#  Copyright 2026 zhaoxi826
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

from pydantic_ai import RunContext
from pretor.plugin.tool_plugin.base_tool import BaseToolData
import os


class FileReaderData(BaseToolData):
    """FileReaderData 核心组件类。
    这是一个领域数据模型或功能封装类，承载了 FileReaderData 相关的内聚属性定义与状态维护。它的存在隔离了局部的业务复杂性，并对外提供了类型安全的访问接口。"""

    is_system: bool = True
    name: str = "file_reader"
    description: str = "读取本地文件的内容"


def file_reader(ctx: RunContext, filepath: str) -> str:
    """读取本地文件内容的工具。

    Args:
        filepath: 目标文件的绝对路径或相对路径。

    Returns:
        如果文件存在并可读，返回文件内容；否则返回错误信息。
    """
    if not os.path.exists(filepath):
        return f"Error: 文件 {filepath} 不存在。"
    if not os.path.isfile(filepath):
        return f"Error: {filepath} 不是一个文件。"

    try:
        with open(filepath, "r", encoding="utf-8") as f:
            content = f.read()
        return content
    except Exception as e:
        return f"Error: 读取文件失败，原因：{str(e)}"