from __future__ import annotations

from typing import Optional

import pytest

from datatypes.epc.domain.epc import Epc
from datatypes.epc.domain.epc_property_data import EpcPropertyData
from domain.property_baseline.performance import Performance
from domain.property_baseline.rebaseliner import RebaselineNotImplemented, StubRebaseliner


def _epc(*, sap_version: Optional[float]) -> EpcPropertyData:
    epc = object.__new__(EpcPropertyData)
    epc.sap_version = sap_version
    return epc


def _lodged() -> Performance:
    return Performance(
        sap_score=72, epc_band=Epc.C, co2_emissions=1.8, primary_energy_intensity=180
    )


def test_sap10_epc_is_not_rebaselined_so_effective_equals_lodged() -> None:
    # Arrange — a SAP 10.2 cert: no rebaselining trigger fires.
    epc = _epc(sap_version=10.2)
    lodged = _lodged()
    rebaseliner = StubRebaseliner()

    # Act
    effective, reason = rebaseliner.rebaseline(10, epc, lodged)

    # Assert — Effective Performance equals Lodged, reason "none".
    assert effective == lodged
    assert reason == "none"


def test_pre_sap10_epc_raises_because_rebaselining_is_not_implemented() -> None:
    # Arrange — a cert lodged under a pre-SAP10 schema genuinely needs ML
    # rebaselining, which does not exist yet; the stub must not fabricate a
    # "none" answer for it.
    epc = _epc(sap_version=9.94)
    rebaseliner = StubRebaseliner()

    # Act / Assert
    with pytest.raises(RebaselineNotImplemented):
        rebaseliner.rebaseline(10, epc, _lodged())