from datetime import timedelta

def predict_next_service(last_service_date, usage_hours, days_per_week, equipment_type):
    """
    Predict AMC date based on usage + type of equipment.
    """

    # Usage intensity score
    usage_score = usage_hours * days_per_week

    # Base interval in days
    base_interval = 180  # standard

    # Adjust interval based on usage
    if usage_score >= 120:
        interval = 90
    elif usage_score >= 80:
        interval = 120
    elif usage_score >= 40:
        interval = 150
    else:
        interval = 180

    # Further adjustment based on equipment type (example rules)
    if equipment_type in ["Analyzer", "Centrifuge"]:
        interval -= 15  # more sensitive
    elif equipment_type == "Incubator":
        interval += 15  # more stable

    next_date = last_service_date + timedelta(days=interval)
    return next_date