from __future__ import annotations

import logging
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.calculator_rebaseliner import CalculatorRebaseliner
from domain.property_baseline.performance import Performance
from domain.sap10_calculator.calculator import SapCalculator, SapResult
from domain.sap10_calculator.exceptions import UnmappedSapCode


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 _sap_result(
    *,
    sap_score: int = 72,
    co2_kg_per_yr: float = 1800.0,
    primary_energy_kwh_per_m2: float = 180.0,
) -> SapResult:
    return SapResult(
        sap_score=sap_score,
        sap_score_continuous=float(sap_score),
        ecf=0.0,
        total_fuel_cost_gbp=0.0,
        co2_kg_per_yr=co2_kg_per_yr,
        space_heating_kwh_per_yr=0.0,
        space_cooling_kwh_per_yr=0.0,
        fabric_energy_efficiency_kwh_per_m2_yr=0.0,
        main_heating_fuel_kwh_per_yr=0.0,
        main_2_heating_fuel_kwh_per_yr=0.0,
        secondary_heating_fuel_kwh_per_yr=0.0,
        space_cooling_fuel_kwh_per_yr=0.0,
        hot_water_kwh_per_yr=0.0,
        pumps_fans_kwh_per_yr=0.0,
        lighting_kwh_per_yr=0.0,
        appliances_kwh_per_yr=0.0,
        cooking_kwh_per_yr=0.0,
        main_heating_fuel_code=None,
        main_2_heating_fuel_code=None,
        secondary_heating_fuel_code=None,
        hot_water_fuel_code=None,
        pv_exported_kwh_per_yr=0.0,
        primary_energy_kwh_per_yr=0.0,
        primary_energy_kwh_per_m2=primary_energy_kwh_per_m2,
        monthly=(),
        intermediate={},
    )


class _StubCalculator(SapCalculator):
    def __init__(self, result: SapResult) -> None:
        self._result = result

    def calculate(self, epc: EpcPropertyData) -> SapResult:
        return self._result


def test_pre_10_2_cert_is_rebaselined_to_the_calculator_output() -> None:
    # Arrange — a SAP 10.0 cert: lodged figures are a superseded methodology, so
    # the calculator's output becomes Effective Performance (ADR-0013 amendment).
    sap_result = _sap_result(
        sap_score=70, co2_kg_per_yr=1900.0, primary_energy_kwh_per_m2=185.4
    )
    calculator = _StubCalculator(sap_result)
    rebaseliner = CalculatorRebaseliner(calculator)
    epc = _epc(sap_version=10.0)

    # Act
    result = rebaseliner.rebaseline(
        property_id=10, effective_epc=epc, lodged=_lodged()
    )

    # Assert — calculated Performance: band from the score, CO2 kg->t, PEUI rounded;
    # the SapResult rides on the result for Bill Derivation.
    assert result.effective == Performance(
        sap_score=70, epc_band=Epc.C, co2_emissions=1.9, primary_energy_intensity=185
    )
    assert result.reason == "pre_sap10"
    assert result.sap_result is sap_result


def test_a_10_2_cert_keeps_the_lodged_figures() -> None:
    # Arrange — a SAP 10.2 cert: the API's lodged figures are on-target, so they
    # stand; the calculator runs only to validate.
    sap_result = _sap_result(sap_score=72)
    calculator = _StubCalculator(sap_result)
    rebaseliner = CalculatorRebaseliner(calculator)
    epc = _epc(sap_version=10.2)

    # Act
    result = rebaseliner.rebaseline(
        property_id=10, effective_epc=epc, lodged=_lodged()
    )

    # Assert — lodged kept as effective, but the SapResult still rides along for
    # Bill Derivation (the bill prices it regardless of which figures win).
    assert result.effective == _lodged()
    assert result.reason == "none"
    assert result.sap_result is sap_result


def test_a_10_2_cert_with_changed_physical_state_uses_the_calculator() -> None:
    # Arrange — a 10.2 cert whose physical state was changed by Landlord
    # Overrides (or assembled by Prediction): the accredited lodged figure no
    # longer describes the dwelling, so the calculator's output becomes Effective
    # Performance (Rebaselining trigger (b)/(c), CONTEXT.md), not the lodged value.
    sap_result = _sap_result(
        sap_score=67, co2_kg_per_yr=2100.0, primary_energy_kwh_per_m2=210.0
    )
    rebaseliner = CalculatorRebaseliner(_StubCalculator(sap_result))
    epc = _epc(sap_version=10.2)

    # Act
    result = rebaseliner.rebaseline(
        property_id=10,
        effective_epc=epc,
        lodged=_lodged(),
        physical_state_changed=True,
    )

    # Assert — calculated Performance wins, tagged physical_state_changed.
    assert result.effective == Performance(
        sap_score=67, epc_band=Epc.D, co2_emissions=2.1, primary_energy_intensity=210
    )
    assert result.reason == "physical_state_changed"
    assert result.sap_result is sap_result


def test_a_pre_10_2_cert_with_changed_physical_state_is_reason_both() -> None:
    # Arrange — both triggers fire: a superseded methodology (sap_version < 10.2)
    # AND a physical-state change. The calculator wins (as for either alone); the
    # reason records both.
    rebaseliner = CalculatorRebaseliner(_StubCalculator(_sap_result(sap_score=65)))
    epc = _epc(sap_version=10.0)

    # Act
    result = rebaseliner.rebaseline(
        property_id=10,
        effective_epc=epc,
        lodged=_lodged(),
        physical_state_changed=True,
    )

    # Assert
    assert result.effective.sap_score == 65
    assert result.reason == "both"


def test_a_10_2_cert_with_changed_state_does_not_log_divergence(
    caplog: pytest.LogCaptureFixture,
) -> None:
    # Arrange — when we ADOPT the calculator output (physical state changed),
    # there is no accredited lodged figure to validate against, so no divergence
    # warning is emitted (calc 90 vs lodged 72 would otherwise warn).
    rebaseliner = CalculatorRebaseliner(_StubCalculator(_sap_result(sap_score=90)))
    epc = _epc(sap_version=10.2)

    # Act
    with caplog.at_level(logging.WARNING):
        rebaseliner.rebaseline(
            property_id=42,
            effective_epc=epc,
            lodged=_lodged(),
            physical_state_changed=True,
        )

    # Assert — no divergence log when the calculator output is adopted.
    assert caplog.records == []


def test_a_10_2_cert_logs_divergence_when_the_calculator_disagrees(
    caplog: pytest.LogCaptureFixture,
) -> None:
    # Arrange — calculated SAP 76 vs lodged 72 (> 0.5 out) on a 10.2 cert.
    calculator = _StubCalculator(_sap_result(sap_score=76))
    rebaseliner = CalculatorRebaseliner(calculator)
    epc = _epc(sap_version=10.2)

    # Act
    with caplog.at_level(logging.WARNING):
        rebaseliner.rebaseline(property_id=42, effective_epc=epc, lodged=_lodged())

    # Assert — a divergence warning, tagged with property_id + sap_version.
    assert len(caplog.records) == 1
    message = caplog.records[0].getMessage()
    assert "sap_score" in message
    assert "property_id=42" in message
    assert "sap_version=10.2" in message


def test_a_calculator_raise_propagates_and_aborts() -> None:
    # Arrange — the calculator is load-bearing, so a raise is not swallowed.
    class _Raising(SapCalculator):
        def calculate(self, epc: EpcPropertyData) -> SapResult:
            raise UnmappedSapCode("heat_emitter_type", 99)

    rebaseliner = CalculatorRebaseliner(_Raising())
    epc = _epc(sap_version=10.0)

    # Act / Assert
    with pytest.raises(UnmappedSapCode):
        rebaseliner.rebaseline(property_id=10, effective_epc=epc, lodged=_lodged())


def test_full_sap_mapped_cert_rebaselines_off_the_lodged_sap_2012_value() -> None:
    # Regression for the portfolio-796 "impossible downgrade" (ADR-0037). A
    # full-SAP cert lodges SAP 2012 (sap_version 9.92). The WIP mapper dropped
    # sap_version, so the rebaseliner couldn't fire trigger (a) and Effective
    # stayed stuck on the lodged SAP-2012 value while the plan modelled SAP-10.2.
    # End-to-end: a real full-SAP fixture, once mapped, now carries sap_version
    # so Effective becomes the calc output (not lodged).
    import json
    import os

    from datatypes.epc.domain.mapper import EpcPropertyDataMapper
    from datatypes.epc.schema.sap_schema_17_1 import SapSchema17_1
    from datatypes.epc.schema.tests.helpers import from_dict

    fixtures = os.path.join(
        os.path.dirname(__file__),
        "../../../datatypes/epc/schema/tests/fixtures",
    )
    with open(os.path.join(fixtures, "sap_17_1.json")) as f:
        raw = json.load(f)
    effective_epc = EpcPropertyDataMapper.from_sap_schema_17_1(
        from_dict(SapSchema17_1, raw)
    )
    # The mapped cert carries the lodged SAP 2012 version, gating the flip.
    assert effective_epc.sap_version == 9.92
    rebaseliner = CalculatorRebaseliner(_StubCalculator(_sap_result(sap_score=70)))

    # Act
    result = rebaseliner.rebaseline(
        property_id=1, effective_epc=effective_epc, lodged=_lodged()
    )

    # Assert — Effective is the SAP-10.2 calc (70), NOT the lodged SAP-2012 (72).
    assert result.reason == "pre_sap10"
    assert result.effective.sap_score == 70