import asyncio


async def search_file(
    keyword: str,
    directory: str = ".",
    file_pattern: str = "*",
    max_results: int = 20,
) -> str:
    """在指定目录下递归搜索包含关键字的文件内容。

    Args:
        keyword: 要搜索的关键字或正则表达式
        directory: 搜索的根目录，默认当前目录
        file_pattern: 文件名匹配模式，如 "*.py"
        max_results: 最大返回结果数

    Returns:
        匹配的文件名和行内容
    """
    from kilostar.utils.sandbox import validate_path, PathViolation

    try:
        directory = validate_path(directory, write=False)
    except PathViolation as e:
        return f"[Sandbox] {e}"

    max_results = min(max_results, 100)

    try:
        grep_args = [
            "grep", "-rn",
            f"--include={file_pattern}",
            "-m", str(max_results),
            "--", keyword, directory,
        ]
        proc = await asyncio.create_subprocess_exec(
            *grep_args,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )
        stdout, _ = await asyncio.wait_for(
            proc.communicate(), timeout=30
        )
        output = stdout.decode("utf-8", errors="replace").strip()
        if not output:
            return f"未找到包含 '{keyword}' 的匹配项"
        lines = output.split("\n")
        if len(lines) > max_results:
            output = "\n".join(lines[:max_results])
        return output
    except asyncio.TimeoutError:
        return "[Error] 搜索超时"
    except Exception as e:
        return f"[Error] 搜索失败: {e}"