import asyncio
import time
import hashlib
from typing import Dict, Optional
from core.agent import create_langchain_agent
from utils.logger import chat_logger


class AgentManager:

    def __init__(self):
        self._local_agent_cache = {}  # 仅缓存agent配置，不缓存实例
        self._is_shutdown = False

    async def initialize(self):
        """异步初始化管理器"""
        self._is_shutdown = False
        chat_logger.info("🔧🔧🔧🔧 Agent管理器初始化完成")

    async def shutdown(self):
        """异步关闭管理器"""
        self._is_shutdown = True
        self._local_agent_cache.clear()
        chat_logger.info("🧹🧹🧹🧹 Agent管理器已关闭")

    def _get_agent_config_key(
        self, thread_id: str, username: str, backend_url: str, token: str
    ) -> str:
        """生成agent配置的缓存key"""
        key_data = f"{thread_id}:{username}:{backend_url}:{token}"
        return hashlib.md5(key_data.encode()).hexdigest()

    def _get_user_identifier(self, username: str, token: str) -> str:
        """生成用户标识符"""
        if not username or username == "default":
            username_part = "anonymous"
        else:
            username_part = username

        if token and len(token) >= 8:
            token_part = token[:8]
        else:
            token_part = "notoken"

        return f"{username_part}_{token_part}"

    async def get_agent_instance(
        self, thread_id: str, username: str, backend_url: str, token: str
    ):
        if self._is_shutdown:
            raise RuntimeError("Agent管理器已关闭")

        clean_username = username or "anonymous"
        clean_backend = backend_url or ""
        clean_token = token or ""

        user_id = self._get_user_identifier(clean_username, clean_token)
        config_key = self._get_agent_config_key(
            thread_id, clean_username, clean_backend, clean_token
        )

        # 检查本地配置缓存
        current_time = time.time()
        if config_key in self._local_agent_cache:
            agent_instance, timestamp = self._local_agent_cache[config_key]
            if current_time - timestamp <= 300:  # 5分钟本地缓存
                chat_logger.info(f"使用本地缓存的agent配置: 用户={user_id}")
                return agent_instance

        chat_logger.info(f"创建新的agent实例: 用户={user_id}")
        agent_instance = await self._create_agent_async(
            backend_url=clean_backend,
            token=clean_token,
            username=clean_username,
            thread_id=thread_id,
        )

        # 缓存agent配置到本地
        self._local_agent_cache[config_key] = (agent_instance, current_time)
        chat_logger.info(f"Agent配置已缓存: 用户={user_id}")

        return agent_instance

    async def _create_agent_async(
        self, backend_url: str, token: str, username: str, thread_id: str
    ):
        """创建agent实例"""

        def sync_create_agent():
            return create_langchain_agent(
                backend_url=backend_url,
                token=token,
                username=username,
                thread_id=thread_id,
            )

        loop = asyncio.get_event_loop()
        return await loop.run_in_executor(None, sync_create_agent)

    async def clear_user_agent(
        self, thread_id: str, username: str, backend_url: str, token: str
    ):
        """清除特定用户的agent配置缓存"""
        config_key = self._get_agent_config_key(thread_id, username, backend_url, token)

        # 清除本地缓存
        if config_key in self._local_agent_cache:
            del self._local_agent_cache[config_key]

        user_id = self._get_user_identifier(username, token)
        chat_logger.info(f"已清除用户Agent配置缓存: {user_id}")

    async def get_cache_status(self):
        """获取缓存状态"""
        if self._is_shutdown:
            return {"status": "shutdown", "cache_size": 0}

        return {
            "local_config_cache_size": len(self._local_agent_cache),
            "status": "active",
            "message": "",
        }

    async def clear_cache(self):
        """清空本地配置缓存"""
        local_count = len(self._local_agent_cache)
        self._local_agent_cache.clear()
        chat_logger.info(f"清空本地配置缓存: {local_count}个配置")
        return local_count


# 全局实例
agent_manager = AgentManager()