#!/bin/sh

# TODO :
# - add root user detection
# - verify curl output to prevent overwriting config file with an HTTP answer

_usage() {
  echo "
  Usage: $0 <command> --url <wgportal_url> [options...]

Commands :
  -d, --download            only download config file
  -i, --install             download config file and install the service (UNIMPLEMENTED)

Parameters:
  -u, --url <url>           Specify your WG Portal base URL
  -f, --filename <file>     Specify Wireguard filename (default: /etc/wireguard/wg0.conf)
  "
  _version
}

_version() {
  printf "%s version pre-alpha 0.1 (yes we're very cautious)\n" "$0"
  printf "USE AT YOUR OWN RISK and read the code before\n"
}

_startswith() {
  _str="$1"
  _sub="$2"
  echo "$_str" | grep "^$_sub" >/dev/null 2>&1
}

_download() {
  [ -z "$WGPORTAL_URL" ] && printf "Please set wg-portal URL (see help)\n" && return 1
  [ -z "$WG_CONFFILE" ] && WG_CONFFILE=/etc/wireguard/wg0.conf

  trap 'stty echo; exit 99;' INT

  if [ -f $WG_CONFFILE -a "$OVERWRITE" != "on" ]; then
    printf "WARNING : Wireguard config file already exists\n"
    printf "Exiting now to prevent overrid of your actual parameters\n"
    printf "You can force config overwriting with :\n"
    printf "OVERWRITE=on %s %s\n" "$0" "$_ARGS"
    exit 1;
  fi

  printf "Username: "
  IFS= read -r username

  printf "Password: "
  stty -echo
  IFS= read -r password
  stty echo
  printf "\n"

  printf "Peer public key: "
  IFS= read -r wgpubkey
  printf "\n"

  HTTP_STATUS=$(curl -w "%{http_code}" -G -s -o $WG_CONFFILE --user $username:$password --data-urlencode "pkey=$wgpubkey" -X GET $WGPORTAL_URL"api/v1/provisioning/peer" -H  "accept: text/plain")
  res=$?
  if [ "$res" != "0" ]; then
    echo "the curl command failed with: $res"
  fi

  [ $HTTP_STATUS -ne 200 ] &&  printf "Curl returned HTTP code %s\n" "$HTTP_STATUS" && exit 1

  printf "WG config successfully download at %s\n" "$WG_CONFFILE"
}

_install() {
  printf "install : This command does nothing ... yet (TDB)\n"
}

_process() {
  while [ ${#} -gt 0 ]; do
    case "${1}" in
      --help | -h)
        _usage
        return
        ;;
      --version | -v)
        _version
        return
        ;;
      --download | -d)
        _CMD="download"
        ;;
      --url | -u)
        WGPORTAL_URL="$2"
        shift
        ;;
      --filename | -f)
        WG_CONFFILE="$2"
        shift
        ;;
      --install | -i)
        _CMD="install"
        ;;
      *)
        printf "Unknown parameter : %s\n" "$1"
        return 1
        ;;
    esac

    shift 1
  done
  case "${_CMD}" in
    download)
      _download
      ;;
    install)
      _install
      ;;
    *)
    if [ "$_CMD" ]; then
      printf "Invalid command: %s\n" "$_CMD"
    fi
  esac
}

main() {
  [ -z "$1" ] && _usage && return
  if _startswith "$1" '-'; then _process "$@"; else "$@"; fi
}

_ARGS="$*"
main "$@"