from datetime import datetime, timezone

def format_size(bytes_size):
    """Convertit une taille en octets en format lisible (Ko, Mo, Go, ...)."""
    for unit in ['o', 'Ko', 'Mo', 'Go', 'To']:
        if bytes_size < 1024:
            return f"{bytes_size:.2f} {unit}"
        bytes_size /= 1024
    return f"{bytes_size:.2f} Po"

def calculate_age(uploaded_at_iso):
    uploaded_date = datetime.fromisoformat(uploaded_at_iso.rstrip('Z')).replace(tzinfo=timezone.utc)
    now = datetime.now(timezone.utc)
    delta_days = (now.date() - uploaded_date.date()).days

    # human
    if delta_days < 30:
        age_human = f"{delta_days} j"
    elif delta_days < 365:
        months = delta_days // 30
        age_human = f"{months} mois"
    else:
        years = delta_days // 365
        age_human = f"{years} ans"

    return delta_days, age_human