import os
from typing import Optional, Type

from pydantic import BaseModel, Field

from langchain.callbacks.manager import CallbackManagerForToolRun
from langchain.tools.base import BaseTool
from langchain.tools.file_management.utils import (
    INVALID_PATH_TEMPLATE,
    BaseFileToolMixin,
    FileValidationError,
)


class DirectoryListingInput(BaseModel):
    """Input for ListDirectoryTool."""

    dir_path: str = Field(default=".", description="Subdirectory to list.")


class ListDirectoryTool(BaseFileToolMixin, BaseTool):
    """Tool that lists files and directories in a specified folder."""

    name: str = "list_directory"
    args_schema: Type[BaseModel] = DirectoryListingInput
    description: str = "List files and directories in a specified folder"

    def _run(
        self,
        dir_path: str = ".",
        run_manager: Optional[CallbackManagerForToolRun] = None,
    ) -> str:
        try:
            dir_path_ = self.get_relative_path(dir_path)
        except FileValidationError:
            return INVALID_PATH_TEMPLATE.format(arg_name="dir_path", value=dir_path)
        try:
            entries = os.listdir(dir_path_)
            if entries:
                return "\n".join(entries)
            else:
                return f"No files found in directory {dir_path}"
        except Exception as e:
            return "Error: " + str(e)

    # TODO: Add aiofiles method
