feat(auth): POST /wechat-login(openid 命中即登入,否则发绑号令牌)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/api/v1/auth.py

@@ -17,9 +17,16 @@ from fastapi import APIRouter, HTTPException, Request, status
 from app.api.deps import CurrentUser, DbSession
 from app.core import test_account
 from app.core.ratelimit import enforce_rate_limit
-from app.core.security import TokenError, decode_token, issue_token_pair
+from app.core.security import (
+    TokenError,
+    create_bind_ticket,
+    decode_bind_ticket,
+    decode_token,
+    issue_token_pair,
+)
 from app.integrations.jiguang import JiguangError, mask_phone, verify_and_get_phone
 from app.integrations.sms import SmsError, send_code, verify_code
+from app.integrations import wxpay
 from app.repositories import onboarding as onboarding_repo
 from app.repositories import user as user_repo
 from app.schemas.auth import (
@@ -32,6 +39,8 @@ from app.schemas.auth import (
     TokenPair,
     TokenWithUser,
     UserOut,
+    WechatLoginRequest,
+    WechatLoginResponse,
 )
 
 logger = logging.getLogger("shagua.auth")
@@ -166,6 +175,54 @@ def sms_login(req: SmsLoginRequest, request: Request, db: DbSession) -> TokenWit
     return _login_response(user, onboarding_completed=completed)
 
 
+# ===================== 微信登录 =====================
+
+@router.post(
+    "/wechat-login",
+    response_model=WechatLoginResponse,
+    summary="微信登录(openid 命中即登入,否则发绑号令牌)",
+)
+def wechat_login(req: WechatLoginRequest, db: DbSession) -> WechatLoginResponse:
+    from app.core.config import settings  # 局部 import,避免循环
+
+    # 微信登录只需 code→openid(sns/oauth2),不需要商户转账证书;故只校验 APP_ID/SECRET。
+    if not (settings.WECHAT_APP_ID and settings.WECHAT_APP_SECRET):
+        raise HTTPException(status_code=503, detail="wechat login not configured")
+
+    try:
+        info = wxpay.code_to_userinfo(req.code)  # {openid, nickname, avatar_url, raw};失败抛 ValueError
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e)) from e
+
+    openid = info["openid"]
+    user = user_repo.get_user_by_wechat_openid(db, openid)
+    if user is not None:
+        # openid 命中 → 直接登入(绝不套用提现 bind-wechat 的"撞号即 409"逻辑)
+        if user.status != "active":
+            raise HTTPException(status_code=403, detail="account disabled")
+        user_repo.touch_last_login(db, user)
+        completed = onboarding_repo.is_completed(db, user_id=user.id, device_id=req.device_id)
+        logger.info("wechat_login hit user_id=%d openid=%s*** onboarded=%s", user.id, openid[:6], completed)
+        return WechatLoginResponse(
+            status="logged_in",
+            token=_login_response(user, onboarding_completed=completed),
+        )
+
+    # 未命中 → 签发短时 bind_ticket,进手机号绑定流程(账号此刻还不建)
+    ticket = create_bind_ticket(
+        openid=openid,
+        wechat_nickname=info["nickname"],
+        wechat_avatar_url=info["avatar_url"],
+    )
+    logger.info("wechat_login new openid=%s*** issue bind_ticket", openid[:6])
+    return WechatLoginResponse(
+        status="need_bind_phone",
+        bind_ticket=ticket,
+        wechat_nickname=info["nickname"],
+        wechat_avatar_url=info["avatar_url"],
+    )
+
+
 # ===================== Refresh =====================
 
 @router.post("/refresh", response_model=TokenPair, summary="用 refresh_token 换新 token 对")

app/repositories/user.py

@@ -86,6 +86,19 @@ def get_user_by_phone(db: Session, phone: str) -> User | None:
     return db.execute(stmt).scalar_one_or_none()
 
 
+def get_user_by_wechat_openid(db: Session, openid: str) -> User | None:
+    stmt = select(User).where(User.wechat_openid == openid)
+    return db.execute(stmt).scalar_one_or_none()
+
+
+def touch_last_login(db: Session, user: User) -> User:
+    """openid 命中登录时更新 last_login_at(手机号登录在 upsert_user_for_login 里已更新)。"""
+    user.last_login_at = datetime.now(timezone.utc)
+    db.commit()
+    db.refresh(user)
+    return user
+
+
 def upsert_user_for_login(
     db: Session,
     *,

app/schemas/auth.py

@@ -102,3 +102,22 @@ class RefreshRequest(BaseModel):
 
 class LogoutResponse(BaseModel):
     ok: bool = True
+
+
+# ===== 微信登录 =====
+
+class WechatLoginRequest(BaseModel):
+    code: str = Field(..., min_length=1, description="微信 App 授权拿到的 code(单次有效)")
+    device_id: str = Field(
+        "", max_length=64,
+        description="硬件级设备标识(Android ANDROID_ID),用于新手引导按 设备+账号 去重;空=按未完成处理",
+    )
+
+
+class WechatLoginResponse(BaseModel):
+    # status="logged_in" → openid 命中,token 有值;"need_bind_phone" → 未命中,bind_ticket 有值
+    status: str
+    token: TokenWithUser | None = None
+    bind_ticket: str | None = None
+    wechat_nickname: str | None = None
+    wechat_avatar_url: str | None = None

tests/test_wechat_login.py

@@ -42,3 +42,25 @@ def test_bind_ticket_expired_rejected(monkeypatch) -> None:
     token = security.create_bind_ticket(openid="oid", wechat_nickname=None, wechat_avatar_url=None)
     with pytest.raises(security.TokenError):
         security.decode_bind_ticket(token)
+
+
+# ===== Task 2: wechat-login =====
+
+def test_wechat_login_new_openid_returns_bind_ticket(client, monkeypatch) -> None:
+    monkeypatch.setattr(wxpay, "code_to_userinfo", _fake_userinfo("openid_new_1", "小明", "http://x/m.png"))
+    r = client.post("/api/v1/auth/wechat-login", json={"code": "wxcode1", "device_id": "devA"})
+    assert r.status_code == 200, r.text
+    body = r.json()
+    assert body["status"] == "need_bind_phone"
+    assert body["bind_ticket"]
+    assert body["wechat_nickname"] == "小明"
+    assert body["wechat_avatar_url"] == "http://x/m.png"
+    assert body["token"] is None
+
+
+def test_wechat_login_invalid_code_returns_400(client, monkeypatch) -> None:
+    def _raise(code: str) -> dict:
+        raise ValueError("微信授权失败: invalid code")
+    monkeypatch.setattr(wxpay, "code_to_userinfo", _raise)
+    r = client.post("/api/v1/auth/wechat-login", json={"code": "bad", "device_id": "devA"})
+    assert r.status_code == 400, r.text