from __future__ import annotations

import pytest

from domain.epc.property_overrides.water_heating_guard import water_heating_guard
from domain.epc.property_overrides.water_heating_type import WaterHeatingType


@pytest.mark.parametrize(
    ("description", "expected"),
    [
        # The biomass/wood family the LLM funnelled into "house coal" (#1376).
        (
            "From main heating system: Wood Logs",
            WaterHeatingType.FROM_MAIN_WOOD_LOGS,
        ),
        (
            "From main heating system: Dual Fuel: Mineral and Wood",
            WaterHeatingType.FROM_MAIN_DUAL_FUEL_MINERAL_WOOD,
        ),
        # "Hot-water only community scheme" flattens to "from main", per the
        # existing convention (community mains-gas already resolves that way).
        (
            "From main heating system: Biomass (Community)",
            WaterHeatingType.FROM_MAIN_BIOMASS_COMMUNITY,
        ),
        (
            "Hot-water only community scheme - boilers: Biomass (Community)",
            WaterHeatingType.FROM_MAIN_BIOMASS_COMMUNITY,
        ),
        (
            "Hot-water only community scheme - boilers: Heat from Boilers "
            "using Biodiesel from any source (Community)",
            WaterHeatingType.FROM_MAIN_BIODIESEL_COMMUNITY,
        ),
        # "No Heating or Hot Water" under "electric immersion assumed" is the
        # assessment's own immersion assumption — honour it (ADR-0043).
        (
            "No hot water system present - electric immersion assumed: "
            "No Heating or Hot Water",
            WaterHeatingType.ELECTRIC_IMMERSION,
        ),
        # A genuinely coal DHW stays house coal.
        (
            "From main heating system: House Coal",
            WaterHeatingType.FROM_MAIN_HOUSE_COAL,
        ),
    ],
)
def test_guard_resolves_the_structured_biomass_and_immersion_descriptions(
    description: str, expected: WaterHeatingType
) -> None:
    # Act
    result = water_heating_guard(description)

    # Assert
    assert result is expected


@pytest.mark.parametrize(
    "description",
    [
        # Fuels the LLM already classifies correctly — the guard must not claim
        # them (it only rescues the previously-misclassified structured cases).
        "From main heating system: Mains Gas",
        "Electric immersion: Electricity",
        "From main heating system: Oil",
        # A varied / unstructured phrasing is the LLM's job.
        "hot water from the wood burner",
        "",
    ],
)
def test_guard_defers_recognised_and_unstructured_descriptions_to_the_llm(
    description: str,
) -> None:
    # Act
    result = water_heating_guard(description)

    # Assert
    assert result is None