"""Behaviour of the Overlay Applicator: folding Simulation Overlays
(EpcSimulation) onto a baseline EpcPropertyData to produce a new one for
the calculator. See ADR-0016 and the Modelling glossary in CONTEXT.md.
"""

from datatypes.epc.domain.epc_property_data import (
    BuildingPartIdentifier,
    EpcPropertyData,
    PhotovoltaicArray,
    PvBatteries,
    PvBattery,
    SapBuildingPart,
    SapVentilation,
)
from domain.modelling.simulation import (
    BuildingPartOverlay,
    EpcSimulation,
    HeatingOverlay,
    LightingOverlay,
    SecondaryHeatingOverlay,
    SolarOverlay,
    VentilationOverlay,
    WindowOverlay,
)
from domain.modelling.scoring.overlay_applicator import apply_simulations
from tests.domain.sap10_calculator.worksheet._elmhurst_worksheet_000490 import (
    build_epc,
)


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


def test_apply_writes_targeted_building_part_and_leaves_others_untouched() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    extension_before: int | str = _part(
        baseline, BuildingPartIdentifier.EXTENSION_1
    ).wall_insulation_type
    simulation = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(wall_insulation_type=1)
        }
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert
    assert _part(result, BuildingPartIdentifier.MAIN).wall_insulation_type == 1
    assert (
        _part(result, BuildingPartIdentifier.EXTENSION_1).wall_insulation_type
        == extension_before
    )


def test_flat_roof_construction_type_folds_onto_the_part() -> None:
    # ADR-0033: a flat-roof landlord override sets `roof_construction_type` so the
    # calculator's flat path (`"flat" in roof_construction_type`) fires the
    # age-band default. Proves the generic field loop wires the new overlay field.
    # Arrange
    baseline: EpcPropertyData = build_epc()
    simulation = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(
                roof_construction_type="Flat"
            )
        }
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert
    assert _part(result, BuildingPartIdentifier.MAIN).roof_construction_type == "Flat"


def test_empty_simulation_is_a_no_op() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [EpcSimulation()])

    # Assert
    assert result == baseline


def test_later_simulation_wins_on_a_shared_field() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    first = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(wall_insulation_type=1)
        }
    )
    second = EpcSimulation(
        building_parts={
            BuildingPartIdentifier.MAIN: BuildingPartOverlay(wall_insulation_type=2)
        }
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [first, second])

    # Assert
    assert _part(result, BuildingPartIdentifier.MAIN).wall_insulation_type == 2


def test_apply_writes_dwelling_ventilation_onto_sap_ventilation() -> None:
    # Arrange — a Measure Dependency overlay targets the whole-dwelling
    # ventilation system (no building part), e.g. retrofit MEV.
    baseline: EpcPropertyData = build_epc()
    simulation = EpcSimulation(
        ventilation=VentilationOverlay(
            mechanical_ventilation_kind="EXTRACT_OR_PIV_OUTSIDE"
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert
    assert result.sap_ventilation is not None
    assert (
        result.sap_ventilation.mechanical_ventilation_kind
        == "EXTRACT_OR_PIV_OUTSIDE"
    )


def test_ventilation_overlay_creates_sap_ventilation_when_baseline_has_none() -> None:
    # Arrange — a naturally-ventilated baseline that lodged no SapVentilation.
    baseline: EpcPropertyData = build_epc()
    baseline.sap_ventilation = None
    simulation = EpcSimulation(
        ventilation=VentilationOverlay(
            mechanical_ventilation_kind="EXTRACT_OR_PIV_OUTSIDE"
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert
    assert isinstance(result.sap_ventilation, SapVentilation)
    assert (
        result.sap_ventilation.mechanical_ventilation_kind
        == "EXTRACT_OR_PIV_OUTSIDE"
    )


def test_ventilation_overlay_leaves_building_parts_and_baseline_untouched() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    main_before: int | str = _part(
        baseline, BuildingPartIdentifier.MAIN
    ).wall_insulation_type
    simulation = EpcSimulation(
        ventilation=VentilationOverlay(
            mechanical_ventilation_kind="EXTRACT_OR_PIV_OUTSIDE"
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert — ventilation overlay touches only sap_ventilation; the baseline
    # is never mutated.
    assert _part(result, BuildingPartIdentifier.MAIN).wall_insulation_type == main_before
    assert baseline.sap_ventilation is not None
    assert baseline.sap_ventilation.mechanical_ventilation_kind is None


def test_baseline_is_not_mutated() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    original: int | str = _part(
        baseline, BuildingPartIdentifier.MAIN
    ).wall_insulation_type

    # Act
    _: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                building_parts={
                    BuildingPartIdentifier.MAIN: BuildingPartOverlay(
                        wall_insulation_type=1
                    )
                }
            )
        ],
    )

    # Assert
    assert (
        _part(baseline, BuildingPartIdentifier.MAIN).wall_insulation_type == original
    )


def test_apply_folds_a_window_overlay_by_index_into_transmission_details() -> None:
    # Arrange — window 0 starts double (glazing_type 2, U 2.8, g 0.76); the
    # overlay upgrades it to a modern double spec, writing the U-value and
    # solar-g into the nested WindowTransmissionDetails (ADR-0022).
    baseline: EpcPropertyData = build_epc()

    # Act — target window 0 by its sap_windows index.
    result: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                windows={
                    0: WindowOverlay(
                        glazing_type=5, u_value=1.40, solar_transmittance=0.72
                    )
                }
            )
        ],
    )

    # Assert — glazing_type set on the window; U/g routed into the transmission
    # details (where the cascade reads them); other windows untouched.
    upgraded = result.sap_windows[0]
    assert upgraded.glazing_type == 5
    assert upgraded.window_transmission_details is not None
    assert abs(upgraded.window_transmission_details.u_value - 1.40) <= 1e-9
    assert abs(upgraded.window_transmission_details.solar_transmittance - 0.72) <= 1e-9
    assert result.sap_windows[1].window_transmission_details is not None
    assert abs(result.sap_windows[1].window_transmission_details.u_value - 2.8) <= 1e-9


def test_baseline_windows_are_not_mutated_by_a_window_overlay() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    assert baseline.sap_windows[0].window_transmission_details is not None
    original_u: float = baseline.sap_windows[0].window_transmission_details.u_value

    # Act
    _: EpcPropertyData = apply_simulations(
        baseline,
        [EpcSimulation(windows={0: WindowOverlay(u_value=1.40)})],
    )

    # Assert
    assert baseline.sap_windows[0].window_transmission_details is not None
    assert (
        baseline.sap_windows[0].window_transmission_details.u_value == original_u
    )


def test_apply_writes_dwelling_lighting_onto_top_level_bulb_counts() -> None:
    # Arrange — a whole-dwelling lighting change (no building part), e.g. an
    # all-LED upgrade folded onto the top-level bulb counts (ADR-0023).
    baseline: EpcPropertyData = build_epc()
    simulation = EpcSimulation(
        lighting=LightingOverlay(
            led_fixed_lighting_bulbs_count=8,
            cfl_fixed_lighting_bulbs_count=0,
            incandescent_fixed_lighting_bulbs_count=0,
            low_energy_fixed_lighting_bulbs_count=0,
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert
    assert result.led_fixed_lighting_bulbs_count == 8
    assert result.cfl_fixed_lighting_bulbs_count == 0
    assert result.incandescent_fixed_lighting_bulbs_count == 0
    assert result.low_energy_fixed_lighting_bulbs_count == 0


def test_apply_folds_a_heating_overlay_across_all_five_locations() -> None:
    # Arrange — a whole-system HHR storage bundle replacing 000490's gas combi
    # (fuel 26, control 2106, no cylinder, mains_gas True). The heating overlay
    # is the deepest surface: it writes across main_heating_details[0],
    # sap_heating, the top-level EpcPropertyData, and sap_energy_source at once
    # (ADR-0024).
    baseline: EpcPropertyData = build_epc()
    simulation = EpcSimulation(
        heating=HeatingOverlay(
            main_fuel_type=30,
            sap_main_heating_code=409,
            main_heating_control=2404,
            water_heating_code=903,
            water_heating_fuel=30,
            cylinder_size=2,
            cylinder_insulation_type=1,
            cylinder_insulation_thickness_mm=120,
            has_hot_water_cylinder=True,
            meter_type="18 Hour",
            mains_gas=False,
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert — every targeted field routed to its home object.
    main = result.sap_heating.main_heating_details[0]
    assert main.main_fuel_type == 30
    assert main.sap_main_heating_code == 409
    assert main.main_heating_control == 2404
    assert result.sap_heating.water_heating_code == 903
    assert result.sap_heating.water_heating_fuel == 30
    assert result.sap_heating.cylinder_size == 2
    assert result.sap_heating.cylinder_insulation_type == 1
    assert result.sap_heating.cylinder_insulation_thickness_mm == 120
    assert result.has_hot_water_cylinder is True
    assert result.sap_energy_source is not None
    assert result.sap_energy_source.meter_type == "18 Hour"
    assert result.sap_energy_source.mains_gas is False


def test_secondary_heating_overlay_clears_the_lodged_secondary() -> None:
    # Arrange — 000490 lodges a secondary system (SAP code 691, electric panel/
    # convector/radiant heaters). Pin a fuel on it too so we prove the fold
    # clears BOTH the type and the fuel (ADR-0028).
    baseline: EpcPropertyData = build_epc()
    baseline.sap_heating.secondary_fuel_type = 30
    assert baseline.sap_heating.secondary_heating_type == 691

    # Act — fold a removal overlay.
    result: EpcPropertyData = apply_simulations(
        baseline, [EpcSimulation(secondary_heating=SecondaryHeatingOverlay())]
    )

    # Assert — the secondary is gone from the dwelling handed to the calculator.
    assert result.sap_heating.secondary_heating_type is None
    assert result.sap_heating.secondary_fuel_type is None


def test_secondary_heating_removal_does_not_mutate_the_baseline() -> None:
    # Arrange — 000490 lodges secondary SAP code 691.
    baseline: EpcPropertyData = build_epc()
    assert baseline.sap_heating.secondary_heating_type == 691

    # Act — fold a removal overlay.
    _: EpcPropertyData = apply_simulations(
        baseline, [EpcSimulation(secondary_heating=SecondaryHeatingOverlay())]
    )

    # Assert — the baseline's secondary is untouched (the fold copies first).
    assert baseline.sap_heating.secondary_heating_type == 691


def test_baseline_heating_is_not_mutated_by_a_heating_overlay() -> None:
    # Arrange — 000490 lodges a mains-gas combi (fuel 26, control 2106, no
    # cylinder, mains_gas True).
    baseline: EpcPropertyData = build_epc()
    original_fuel = baseline.sap_heating.main_heating_details[0].main_fuel_type
    original_control = baseline.sap_heating.main_heating_details[0].main_heating_control
    original_wh_code: int | None = baseline.sap_heating.water_heating_code
    original_cylinder = baseline.has_hot_water_cylinder
    assert baseline.sap_energy_source is not None
    original_mains_gas = baseline.sap_energy_source.mains_gas

    # Act — fold an HHR storage bundle.
    _: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                heating=HeatingOverlay(
                    main_fuel_type=30,
                    sap_main_heating_code=409,
                    main_heating_control=2404,
                    water_heating_code=903,
                    has_hot_water_cylinder=True,
                    mains_gas=False,
                )
            )
        ],
    )

    # Assert — the baseline's heating is untouched.
    assert baseline.sap_heating.main_heating_details[0].main_fuel_type == original_fuel
    assert (
        baseline.sap_heating.main_heating_details[0].main_heating_control
        == original_control
    )
    assert baseline.sap_heating.water_heating_code == original_wh_code
    assert baseline.has_hot_water_cylinder == original_cylinder
    assert baseline.sap_energy_source.mains_gas == original_mains_gas


def test_heating_index_overlay_clears_a_stale_sap_main_heating_code() -> None:
    # Arrange — 000490's gas combi lodges a Table 4a code; an ASHP bundle sets a
    # PCDB index instead. The two are mutually-exclusive efficiency anchors, so
    # the stale code must be cleared or it wins the calculator's dispatch.
    baseline: EpcPropertyData = build_epc()
    baseline.sap_heating.main_heating_details[0].sap_main_heating_code = 104

    # Act
    result: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                heating=HeatingOverlay(
                    main_heating_index_number=101413, main_heating_category=4
                )
            )
        ],
    )

    # Assert — the index is set and the old SAP code is gone.
    main = result.sap_heating.main_heating_details[0]
    assert main.main_heating_index_number == 101413
    assert main.sap_main_heating_code is None


def test_heating_sap_code_overlay_clears_a_stale_index() -> None:
    # Arrange — a dwelling with a PCDB-indexed system; an HHR storage bundle sets
    # a Table 4a code instead, so the stale index must be cleared.
    baseline: EpcPropertyData = build_epc()
    baseline.sap_heating.main_heating_details[0].main_heating_index_number = 8262

    # Act
    result: EpcPropertyData = apply_simulations(
        baseline,
        [EpcSimulation(heating=HeatingOverlay(sap_main_heating_code=409))],
    )

    # Assert
    main = result.sap_heating.main_heating_details[0]
    assert main.sap_main_heating_code == 409
    assert main.main_heating_index_number is None


def test_apply_folds_a_solar_overlay_onto_the_energy_source() -> None:
    # Arrange — 000490 lodges no PV, not export-capable, no diverter. A Solar PV
    # Option installs a two-segment array, ensures export, and adds a battery
    # (ADR-0026). The solar overlay is the sixth surface; it writes onto
    # sap_energy_source.
    baseline: EpcPropertyData = build_epc()
    arrays = [
        PhotovoltaicArray(peak_power=4.8, pitch=2, orientation=5, overshading=1),
        PhotovoltaicArray(peak_power=1.2, pitch=2, orientation=6, overshading=2),
    ]
    simulation = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=arrays,
            pv_diverter_present=True,
            pv_connection=1,
            is_dwelling_export_capable=True,
            pv_batteries=PvBatteries(pv_battery=PvBattery(battery_capacity=5.0)),
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert — every field routed onto sap_energy_source.
    source = result.sap_energy_source
    assert source.photovoltaic_arrays is not None
    assert [a.peak_power for a in source.photovoltaic_arrays] == [4.8, 1.2]
    assert [a.orientation for a in source.photovoltaic_arrays] == [5, 6]
    assert [a.overshading for a in source.photovoltaic_arrays] == [1, 2]
    assert source.pv_diverter_present is True
    assert source.pv_connection == 1
    assert source.is_dwelling_export_capable is True
    assert source.pv_batteries is not None
    assert abs(source.pv_batteries.pv_battery.battery_capacity - 5.0) <= 1e-9


def test_solar_overlay_leaves_diverter_unset_when_omitted() -> None:
    # Arrange — a combi dwelling gets PV without a diverter (nothing to divert
    # to); the omitted field leaves the baseline False unchanged.
    baseline: EpcPropertyData = build_epc()
    simulation = EpcSimulation(
        solar=SolarOverlay(
            photovoltaic_arrays=[
                PhotovoltaicArray(peak_power=3.2, pitch=2, orientation=5, overshading=1)
            ],
            is_dwelling_export_capable=True,
        )
    )

    # Act
    result: EpcPropertyData = apply_simulations(baseline, [simulation])

    # Assert — diverter untouched (still False), export flipped True.
    assert result.sap_energy_source.pv_diverter_present is False
    assert result.sap_energy_source.is_dwelling_export_capable is True


def test_baseline_energy_source_is_not_mutated_by_a_solar_overlay() -> None:
    # Arrange
    baseline: EpcPropertyData = build_epc()
    original_export = baseline.sap_energy_source.is_dwelling_export_capable
    original_arrays = baseline.sap_energy_source.photovoltaic_arrays

    # Act
    _: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                solar=SolarOverlay(
                    photovoltaic_arrays=[
                        PhotovoltaicArray(
                            peak_power=3.2, pitch=2, orientation=5, overshading=1
                        )
                    ],
                    is_dwelling_export_capable=True,
                )
            )
        ],
    )

    # Assert — the baseline's energy source is untouched.
    assert baseline.sap_energy_source.is_dwelling_export_capable == original_export
    assert baseline.sap_energy_source.photovoltaic_arrays == original_arrays


def test_baseline_lighting_is_not_mutated_by_a_lighting_overlay() -> None:
    # Arrange — 000490 lodges 8 low-energy-unknown bulbs, 0 LED.
    baseline: EpcPropertyData = build_epc()
    original_led: int = baseline.led_fixed_lighting_bulbs_count
    original_lel: int | None = baseline.low_energy_fixed_lighting_bulbs_count

    # Act — fold an all-LED overlay (led = the 8 total).
    _: EpcPropertyData = apply_simulations(
        baseline,
        [
            EpcSimulation(
                lighting=LightingOverlay(
                    led_fixed_lighting_bulbs_count=8,
                    low_energy_fixed_lighting_bulbs_count=0,
                )
            )
        ],
    )

    # Assert — the baseline's counts are untouched.
    assert baseline.led_fixed_lighting_bulbs_count == original_led
    assert baseline.low_energy_fixed_lighting_bulbs_count == original_lel