"""Shell 执行: subprocess 跑命令,有黑名单拦明显危险操作。"""
from __future__ import annotations

import os
import re
import shlex
import subprocess
import sys

from .base import Tool


class ShellTool(Tool):
    name = "shell"
    description = (
        "Execute a shell command and return stdout/stderr/exit_code. "
        "Default 60s timeout. Working directory is the agent's base dir."
    )
    parameters = {
        "type": "object",
        "properties": {
            "command": {"type": "string"},
            "timeout": {"type": "integer", "default": 60, "description": "Seconds before kill"},
        },
        "required": ["command"],
    }

    BLOCKED_PATTERNS = (
        "rm -rf /",
        "rm -rf ~",
        "rm -rf $HOME",
        ":(){ :|:& };:",
        "mkfs",
        "dd if=/dev/zero",
        "> /dev/sda",
        "format c:",
    )

    # Windows cmd 不识别 unix flag,常见踩坑命令直接在工具层兜底
    _MKDIR_P_RE = re.compile(r"^\s*mkdir\s+-p\s+(.+?)\s*$")

    def _windows_compat(self, command: str) -> tuple[str, str | None]:
        """Windows cmd 下把 unix 风格命令转译为可执行形式。

        返回 (转译后命令, 转译说明 or None)。无需转译时第二项为 None。
        """
        if sys.platform != "win32":
            return command, None
        m = self._MKDIR_P_RE.match(command)
        if m:
            paths = shlex.split(m.group(1), posix=False)
            for p in paths:
                p = p.strip('"').strip("'")
                os.makedirs(p, exist_ok=True)
            return (
                "echo [shell-tool] mkdir -p handled in-process (Windows cmd doesn't support -p)",
                f"intercepted `mkdir -p`: created {paths} via os.makedirs",
            )
        return command, None

    def execute(self, command: str, timeout: int = 60) -> str:
        normalized = command.lower()
        for pat in self.BLOCKED_PATTERNS:
            if pat in normalized:
                return f"[Error] blocked dangerous command pattern: {pat!r}"

        command, note = self._windows_compat(command)

        try:
            result = subprocess.run(
                command,
                shell=True,
                cwd=str(self.base_dir),
                capture_output=True,
                timeout=timeout,
                text=True,
                encoding="utf-8",
                errors="replace",
            )
        except subprocess.TimeoutExpired:
            return f"[Error] command timed out after {timeout}s"
        except FileNotFoundError as e:
            return f"[Error] {e}"

        if note:
            result.stdout = (result.stdout or "") + f"\n[note] {note}"

        parts = []
        if result.stdout:
            parts.append(f"[stdout]\n{result.stdout.rstrip()}")
        if result.stderr:
            parts.append(f"[stderr]\n{result.stderr.rstrip()}")
        parts.append(f"[exit {result.returncode}]")
        return "\n".join(parts)