"""
上下文管理器
管理对话历史和上下文
"""
from typing import List, Dict, Optional
from app.services.db_service import db_service
from app.utils.logger import logger


class ContextManager:
    """上下文管理器"""

    def __init__(self, max_history: int = 10):
        """
        初始化上下文管理器

        Args:
            max_history: 最大历史消息数
        """
        self.max_history = max_history

    def get_context(self, session_id: str) -> List[Dict[str, str]]:
        """
        获取对话上下文

        Args:
            session_id: 会话ID

        Returns:
            消息列表
        """
        messages = db_service.get_conversation_history(session_id, limit=self.max_history)

        context = []
        for msg in messages:
            context.append({
                "role": msg.role,
                "content": msg.content
            })

        return context

    def add_message(
        self,
        session_id: str,
        role: str,
        content: str,
        metadata: Optional[dict] = None
    ):
        """
        添加消息到上下文

        Args:
            session_id: 会话ID
            role: 角色（user/assistant）
            content: 消息内容
            metadata: 元数据
        """
        db_service.add_message(session_id, role, content, metadata)
        logger.info(f"添加消息到上下文: {session_id}, {role}")

    def clear_context(self, session_id: str):
        """
        清除上下文（暂不实现删除，保留历史）

        Args:
            session_id: 会话ID
        """
        logger.info(f"清除上下文请求: {session_id}")
        # 实际不删除，只是标记
        pass

    def format_context_for_llm(self, session_id: str) -> str:
        """
        格式化上下文供LLM使用

        Args:
            session_id: 会话ID

        Returns:
            格式化的上下文字符串
        """
        context = self.get_context(session_id)

        if not context:
            return ""

        formatted = []
        for msg in context:
            role = "用户" if msg["role"] == "user" else "助手"
            formatted.append(f"{role}: {msg['content']}")

        return "\n".join(formatted)