def compute_km_for_entry(journey_profile_id: str | None, journeys: dict) -> dict[str, int]:
    if not journey_profile_id:
        return {}
    profile = journeys.get(journey_profile_id, {})
    return dict(profile.get("distances", {}))


def compute_co2_grams(km_by_vehicle: dict[str, int], vehicles: dict) -> float:
    total = 0.0
    for vehicle_id, km in km_by_vehicle.items():
        vehicle = vehicles.get(vehicle_id, {})
        co2 = vehicle.get("co2_per_km", 0)
        total += km * co2
    return total


def compute_frais_reels(total_km_voiture: float, tranches: list[dict]) -> float:
    if not tranches or total_km_voiture <= 0:
        return 0.0
    for tranche in tranches:
        km_max = tranche["km_max"]
        if km_max == 0 or total_km_voiture <= km_max:
            return total_km_voiture * tranche["taux"] + tranche.get("forfait", 0)
    last = tranches[-1]
    return total_km_voiture * last["taux"] + last.get("forfait", 0)