import json
import aiohttp
import config

async def chat_with_ai(message: str, history: list):
    """
    与 AI 模型进行流式对话。
    """
    system_prompt = """你是一位精通自动控制原理的专家教授。请用清晰、准确、专业的中文来回答有关自动控制课程内容的问题。

重要规则：
1. 当需要表达数学公式时，必须使用 LaTeX 格式
2. 行内公式使用 $公式$ 或 \\(公式\\)
3. 独立公式使用 $$公式$$ 或 \\[公式\\]
4. 例如：传递函数可以写成 $G(s) = \\frac{K}{s(s+1)}$
5. 二阶系统标准形式：$$G(s) = \\frac{\\omega_n^2}{s^2 + 2\\zeta\\omega_n s + \\omega_n^2}$$

请在适当的时候使用公式和示例来辅助解释。"""
    
    if not config.API_KEY or config.API_KEY.strip() == "":
        history.append({"role": "assistant", "content": "❌ 错误：API_KEY 未配置。请在 config.py 文件中配置 API_KEY。"})
        yield history
        return
    
    history.append({"role": "user", "content": message})
    
    # 添加临时的 "正在思考" 消息
    history.append({"role": "assistant", "content": "正在思考..."})
    yield history

    bot_response = ""
    
    try:
        if config.API_TYPE == "deepseek":
            api_url = f"{config.API_BASE_URL}/chat/completions"
            messages_for_api = [{"role": "system", "content": system_prompt}] + history[:-1]
            
            payload = {
                "model": config.API_MODEL,
                "messages": messages_for_api,
                "stream": True, "temperature": 0.7, "max_tokens": 2048
            }
            headers = {
                "Content-Type": "application/json",
                "Authorization": f"Bearer {config.API_KEY}"
            }
            
            async with aiohttp.ClientSession() as session:
                async with session.post(api_url, json=payload, headers=headers, timeout=aiohttp.ClientTimeout(total=60)) as response:
                    if response.status == 200:
                        async for line in response.content:
                            line = line.decode('utf-8').strip()
                            if not line or line == "data: [DONE]": continue
                            if line.startswith("data: "): line = line[6:]
                            try:
                                data = json.loads(line)
                                if "choices" in data and len(data["choices"]) > 0:
                                    delta = data["choices"][0].get("delta", {})
                                    content = delta.get("content", "")
                                    if content:
                                        bot_response += content
                                        history[-1]["content"] = bot_response
                                        yield history
                            except json.JSONDecodeError:
                                pass
                        
                        if not bot_response:
                            history[-1]["content"] = "⚠️ API 返回了空响应，请稍后重试。"
                            yield history
                    else:
                        error_text = await response.text()
                        history[-1]["content"] = f"❌ API请求出错 (状态码: {response.status}):\n{error_text}"
                        yield history
        else:
            history[-1]["content"] = f"❌ 不支持的 API 类型: {config.API_TYPE}"
            yield history

    except aiohttp.ClientError as e:
        history[-1]["content"] = f"❌ 网络连接错误: {e}"
        yield history
    except Exception as e:
        history[-1]["content"] = f"❌ 发生错误: {type(e).__name__}: {e}"
        yield history