"""The Package Scorer — the reusable scoring primitive (ADR-0016).

Composes an ordered set of Simulation Overlays onto a baseline EpcPropertyData
(via the Overlay Applicator) and scores the throwaway result on a deterministic
SAP calculator, returning the headline metrics. The same primitive powers the
optimiser's whole-package re-score and any future live re-score of a
user-assembled plan.
"""

from dataclasses import dataclass
from typing import Optional, Sequence

from datatypes.epc.domain.epc_property_data import EpcPropertyData
from domain.modelling.scoring.overlay_applicator import apply_simulations
from domain.modelling.simulation import EpcSimulation
from domain.sap10_calculator.calculator import SapCalculator, SapResult


@dataclass(frozen=True)
class Score:
    """The headline metrics of a scored package. `sap_continuous` is the
    un-rounded SAP rating (used for deltas); carbon and primary energy are the
    annual totals.

    `sap_result` is the calculator output the headline figures were taken from,
    carried so Bill Derivation can price the scored end-state without a second
    `calculate` (ADR-0014 amendment). The optimiser never reads it — it works
    off `sap_continuous` only — so it stays domain-agnostic and a stub scorer
    may leave it `None`."""

    sap_continuous: float
    co2_kg_per_yr: float
    primary_energy_kwh_per_yr: float
    sap_result: Optional[SapResult] = None


class PackageScorer:
    """Scores a package of Simulation Overlays against a baseline EpcPropertyData
    on an injected SAP calculator (depends on the `SapCalculator` abstraction,
    not a concrete engine)."""

    def __init__(self, calculator: SapCalculator) -> None:
        self._calculator = calculator

    def score(
        self, baseline: EpcPropertyData, simulations: Sequence[EpcSimulation]
    ) -> Score:
        simulated: EpcPropertyData = apply_simulations(baseline, simulations)
        result: SapResult = self._calculator.calculate(simulated)
        return Score(
            sap_continuous=result.sap_score_continuous,
            co2_kg_per_yr=result.co2_kg_per_yr,
            primary_energy_kwh_per_yr=result.primary_energy_kwh_per_yr,
            sap_result=result,
        )