from typing import Optional, Dict, Any
import httpx
import logging
from app.config import settings

logger = logging.getLogger(__name__)


class WeChatService:
    def __init__(self):
        self.app_id = settings.WECHAT_APP_ID
        self.app_secret = settings.WECHAT_APP_SECRET
        self.api_base = "https://api.weixin.qq.com"

    async def code2session(self, js_code: str) -> Optional[Dict[str, Any]]:
        if not self.app_id or not self.app_secret:
            logger.warning("WeChat not configured")
            return None

        async with httpx.AsyncClient() as client:
            resp = await client.get(
                f"{self.api_base}/sns/jscode2session",
                params={
                    "appid": self.app_id,
                    "secret": self.app_secret,
                    "js_code": js_code,
                    "grant_type": "authorization_code",
                },
                timeout=10,
            )
            data = resp.json()

            if data.get("errcode", 0) != 0:
                logger.error(f"WeChat code2session failed: {data}")
                return None

            return {
                "openid": data.get("openid"),
                "session_key": data.get("session_key"),
                "unionid": data.get("unionid"),
            }

    async def get_phone_number(self, code: str) -> Optional[str]:
        if not self.app_id or not self.app_secret:
            return None

        access_token = await self._get_access_token()
        if not access_token:
            return None

        async with httpx.AsyncClient() as client:
            resp = await client.post(
                f"{self.api_base}/wxa/business/getuserphonenumber",
                params={"access_token": access_token},
                json={"code": code},
                timeout=10,
            )
            data = resp.json()
            if data.get("errcode", 0) != 0:
                logger.error(f"WeChat getPhoneNumber failed: {data}")
                return None

            return data.get("phone_info", {}).get("phoneNumber")

    async def _get_access_token(self) -> Optional[str]:
        async with httpx.AsyncClient() as client:
            resp = await client.get(
                f"{self.api_base}/cgi-bin/token",
                params={
                    "grant_type": "client_credential",
                    "appid": self.app_id,
                    "secret": self.app_secret,
                },
                timeout=10,
            )
            data = resp.json()
            return data.get("access_token")


wechat_service = WeChatService()