fix: 修复点单商品在多店铺间跳动

扫码绑店参数只消费一次，避免 Tab 返回反复换绑；一人多条脏绑定取最新并在换绑时清理，hqsp 稳定取当前店。

Co-authored-by: Cursor <cursoragent@cursor.com>

users/services/c_invite.py

@@ -2,7 +2,12 @@
 from django.db import transaction
 from django.db.models import F
 
-from shop.models import Dianpu, YonghuDianpuBangding
+from shop.models import Dianpu
+from shop.services.shop_binding import (
+    clear_user_shop_binding,
+    get_user_shop_binding,
+    set_user_shop_binding,
+)
 from users.models import YonghuCYaoqing
 from users.business_models import User
 
@@ -17,68 +22,21 @@ def get_or_create_c_yaoqing(user):
     return profile
 
 
-def _unbind_shop(user_locked):
-    """解除用户店铺绑定并扣减旧店绑定人数。"""
-    binding = (
-        YonghuDianpuBangding.objects.select_for_update()
-        .filter(yonghu=user_locked)
-        .select_related('dianpu')
-        .first()
-    )
-    if not binding:
-        return None
-    old = binding.dianpu
-    old.bangding_yonghushu = F('bangding_yonghushu') - 1
-    old.save(update_fields=['bangding_yonghushu'])
-    binding.delete()
-    return old.id
-
-
-def _bind_shop(user_locked, dianpu_locked):
-    """将用户绑定到指定店铺（已存在则换绑）。返回 (changed, msg)。"""
-    if dianpu_locked.zhuangtai != 1:
-        return False, '推荐官店铺已被封禁'
-
-    try:
-        existing = YonghuDianpuBangding.objects.select_for_update().get(yonghu=user_locked)
-        if existing.dianpu_id == dianpu_locked.id:
-            return False, '已绑定该店铺'
-        old = existing.dianpu
-        old.bangding_yonghushu = F('bangding_yonghushu') - 1
-        old.save(update_fields=['bangding_yonghushu'])
-        existing.dianpu = dianpu_locked
-        existing.save(update_fields=['dianpu', 'UpdateTime'])
-    except YonghuDianpuBangding.DoesNotExist:
-        YonghuDianpuBangding.query.create(yonghu=user_locked, dianpu=dianpu_locked)
-
-    dianpu_locked.bangding_yonghushu = F('bangding_yonghushu') + 1
-    dianpu_locked.save(update_fields=['bangding_yonghushu'])
-    return True, '店铺已跟随推荐官换绑'
-
-
 def sync_shop_from_inviter(invitee_user, inviter_user):
     """
     按推荐官店铺同步被推荐人店铺：
-    - 推荐官有正常店铺 → 被推荐人绑到同一店
+    - 推荐官有正常店铺 → 被推荐人绑到同一店（一人一店）
     - 推荐官无店铺 → 被推荐人解绑店铺（回落平台公共商品逻辑）
     须在 transaction.atomic 内调用。
     """
-    invitee_locked = User.objects.select_for_update().get(UserUUID=invitee_user.UserUUID)
-    inviter_locked = User.objects.select_for_update().get(UserUUID=inviter_user.UserUUID)
-
-    inviter_binding = (
-        YonghuDianpuBangding.objects.select_for_update()
-        .filter(yonghu=inviter_locked)
-        .select_related('dianpu')
-        .first()
-    )
+    inviter_binding = get_user_shop_binding(inviter_user)
 
     if inviter_binding and inviter_binding.dianpu.zhuangtai == 1:
-        dianpu_locked = Dianpu.objects.select_for_update().get(id=inviter_binding.dianpu_id)
-        changed, msg = _bind_shop(invitee_locked, dianpu_locked)
-        return {'shop_synced': True, 'dianpu_id': dianpu_locked.id, 'changed': changed, 'msg': msg}
+        dianpu = Dianpu.objects.select_for_update().get(id=inviter_binding.dianpu_id)
+        changed, msg = set_user_shop_binding(invitee_user, dianpu)
+        return {'shop_synced': True, 'dianpu_id': dianpu.id, 'changed': changed, 'msg': msg}
 
-    old_id = _unbind_shop(invitee_locked)
+    old_id = clear_user_shop_binding(invitee_user)
     return {
         'shop_synced': False,
         'dianpu_id': None,
@@ -107,7 +65,6 @@ def bind_c_inviter_by_uid(invitee_user, inviter_uid):
         return {'code': 400, 'msg': '不能绑定自己为推荐官', 'data': None}
 
     with transaction.atomic():
-        # 推荐官侧也要有档案，便于计数「我推荐的人」
         inviter_profile = get_or_create_c_yaoqing(inviter)
         invitee_profile = get_or_create_c_yaoqing(invitee_user)
         invitee_profile = YonghuCYaoqing.objects.select_for_update().get(pk=invitee_profile.pk)