# -*- coding: utf-8 -*-

from django.db import IntegrityError, transaction
from django.utils import timezone
from django_logit import logit
from django_response import response
from django.db.models import Q

from account.models import UserInfo
from sales.models import LotteryCampaignInfo, LotteryEntryInfo
from utils.error.errno_utils import LotteryStatusCode, UserStatusCode

def join_lottery(user, serial_no, model_id='', campaign_id='', submit_pk='', phone='', model_name=''):
    """
    写入抽奖名额（幂等）

    返回 (entry, campaign, is_new)：
      · 没有进行中的活动 → (None, None, False)
      · 已有名额         → (entry, campaign, False)
      · 首次参与         → (entry, campaign, True)
    """
    serial_no = (serial_no or '').strip()

    campaign = LotteryCampaignInfo.objects.get(status=True, campaign_id=campaign_id)

    if not campaign:
        return None, None

    # 嵌套 atomic 生成 savepoint：并发插入冲突后还能继续查询
    with transaction.atomic():
        entry, created = LotteryEntryInfo.objects.get_or_create(
            campaign_id=campaign.campaign_id,
            serial_no=serial_no,
            submit_pk=submit_pk,
            title=campaign.title,
            phone=phone,
            user_id=user.user_id,
            model_id=model_id,
            model_name=model_name,
        )

    return entry, campaign


@logit(res=True)
@transaction.atomic
def lottery_join_api(request):
    """抽奖参与接口：写入名额"""
    user_id = request.POST.get('user_id', '')
    serial_no = request.POST.get('serial_no')
    model_id = request.POST.get('model_id')
    campaign_id = request.POST.get('campaign_id', '')
    submit_pk = request.POST.get('submit_pk', '')
    phone = request.POST.get('phone', '')
    model_name = request.POST.get('model_name', '')

    try:
        user = UserInfo.objects.select_for_update().get(user_id=user_id)
    except UserInfo.DoesNotExist:
        return response(UserStatusCode.USER_NOT_FOUND)

    # TODO 安全：应校验该序列号确实绑定在当前用户名下，防止传入他人序列号刷名额

    entry, campaign = join_lottery(user, serial_no, model_id, campaign_id, submit_pk, phone, model_name)

    if not campaign:
        return response(LotteryStatusCode.CAMPAIGN_NOT_FOUND)

    return response(200, data={
        'campaign': serialize_campaign(campaign),
        'entry': serialize_entry(entry),
    })