import aiohttp
from app.core.config import settings
import requests
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives import serialization
import json
import base64
import time
import random
import string
from cryptography.x509 import load_pem_x509_certificate
from cryptography.hazmat.primitives.ciphers.aead import AESGCM

def generate_random_string(length=32):
    """生成指定长度的随机字符串"""
    return ''.join(random.choices(string.ascii_letters + string.digits, k=length))


class WeChatClient:
    """微信客户端"""
    
    def __init__(self):
        self.appid = settings.WECHAT_APPID
        self.secret = settings.WECHAT_SECRET
    
    async def get_access_token(self):
        """获取小程序全局接口调用凭据"""
        url = "https://api.weixin.qq.com/cgi-bin/token"
        params = {
            "grant_type": "client_credential",
            "appid": self.appid,
            "secret": self.secret
        }
        
        async with aiohttp.ClientSession() as session:
            async with session.get(url, params=params) as response:
                text = await response.text()
                try:
                    result = json.loads(text)
                except json.JSONDecodeError:
                    raise Exception(f"解析微信返回数据失败: {text}")
                
                if "errcode" in result and result["errcode"] != 0:
                    raise Exception(result.get("errmsg", "获取access_token失败"))
                
                return result.get("access_token")
    
    async def get_phone_number(self, code: str) -> dict:
        """获取用户手机号"""
        access_token = await self.get_access_token()
        url = f"https://api.weixin.qq.com/wxa/business/getuserphonenumber?access_token={access_token}"
        
        async with aiohttp.ClientSession() as session:
            async with session.post(url, json={"code": code}) as response:
                text = await response.text()
                try:
                    result = json.loads(text)
                except json.JSONDecodeError:
                    raise Exception(f"解析微信返回数据失败: {text}")
                
                # 打印调试信息
                print(f"微信返回数据: {result}")
                
                if result.get("errcode", 0) != 0:
                    raise Exception(result.get("errmsg", "获取手机号失败"))
                
                # 正确获取 phone_info
                phone_info = result.get("phone_info")
                if not phone_info:
                    raise Exception("未获取到手机号信息")
                
                return {
                    "phone_number": phone_info.get("phoneNumber"),
                    "pure_phone_number": phone_info.get("purePhoneNumber"),
                    "country_code": phone_info.get("countryCode"),
                }
    
    
    async def code2session(self, code: str) -> dict:
        """通过 code 获取用户 openid"""
        url = f"https://api.weixin.qq.com/sns/jscode2session"
        params = {
            "appid": self.appid,
            "secret": self.secret,
            "js_code": code,
            "grant_type": "authorization_code"
        }
        
        async with aiohttp.ClientSession() as session:
            async with session.get(url, params=params) as response:
                text = await response.text()
                try:
                    result = json.loads(text)
                except json.JSONDecodeError:
                    raise Exception(f"解析微信返回数据失败: {text}")
                
                if "errcode" in result and result["errcode"] != 0:
                    raise Exception(result.get("errmsg", "获取openid失败"))
                
                return result