import httpx
from fastapi import APIRouter, Request
from fastapi.responses import RedirectResponse
import os

router = APIRouter()

GOOGLE_CLIENT_ID = os.getenv("GOOGLE_CLIENT_ID")
GOOGLE_CLIENT_SECRET = os.getenv("GOOGLE_CLIENT_SECRET")

REDIRECT_URI = "http://localhost:8000/auth/callback"

GOOGLE_AUTH_URL = "https://accounts.google.com/o/oauth2/v2/auth"
GOOGLE_TOKEN_URL = "https://oauth2.googleapis.com/token"
GOOGLE_USERINFO_URL = "https://www.googleapis.com/oauth2/v2/userinfo"


@router.get("/login/google")
def login_google():
    url = (
        f"{GOOGLE_AUTH_URL}"
        f"?client_id={GOOGLE_CLIENT_ID}"
        f"&redirect_uri={REDIRECT_URI}"
        f"&response_type=code"
        f"&scope=openid email profile"
    )
    return RedirectResponse(url)


@router.get("/auth/callback")
async def auth_callback(code: str):
    async with httpx.AsyncClient() as client:
        # 1. 用 code 换 token
        token_res = await client.post(
            GOOGLE_TOKEN_URL,
            data={
                "code": code,
                "client_id": GOOGLE_CLIENT_ID,
                "client_secret": GOOGLE_CLIENT_SECRET,
                "redirect_uri": REDIRECT_URI,
                "grant_type": "authorization_code",
            },
        )
        token_json = token_res.json()
        access_token = token_json["access_token"]

        # 2. 获取用户信息
        user_res = await client.get(
            GOOGLE_USERINFO_URL,
            headers={"Authorization": f"Bearer {access_token}"},
        )
        user_info = user_res.json()

    # 这里你可以写入数据库
    return {
        "email": user_info["email"],
        "name": user_info["name"],
        "picture": user_info["picture"],
    }