"""
Agent 工具集 - 知识库 & 图谱相关

这些工具在 LangChain ToolNode 中被调用。
由于 LangChain 工具系统是同步的，内部用 run_in_executor 处理 async 逻辑。
"""

from langchain_core.tools import tool
from concurrent.futures import ThreadPoolExecutor
from app.database import async_session
from app.agents.context import get_current_user
import asyncio

_executor = ThreadPoolExecutor(max_workers=4)


def _run_async(coro, timeout: int = 30):
    """在同步上下文中运行 async 代码"""
    try:
        loop = asyncio.get_running_loop()
        future = loop.run_in_executor(_executor, lambda: asyncio.run(coro))
        return future.result(timeout=timeout)
    except RuntimeError:
        return asyncio.run(coro)


@tool
def search_knowledge(query: str, top_k: int = 5) -> str:
    """
    搜索用户的私人知识库。根据查询返回最相关的文档片段，支持语义检索。

    Args:
        query: 搜索查询
        top_k: 返回结果数量，默认5条

    Returns:
        包含相关文档片段和来源信息的格式化文本
    """
    from app.services.knowledge_service import KnowledgeService
    uid = get_current_user()

    async def _search():
        async with async_session() as db:
            service = KnowledgeService(db, user_id=uid)
            results = await service.retrieve(query, user_id=uid, top_k=top_k)
            if not results:
                return "未找到相关知识。知识库可能为空，或尝试用其他关键词搜索。"
            texts = []
            for i, r in enumerate(results, 1):
                prev = f"\n上一段: {r.prev_chunk[:100]}..." if r.prev_chunk else ""
                next_ = f"\n下一段: {r.next_chunk[:100]}..." if r.next_chunk else ""
                texts.append(
                    f"[{i}] 来源: {r.document_title}\n"
                    f"相关度: {r.score:.2f}\n"
                    f"{prev}{next_}\n"
                    f"内容: {r.content[:300]}{'...' if len(r.content) > 300 else ''}"
                )
            return "\n\n---\n\n".join(texts)

    try:
        return _run_async(_search(), timeout=30)
    except Exception as e:
        return f"知识检索失败: {str(e)}"


@tool
def get_knowledge_graph_context(entity: str | None = None) -> str:
    """
    获取用户知识图谱的上下文信息。

    Args:
        entity: 可选，指定要查询的实体名称。如果为空则返回整体图谱摘要。

    Returns:
        知识图谱节点和关系的描述
    """
    from app.services.graph_service import GraphService
    uid = get_current_user()

    async def _get():
        async with async_session() as db:
            service = GraphService(db)
            if entity:
                return await service.get_entity_context(entity, uid)
            return await service.get_graph_summary(uid)

    try:
        return _run_async(_get(), timeout=30)
    except Exception as e:
        return f"图谱查询失败: {str(e)}"


@tool
def build_knowledge_graph(document_ids: list[str] | None = None) -> str:
    """
    从文档构建/更新知识图谱。

    Args:
        document_ids: 可选，指定要处理的文档ID列表。如果为空则处理所有文档。

    Returns:
        构建结果摘要
    """
    from app.services.graph_service import GraphService
    uid = get_current_user()

    async def _build():
        async with async_session() as db:
            service = GraphService(db)
            await service.build_graph(user_id=uid, document_ids=document_ids)
            return "知识图谱构建完成"

    try:
        return _run_async(_build(), timeout=120)
    except Exception as e:
        return f"图谱构建失败: {str(e)}"


@tool
def hybrid_search(query: str, top_k: int = 5) -> str:
    """
    混合搜索，结合向量语义检索和关键词匹配，返回最相关结果。

    Args:
        query: 搜索查询
        top_k: 返回结果数量，默认5条

    Returns:
        混合检索结果
    """
    from app.services.knowledge_service import KnowledgeService
    uid = get_current_user()

    async def _search():
        async with async_session() as db:
            service = KnowledgeService(db, user_id=uid)
            results = await service.hybrid_search(query, user_id=uid, top_k=top_k)
            if not results:
                return "未找到相关知识。"
            texts = []
            for i, r in enumerate(results, 1):
                texts.append(
                    f"[{i}] {r.document_title} (相关度: {r.score:.2f})\n"
                    f"{r.content[:200]}{'...' if len(r.content) > 200 else ''}"
                )
            return "\n\n---\n\n".join(texts)

    try:
        return _run_async(_search(), timeout=30)
    except Exception as e:
        return f"混合搜索失败: {str(e)}"


__all__ = [
    "search_knowledge",
    "get_knowledge_graph_context",
    "build_knowledge_graph",
    "hybrid_search",
]