import json
import time
import hmac
import hashlib
import base64
import uuid
import logging
import aiohttp
from typing import List, Dict, Any, Optional
from app.core.config import settings

class UniSMSClient:
    """UniSMS短信客户端"""
    
    def __init__(self):
        self.access_key_id = settings.UNISMS_ACCESS_KEY_ID
        self.access_key_secret = settings.UNISMS_ACCESS_KEY_SECRET
        self.base_url = "https://uni.apistd.com"
        self.endpoint = "/2022-12-28/sms/send"
        self.signature_method = "HMAC-SHA256"
        self.signature_version = "1"
    
    def _generate_signature(self, string_to_sign: str) -> str:
        """生成签名"""
        key = self.access_key_secret.encode('utf-8')
        message = string_to_sign.encode('utf-8')
        sign = hmac.new(key, message, digestmod=hashlib.sha256).digest()
        return base64.b64encode(sign).decode('utf-8')
    
    def _build_request_headers(self, body: Dict[str, Any]) -> Dict[str, str]:
        """构建请求头"""
        timestamp = str(int(time.time()))
        nonce = str(uuid.uuid4()).replace('-', '')
        content_md5 = hashlib.md5(json.dumps(body).encode('utf-8')).hexdigest()
        
        # 构建待签名字符串
        string_to_sign = "\n".join([
            self.endpoint,
            timestamp,
            nonce,
            content_md5
        ])
        
        # 生成签名
        signature = self._generate_signature(string_to_sign)
        
        # 构建请求头
        headers = {
            "Content-Type": "application/json",
            "Accept": "application/json",
            "X-Uni-Timestamp": timestamp,
            "X-Uni-Nonce": nonce,
            "X-Uni-Content-MD5": content_md5,
            "X-Uni-Signature-Method": self.signature_method,
            "X-Uni-Signature-Version": self.signature_version,
            "X-Uni-Signature": signature,
            "X-Uni-AccessKeyId": self.access_key_id,
        }
        
        return headers
    
    async def send_sms(
        self, 
        to: str, 
        signature: str, 
        template_id: str, 
        template_data: Dict[str, Any] = None
    ) -> Dict[str, Any]:
        """
        发送短信
        
        Args:
            to: 接收短信的手机号码
            signature: 短信签名
            template_id: 短信模板ID
            template_data: 短信模板参数
        
        Returns:
            Dict[str, Any]: 发送结果
        """
        try:
            # 构建请求体
            body = {
                "to": to,
                "signature": signature,
                "templateId": template_id,
            }
            
            if template_data:
                body["templateData"] = template_data
            
            # 构建请求头
            headers = self._build_request_headers(body)
            
            # 发送请求
            url = f"{self.base_url}{self.endpoint}"
            
            async with aiohttp.ClientSession() as session:
                async with session.post(url, json=body, headers=headers) as response:
                    result = await response.json()
                    logging.info(f"UniSMS响应: {result}")
                    
                    if result.get("status") != "success":
                        logging.error(f"发送短信失败: {result}")
                        return {
                            "success": False,
                            "error": result.get("message", "发送短信失败")
                        }
                    
                    return {
                        "success": True,
                        "message_id": result.get("data", {}).get("messageId", ""),
                        "fee": result.get("data", {}).get("fee", 0)
                    }
                    
        except Exception as e:
            logging.error(f"发送短信异常: {str(e)}")
            return {
                "success": False,
                "error": f"发送短信异常: {str(e)}"
            }
    
    async def send_verification_code(self, phone: str, code: str) -> Dict[str, Any]:
        """
        发送验证码短信
        
        Args:
            phone: 手机号码
            code: 验证码
            
        Returns:
            Dict[str, Any]: 发送结果
        """
        # 使用验证码短信模板
        template_id = settings.UNISMS_VERIFICATION_TEMPLATE_ID
        signature = settings.UNISMS_SIGNATURE
        template_data = {"code": code}
        
        return await self.send_sms(
            to=phone,
            signature=signature,
            template_id=template_id,
            template_data=template_data
        )