"""Recommendation and Measure Option — the Modelling stage's proposal types.

A Recommendation is a labelled group of mutually-exclusive Measure Options for
one target surface; the Optimiser selects at most one. The target itself is
encoded entirely in each Option's Simulation Overlay (which addresses building
parts, windows, or systems), so this type stays stable as new surfaces land.
Impact is never stored here — it is cascade-conditional (ADR-0016). See
CONTEXT.md.
"""

from dataclasses import dataclass
from typing import Optional

from domain.modelling.simulation import EpcSimulation


@dataclass(frozen=True)
class Cost:
    """A Measure Option's cost: a single fully-loaded total (labour + VAT +
    preliminaries + margin rolled in) plus a separately-carried per-Measure-Type
    contingency rate."""

    total: float
    contingency_rate: float


@dataclass(frozen=True)
class MeasureOption:
    """One mutually-exclusive way to treat a Recommendation's surface."""

    measure_type: str
    description: str
    overlay: EpcSimulation
    cost: Optional[Cost] = None
    # The catalogue id of the Product this Option installs (Product.id), carried
    # through to the persisted Plan Measure's ``material_id``. None when priced
    # from a catalogue with no ids.
    material_id: Optional[int] = None


@dataclass(frozen=True)
class Recommendation:
    """A target surface and the mutually-exclusive Measure Options that treat
    it. `surface` is a human label for display/grouping; the actual target is
    in each Option's overlay."""

    surface: str
    options: tuple[MeasureOption, ...]