"""Install psutil on managed servers via SSH (system Python for watch probe)."""

from __future__ import annotations

import re

from server.application.server_batch_common import sudo_wrap
from server.domain.models import Server
from server.infrastructure.ssh.asyncssh_pool import exec_ssh_command

# pip --user first (no root); package managers and system pip via run_root (sudo when non-root).
PSUTIL_INSTALL_SHELL = r"""
run_root() {
  if [ "$(id -u)" -eq 0 ]; then
    "$@"
  else
    sudo "$@"
  fi
}

verify_psutil() {
  for py in python3 python3.12 python3.11 python3.10; do
    if command -v "$py" >/dev/null 2>&1 && "$py" -c "import psutil" 2>/dev/null; then
      echo psutil_ok
      exit 0
    fi
  done
  return 1
}

verify_psutil && exit 0

for py in python3 python3.12 python3.11 python3.10; do
  command -v "$py" >/dev/null 2>&1 || continue
  if "$py" -m pip install --user -q psutil 2>/dev/null; then
    verify_psutil && exit 0
  fi
done

if command -v apt-get >/dev/null 2>&1; then
  if run_root apt-get update -qq \
    && run_root env DEBIAN_FRONTEND=noninteractive apt-get install -y -qq python3-psutil; then
    verify_psutil && exit 0
  fi
fi
if command -v dnf >/dev/null 2>&1; then
  if run_root dnf install -y -q python3-psutil; then
    verify_psutil && exit 0
  fi
fi
if command -v yum >/dev/null 2>&1; then
  if run_root yum install -y -q python3-psutil; then
    verify_psutil && exit 0
  fi
fi

for py in python3 python3.12 python3.11 python3.10; do
  command -v "$py" >/dev/null 2>&1 || continue
  if run_root "$py" -m pip install -q psutil 2>/dev/null; then
    verify_psutil && exit 0
  fi
done

echo "ERROR: psutil install failed — pip/apt unavailable or permission denied" >&2
exit 1
"""

_APT_PERM_RE = re.compile(
    r"lock file|permission denied|unable to lock|not allowed to execute",
    re.I,
)


def _psutil_install_error_zh(stderr: str, stdout: str) -> str:
    text = f"{stderr}\n{stdout}"
    if _APT_PERM_RE.search(text):
        return (
            "安装 psutil 需要 root 或免密 sudo（apt/pip）。"
            "请改用 root SSH，或在子机配置免密 sudo 后重试；也可手动执行："
            "sudo apt-get install -y python3-psutil"
        )
    if "sudo requires a password" in text.lower():
        return "sudo 需要密码，请配置免密 sudo 或使用 root SSH 登录"
    line = ""
    for chunk in (stderr, stdout):
        for raw in reversed(chunk.splitlines()):
            raw = raw.strip()
            if raw and not raw.startswith("W:"):
                line = raw[:300]
                break
        if line:
            break
    return line or "psutil 安装失败"


def build_psutil_install_cmd(*, ssh_user: str) -> str:
    return sudo_wrap(PSUTIL_INSTALL_SHELL.strip(), ssh_user)


async def install_psutil_via_ssh(server: Server, *, timeout: int = 120) -> dict[str, str | int | bool]:
    """Run remote install; returns success, message, stdout/stderr."""
    ssh_user = (server.username or "root").strip()
    cmd = build_psutil_install_cmd(ssh_user=ssh_user)
    result = await exec_ssh_command(server, cmd, timeout=timeout)
    stdout = (result.get("stdout") or "").strip()
    stderr = (result.get("stderr") or "").strip()
    raw_exit = result.get("exit_code")
    exit_code = int(raw_exit) if raw_exit is not None else 1
    if exit_code == 0 and "psutil_ok" in stdout:
        return {
            "success": True,
            "exit_code": 0,
            "stdout": stdout[:2000],
            "stderr": stderr[:500],
            "message": "psutil 已就绪",
        }
    return {
        "success": False,
        "exit_code": exit_code,
        "stdout": stdout[:2000],
        "stderr": stderr[:500],
        "message": _psutil_install_error_zh(stderr, stdout),
    }