdf"
    )
    overlay = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(
                wall_insulation_type=_WALL_INSULATION_INTERNAL,
                wall_insulation_thickness=_SOLID_WALL_INSULATION_MM,
            )
        }
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_solid_brick_generator_offers_ewi_and_iwi_each_pinning_its_after() -> None:
    # Arrange — one uninsulated solid-brick before, two re-lodged afters.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )
    ewi_after: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_after.pdf"
    )
    iwi_after: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_iwi_001431_after.pdf"
    )

    # Act — solid brick is suitable for both, unrestricted.
    recommendation: Recommendation | None = recommend_solid_wall(before, _AnyProduct())
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — both Options offered, and each Option's overlay reproduces its
    # own re-lodged after at the pin tolerance.
    assert set(options) == {"external_wall_insulation", "internal_wall_insulation"}
    _assert_overlay_reproduces_after(
        before, ewi_after, options["external_wall_insulation"].overlay
    )
    _assert_overlay_reproduces_after(
        before, iwi_after, options["internal_wall_insulation"].overlay
    )


def test_system_built_generator_offers_ewi_and_iwi_each_pinning_its_after() -> None:
    # Arrange — system-built (precast concrete) takes both Options like solid
    # brick (ADR-0019): one uninsulated before, two re-lodged afters.
    before: EpcPropertyData = parse_recommendation_summary(
        "system_built_ewi_001431_before.pdf"
    )
    ewi_after: EpcPropertyData = parse_recommendation_summary(
        "system_built_ewi_001431_after.pdf"
    )
    iwi_after: EpcPropertyData = parse_recommendation_summary(
        "system_built_iwi_001431_after.pdf"
    )

    # Act
    recommendation: Recommendation | None = recommend_solid_wall(before, _AnyProduct())
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — both Options offered, each reproducing its own re-lodged after.
    assert set(options) == {"external_wall_insulation", "internal_wall_insulation"}
    _assert_overlay_reproduces_after(
        before, ewi_after, options["external_wall_insulation"].overlay
    )
    _assert_overlay_reproduces_after(
        before, iwi_after, options["internal_wall_insulation"].overlay
    )


def test_timber_frame_generator_offers_iwi_only_pinning_its_after() -> None:
    # Arrange — timber frame takes IWI but EWI is not constructable (ADR-0019).
    before: EpcPropertyData = parse_recommendation_summary(
        "timber_frame_iwi_001431_before.pdf"
    )
    iwi_after: EpcPropertyData = parse_recommendation_summary(
        "timber_frame_iwi_001431_after.pdf"
    )

    # Act
    recommendation: Recommendation | None = recommend_solid_wall(before, _AnyProduct())
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — IWI only, and it reproduces the re-lodged after.
    assert set(options) == {"internal_wall_insulation"}
    _assert_overlay_reproduces_after(
        before, iwi_after, options["internal_wall_insulation"].overlay
    )


def test_conservation_area_drops_ewi_but_keeps_iwi() -> None:
    # Arrange — a conservation area blocks the external-appearance change only.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )

    # Act
    recommendation: Recommendation | None = recommend_solid_wall(
        before, _AnyProduct(), PlanningRestrictions(in_conservation_area=True)
    )

    # Assert — IWI survives, EWI is gone.
    assert recommendation is not None
    assert {option.measure_type for option in recommendation.options} == {
        "internal_wall_insulation"
    }


def test_listed_building_blocks_all_solid_wall_insulation() -> None:
    # Arrange — listed/heritage protect the fabric, so both EWI and IWI go.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )

    # Act / Assert
    assert (
        recommend_solid_wall(
            before, _AnyProduct(), PlanningRestrictions(is_listed=True)
        )
        is None
    )


def test_flat_drops_ewi_but_keeps_iwi() -> None:
    # Arrange — a flat can take IWI to its own unit, but EWI needs whole-block
    # coordination (ADR-0019). property_type "Flat" is the Elmhurst name form.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )
    flat: EpcPropertyData = replace(before, property_type="Flat")

    # Act
    recommendation: Recommendation | None = recommend_solid_wall(flat, _AnyProduct())

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


def test_flat_detected_from_api_property_type_code() -> None:
    # Arrange — the API path lodges property_type as a stringified code
    # ("2" = Flat per PROPERTY_TYPE_LOOKUP), not the name.
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_brick_ewi_001431_before.pdf"
    )
    flat: EpcPropertyData = replace(before, property_type="2")

    # Act
    recommendation: Recommendation | None = recommend_solid_wall(flat, _AnyProduct())

    # Assert — same gate fires regardless of representation.
    assert recommendation is not None
    assert {option.measure_type for option in recommendation.options} == {
        "internal_wall_insulation"
    }


def test_cavity_wall_gets_no_solid_wall_recommendation() -> None:
    # Arrange — a cavity wall is handled by recommend_cavity_wall, never here.
    before: EpcPropertyData = parse_recommendation_summary(
        "cavity_wall_001431_before.pdf"
    )

    # Act / Assert
    assert recommend_solid_wall(before, _AnyProduct()) is None


def test_loft_overlay_reproduces_the_relodged_after() -> None:
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "loft_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "loft_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_roof_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_roof_generator_insulates_a_sloping_ceiling_pinning_its_after() -> None:
    # Arrange — a pitched roof with an uninsulated sloping ceiling; the re-lodged
    # after raises its insulation from As Built to 100 mm (ADR-0021).
    before: EpcPropertyData = parse_recommendation_summary(
        "sloping_ceiling_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "sloping_ceiling_001431_after.pdf"
    )

    # Act — the dispatcher detects "sloping ceiling" and offers the sloping
    # measure (not loft).
    recommendation: Recommendation | None = recommend_roof_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — one sloping-ceiling Option whose overlay reproduces the after.
    assert set(options) == {"sloping_ceiling_insulation"}
    _assert_overlay_reproduces_after(
        before, after, options["sloping_ceiling_insulation"].overlay
    )


def test_roof_generator_insulates_a_thatched_roof_as_loft_pinning_its_after() -> None:
    # Arrange — a thatched pitched roof. Thatch is NOT excluded: the covering
    # doesn't block insulating the loft floor, so it takes loft (joist)
    # insulation, re-lodged None → 300 mm (ADR-0021).
    before: EpcPropertyData = parse_recommendation_summary(
        "loft_thatched_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "loft_thatched_001431_after.pdf"
    )

    # Act — the dispatcher routes a thatched roof to the loft branch.
    recommendation: Recommendation | None = recommend_roof_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — one loft Option whose overlay reproduces the after.
    assert set(options) == {"loft_insulation"}
    _assert_overlay_reproduces_after(
        before, after, options["loft_insulation"].overlay
    )


def test_roof_generator_insulates_a_flat_roof_pinning_its_after() -> None:
    # Arrange — a flat roof, uninsulated (As Built → None on the Elmhurst path);
    # the re-lodged after raises it to 200 mm (ADR-0021).
    before: EpcPropertyData = parse_recommendation_summary(
        "flat_roof_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "flat_roof_001431_after.pdf"
    )

    # Act
    recommendation: Recommendation | None = recommend_roof_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None
    options: dict[str, MeasureOption] = {
        option.measure_type: option for option in recommendation.options
    }

    # Assert — one flat-roof Option whose overlay reproduces the after.
    assert set(options) == {"flat_roof_insulation"}
    _assert_overlay_reproduces_after(
        before, after, options["flat_roof_insulation"].overlay
    )


def test_solid_floor_overlay_reproduces_the_relodged_after() -> None:
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "solid_floor_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "solid_floor_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_floor_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_suspended_floor_overlay_reproduces_the_relodged_after() -> None:
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "suspended_floor_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "suspended_floor_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_floor_insulation(
        before, _AnyProduct()
    )
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_double_glazing_overlay_reproduces_the_relodged_after_windows() -> None:
    # The full-SAP pin below is xfail (draught-proofing coupling), but the
    # overlay's actual job — turning every single-glazed window into the
    # relodged spec — is deterministic and must hold exactly: it proves the
    # generator detects BOTH single-glazing codes (1 and 15) on the real cert.
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "double_glazing_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "double_glazing_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_glazing(before, _AnyProduct())
    assert recommendation is not None

    # Act — apply the overlay to the parsed before.
    applied: EpcPropertyData = apply_simulations(
        before, [recommendation.options[0].overlay]
    )

    # Assert — every window's glazing_type + lodged U/g matches the after.
    def _window_spec(epc: EpcPropertyData) -> list[tuple[object, object, object]]:
        specs: list[tuple[object, object, object]] = []
        for window in epc.sap_windows:
            details = window.window_transmission_details
            specs.append(
                (
                    window.glazing_type,
                    details.u_value if details is not None else None,
                    details.solar_transmittance if details is not None else None,
                )
            )
        return specs

    assert _window_spec(applied) == _window_spec(after)


_GLAZING_DRAUGHT_COUPLING_REASON: Final[str] = (
    "Blocked on the glazing measure's draught-proofing coupling. The window "
    "U/g overlay reproduces the after's 14 windows EXACTLY (all four single-"
    "glazed panes — codes 1 and 15 — become the relodged double/secondary "
    "spec). The residual ~0.7 SAP is a secondary effect the overlay does not "
    "model: replacing the single-glazed (lodged draught_proofed=No) windows "
    "with sealed units re-lodges percent_draughtproofed 84->100 (~0.3 SAP) and "
    "lowers fabric heat loss by ~+150 kWh space heating (~0.4 SAP) not yet "
    "isolated. Flips green once the glazing overlay propagates draught-proofing "
    "(and the residual fabric coupling is modelled)."
)


@pytest.mark.xfail(strict=True, reason=_GLAZING_DRAUGHT_COUPLING_REASON)
def test_double_glazing_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — cert 001431 lodges four single-glazed windows (codes 1 and 15,
    # "single glazing, known data"); the after re-lodges every one as double
    # (gt=5, U=1.40, g=0.72).
    before: EpcPropertyData = parse_recommendation_summary(
        "double_glazing_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "double_glazing_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_glazing(before, _AnyProduct())
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


@pytest.mark.xfail(strict=True, reason=_GLAZING_DRAUGHT_COUPLING_REASON)
def test_secondary_glazing_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — a planning protection forces secondary glazing; the after
    # re-lodges every single-glazed window as secondary (gt=11, U=2.90, g=0.85).
    before: EpcPropertyData = parse_recommendation_summary(
        "secondary_glazing_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "secondary_glazing_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_glazing(
        before, _AnyProduct(), PlanningRestrictions(in_conservation_area=True)
    )
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_lighting_overlay_reproduces_the_relodged_after_zero_existing_leds() -> None:
    # Arrange — a dwelling with no LEDs (20 incandescent); the after re-lodges
    # all 20 as LED. Lighting only changes bulb counts → Appendix L (232), with
    # no fabric coupling, so the full-SAP pin closes cleanly.
    before: EpcPropertyData = parse_recommendation_summary(
        "low_energy_lighting_zero_leds_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "low_energy_lighting_zero_leds_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_lighting(before, _AnyProduct())
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_lighting_overlay_reproduces_the_relodged_after_some_existing_leds() -> None:
    # Arrange — a dwelling with some LEDs already (5 LED + 15 incandescent); the
    # after re-lodges all 20 as LED. Exercises the partial-upgrade path: the
    # overlay tops led up to the total rather than starting from zero.
    before: EpcPropertyData = parse_recommendation_summary(
        "low_energy_lighting_some_leds_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "low_energy_lighting_some_leds_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_lighting(before, _AnyProduct())
    assert recommendation is not None

    # Act / Assert
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_hhr_storage_overlay_reproduces_the_relodged_after_from_electric_storage() -> None:
    # Arrange — an existing electric storage system re-lodged as high-heat-
    # retention storage (Table 4a 402 -> 409, control 2401 -> 2404), gaining an
    # off-peak immersion cylinder and a dual meter (ADR-0024).
    before: EpcPropertyData = parse_recommendation_summary(
        "hhr_storage_from_electric_storage_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "hhr_storage_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o
        for o in recommendation.options
        if o.measure_type == "high_heat_retention_storage_heaters"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_hhr_storage_overlay_reproduces_the_relodged_after_from_no_system() -> None:
    # Arrange — a "no system present" electric dwelling re-lodged as HHR storage;
    # the same absolute-target overlay must reproduce the common after.
    before: EpcPropertyData = parse_recommendation_summary(
        "hhr_storage_from_no_system_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "hhr_storage_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o
        for o in recommendation.options
        if o.measure_type == "high_heat_retention_storage_heaters"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_ashp_overlay_scores_the_vaillant_end_state_from_a_gas_boiler() -> None:
    # Arrange — a typical mains-gas combi house re-cast as an air-source heat
    # pump (fuel 26 -> 30, SAP code 104 -> Vaillant aroTHERM plus 5 kW index
    # 110257 + category 4, control 2106 -> 2210), off mains gas, gaining a heat-
    # pump cylinder (ADR-0024). The boiler-1 after-cert predates the Vaillant
    # swap (it lodges the old index 101413), so this snapshots the Vaillant
    # overlay's own output rather than re-pinning a stale relodged PDF — taken as
    # correct because the same overlay reproduces the corrected Vaillant cert at
    # delta 0 in the system-boiler pin below.
    before: EpcPropertyData = parse_recommendation_summary(
        "ashp_from_gas_boiler_001431_before.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "air_source_heat_pump"
    )

    # Act / Assert — re-pinned after merging main's fabric fixes (roof "Unknown"
    # U → Table 18 default, Room-in-Roof U leak), which shift this 001431
    # dwelling's baseline fabric and so the ASHP end-state SAP. Still a snapshot
    # of the Vaillant overlay's own output, validated transitively by the
    # system-boiler pin below (which reproduces a real Vaillant cert at delta 0).
    # CO2/PE are the postcode DEMAND cascade now that `Sap10Calculator.
    # calculate` computes EPC emissions/PE on local weather (SAP 10.2
    # Appendix U p.124); SAP is unchanged (UK-average rating cascade).
    _assert_overlay_scores(
        before,
        option.overlay,
        sap=51.99820176096402,
        co2=1065.7593506066496,
        pe=10995.781557709413,
    )


def test_ashp_overlay_scores_the_vaillant_end_state_from_a_gas_boiler_instant_hw() -> None:
    # Arrange — a gas boiler whose hot water is electric/instantaneous (water-
    # heating SAP code 909, no cylinder) re-cast as an ASHP. Exercises the
    # overlay's water_heating_code reset (909 -> 901, "from the heat pump") that
    # boiler-1 didn't (its HW was already 901). Snapshots the Vaillant overlay's
    # output (the after-cert predates the Vaillant swap), validated transitively
    # by the system-boiler pin below.
    before: EpcPropertyData = parse_recommendation_summary(
        "ashp_from_gas_boiler_instant_hw_001431_before.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "air_source_heat_pump"
    )

    # Act / Assert — re-pinned after merging main's fabric fixes (see the
    # boiler-1 pin above); the same merge also resolved this cert's main-fuel
    # mapper gap (§14.2 mains-gas derivation), so its raw before now baselines —
    # see `test_gas_boiler_instant_hw_before_baselines`.
    # CO2/PE are the postcode DEMAND cascade now (see the boiler-1 pin above);
    # SAP is unchanged (UK-average rating cascade).
    _assert_overlay_scores(
        before,
        option.overlay,
        sap=39.00740809309464,
        co2=1845.8588018295509,
        pe=18944.42568846759,
    )


def test_ashp_overlay_reproduces_the_relodged_after_from_a_system_boiler_with_cylinder() -> None:
    # Arrange — a mains-gas *regular/system* boiler (SAP code 101, not a combi)
    # that already heats its own hot-water cylinder (size 2 / insulation type 2 /
    # 80 mm) re-lodged as an ASHP. This exercises the cylinder OVERWRITE path that
    # boiler-1/boiler-2 didn't: those added a cylinder where none existed, whereas
    # here the overlay must overwrite the existing cylinder to the fixed heat-pump
    # cylinder (size 4 / insulation type 1 / 50 mm). The dwelling also goes off
    # mains gas (fuel 26 -> 30, code 101 -> Vaillant aroTHERM plus 5 kW index
    # 110257 + category 4, control 2113 -> 2210). After-cert re-lodged with the
    # Vaillant: ASHP raises this dwelling's SAP 63.85 -> 72.30.
    before: EpcPropertyData = parse_recommendation_summary(
        "ashp_from_system_boiler_with_cylinder_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "ashp_from_system_boiler_with_cylinder_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "air_source_heat_pump"
    )

    # Act / Assert — the absolute overlay overwrites the existing cylinder and
    # reproduces the after exactly.
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_gas_boiler_instant_hw_before_baselines() -> None:
    # The Modelling pipeline baselines the dwelling before modelling it, so the
    # before must be scorable on its own. This was previously blocked: the gas
    # boiler lodged with EES 'BGB' / SAP code 102 derived no main_fuel_type, so
    # Sap10Calculator raised MissingMainFuelType. Merging main's mapper fix
    # (resolve gas-boiler main fuel from the §14.2 mains-gas meter) closed that
    # gap, so the raw before now baselines.
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "ashp_from_gas_boiler_instant_hw_001431_before.pdf"
    )

    # Act
    result: SapResult = Sap10Calculator().calculate(before)

    # Assert — it baselines without raising, on mains gas.
    assert result.sap_score_continuous > 0.0


def test_boiler_with_cylinder_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — a mains-gas wet boiler (SAP code 114) heating an uninsulated
    # hot-water cylinder (no insulation, no thermostat) re-lodged as a new gas
    # condensing boiler with a cylinder (SAP code 102, fanned flue), the cylinder
    # jacketed (insulation type 2 / 80 mm) and given a thermostat. The boiler
    # upgrade leaves the (already adequate) controls + cylinder size + meter
    # unchanged. Validates the boiler-with-cylinder option end-state at delta 0.
    #
    # NB the absolute SAP on this dwelling is subject to a separate Summary-path
    # mapper roof-fidelity gap (our calculator reads the roof better-insulated
    # than Elmhurst, so it scores ~75 where Elmhurst prints 56); the gap is
    # identical on before + after (the boiler measure never touches the roof), so
    # it cancels and this pin still proves the overlay applies Elmhurst's exact
    # heating field-delta. Tracked on the calculator branch, not here.
    before: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_gas_001431_before.pdf"
    )
    # The cert lodges code 114 (already condensing), which the efficiency gate
    # excludes from a like-for-like swap; recast to a pre-1998 non-condensing
    # boiler (110) so the upgrade is offered. The overlay overwrites the code to
    # 102 regardless, so this changes only eligibility, not the validated result.
    before.sap_heating.main_heating_details[0].sap_main_heating_code = 110
    after: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_gas_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "gas_boiler_upgrade"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_boiler_combi_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — a mains-gas combi (SAP code 112, no cylinder) with inadequate
    # controls (2111 "TRVs and bypass" — no room thermostat, so no boiler
    # interlock) re-lodged as a new gas condensing combi (code 104, fanned flue)
    # with full programmer + room thermostat + TRV controls (2106). No cylinder,
    # so no cylinder components. Validates the combi end-state + the controls-
    # when-inadequate upgrade at delta 0. (Same Summary-path roof gap as the
    # with-cylinder pin — it cancels across before/after.)
    before: EpcPropertyData = parse_recommendation_summary(
        "boiler_combi_gas_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "boiler_combi_gas_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "gas_boiler_upgrade"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_oil_combi_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — an OIL combi (fuel 28, SAP code 130, no cylinder) on a mains-gas
    # street re-lodged as a gas condensing combi (fuel 28->26, code 104, fanned
    # flue). Validates the non-gas -> gas conversion: the upgrade targets gas
    # because a mains-gas connection is present (ADR-0024 revised). Controls are
    # already adequate (2106), so they are unchanged.
    before: EpcPropertyData = parse_recommendation_summary(
        "boiler_combi_oil_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "boiler_combi_oil_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "gas_boiler_upgrade"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_boiler_with_already_insulated_cylinder_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — a gas boiler heating an ALREADY-jacketed cylinder (insulation
    # type 2 / 80 mm) with no thermostat, re-lodged as a new gas condensing
    # boiler (code 102) with a cylinder thermostat added. Validates the cylinder
    # path's skip-jacket branch (the 80 mm jacket is not re-applied) while the
    # thermostat is still added. (Sourced from an LPG re-lodgement; the Summary
    # mapper reads its fuel as mains gas — fuel 26 — so this exercises the gas
    # cylinder path, not a true LPG conversion. The LPG fuel-mapping gap is a
    # separate mapper-front concern.)
    before: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_lpg_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_lpg_001431_after.pdf"
    )
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "gas_boiler_upgrade"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


def test_coal_boiler_with_cylinder_overlay_reproduces_the_relodged_after() -> None:
    # Arrange — a SOLID-FUEL (coal) boiler (fuel 11, SAP code 153) heating a
    # cylinder, on a mains-gas street, re-lodged as a gas condensing boiler
    # (fuel 11->26, code 102, fanned flue + boiler flue type 2). Exercises the
    # non-gas -> gas conversion for a solid-fuel boiler AND the new
    # `boiler_flue_type` end-state (coal's before lodged none; every other cert
    # already lodged flue type 2). The cylinder is already 80 mm insulated so the
    # jacket is skipped; only the thermostat is added.
    #
    # The relodged after predates the user-locked "always add a cylinder
    # thermostat when absent" rule, so it stale-lodged thermostat 'N'; the test
    # corrects it to the rule's end-state 'Y' (the same correction the gas
    # with-cylinder after received by re-lodging). Controls are already adequate
    # (2106), so they are unchanged.
    before: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_coal_001431_before.pdf"
    )
    after: EpcPropertyData = parse_recommendation_summary(
        "boiler_cyl_coal_001431_after.pdf"
    )
    after.sap_heating.cylinder_thermostat = "Y"
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == "gas_boiler_upgrade"
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


@pytest.mark.parametrize(
    "before_fixture, after_fixture, measure_type",
    [
        # The system tune-up keeps the existing boiler and forces the heating
        # controls to a fixed end-state (standard 2106 / zone 2110) ABSOLUTELY —
        # proven by reproducing each common after from two different starting
        # controls (2101 "no control" and 2113 "room thermostat and TRVs") — plus
        # the conditional cylinder jacket + thermostat (both befores are
        # uninsulated / un-thermostatted, so both fire).
        (
            "tune_up_from_2101_001431_before.pdf",
            "tune_up_standard_001431_after.pdf",
            "system_tune_up",
        ),
        (
            "tune_up_from_2113_001431_before.pdf",
            "tune_up_standard_001431_after.pdf",
            "system_tune_up",
        ),
        (
            "tune_up_from_2101_001431_before.pdf",
            "tune_up_zoned_001431_after.pdf",
            "system_tune_up_zoned",
        ),
        (
            "tune_up_from_2113_001431_before.pdf",
            "tune_up_zoned_001431_after.pdf",
            "system_tune_up_zoned",
        ),
    ],
)
def test_system_tune_up_overlay_reproduces_the_relodged_after(
    before_fixture: str, after_fixture: str, measure_type: str
) -> None:
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(before_fixture)
    after: EpcPropertyData = parse_recommendation_summary(after_fixture)
    recommendation: Recommendation | None = recommend_heating(before, _AnyProduct())
    assert recommendation is not None
    option = next(
        o for o in recommendation.options if o.measure_type == measure_type
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, option.overlay)


# --- Solar PV cascade pins (ADR-0026) -------------------------------------
#
# The solar before/after Summaries lodge *synthetic* PV arrays (each 1.00 kWp,
# varied orientation/pitch/overshading) — deterministic test vectors chosen to
# exercise the overlay -> calculator PV path across the config space, NOT the
# Google-derived production arrays. So these pins hand-build the SolarOverlay
# matching each after-cert's lodged arrays (the generator's own overlay is
# Google-sourced and validated separately in test_solar_recommendation /
# test_solar_overshading); the cascade proves `_fold_solar` + the calculator
# reproduce Elmhurst's PV re-lodgement exactly.
#
# All five certs share one main-heating system lodged with EES code 'WGK' /
# Main Heating SAP code 502, which the Elmhurst mapper does not yet derive a
# main_fuel_type for (it maps to '' -> MissingMainFuelType). The solar overlay
# never touches heating, so the pins patch the shared fuel to mains gas (26) on
# both before and after identically — the heating contribution is then equal on
# both sides and the delta isolates the PV change. The unresolved raw baseline
# is a separate mapper-front gap, tripwired by `test_solar_before_baselines`.

_SOLAR_MAINS_GAS_FUEL: Final[int] = 26


def _parse_solar(fixture_name: str) -> EpcPropertyData:
    """Parse a solar before/after Summary, patching the shared main-heating
    fuel to mains gas (the EES 'WGK' / SAP code 502 mapper-front gap — see the
    section note). Applied identically on before + after, so it cancels in the
    PV delta."""
    epc: EpcPropertyData = parse_recommendation_summary(fixture_name)
    main = epc.sap_heating.main_heating_details[0]
    if not main.main_fuel_type:
        main.main_fuel_type = _SOLAR_MAINS_GAS_FUEL
    return epc


def test_solar_overlay_reproduces_relodged_after_se_sw_shaded() -> None:
    # Arrange — two shaded planes: SE (octant 4) at 30° pitch under significant
    # shading (code 3), and SW (octant 6) at 45° pitch under modest shading
    # (code 2); each a 1.00 kWp array. Exercises the overshading + orientation
    # spread.
    before: EpcPropertyData = _parse_solar("solar_pv_001431_before.pdf")
    after: EpcPropertyData = _parse_solar("solar_pv_no_battery_001431_after_1.pdf")
    overlay = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=[
                PhotovoltaicArray(peak_power=1.0, pitch=2, orientation=4, overshading=3),
                PhotovoltaicArray(peak_power=1.0, pitch=3, orientation=6, overshading=2),
            ],
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
        )
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_solar_overlay_reproduces_relodged_after_e_w_unshaded() -> None:
    # Arrange — E (octant 3) at 60° pitch and W (octant 7) at 45° pitch, both
    # unshaded (code 1). Exercises the steeper pitches with no shading.
    before: EpcPropertyData = _parse_solar("solar_pv_001431_before.pdf")
    after: EpcPropertyData = _parse_solar("solar_pv_no_battery_001431_after_2.pdf")
    overlay = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=[
                PhotovoltaicArray(peak_power=1.0, pitch=4, orientation=3, overshading=1),
                PhotovoltaicArray(peak_power=1.0, pitch=3, orientation=7, overshading=1),
            ],
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
        )
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_solar_overlay_reproduces_relodged_after_nw_n_unshaded() -> None:
    # Arrange — NW (octant 8) at 60° pitch and N (octant 1) at 45° pitch, both
    # unshaded. The least-productive orientations (the N plane in particular)
    # exercise the low-yield end of the SAP Appendix M output.
    before: EpcPropertyData = _parse_solar("solar_pv_001431_before.pdf")
    after: EpcPropertyData = _parse_solar("solar_pv_no_battery_001431_after_3.pdf")
    overlay = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=[
                PhotovoltaicArray(peak_power=1.0, pitch=4, orientation=8, overshading=1),
                PhotovoltaicArray(peak_power=1.0, pitch=3, orientation=1, overshading=1),
            ],
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
        )
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_battery_cert_currently_reproduced_by_the_no_battery_overlay() -> None:
    # Tripwire (user-requested): the "with battery" cert lodges a §19 5 kWh
    # battery, but the current Elmhurst extractor does NOT parse it (the parsed
    # EpcPropertyData has pv_batteries=None). So the cert currently scores
    # identically to its no-battery twin, and the *no-battery* overlay (same NW/N
    # arrays) reproduces it exactly. When the extractor learns to parse the §19
    # Batteries block, the after-cert will gain ~+1.1 SAP from the 5 kWh battery
    # and THIS PIN WILL FAIL — the fix is then to switch to the with-battery
    # overlay below (which the calculator already models, see the next test).
    before: EpcPropertyData = _parse_solar("solar_pv_001431_before.pdf")
    after: EpcPropertyData = _parse_solar("solar_pv_with_battery_001431_after.pdf")
    overlay = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=[
                PhotovoltaicArray(peak_power=1.0, pitch=4, orientation=8, overshading=1),
                PhotovoltaicArray(peak_power=1.0, pitch=3, orientation=1, overshading=1),
            ],
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
        )
    )

    # Act / Assert
    _assert_overlay_reproduces_after(before, after, overlay)


def test_battery_overlay_raises_sap_above_its_no_battery_twin() -> None:
    # The calculator DOES model a PV battery (App M monthly self-consumption), so
    # the recommendation's battery variant is a meaningful, higher-SAP Option —
    # even though the example cert's battery is not yet parsed. This pins the fix
    # target for the tripwire above: once the extractor parses the §19 battery,
    # the with-battery overlay should reproduce the (then battery-bearing) cert.
    before: EpcPropertyData = _parse_solar("solar_pv_001431_before.pdf")
    arrays = [
        PhotovoltaicArray(peak_power=1.0, pitch=4, orientation=8, overshading=1),
        PhotovoltaicArray(peak_power=1.0, pitch=3, orientation=1, overshading=1),
    ]
    no_battery = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=arrays,
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
        )
    )
    with_battery = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=arrays,
            pv_diverter_present=True,
            is_dwelling_export_capable=True,
            pv_batteries=PvBatteries(pv_battery=PvBattery(battery_capacity=5.0)),
        )
    )

    # Act
    scorer = PackageScorer(Sap10Calculator())
    sap_no_battery: float = scorer.score(before, [no_battery]).sap_continuous
    sap_with_battery: float = scorer.score(before, [with_battery]).sap_continuous

    # Assert — the 5 kWh battery raises SAP by a meaningful margin.
    assert sap_with_battery > sap_no_battery + 1e-3


_SOLAR_FUEL_GAP_REASON: Final[str] = (
    "Blocked on the Elmhurst mapper deriving main_fuel_type for the main heating "
    "lodged with EES code 'WGK' / Main Heating SAP code 502: it currently maps to "
    "'' (empty), so Sap10Calculator raises MissingMainFuelType when baselining the "
    "raw solar before. The solar overlay never touches heating, so the cascade "
    "pins above patch the shared fuel to mains gas (26) on before + after to "
    "isolate the PV delta — only baselining the unmodified before is blocked. "
    "Flips green once the mapper derives mains gas from the WGK/502 lodgement. "
    "Owner: mapper/extractor front."
)


@pytest.mark.xfail(strict=True, reason=_SOLAR_FUEL_GAP_REASON)
def test_solar_before_baselines() -> None:
    # The Modelling pipeline baselines the dwelling before modelling it, so the
    # before must be scorable on its own. This solar cert is not yet: its main
    # fuel is unresolved (see reason). A failing tripwire for the mapper fix.
    # Arrange
    before: EpcPropertyData = parse_recommendation_summary(
        "solar_pv_001431_before.pdf"
    )

    # Act / Assert — currently raises MissingMainFuelType.
    Sap10Calculator().calculate(before)


# --- Secondary Heating Removal (ADR-0028) ----------------------------------
# The user's Elmhurst before/after Summary for this measure (cert 001431,
# electric-storage main + secondary 691) cannot be parsed — that PDF export
# trips the documented 001431 Summary window-extraction bug. So these pins use
# the worksheet-pinned `build_epc()` (a validated real-001431 representation,
# the repo's sanctioned 001431 baseline) with the secondary configuration set on
# it, exercising the real generator → overlay → calculator cascade.


def test_secondary_removal_on_an_electric_storage_main_is_a_no_op() -> None:
    # Arrange — 001431 recast to an electric-storage main (SAP code 402, fuel 30)
    # with a lodged secondary (691). RdSAP §A.2.2 forces a default secondary back
    # on storage mains, so removal reproduces the after at delta 0 — exactly why
    # the user's before/after Summaries both print SAP F35.
    before: EpcPropertyData = build_001431_epc()
    main = before.sap_heating.main_heating_details[0]
    main.sap_main_heating_code = _ELECTRIC_STORAGE_MAIN_CODE
    main.main_fuel_type = _STANDARD_ELECTRICITY_FUEL
    main.main_heating_index_number = None
    before.sap_heating.secondary_heating_type = _SECONDARY_ELECTRIC_PANEL_CODE
    after: EpcPropertyData = copy.deepcopy(before)
    after.sap_heating.secondary_heating_type = None
    after.sap_heating.secondary_fuel_type = None
    recommendation: Recommendation | None = recommend_secondary_heating_removal(
        before, _AnyProduct()
    )
    assert recommendation is not None

    # Act / Assert — the overlay reproduces the secondary-removed cert at delta 0.
    _assert_overlay_reproduces_after(
        before, after, recommendation.options[0].overlay
    )


def test_secondary_removal_on_a_non_forced_main_raises_sap() -> None:
    # Arrange — 001431's lodged gas combi (SAP code 104, NOT a forced-secondary
    # main) with an added electric secondary (691). Removing it reallocates the
    # Table 11 secondary fraction to the cheaper gas main, so cost-based SAP rises
    # (the value path the forced-secondary example can't exercise).
    before: EpcPropertyData = build_001431_epc()
    before.sap_heating.secondary_heating_type = _SECONDARY_ELECTRIC_PANEL_CODE
    recommendation: Recommendation | None = recommend_secondary_heating_removal(
        before, _AnyProduct()
    )
    assert recommendation is not None
    scorer = PackageScorer(Sap10Calculator())

    # Act
    with_secondary: Score = scorer.score(before, [])
    removed: Score = scorer.score(before, [recommendation.options[0].overlay])

    # Assert — removal strictly raises SAP (delta well above the pin tolerance).
    assert removed.sap_continuous - with_secondary.sap_continuous > _PIN_ABS