#!/bin/sh
# Moku · check Remote Login on this Mac and show how to connect.
# https://portholelab.com/ssh · v2 (this file never changes; fixes ship as v3)
#
# What this does:
#   1. Checks whether Remote Login (the Mac's SSH server) is on.
#   2. If it's off, opens System Settings at Sharing and waits while you
#      switch Remote Login on yourself.
#   3. Prints your username and this Mac's address, and opens a page with
#      a QR code for the Moku app to scan.
#
# What it does not do: ask for your password, use sudo, change any
# setting itself, or send anything to anyone.
#
# Everything runs from main(), called on the very last line, so a download
# cut short runs nothing.

MOKU_PAGE='https://portholelab.com/ssh/'

zh() {
  case "${LC_ALL:-${LC_MESSAGES:-${LANG:-}}}" in zh*) return 0 ;; esac
  # Terminal on a Chinese Mac often leaves LANG unset.
  defaults read -g AppleLanguages 2>/dev/null | sed -n '2p' | grep -q 'zh'
}

say() { if zh; then printf '%s\n' "$1"; else printf '%s\n' "$2"; fi; }

ssh_on() { nc -z -G 1 127.0.0.1 22 >/dev/null 2>&1; }

primary_ip() {
  dev=$(route -n get default 2>/dev/null | awk '/interface:/ {print $2; exit}')
  ip=''
  [ -n "$dev" ] && ip=$(ipconfig getifaddr "$dev" 2>/dev/null)
  [ -n "$ip" ] || ip=$(ipconfig getifaddr en0 2>/dev/null)
  printf '%s' "$ip"
}

main() {
  if [ "$(uname -s)" != Darwin ]; then
    say "这条命令是给 Mac 用的。请回到 portholelab.com/ssh 选你的系统。" \
      "This command is for Macs. Go back to portholelab.com/ssh and pick your system."
    exit 1
  fi

  if ssh_on; then
    say "远程登录已经打开。" "Remote Login is already on."
  else
    say "远程登录还没打开。正在打开「系统设置 › 通用 › 共享」……" \
      "Remote Login is off. Opening System Settings › General › Sharing…"
    say "请打开「远程登录」开关。打开后这里会自动继续。" \
      "Switch on \"Remote Login\". This continues by itself once it's on."
    open 'x-apple.systempreferences:com.apple.Sharing-Settings.extension' 2>/dev/null ||
      open /System/Library/PreferencePanes/SharingPref.prefPane 2>/dev/null
    tries=0
    until ssh_on; do
      tries=$((tries + 1))
      if [ "$tries" -ge 300 ]; then
        say "等了 5 分钟还没打开。打开后再运行一次这条命令即可。" \
          "Still off after 5 minutes. Run this command again once it's on."
        exit 1
      fi
      sleep 1
    done
    say "好了，远程登录已打开。" "Remote Login is on."
  fi

  addr=$(primary_ip)
  user=$(id -un)
  # Run through sudo (it isn't needed), still name the person who typed it.
  if [ "$user" = root ] && [ -n "${SUDO_USER:-}" ] && [ "$SUDO_USER" != root ]; then
    user=$SUDO_USER
  fi

  printf '\n\033[1;32m'
  say "完成。在 Moku 里填这些：" "Done. In Moku, enter:"
  printf '\033[0m'
  say "  用户名：$user" "  Username: $user"
  say "  地址：  ${addr:-?}" "  Address:  ${addr:-?}"
  say "  密码：  你开机登录 Mac 用的密码" "  Password: the one you use to log in to this Mac"

  if [ -z "$addr" ]; then
    say "没找到这台 Mac 的网络地址。请确认它连着 Wi-Fi 或网线。" \
      "Couldn't find this Mac's network address. Check it's on Wi-Fi or Ethernet."
    return 0
  fi

  case "$user" in
    *[!A-Za-z0-9._-]*) target="$addr" ;;
    *) target="$user%40$addr" ;;
  esac
  # The page reads this after "#", which browsers never send to a server.
  url="${MOKU_PAGE}#show=ssh%3A%2F%2F$target:22"
  printf '\n'
  say "或者在 Moku 里点「扫码导入」，扫这个页面上的二维码：" \
    "Or tap \"Scan QR code\" in Moku and scan the code on this page:"
  printf '  %s\n' "$url"
  open "$url" 2>/dev/null
  printf '\n'
  say "别让陌生人连你的 Wi-Fi：同一网络里的人都能尝试登录这台 Mac。" \
    "Keep strangers off your Wi-Fi: anyone on the same network can try to log in to this Mac."
}

main "$@"