from django.utils import timezone

from menu.models import Order


class OrderService:
    """订单业务逻辑"""

    @staticmethod
    def get_queryset(status_filter=None):
        """获取订单查询集"""
        queryset = Order.objects.prefetch_related('dishes', 'dishes__category')
        if status_filter:
            queryset = queryset.filter(status=status_filter)
        return queryset

    @staticmethod
    def create_order(serializer, dish_ids):
        """创建订单并绑定菜品"""
        if dish_ids is None:
            dish_ids = []

        order = serializer.save(dish_ids=dish_ids)
        return Order.objects.prefetch_related('dishes', 'dishes__category').get(pk=order.pk)

    @staticmethod
    def complete_order(order):
        """完成订单"""
        order.status = 'completed'
        order.completed_at = timezone.now()
        order.save()
        return order