import logging

logger = logging.getLogger(__name__)


def on_pre_sales_order_created(sender, **kwargs):
    """Handle PreSalesOrder created domain event.

    For now: log only (no side effects).
    """

    order = kwargs.get('instance')
    created_by = kwargs.get('created_by')
    operator = kwargs.get('operator')
    items_count = kwargs.get('items_count')

    if order is None:
        logger.warning('[business.handlers] pre_sales_order_created 缺少 instance，已跳过')
        return

    created_by_label = getattr(created_by, 'username', None) if created_by else None
    operator_label = getattr(operator, 'name', None) if operator else None

    logger.info(
        '[business.handlers] pre_sales_order_created: id=%s human_id=%s merchant_id=%s customer_id=%s '
        'created_by=%s operator=%s items_count=%s',
        getattr(order, 'id', None),
        getattr(order, 'human_id', None),
        getattr(order, 'merchant_id', None),
        getattr(order, 'customer_id', None),
        created_by_label or '-',
        operator_label or '-',
        items_count if items_count is not None else '-',
    )