"""
DeepSeek AI 服务
"""
import httpx
import json
from typing import AsyncGenerator
from utils.config import settings
from utils.logger import logger


class DeepSeekService:
    def __init__(self):
        self.api_key = settings.deepseek.api_key
        self.api_url = settings.deepseek.api_url
        self.base_url = f"{self.api_url}/v1"

        self._timeout = httpx.Timeout(120.0, connect=10.0)
        self._limits = httpx.Limits(max_connections=50, max_keepalive_connections=20)
        self._client = httpx.AsyncClient(timeout=self._timeout, limits=self._limits)

    async def aclose(self) -> None:
        await self._client.aclose()
    
    async def chat(self, messages: list, model: str = "deepseek-chat") -> str:
        """同步聊天"""
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json"
        }
        
        data = {
            "model": model,
            "messages": messages,
            "temperature": 0.7
        }
        
        try:
            response = await self._client.post(
                f"{self.base_url}/chat/completions",
                headers=headers,
                json=data,
            )
            response.raise_for_status()
            result = response.json()
            return result['choices'][0]['message']['content']
        except Exception as e:
            logger.error(f"DeepSeek API 调用失败: {e}")
            raise
    
    async def stream_chat(self, messages: list, model: str = "deepseek-chat") -> AsyncGenerator[str, None]:
        """流式聊天"""
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json"
        }
        
        data = {
            "model": model,
            "messages": messages,
            "temperature": 0.7,
            "stream": True
        }
        
        try:
            async with self._client.stream(
                "POST",
                f"{self.base_url}/chat/completions",
                headers=headers,
                json=data,
            ) as response:
                response.raise_for_status()
                async for line in response.aiter_lines():
                    if line.startswith("data: "):
                        data_str = line[6:]
                        if data_str == "[DONE]":
                            break
                        try:
                            data_json = json.loads(data_str)
                            if 'choices' in data_json and len(data_json['choices']) > 0:
                                delta = data_json['choices'][0].get('delta', {})
                                content = delta.get('content', '')
                                if content:
                                    yield content
                        except json.JSONDecodeError:
                            continue
        except Exception as e:
            logger.error(f"DeepSeek 流式 API 调用失败: {e}")
            raise


# 全局实例
deepseek_service = DeepSeekService()