"""视图辅助：以商家身份代理调用现有订单 View（不修改原接口）。"""
import logging

from backend.utils import pick_order_id
from merchant_ops.services.authz import StaffAuthError, member_has_perm
from merchant_ops.models import MerchantOrderDispatch
from orders.models import MerchantOrderExt
from users.business_models import User

logger = logging.getLogger(__name__)


def get_merchant_user(merchant_id):
    return User.query.get(UserUID=merchant_id)


def staff_can_access_order(member, order_id, perm_all='order_view_all', perm_self='order_view_self'):
    ext = MerchantOrderExt.query.filter(
        MerchantID=member.merchant_id,
        Order__OrderID=order_id,
    ).first()
    if not ext:
        return False, None
    if member_has_perm(member, perm_all):
        return True, ext
    if member_has_perm(member, perm_self):
        disp = MerchantOrderDispatch.query.filter(order_id=order_id).first()
        if disp and disp.staff_member_id == member.id:
            return True, ext
    return False, ext


def proxy_merchant_order_view(request, member, view_class, perm_code):
    """子客服通过商家 User 代理调用现有 View.post。"""
    if not member_has_perm(member, perm_code):
        raise StaffAuthError(403, f'无权限: {perm_code}')

    order_id = pick_order_id(request.data)
    if order_id:
        ok, _ = staff_can_access_order(member, order_id)
        if not ok:
            raise StaffAuthError(403, '无权操作该订单')

    merchant_user = get_merchant_user(member.merchant_id)
    old_user = request.user
    request.user = merchant_user
    request._staff_member = member
    try:
        return view_class().post(request)
    finally:
        request.user = old_user
        if hasattr(request, '_staff_member'):
            delattr(request, '_staff_member')