Django/users/services/c_invite.py

"""点单端 C 用户邀请：邀请码、换绑、店铺跟随。"""
from django.db import transaction
from django.db.models import F

from shop.models import Dianpu, YonghuDianpuBangding
from users.models import YonghuCYaoqing
from users.business_models import User
from utils.invitationcode_utils import CreateInvitationCode, VerifyInvitationCode

import logging

logger = logging.getLogger(__name__)


def get_or_create_c_yaoqing(user):
    """获取或创建用户的点单端邀请扩展记录。"""
    profile, _ = YonghuCYaoqing.objects.get_or_create(user=user)
    return profile


def ensure_c_invite_code(user):
    """确保用户有邀请码，返回 (profile, yaoqingma, is_new)。"""
    profile = get_or_create_c_yaoqing(user)
    existing = (profile.yaoqingma or '').strip()
    if existing:
        return profile, existing, False

    new_code = CreateInvitationCode(str(user.UserUID))
    if not VerifyInvitationCode(new_code):
        raise ValueError('邀请码生成失败')

    # 极低概率冲突时再生成一次
    if YonghuCYaoqing.query.filter(yaoqingma=new_code).exclude(pk=profile.pk).exists():
        new_code = CreateInvitationCode(str(user.UserUID) + 'R')
        if not VerifyInvitationCode(new_code):
            raise ValueError('邀请码生成失败')

    profile.yaoqingma = new_code
    profile.save(update_fields=['yaoqingma', 'UpdateTime'])
    return profile, new_code, True


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, '邀请人店铺已被封禁'

    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, '店铺已跟随邀请人换绑'


def sync_shop_from_inviter(invitee_user, inviter_user):
    """
    按邀请人店铺同步被邀请人店铺：
    - 邀请人有正常店铺 → 被邀请人绑到同一店
    - 邀请人无店铺 → 被邀请人解绑店铺（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()
    )

    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}

    old_id = _unbind_shop(invitee_locked)
    return {
        'shop_synced': False,
        'dianpu_id': None,
        'changed': bool(old_id),
        'msg': '邀请人未绑定店铺，已解除店铺绑定' if old_id else '邀请人未绑定店铺',
    }


def bind_c_inviter_by_code(invitee_user, invite_code):
    """
    用邀请码绑定/换绑邀请人，并同步店铺。
    返回 dict: code/msg/data
    """
    code = (invite_code or '').strip()
    if not code:
        return {'code': 400, 'msg': '邀请码不能为空', 'data': None}
    if len(code) > 100:
        return {'code': 400, 'msg': '邀请码格式错误', 'data': None}

    try:
        inviter_profile = YonghuCYaoqing.query.select_related('user').get(yaoqingma=code)
    except YonghuCYaoqing.DoesNotExist:
        return {'code': 404, 'msg': '邀请码无效', 'data': None}

    inviter = inviter_profile.user
    if inviter.UserUID == invitee_user.UserUID:
        return {'code': 400, 'msg': '不能绑定自己为邀请人', 'data': None}

    with transaction.atomic():
        invitee_profile = get_or_create_c_yaoqing(invitee_user)
        invitee_profile = YonghuCYaoqing.objects.select_for_update().get(pk=invitee_profile.pk)
        inviter_profile = YonghuCYaoqing.objects.select_for_update().get(pk=inviter_profile.pk)

        old_inviter_uid = (invitee_profile.yaoqingren or '').strip() or None
        new_inviter_uid = inviter.UserUID

        if old_inviter_uid == new_inviter_uid:
            shop_info = sync_shop_from_inviter(invitee_user, inviter)
            return {
                'code': 200,
                'msg': '已绑定该邀请人',
                'data': {
                    'yaoqingren': new_inviter_uid,
                    'rebinding': False,
                    'shop': shop_info,
                },
            }

        # 换绑：旧邀请人计数 -1，新邀请人 +1
        if old_inviter_uid:
            old_p = (
                YonghuCYaoqing.objects.select_for_update()
                .filter(user__UserUID=old_inviter_uid)
                .first()
            )
            if old_p and old_p.yaogingshuliang > 0:
                old_p.yaogingshuliang = F('yaogingshuliang') - 1
                old_p.save(update_fields=['yaogingshuliang', 'UpdateTime'])

        inviter_profile.yaogingshuliang = F('yaogingshuliang') + 1
        inviter_profile.save(update_fields=['yaogingshuliang', 'UpdateTime'])

        invitee_profile.yaoqingren = new_inviter_uid
        invitee_profile.save(update_fields=['yaoqingren', 'UpdateTime'])

        shop_info = sync_shop_from_inviter(invitee_user, inviter)

    logger.info(
        'C端邀请绑定: invitee=%s inviter=%s old=%s shop=%s',
        invitee_user.UserUID, new_inviter_uid, old_inviter_uid, shop_info,
    )
    return {
        'code': 200,
        'msg': '绑定成功' if not old_inviter_uid else '已换绑邀请人',
        'data': {
            'yaoqingren': new_inviter_uid,
            'rebinding': bool(old_inviter_uid),
            'shop': shop_info,
        },
    }