# app/rag_initializer.py
from app.rag.tools import create_rag_tool
from app.rag.retriever import create_parent_hybrid_retriever
from app.model_services import get_embedding_service
from app.logger import info, warning
import sys

# 全局 RAG 工具
_rag_tool = None
_initialized = False


def get_rag_tool() -> callable:
    """获取全局 RAG 工具"""
    return _rag_tool


def is_initialized() -> bool:
    """检查是否已初始化"""
    return _initialized


async def init_rag_tool(local_llm_creator, force: bool = False):
    """
    初始化 RAG 工具（注册到模块级变量）

    Args:
        local_llm_creator: 返回 LLM 实例的函数
        force: 是否强制重新初始化

    Returns:
        RAG 工具（@tool 装饰函数）或 None
    """
    global _rag_tool, _initialized

    # 防止重复初始化
    if _initialized and not force:
        info("[RAG] 已初始化，跳过")
        return _rag_tool

    try:
        info("🔄 正在初始化 RAG 检索系统...")
        embeddings = get_embedding_service()
        retriever = create_parent_hybrid_retriever(
            collection_name="rag_documents",
            search_k=5,
            embeddings=embeddings
        )
        rewrite_llm = local_llm_creator()

        rag_tool = create_rag_tool(
            retriever=retriever,
            llm=rewrite_llm,
            num_queries=3,
            rerank_top_n=5
        )

        _rag_tool = rag_tool
        _initialized = True
        info(f"✅ RAG 检索工具初始化成功 (id={id(rag_tool)})")
        return rag_tool

    except Exception as e:
        warning(f"⚠️ RAG 检索工具初始化失败: {e}")
        return None


def reset():
    """重置（用于测试）"""
    global _rag_tool, _initialized
    _rag_tool = None
    _initialized = False