import uuid

from fastapi import APIRouter, HTTPException
from pymongo.errors import DuplicateKeyError

from app.models.user import User
from app.schemas.auth import WechatLoginRequest, PhoneLoginRequest, TokenResponse
from app.middleware.auth import create_access_token
from app.services.wechat import code_to_session

router = APIRouter()


@router.post("/demo-login", response_model=TokenResponse)
async def demo_login():
    """Web 体验用的演示登录，每次创建独立的临时用户"""
    demo_openid = f"demo_{uuid.uuid4().hex[:12]}"
    user = User(
        openid=demo_openid,
        name="体验用户",
    )
    await user.insert()

    token = create_access_token(str(user.id))
    return TokenResponse(
        access_token=token,
        user_id=str(user.id),
        is_new_user=True,
    )


@router.post("/wechat-login", response_model=TokenResponse)
async def wechat_login(req: WechatLoginRequest):
    """微信小程序登录"""
    try:
        wechat_data = await code_to_session(req.code)
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

    openid = wechat_data["openid"]
    user = await User.find_one(User.openid == openid)
    is_new = user is None

    if not user:
        user = User(
            openid=openid,
            session_key=wechat_data.get("session_key"),
            union_id=wechat_data.get("unionid"),
        )
        await user.insert()
    else:
        user.session_key = wechat_data.get("session_key")
        await user.save()

    token = create_access_token(str(user.id))
    return TokenResponse(
        access_token=token,
        user_id=str(user.id),
        is_new_user=is_new,
    )


@router.post("/phone-login", response_model=TokenResponse)
async def phone_login(req: PhoneLoginRequest):
    """手机号登录（简化版，生产环境需接入短信验证）"""
    # TODO: 接入真实短信验证服务
    if req.sms_code != "123456":
        raise HTTPException(status_code=400, detail="验证码错误")

    user = await User.find_one(User.phone == req.phone)
    is_new = user is None

    if not user:
        try:
            user = User(openid=f"phone_{req.phone}", phone=req.phone)
            await user.insert()
        except DuplicateKeyError:
            # 并发竞态：另一个请求已创建该用户，回退查找
            user = await User.find_one(User.phone == req.phone)
            is_new = False

    token = create_access_token(str(user.id))
    return TokenResponse(
        access_token=token,
        user_id=str(user.id),
        is_new_user=is_new,
    )