#!/usr/bin/env bash

#  filename: get-acme
#  requires: crontab, curl (or wget), grep, sed
#  author: G. D. LaBossiere, Xview Solutions Inc. <code@XviewSolutions.com>
#  last modified: 2017-03-25
#  license: GNU GPL v3 <http://www.gnu.org/licenses/gpl-3.0.txt>
#  comments: custom installer for <https://github.com/Neilpang/acme.sh/>

################################# global vars #################################

acmeHome="${HOME}/.acme.sh"
acmeCmd="${acmeHome}/acme.sh"
agreeVar="DEFAULT_AGREEMENT="
agreeVal="https://acme-v01.api.letsencrypt.org/terms/"

################################ start program ################################

[[ $EUID -eq 0 ]] && {
  printf "Do not run this script as root.\n"
  exit 1
}

#  prompt if fd 0 (stdin) and fd 1 (stdout) point to a terminal (tty/pts)
[[ -t 0 && -t 1 ]] && {
  printf "\n%b\n" "---------------------------------------------------------------------------------"
  printf "This script will download, install and modify the acme.sh environment for working\n"
  printf "with LetsEncrypt.org domain-validated SSL certificates. Enter C or c to continue,\n"
  printf "any other key to quit: "; read myChoice
  case $myChoice in
    c|C ) : ;;
    * ) exit 0 ;;
  esac
  printf "\n%b\n" "---------------------------------------------------------------------------------"
}

#  prefer curl over wget as download tool
type -p wget > /dev/null
[[ $? -eq 0 ]] && pullCmd="wget -q -O - https://get.acme.sh | bash"
type -p curl > /dev/null
[[ $? -eq 0 ]] && pullCmd="curl -s https://get.acme.sh | bash"
[[ -z $pullCmd ]] && {
  printf "Need curl or wget to retrieve acme.sh. Neither found. Quitting.\n"
  exit 1
}
printf "[$(date)] Retrieving script from https://get.acme.sh and running it.\n"
eval $pullCmd

printf "[$(date)] Modifying URL for LetsEncrypt ToS doc (auto-redirects to latest version).\n"
cmdResult="Failed"
#  to avoid escaping '/' inside a sed regex, use an alternate delimiter for
#+ patterns in an address (e.g. '\| ... |') and after 's' (e.g. 's| ... |')
sed -i "\|^[[:space:]]*$agreeVar.*$| s|$agreeVar.*|$agreeVar$agreeVal|" "${acmeCmd}"
printf "[$(date)] "; grep "$agreeVar$agreeVal" "$acmeCmd"
[[ $? -eq 0 ]] && cmdResult="[$(date)] Success"
printf "${cmdResult}!\n"

printf "[$(date)] Disabling certificate auto-renewal (removes cron job added by install script).\n"
cmdResult="Failed"
${acmeCmd} --uninstall-cronjob
[[ -z "$(crontab -l | grep 'acme.sh')" ]] && cmdResult="Success"
printf "[$(date)] ${cmdResult}!\n"

printf "[$(date)] Modifications complete.\n"
printf "%b\n" "---------------------------------------------------------------------------------"
printf "To update your environment without having to log out and then log back in again,\n"
printf "type: \"source \$HOME/.acme.sh/acme.sh.env\" (omit the quotes) and press Enter.\n"

#  end program