Calculateur de Taux d'Alcoolémie

def calculate_bac(
    drinks: list[dict],
    weight_kg: float,
    gender: str,
    hours_elapsed: float
) -> float:
    """
    Estimate Blood Alcohol Content using the Widmark formula.
    BAC = (alcohol_grams / (weight_kg * r * 10)) - (0.015 * hours)
    r = 0.68 for male, 0.55 for female

    drinks: list of {"abv": float (%), "volume_ml": float}
    WARNING: For estimation only. Never use to determine fitness to drive.
    """
    r = 0.68 if gender.lower() == "male" else 0.55
    total_alcohol_grams = sum(
        d["volume_ml"] * (d["abv"] / 100) * 0.789  # ethanol density = 0.789 g/ml
        for d in drinks
    )
    bac = (total_alcohol_grams / (weight_kg * r * 10)) - (0.015 * hours_elapsed)
    return max(bac, 0.0)

# Example: 80kg male, 2 beers (5%, 355ml), 1 hour elapsed
drinks = [
    {"abv": 5, "volume_ml": 355},
    {"abv": 5, "volume_ml": 355},
]
bac = calculate_bac(drinks, weight_kg=80, gender="male", hours_elapsed=1)
print(f"Estimated BAC: {bac:.4f}%")  # ~0.0367%