"""Equivalences post-processor mapping kgCO2eq to concrete equivalents."""
from config import settings
from ..context import RunContext


class EquivalencesProcessor:
    name = "equivalences"

    def process(self, ctx: RunContext) -> None:
        kg = ctx.metadata_out.get("emissions_kgCO2eq")
        if kg is None:
            return
        ratios = getattr(settings, "equivalence_ratios", {})
        try:
            eq = {
                "water_liters": round(kg * float(ratios.get("water_l_per_kgCO2eq", 0)), 4),
                "car_km": round(kg * float(ratios.get("car_km_per_kgCO2eq", 0)), 4),
                "tgv_km": round(kg * float(ratios.get("tgv_km_per_kgCO2eq", 0)), 4),
                "smartphone": round(kg * float(ratios.get("smartphone_per_kgCO2eq", 0)), 4),
            }
        except Exception:
            return
        ctx.metadata_out["equivalences"] = eq