"""
工具注册表 — 管理所有可用工具（内置 / HTTP / 代码段）。

提供统一的工具注册、查找和执行接口。
"""
from __future__ import annotations

import json
import logging
import traceback
from typing import Any, Callable, Dict, List, Optional

from app.models.tool import Tool
from sqlalchemy.orm import Session

logger = logging.getLogger(__name__)


# 代码工具的安全内置模块
_CODE_SAFE_GLOBALS = {
    "json": json,
    "dict": dict,
    "list": list,
    "str": str,
    "int": int,
    "float": float,
    "bool": bool,
    "len": len,
    "range": range,
    "enumerate": enumerate,
    "zip": zip,
    "map": map,
    "filter": filter,
    "sorted": sorted,
    "min": min,
    "max": max,
    "sum": sum,
    "abs": abs,
    "round": round,
    "isinstance": isinstance,
    "type": type,
    "True": True,
    "False": False,
    "None": None,
}


class ToolRegistry:
    """工具注册表 — 管理所有可用工具。"""

    def __init__(self):
        self._builtin_tools: Dict[str, Callable] = {}
        self._tool_schemas: Dict[str, Dict[str, Any]] = {}
        # 自定义工具配置（从 DB 加载的非 builtin 工具）
        self._custom_tool_configs: Dict[str, Dict[str, Any]] = {}

    # ─── 内置工具注册 ─────────────────────────────────────────

    def register_builtin_tool(self, name: str, func: Callable, schema: Dict[str, Any]):
        """
        注册内置工具。

        Args:
            name: 工具名称
            func: 工具函数（同步或异步）
            schema: OpenAI function calling 格式 schema
        """
        self._builtin_tools[name] = func
        self._tool_schemas[name] = schema
        logger.debug("注册内置工具: %s", name)

    def register_external_tool(self, name: str, description: str, parameters: dict, category: str = "plugin"):
        """注册外部/插件工具 schema（无实际执行函数，仅用于工作流编辑器展示）。"""
        schema = {
            "name": name,
            "description": description,
            "parameters": parameters,
        }
        self._tool_schemas[name] = schema
        self._custom_tool_configs[name] = {"category": category, "description": description}
        logger.debug("注册外部工具 schema: %s (category=%s)", name, category)

    # ─── 工具信息查询 ─────────────────────────────────────────

    def get_tool_schema(self, name: str) -> Optional[Dict[str, Any]]:
        return self._tool_schemas.get(name)

    def get_tool_function(self, name: str) -> Optional[Callable]:
        return self._builtin_tools.get(name)

    def get_all_tool_schemas(self) -> List[Dict[str, Any]]:
        return list(self._tool_schemas.values())

    def builtin_tool_count(self) -> int:
        return len(self._builtin_tools)

    def builtin_tool_names(self) -> List[str]:
        return sorted(self._builtin_tools.keys())

    def get_tools_by_names(self, tool_names: List[str]) -> List[Dict[str, Any]]:
        tools = []
        for name in tool_names:
            schema = self.get_tool_schema(name)
            if schema:
                tools.append(schema)
            else:
                logger.warning("工具 %s 未找到", name)
        return tools

    # ─── 从数据库加载自定义工具 ──────────────────────────────

    def load_tools_from_db(self, db: Session, tool_names: Optional[List[str]] = None):
        """
        从数据库加载工具定义。

        Args:
            db: 数据库会话
            tool_names: 指定名称列表；None 则加载所有公开工具
        """
        query = db.query(Tool).filter(Tool.is_public == True)
        if tool_names:
            query = query.filter(Tool.name.in_(tool_names))

        tools = query.all()
        count = 0
        for tool in tools:
            self._tool_schemas[tool.name] = tool.function_schema
            if tool.implementation_type == "builtin":
                if tool.name not in self._builtin_tools:
                    logger.warning("工具 %s 标记为 builtin 但未注册", tool.name)
            else:
                # 存储自定义工具配置
                config = tool.implementation_config or {}
                config["_type"] = tool.implementation_type
                config["_db_id"] = tool.id
                self._custom_tool_configs[tool.name] = config
                count += 1

        if count:
            logger.info("从数据库加载了 %d 个自定义工具", count)

    # ─── 工具执行 ─────────────────────────────────────────────

    async def execute_tool(self, name: str, args: Dict[str, Any]) -> str:
        """
        执行任意工具（内置 / HTTP / 代码段）。

        Args:
            name: 工具名称
            args: 参数字典

        Returns:
            结果字符串
        """
        # 1. 内置工具
        func = self._builtin_tools.get(name)
        if func:
            return await self._run_function(func, name, args)

        # 2. 自定义工具
        config = self._custom_tool_configs.get(name)
        if not config:
            return json.dumps({"error": f"工具 '{name}' 不存在"}, ensure_ascii=False)

        impl_type = config.get("_type", "")
        try:
            if impl_type == "http":
                return await self._execute_http_tool(name, config, args)
            elif impl_type == "code":
                return await self._execute_code_tool(name, config, args)
            elif impl_type == "workflow":
                return json.dumps({"error": "工作流工具暂不支持动态执行"},
                                  ensure_ascii=False)
            else:
                return json.dumps({"error": f"不支持的实现类型: {impl_type}"},
                                  ensure_ascii=False)
        except Exception as e:
            logger.error("工具 %s 执行失败: %s", name, e, exc_info=True)
            return json.dumps({"error": f"工具 '{name}' 执行失败: {e}"},
                              ensure_ascii=False)

    @staticmethod
    async def _run_function(func: Callable, name: str, args: Dict[str, Any]) -> str:
        """执行内置工具函数。"""
        import asyncio
        try:
            if asyncio.iscoroutinefunction(func):
                result = await func(**args)
            else:
                result = func(**args)
            if isinstance(result, (dict, list)):
                return json.dumps(result, ensure_ascii=False)
            return str(result)
        except Exception as e:
            logger.error("工具 '%s' 执行失败: %s", name, e, exc_info=True)
            return json.dumps({"error": f"工具 '{name}' 执行失败: {e}"},
                              ensure_ascii=False)

    # ─── HTTP 工具 ────────────────────────────────────────────

    async def _execute_http_tool(
        self, name: str, config: Dict[str, Any], args: Dict[str, Any]
    ) -> str:
        """
        执行 HTTP 工具。

        implementation_config 格式:
        {
            "url": "https://api.example.com/{path_param}",
            "method": "GET",
            "headers": {"Authorization": "Bearer xxx"},
            "body_template": {"key": "{param}"},   # 可选
            "timeout": 30
        }
        URL 和 body_template 中的 {param} 会被 args 替换。
        """
        import httpx

        url = config.get("url", "")
        method = (config.get("method") or "GET").upper()
        headers = config.get("headers") or {}
        body_template = config.get("body_template")
        timeout = config.get("timeout", 30)

        if not url:
            return json.dumps({"error": "HTTP 工具未配置 URL"}, ensure_ascii=False)

        # 模板替换：{param} → args["param"]
        def _fmt(template: str) -> str:
            try:
                return template.format(**args)
            except KeyError:
                return template

        url = _fmt(url)
        body: Any = None
        if body_template:
            body_str = json.dumps(body_template)
            body_str = _fmt(body_str)
            try:
                body = json.loads(body_str)
            except json.JSONDecodeError:
                body = body_str

        async with httpx.AsyncClient(timeout=timeout) as client:
            response = await client.request(method, url, headers=headers, json=body)
            text = response.text[:10000]  # 截断过长的响应

        result = {
            "status_code": response.status_code,
            "body": text,
        }
        return json.dumps(result, ensure_ascii=False)

    # ─── 代码工具 ─────────────────────────────────────────────

    async def _execute_code_tool(
        self, name: str, config: Dict[str, Any], args: Dict[str, Any]
    ) -> str:
        """
        执行代码工具。

        implementation_config 格式:
        {
            "source": "def run(args):\\n    return {'sum': args['a'] + args['b']}",
            "language": "python"
        }
        代码工具需定义一个 run(args) 函数作为入口。
        source 在沙箱环境中执行，不可访问文件系统/网络。
        """
        source = config.get("source", "")
        if not source:
            return json.dumps({"error": "代码工具未配置 source"}, ensure_ascii=False)

        # 编译代码，限制可访问的全局变量
        safe_globals = _CODE_SAFE_GLOBALS.copy()
        safe_globals["__builtins__"] = {}  # 禁用所有内置函数

        try:
            exec(source, safe_globals)
        except Exception as e:
            return json.dumps({
                "error": f"代码编译失败: {e}",
                "traceback": traceback.format_exc(),
            }, ensure_ascii=False)

        run_func = safe_globals.get("run")
        if not run_func or not callable(run_func):
            return json.dumps({
                "error": "代码工具必须定义一个 run(args) 函数"
            }, ensure_ascii=False)

        try:
            result = run_func(args)
            if isinstance(result, (dict, list)):
                return json.dumps(result, ensure_ascii=False)
            return str(result)
        except Exception as e:
            return json.dumps({
                "error": f"代码执行失败: {e}",
                "traceback": traceback.format_exc(),
            }, ensure_ascii=False)

    # ─── 测试工具（不保存，直接执行）─────────────────────────

    async def test_http_tool(
        self, url: str, method: str, headers: Dict[str, str],
        body: Optional[Dict[str, Any]], args: Dict[str, Any],
        timeout: int = 30,
    ) -> Dict[str, Any]:
        """测试 HTTP 工具配置（不保存到 DB）。"""
        import httpx

        def _fmt(template: str) -> str:
            try:
                return template.format(**args)
            except KeyError:
                return template

        url = _fmt(url)
        body_sent = None
        if body:
            body_str = json.dumps(body)
            body_str = _fmt(body_str)
            try:
                body_sent = json.loads(body_str)
            except json.JSONDecodeError:
                body_sent = body_str

        start = __import__("time").time()
        try:
            async with httpx.AsyncClient(timeout=timeout) as client:
                response = await client.request(method.upper(), url,
                                                headers=headers, json=body_sent)
            elapsed_ms = int((__import__("time").time() - start) * 1000)
            return {
                "success": True,
                "status_code": response.status_code,
                "elapsed_ms": elapsed_ms,
                "body": response.text[:10000],
            }
        except Exception as e:
            return {"success": False, "error": str(e)}

    async def test_code_tool(
        self, source: str, args: Dict[str, Any]
    ) -> Dict[str, Any]:
        """测试代码工具（不保存到 DB）。"""
        safe_globals = _CODE_SAFE_GLOBALS.copy()
        safe_globals["__builtins__"] = {}

        try:
            exec(source, safe_globals)
        except Exception as e:
            return {"success": False, "error": f"编译失败: {e}"}

        run_func = safe_globals.get("run")
        if not run_func:
            return {"success": False, "error": "代码须定义 run(args) 函数"}

        try:
            start = __import__("time").time()
            result = run_func(args)
            elapsed_ms = int((__import__("time").time() - start) * 1000)
            return {"success": True, "elapsed_ms": elapsed_ms, "result": result}
        except Exception as e:
            return {"success": False, "error": f"执行失败: {e}"}


# 全局单例
tool_registry = ToolRegistry()