auto-update Automatic security updates

#!/usr/bin/env bash
# Served by xyz.sh/auto-update
# Human-readable page: https://xyz.sh/auto-update
# This file is the common library followed by the script body.
# No telemetry is added by xyz.sh.
# =============================================================================
# xyz.sh common library
# Shared helpers for every script served by xyz.sh.
#
# Promises:
#   - No telemetry, analytics, or background "phone-home" calls
#   - No hidden installs or config changes beyond what the script announces
#   - Official upstream URLs are printed before any remote code is executed
#   - Destructive or system-changing steps ask for confirmation (or YES=1 / -y)
# =============================================================================

if [[ -n "${XYZ_COMMON_LOADED:-}" ]]; then
  # When sourced a second time, return. When executed as a file, return fails.
  # shellcheck disable=SC2317
  return 0 2>/dev/null || true
fi
# shellcheck disable=SC2034
XYZ_COMMON_LOADED=1

set -euo pipefail

XYZ_VERSION="1.3.0"
XYZ_BASE="${XYZ_BASE:-https://xyz.sh}"
XYZ_NAME="${XYZ_NAME:-unknown}"

# --- language ---------------------------------------------------------------
# Override with XYZ_LANG=zh or XYZ_LANG=en.
if [[ -z "${XYZ_LANG:-}" ]]; then
  case "${LC_ALL:-${LC_MESSAGES:-${LANG:-}}}" in
    zh*|ZH*|cmn*|CMN*) XYZ_LANG="zh" ;;
    *) XYZ_LANG="en" ;;
  esac
fi

xyz_t() {
  # xyz_t "English text" "中文文本"
  if [[ "${XYZ_LANG}" == "zh" ]]; then
    printf '%s' "${2:-$1}"
  else
    printf '%s' "$1"
  fi
}

# --- colors (TTY only) ------------------------------------------------------
# XYZ_COLOR=always|never|auto (default auto: TTY and no NO_COLOR); --no-color.
_xyz_color=0
case "${XYZ_COLOR:-auto}" in
  always) _xyz_color=1 ;;
  never) _xyz_color=0 ;;
  *) [[ -t 1 && -z "${NO_COLOR:-}" ]] && _xyz_color=1 ;;
esac
[[ "${XYZ_NO_COLOR:-0}" == "1" ]] && _xyz_color=0
if [[ "${_xyz_color}" == "1" ]]; then
  XYZ_C_RESET=$'\033[0m'
  XYZ_C_BOLD=$'\033[1m'
  XYZ_C_DIM=$'\033[2m'
  XYZ_C_RED=$'\033[31m'
  XYZ_C_GREEN=$'\033[32m'
  XYZ_C_YELLOW=$'\033[33m'
  XYZ_C_CYAN=$'\033[36m'
else
  XYZ_C_RESET=""
  XYZ_C_BOLD=""
  XYZ_C_DIM=""
  XYZ_C_RED=""
  XYZ_C_GREEN=""
  XYZ_C_YELLOW=""
  XYZ_C_CYAN=""
fi

xyz_info()  { printf '%s[INFO]%s %s\n'  "${XYZ_C_GREEN}"  "${XYZ_C_RESET}" "$*"; }
xyz_warn()  { printf '%s[WARN]%s %s\n'  "${XYZ_C_YELLOW}" "${XYZ_C_RESET}" "$*" >&2; }
xyz_error() { printf '%s[ERROR]%s %s\n' "${XYZ_C_RED}"    "${XYZ_C_RESET}" "$*" >&2; }
xyz_step()  { printf '%s==>%s %s\n'     "${XYZ_C_CYAN}"   "${XYZ_C_RESET}" "$*"; }

# --- args / init ------------------------------------------------------------
XYZ_ARGS=()
XYZ_YES=0
XYZ_DRY_RUN=0

xyz_parse_global_args() {
  local filtered=()
  local arg
  for arg in "$@"; do
    case "${arg}" in
      -y|--yes)
        XYZ_YES=1
        ;;
      --lang=zh|zh)
        XYZ_LANG="zh"
        ;;
      --lang=en|en)
        XYZ_LANG="en"
        ;;
      --dry-run)
        XYZ_DRY_RUN=1
        ;;
      --no-color)
        XYZ_NO_COLOR=1
        XYZ_C_RESET=""; XYZ_C_BOLD=""; XYZ_C_DIM=""; XYZ_C_RED=""
        XYZ_C_GREEN=""; XYZ_C_YELLOW=""; XYZ_C_CYAN=""
        ;;
      --help|-h)
        XYZ_HELP=1
        filtered+=("${arg}")
        ;;
      *)
        filtered+=("${arg}")
        ;;
    esac
  done
  XYZ_ARGS=("${filtered[@]+"${filtered[@]}"}")
  if [[ "${YES:-}" =~ ^(1|yes|true|YES)$ || "${XYZ_ASSUME_YES:-}" == "1" ]]; then
    XYZ_YES=1
  fi
  # Exported so individual scripts can read flags set here.
  export XYZ_ARGS XYZ_YES XYZ_LANG XYZ_HELP="${XYZ_HELP:-}" XYZ_DRY_RUN="${XYZ_DRY_RUN:-0}"
  export XYZ_NO_COLOR="${XYZ_NO_COLOR:-0}"
  if declare -F xyz_ui_init >/dev/null; then xyz_ui_init; fi
}

xyz_banner() {
  local title="${XYZ_TITLE:-$XYZ_NAME}"
  printf '\n%s%sxyz.sh/%s%s  v%s\n' "${XYZ_C_BOLD}" "${XYZ_C_CYAN}" "${XYZ_NAME}" "${XYZ_C_RESET}" "${XYZ_VERSION}"
  printf '%s\n' "${XYZ_C_DIM}----------------------------------------${XYZ_C_RESET}"
  printf '  %s: %s/%s\n' "$(xyz_t "Page" "页面")" "${XYZ_BASE}" "${XYZ_NAME}"
  printf '  %s: %s/%s.sh\n' "$(xyz_t "Raw" "源码")" "${XYZ_BASE}" "${XYZ_NAME}"
  if [[ -n "${XYZ_UPSTREAM:-}" ]]; then
    printf '  %s: %s\n' "$(xyz_t "Upstream" "上游来源")" "${XYZ_UPSTREAM}"
  fi
  printf '  %s\n' "$(xyz_t "No telemetry, no hidden actions." "无遥测、无隐藏操作。")"
  printf '%s\n\n' "${XYZ_C_DIM}----------------------------------------${XYZ_C_RESET}"
  if [[ -n "${title}" && "${title}" != "${XYZ_NAME}" ]]; then
    xyz_step "${title}"
  fi
}

xyz_init() {
  xyz_parse_global_args "$@"
  xyz_detect_os
  xyz_banner
}

# --- root / OS --------------------------------------------------------------
xyz_is_root() {
  [[ "${EUID:-$(id -u)}" -eq 0 ]]
}

xyz_require_root() {
  if ! xyz_is_root; then
    xyz_error "$(xyz_t \
      "This script must be run as root. Try: sudo bash" \
      "请使用 root 运行。可尝试：sudo bash")"
    exit 1
  fi
}

xyz_prefer_root() {
  if ! xyz_is_root; then
    xyz_warn "$(xyz_t \
      "Not running as root; some information or tests may be limited." \
      "当前不是 root，部分信息或测试可能不完整。")"
  fi
}

XYZ_OS_ID=""
XYZ_OS_LIKE=""
XYZ_OS_VERSION=""
XYZ_OS_FAMILY=""   # debian | rhel | unknown
XYZ_OS_PRETTY=""

xyz_detect_os() {
  XYZ_OS_ID=""
  XYZ_OS_LIKE=""
  XYZ_OS_VERSION=""
  XYZ_OS_FAMILY="unknown"
  XYZ_OS_PRETTY="unknown"
  if [[ -r /etc/os-release ]]; then
    # shellcheck disable=SC1091
    . /etc/os-release
    XYZ_OS_ID="${ID:-}"
    XYZ_OS_LIKE="${ID_LIKE:-}"
    XYZ_OS_VERSION="${VERSION_ID:-}"
    XYZ_OS_PRETTY="${PRETTY_NAME:-$XYZ_OS_ID}"
    export XYZ_OS_ID XYZ_OS_LIKE XYZ_OS_VERSION XYZ_OS_FAMILY XYZ_OS_PRETTY
  fi
  case "${XYZ_OS_ID}" in
    debian|ubuntu)
      XYZ_OS_FAMILY="debian"
      ;;
    centos|rhel|rocky|almalinux|alma|fedora)
      XYZ_OS_FAMILY="rhel"
      ;;
    *)
      case " ${XYZ_OS_ID} ${XYZ_OS_LIKE} " in
        *debian*|*ubuntu*) XYZ_OS_FAMILY="debian" ;;
        *rhel*|*centos*|*fedora*|*rocky*|*alma*) XYZ_OS_FAMILY="rhel" ;;
        *) : ;;
      esac
      ;;
  esac
}

xyz_os_supported() {
  case "${XYZ_OS_ID}" in
    debian|ubuntu|centos|rocky|almalinux) return 0 ;;
    *) : ;;
  esac
  case " ${XYZ_OS_LIKE} " in
    *debian*|*ubuntu*|*rhel*|*centos*|*rocky*|*alma*) return 0 ;;
    *) : ;;
  esac
  return 1
}

xyz_require_supported_os() {
  xyz_detect_os
  if ! xyz_os_supported; then
    xyz_warn "$(xyz_t \
      "Unrecognized distribution: ${XYZ_OS_ID:-unknown} (${XYZ_OS_PRETTY}). Officially supported: Debian, Ubuntu, CentOS, Rocky, AlmaLinux." \
      "未能识别的发行版：${XYZ_OS_ID:-unknown}（${XYZ_OS_PRETTY}）。官方支持：Debian、Ubuntu、CentOS、Rocky、AlmaLinux。")"
    if ! xyz_confirm "$(xyz_t "Continue anyway?" "仍然继续？")"; then
      exit 1
    fi
  else
    xyz_info "$(xyz_t "Detected OS:" "检测到系统：") ${XYZ_OS_PRETTY} (${XYZ_OS_FAMILY})"
  fi
}

# --- packages / commands ----------------------------------------------------
xyz_need_cmd() {
  command -v "$1" >/dev/null 2>&1
}

xyz_pkg_install() {
  xyz_detect_os
  if (( $# == 0 )); then
    return 0
  fi
  case "${XYZ_OS_FAMILY}" in
    debian)
      export DEBIAN_FRONTEND=noninteractive
      apt-get update -y || xyz_warn "$(xyz_t "apt-get update reported errors (a repository may be unreachable); trying to install anyway." "apt-get update 报错（可能有软件源无法访问），仍尝试安装。")"
      apt-get install -y --no-install-recommends "$@"
      ;;
    rhel)
      if xyz_need_cmd dnf; then
        dnf install -y "$@"
      elif xyz_need_cmd yum; then
        yum install -y "$@"
      else
        xyz_error "$(xyz_t "Neither dnf nor yum is available." "找不到 dnf 或 yum。")"
        exit 1
      fi
      ;;
    *)
      xyz_error "$(xyz_t "Cannot install packages on this OS automatically." "无法在此系统上自动安装软件包。")"
      exit 1
      ;;
  esac
}

xyz_ensure_cmds() {
  local pkg
  local missing=()
  for pkg in "$@"; do
    if ! xyz_need_cmd "${pkg}"; then
      missing+=("${pkg}")
    fi
  done
  if ((${#missing[@]} > 0)); then
    xyz_info "$(xyz_t "Installing missing commands:" "正在安装缺失命令：") ${missing[*]}"
    xyz_pkg_install "${missing[@]}"
  fi
}

# --- confirmation (safe with curl | bash) -----------------------------------
# A readable /dev/tty node is not enough: in containers or curl|bash without a
# controlling terminal, open() fails with ENXIO ("No such device or address").
# [[ -r /dev/tty ]] is true in that case and must not be used as the check.
xyz_open_tty() {
  # Opens /dev/tty into XYZ_TTY_FD if it is a real terminal. Caller must close.
  local fd
  XYZ_TTY_FD=""
  # Brace group so a failed open cannot leak "No such device or address".
  if { exec {fd}<>/dev/tty; } 2>/dev/null && [[ -t "${fd}" ]]; then
    XYZ_TTY_FD="${fd}"
    return 0
  fi
  if [[ -n "${fd:-}" ]]; then
    exec {fd}>&- 2>/dev/null || true
  fi
  return 1
}

xyz_close_tty() {
  if [[ -n "${XYZ_TTY_FD:-}" ]]; then
    exec {XYZ_TTY_FD}>&- 2>/dev/null || true
    XYZ_TTY_FD=""
  fi
}

xyz_confirm() {
  local prompt="$1"
  if [[ "${XYZ_YES}" == "1" ]]; then
    xyz_info "$(xyz_t "Auto-confirmed (-y / YES=1):" "已自动确认（-y / YES=1）：") ${prompt}"
    return 0
  fi
  local reply=""
  if xyz_open_tty; then
    printf '%s [y/N] ' "${prompt}" >&"${XYZ_TTY_FD}"
    # shellcheck disable=SC2162
    read -r reply <&"${XYZ_TTY_FD}" || true
    xyz_close_tty
  else
    xyz_warn "$(xyz_t \
      "No TTY available for confirmation. Re-run with -y or YES=1 if you accept." \
      "没有可用的终端来确认。若你已了解并同意，请加 -y 或 YES=1 重试。")"
    return 1
  fi
  case "${reply}" in
    y|Y|yes|YES|Yes) return 0 ;;
    *) return 1 ;;
  esac
}

# --- download helpers -------------------------------------------------------
# Create the temp dir in the main shell. xyz_tmpdir is usually called inside
# $(...), a subshell, so creating it (and its EXIT trap) there would delete the
# directory as soon as the subshell returned.
xyz_init_tmpdir() {
  if [[ -z "${XYZ_TMPDIR:-}" || ! -d "${XYZ_TMPDIR}" ]]; then
    XYZ_TMPDIR="$(mktemp -d "${TMPDIR:-/tmp}/xyzsh.XXXXXX")"
    # shellcheck disable=SC2064
    trap "rm -rf '${XYZ_TMPDIR}'" EXIT
  fi
}

xyz_tmpdir() {
  if [[ -z "${XYZ_TMPDIR:-}" || ! -d "${XYZ_TMPDIR}" ]]; then
    xyz_error "internal: temp dir not initialised"
    exit 1
  fi
  printf '%s' "${XYZ_TMPDIR}"
}

xyz_fetch() {
  # xyz_fetch URL DEST
  local url="$1"
  local dest="$2"
  xyz_info "$(xyz_t "Downloading" "正在下载"): ${url}"
  xyz_info "$(xyz_t "Saving to" "保存到"): ${dest}"
  if xyz_need_cmd curl; then
    curl -fsSL --connect-timeout 20 --max-time 180 --retry 2 --retry-delay 1 \
      -o "${dest}" "${url}"
  elif xyz_need_cmd wget; then
    wget -q --timeout=60 -O "${dest}" "${url}"
  else
    xyz_error "$(xyz_t "Need curl or wget to download files." "需要 curl 或 wget 才能下载文件。")"
    exit 1
  fi
  if [[ ! -s "${dest}" ]]; then
    xyz_error "$(xyz_t "Download failed or file is empty:" "下载失败或文件为空：") ${url}"
    exit 1
  fi
  if xyz_need_cmd sha256sum; then
    xyz_info "SHA256: $(sha256sum "${dest}" | awk '{print $1}')"
  elif xyz_need_cmd shasum; then
    xyz_info "SHA256: $(shasum -a 256 "${dest}" | awk '{print $1}')"
  fi
}

xyz_run_upstream() {
  # xyz_run_upstream URL [args...]
  # Downloads an official installer, shows the URL and a short preview, then
  # runs it only after confirmation (unless -y / YES=1).
  local url="$1"
  shift
  local dest
  xyz_init_tmpdir
  dest="$(xyz_tmpdir)/upstream.sh"
  xyz_fetch "${url}" "${dest}"
  chmod +x "${dest}"
  xyz_info "$(xyz_t "Preview (first 20 lines):" "预览（前 20 行）：")"
  sed -n '1,20p' "${dest}" || true
  printf '%s\n' "${XYZ_C_DIM}...${XYZ_C_RESET}"
  # Default --dry-run: verify the download and preview, do not execute.
  # Scripts that forward --dry-run to upstream (e.g. docker) set
  # XYZ_FORWARD_DRY_RUN=1 so the official script still runs with that flag.
  if [[ "${XYZ_DRY_RUN:-0}" == "1" && "${XYZ_FORWARD_DRY_RUN:-0}" != "1" ]]; then
    xyz_info "$(xyz_t \
      "Dry-run: official script downloaded and previewed; not executing it." \
      "演练模式：已下载并预览官方脚本，不会执行。")"
    return 0
  fi
  if ! xyz_confirm "$(xyz_t \
    "Run this official upstream script?" \
    "运行这份官方上游脚本？")"; then
    xyz_error "$(xyz_t "Aborted by user." "已取消。")"
    exit 1
  fi
  xyz_step "$(xyz_t "Executing upstream script" "正在执行上游脚本")"
  # Never let the upstream script inherit our stdin: under `curl | bash` that
  # is the rest of this very script. Give it the terminal if there is one,
  # otherwise /dev/null. Interactive installers set XYZ_UPSTREAM_NEEDS_TTY=1.
  if xyz_open_tty; then
    local tty_fd="${XYZ_TTY_FD}"
    XYZ_TTY_FD=""
    bash "${dest}" "$@" <&"${tty_fd}"
    local rc=$?
    exec {tty_fd}>&- 2>/dev/null || true
    return "${rc}"
  fi
  if [[ "${XYZ_UPSTREAM_NEEDS_TTY:-0}" == "1" ]]; then
    xyz_error "$(xyz_t \
      "This official installer is interactive and needs a terminal. Log in with SSH and run: bash <(curl -fsSL ${XYZ_BASE}/${XYZ_NAME})" \
      "这个官方安装脚本需要交互，必须在终端里运行。请用 SSH 登录后执行：bash <(curl -fsSL ${XYZ_BASE}/${XYZ_NAME})")"
    exit 1
  fi
  bash "${dest}" "$@" </dev/null
}

# --- small shared helpers ----------------------------------------------------
xyz_strip_ansi() {
  sed -e 's/\x1b\[[0-9;?]*[A-Za-z]//g' -e 's/\r//g'
}

# Effective SSH port: sshd -T (what sshd really uses) > config files > env > 22.
xyz_effective_ssh_port() {
  local port=""
  if xyz_need_cmd sshd; then
    port="$(sshd -T 2>/dev/null | awk '$1=="port" {print $2; exit}' || true)"
  fi
  if [[ -z "${port}" && -d /etc/ssh/sshd_config.d ]]; then
    port="$(cat /etc/ssh/sshd_config.d/*.conf 2>/dev/null | awk 'tolower($1)=="port" {print $2; exit}' || true)"
  fi
  if [[ -z "${port}" && -f /etc/ssh/sshd_config ]]; then
    port="$(awk 'tolower($1)=="port" {print $2; exit}' /etc/ssh/sshd_config || true)"
  fi
  if [[ -z "${port}" && -n "${SSH_CONNECTION:-}" ]]; then
    port="$(printf '%s' "${SSH_CONNECTION}" | awk '{print $4}')"
  fi
  printf '%s' "${port:-22}"
}

xyz_has_systemd() {
  [[ -d /run/systemd/system ]] && xyz_need_cmd systemctl
}

# Back up a file once per run as FILE.xyz-bak-YYYYmmddHHMMSS and print the path.
xyz_backup_file() {
  local f="$1"
  local bak
  bak="${f}.xyz-bak-$(date +%Y%m%d%H%M%S)"
  if [[ -e "${f}" ]]; then
    cp -a "${f}" "${bak}"
    printf '%s' "${bak}"
  fi
}

# --- misc -------------------------------------------------------------------
xyz_usage_exit() {
  if [[ "${1:-}" != "" ]]; then
    printf '%s\n' "$1"
  fi
  exit 0
}

XYZ_NAME="auto-update"

# xyz.sh/autoupdate — enable unattended security updates.
#
# Debian / Ubuntu : installs unattended-upgrades and writes
#                   /etc/apt/apt.conf.d/20auto-upgrades (daily list update +
#                   unattended-upgrade). The distro's default policy installs
#                   security updates only. --reboot adds
#                   /etc/apt/apt.conf.d/52xyz-unattended-reboot (reboot at 04:00
#                   only when a package requires it).
# Rocky / Alma 8+ : installs dnf-automatic, edits
#                   /etc/dnf/automatic.conf (upgrade_type = security,
#                   apply_updates = yes; backup kept) and enables
#                   dnf-automatic.timer.
# CentOS 7        : installs yum-cron with update_cmd = security (EOL repos
#                   may no longer work; the script stops with a clear error).
#
# Usage:
#   curl -fsSL xyz.sh/autoupdate | bash -s -- -y
#   curl -fsSL xyz.sh/autoupdate | bash -s -- --reboot -y
#   curl -fsSL xyz.sh/autoupdate | bash -s -- --status
#   curl -fsSL xyz.sh/autoupdate | bash -s -- --disable -y
#   curl -fsSL xyz.sh/autoupdate | bash -s -- --dry-run
#
# Supported: Debian, Ubuntu, CentOS, Rocky, AlmaLinux. Root required.
# No telemetry is added by this wrapper.

set -euo pipefail

if [[ -z "${XYZ_COMMON_LOADED:-}" ]]; then
  _xyz_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
  if [[ -f "${_xyz_dir}/lib/common.sh" ]]; then
    # shellcheck source=lib/common.sh
    source "${_xyz_dir}/lib/common.sh"
  else
    echo "xyz.sh: missing lib/common.sh" >&2
    exit 1
  fi
fi

XYZ_NAME="${XYZ_NAME:-autoupdate}"
case "${XYZ_NAME}" in autoupdate|unattended-upgrades|auto-update) : ;; *) XYZ_NAME="autoupdate" ;; esac
XYZ_TITLE="$(xyz_t "Automatic security updates" "自动安全更新")"
xyz_init "$@"

DO_STATUS=0; DO_DISABLE=0; DO_REBOOT=0; REBOOT_TIME="04:00"
i=0
while [[ $i -lt ${#XYZ_ARGS[@]} ]]; do
  arg="${XYZ_ARGS[$i]}"
  case "${arg}" in
    --status) DO_STATUS=1 ;;
    --disable) DO_DISABLE=1 ;;
    --reboot) DO_REBOOT=1 ;;
    --reboot-time) i=$((i + 1)); REBOOT_TIME="${XYZ_ARGS[$i]:-04:00}"; DO_REBOOT=1 ;;
    --help|-h) XYZ_HELP=1 ;;
    *)
      xyz_error "$(xyz_t "Unknown argument:" "未知参数：") ${arg}"
      exit 1
      ;;
  esac
  i=$((i + 1))
done
[[ "${REBOOT_TIME}" =~ ^[0-2][0-9]:[0-5][0-9]$ ]] || { xyz_error "--reboot-time HH:MM"; exit 1; }

if [[ "${XYZ_HELP:-}" == "1" ]]; then
  cat <<HINT
$(xyz_t "Usage:" "用法：")
  curl -fsSL xyz.sh/autoupdate | bash -s -- -y
  curl -fsSL xyz.sh/autoupdate | bash -s -- --reboot -y
  curl -fsSL xyz.sh/autoupdate | bash -s -- --reboot-time 05:30 -y
  curl -fsSL xyz.sh/autoupdate | bash -s -- --status
  curl -fsSL xyz.sh/autoupdate | bash -s -- --disable -y

$(xyz_t "Security updates only. Automatic reboot is off unless --reboot is given." "只自动安装安全更新。除非加 --reboot，否则不会自动重启。")
HINT
  exit 0
fi

APT_AUTO="/etc/apt/apt.conf.d/20auto-upgrades"
APT_REBOOT="/etc/apt/apt.conf.d/52xyz-unattended-reboot"
DNF_CONF="/etc/dnf/automatic.conf"
YUM_CONF="/etc/yum/yum-cron.conf"

xyz_detect_os
mode=""
case "${XYZ_OS_FAMILY}" in
  debian) mode="apt" ;;
  rhel)
    if xyz_need_cmd dnf; then mode="dnf"; else mode="yum"; fi ;;
  *) mode="" ;;
esac

status() {
  case "${mode}" in
    apt)
      if dpkg -s unattended-upgrades >/dev/null 2>&1; then
        xyz_info "unattended-upgrades: $(dpkg-query -W -f='${Version}' unattended-upgrades)"
      else
        xyz_info "$(xyz_t "unattended-upgrades is not installed." "未安装 unattended-upgrades。")"
      fi
      for f in "${APT_AUTO}" "${APT_REBOOT}"; do [[ -f "${f}" ]] && { xyz_info "${f}:"; sed 's/^/  /' "${f}"; }; done
      if xyz_need_cmd apt-config; then
        apt-config dump 2>/dev/null | grep -E 'APT::Periodic::(Update-Package-Lists|Unattended-Upgrade)|Unattended-Upgrade::Automatic-Reboot' | sed 's/^/  /' || true
      fi
      ;;
    dnf)
      rpm -q dnf-automatic 2>/dev/null || xyz_info "$(xyz_t "dnf-automatic is not installed." "未安装 dnf-automatic。")"
      [[ -f "${DNF_CONF}" ]] && grep -E '^(upgrade_type|apply_updates|reboot)' "${DNF_CONF}" | sed 's/^/  /' || true
      xyz_has_systemd && systemctl is-enabled dnf-automatic.timer 2>/dev/null | sed 's/^/  dnf-automatic.timer: /' || true
      ;;
    yum)
      rpm -q yum-cron 2>/dev/null || xyz_info "$(xyz_t "yum-cron is not installed." "未安装 yum-cron。")"
      [[ -f "${YUM_CONF}" ]] && grep -E '^(update_cmd|apply_updates)' "${YUM_CONF}" | sed 's/^/  /' || true
      ;;
    *) xyz_warn "unsupported OS" ;;
  esac
}

if [[ "${DO_STATUS}" == "1" ]]; then
  status
  exit 0
fi
xyz_require_root
xyz_require_supported_os

if [[ "${DO_DISABLE}" == "1" ]]; then
  xyz_step "$(xyz_t "Will disable automatic updates" "将关闭自动更新")"
  case "${mode}" in
    apt) printf '  %s -> APT::Periodic::Unattended-Upgrade "0"; remove %s\n' "${APT_AUTO}" "${APT_REBOOT}" ;;
    dnf) printf '  systemctl disable --now dnf-automatic.timer\n' ;;
    yum) printf '  systemctl disable --now yum-cron\n' ;;
    *) : ;;
  esac
  if [[ "${XYZ_DRY_RUN:-0}" == "1" ]]; then xyz_info "$(xyz_t "Dry-run: nothing changed." "演练模式：未做修改。")"; exit 0; fi
  xyz_confirm "$(xyz_t "Disable automatic updates?" "关闭自动更新？")" || exit 1
  case "${mode}" in
    apt)
      printf 'APT::Periodic::Update-Package-Lists "1";\nAPT::Periodic::Unattended-Upgrade "0";\n' > "${APT_AUTO}"
      rm -f "${APT_REBOOT}" ;;
    dnf) xyz_has_systemd && systemctl disable --now dnf-automatic.timer || true ;;
    yum) xyz_has_systemd && systemctl disable --now yum-cron || true ;;
    *) : ;;
  esac
  xyz_info "$(xyz_t "Automatic updates disabled." "已关闭自动更新。")"
  exit 0
fi

xyz_step "$(xyz_t "Planned changes" "计划变更")"
case "${mode}" in
  apt)
    printf '  %s: unattended-upgrades\n' "$(xyz_t "Install" "安装")"
    printf '  %s: %s\n' "$(xyz_t "Write" "写入")" "${APT_AUTO}"
    [[ "${DO_REBOOT}" == "1" ]] && printf '  %s: %s (Automatic-Reboot "true" at %s)\n' "$(xyz_t "Write" "写入")" "${APT_REBOOT}" "${REBOOT_TIME}"
    ;;
  dnf)
    printf '  %s: dnf-automatic\n' "$(xyz_t "Install" "安装")"
    printf '  %s: %s (upgrade_type = security, apply_updates = yes%s)\n' "$(xyz_t "Edit" "修改")" "${DNF_CONF}" "$([[ "${DO_REBOOT}" == "1" ]] && printf ', reboot = when-needed')"
    printf '  systemctl enable --now dnf-automatic.timer\n'
    ;;
  yum)
    printf '  %s: yum-cron; %s: %s (update_cmd = security, apply_updates = yes)\n' "$(xyz_t "Install" "安装")" "$(xyz_t "Edit" "修改")" "${YUM_CONF}"
    ;;
  *) xyz_error "unsupported OS"; exit 1 ;;
esac
if [[ "${XYZ_DRY_RUN:-0}" == "1" ]]; then
  xyz_info "$(xyz_t "Dry-run: nothing installed or written." "演练模式：未安装、未写入任何内容。")"
  exit 0
fi
xyz_confirm "$(xyz_t "Enable automatic security updates?" "启用自动安全更新？")" || { xyz_error "$(xyz_t "Aborted by user." "已取消。")"; exit 1; }

set_ini() {
  # set_ini FILE KEY VALUE  (key = value, replaces an existing key)
  local f="$1" k="$2" v="$3"
  if grep -q -E "^[#[:space:]]*${k}[[:space:]]*=" "${f}"; then
    sed -i -E "s|^[#[:space:]]*${k}[[:space:]]*=.*|${k} = ${v}|" "${f}"
  else
    printf '%s = %s\n' "${k}" "${v}" >> "${f}"
  fi
}

case "${mode}" in
  apt)
    xyz_pkg_install unattended-upgrades
    cat > "${APT_AUTO}" <<CONF
// Written by xyz.sh/autoupdate ${XYZ_VERSION}
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
APT::Periodic::AutocleanInterval "7";
CONF
    if [[ "${DO_REBOOT}" == "1" ]]; then
      cat > "${APT_REBOOT}" <<CONF
// Written by xyz.sh/autoupdate ${XYZ_VERSION}
Unattended-Upgrade::Automatic-Reboot "true";
Unattended-Upgrade::Automatic-Reboot-Time "${REBOOT_TIME}";
CONF
    fi
    if xyz_need_cmd unattended-upgrade; then
      if unattended-upgrade --dry-run >/dev/null 2>&1; then
        xyz_info "$(xyz_t "unattended-upgrade --dry-run: OK" "unattended-upgrade --dry-run：正常")"
      else
        xyz_warn "$(xyz_t "unattended-upgrade --dry-run reported a problem (check /var/log/unattended-upgrades/)." "unattended-upgrade --dry-run 报告问题（请看 /var/log/unattended-upgrades/）。")"
      fi
    fi
    if xyz_has_systemd; then
      systemctl enable --now apt-daily.timer apt-daily-upgrade.timer >/dev/null 2>&1 || true
    fi
    ;;
  dnf)
    xyz_pkg_install dnf-automatic
    bak="$(xyz_backup_file "${DNF_CONF}")"
    [[ -n "${bak}" ]] && xyz_info "$(xyz_t "Backup:" "备份：") ${bak}"
    set_ini "${DNF_CONF}" upgrade_type security
    set_ini "${DNF_CONF}" apply_updates yes
    [[ "${DO_REBOOT}" == "1" ]] && set_ini "${DNF_CONF}" reboot when-needed
    if xyz_has_systemd; then
      systemctl enable --now dnf-automatic.timer
    else
      xyz_warn "$(xyz_t "No systemd: enable dnf-automatic.timer after boot." "没有 systemd：请在系统启动后启用 dnf-automatic.timer。")"
    fi
    ;;
  yum)
    xyz_pkg_install yum-cron
    bak="$(xyz_backup_file "${YUM_CONF}")"
    set_ini "${YUM_CONF}" update_cmd security
    set_ini "${YUM_CONF}" apply_updates yes
    if xyz_has_systemd; then systemctl enable --now yum-cron; fi
    ;;
  *) : ;;
esac

status
xyz_info "$(xyz_t "Automatic security updates are enabled." "已启用自动安全更新。")"