from __future__ import annotations

from dataclasses import dataclass

from domain.property_baseline.performance import Performance
from domain.property_baseline.rebaseliner import RebaselineReason


@dataclass(frozen=True)
class PropertyBaselinePerformance:
    """A Property's current performance aggregate (CONTEXT.md, ADR-0004).

    Holds both halves — ``lodged`` (what the gov register says) and
    ``effective`` (what the modelling pipeline scored against) — plus the
    ``rebaseline_reason`` recording *why* they differ (``"none"`` when equal).
    Both halves are always populated, even when equal.

    Carries the part of the energy block that needs no derivation: annual
    ``space_heating_kwh`` / ``water_heating_kwh`` read off the EPC's RHI.
    Fuel split and bills (the rest of EPC Energy Derivation) land in a
    follow-up once a Fuel Rates source exists.
    """

    lodged: Performance
    effective: Performance
    rebaseline_reason: RebaselineReason
    space_heating_kwh: float
    water_heating_kwh: float