"""Behaviour of the Plan / PlanMeasure domain types: the per-Property output
of one Scenario's modelling run. A Plan carries its selected Plan Measures
(the Optimised Package) plus the baseline/post-retrofit Scores, and derives
the persisted headline figures (cost aggregates, CO₂ saving, post-retrofit
band). Single-phase, flat post-retrofit figures (ADR-0005 / ADR-0017).
"""

from __future__ import annotations

from datatypes.epc.domain.epc import Epc
from domain.billing.bill import Bill, BillSection, BillSectionCost
from domain.modelling.scoring.package_scorer import Score
from domain.modelling.plan import Plan, PlanMeasure
from domain.modelling.recommendation import Cost
from domain.modelling.scoring.scoring import MeasureImpact


def _bill(*, heating_kwh: float, total_gbp: float) -> Bill:
    return Bill(
        sections={
            BillSection.HEATING: BillSectionCost(kwh=heating_kwh, cost_gbp=total_gbp)
        },
        standing_charges_gbp=0.0,
        seg_credit_gbp=0.0,
        total_gbp=total_gbp,
    )


def _measure(measure_type: str, total: float, rate: float) -> PlanMeasure:
    return PlanMeasure(
        measure_type=measure_type,
        description=measure_type.replace("_", " "),
        cost=Cost(total=total, contingency_rate=rate),
        impact=MeasureImpact(
            sap_points=1.0, co2_savings_kg_per_yr=1.0, energy_savings_kwh_per_yr=1.0
        ),
    )


def test_plan_aggregates_cost_and_savings_and_bands_the_post_sap() -> None:
    # Arrange
    measures: tuple[PlanMeasure, ...] = (
        _measure("cavity_wall_insulation", total=1000.0, rate=0.10),
        _measure("loft_insulation", total=500.0, rate=0.20),
    )
    baseline = Score(
        sap_continuous=40.0, co2_kg_per_yr=4000.0, primary_energy_kwh_per_yr=20000.0
    )
    post = Score(
        sap_continuous=70.4, co2_kg_per_yr=3600.0, primary_energy_kwh_per_yr=18000.0
    )
    plan = Plan(measures=measures, baseline=baseline, post_retrofit=post)

    # Act / Assert
    assert abs(plan.cost_of_works - 1500.0) <= 1e-9
    assert abs(plan.contingency_cost - 200.0) <= 1e-9  # 1000*0.10 + 500*0.20
    assert abs(plan.co2_savings_kg_per_yr - 400.0) <= 1e-9  # baseline - post
    assert abs(plan.post_sap_continuous - 70.4) <= 1e-9
    assert plan.post_epc_rating is Epc.C  # round(70.4) = 70 → band C (69–80)


def test_plan_derives_post_bill_and_savings_from_the_baseline_and_post_bills() -> None:
    # Arrange — a Plan whose baseline and post-package Bills have been derived.
    baseline = Score(
        sap_continuous=40.0, co2_kg_per_yr=4000.0, primary_energy_kwh_per_yr=20000.0
    )
    post = Score(
        sap_continuous=70.0, co2_kg_per_yr=3600.0, primary_energy_kwh_per_yr=18000.0
    )
    plan = Plan(
        measures=(),
        baseline=baseline,
        post_retrofit=post,
        baseline_bill=_bill(heating_kwh=10000.0, total_gbp=2000.0),
        post_bill=_bill(heating_kwh=6000.0, total_gbp=1400.0),
    )

    # Act / Assert — plan-level energy/bill figures (ADR-0014 amendment).
    assert plan.post_energy_bill == 1400.0
    assert plan.energy_bill_savings == 600.0  # 2000 − 1400
    assert plan.post_energy_consumption == 6000.0  # Σ post section kWh
    assert plan.energy_consumption_savings == 4000.0  # 10000 − 6000


def test_plan_energy_figures_are_none_without_bills() -> None:
    # Arrange — a Plan with no bills derived (the figures persist as NULL).
    score = Score(
        sap_continuous=55.0, co2_kg_per_yr=3000.0, primary_energy_kwh_per_yr=15000.0
    )
    plan = Plan(measures=(), baseline=score, post_retrofit=score)

    # Act / Assert
    assert plan.post_energy_bill is None
    assert plan.energy_bill_savings is None
    assert plan.post_energy_consumption is None
    assert plan.energy_consumption_savings is None