#!/bin/sh

usage () {
  echo "zdtol [options] <name>"
  echo "  Searches a label for partition or disk /dev/<name>"
  echo "  Options:  "
  echo "    -h          Show this message then exit"
  echo "    -d          Discard prefix (/dev/)"
  echo "    -n <num>    Show only nth label"
}

error () {
    printf "\033[1;31m%s\033[0m\n" "$1" >&2
}

while getopts ":hdn:" opt;
do
  case $opt in
    h)
      usage
      exit 0
      ;;
    n)
      if ! echo "$OPTARG" | grep -Eq '^[0-9]+$'
      then
        error "n argument has to be an integer"
        exit 2
      fi
      if [ -z "$OPTARG" ]
      then
        error "n needs an argument"
        exit 2
      fi
      if [ "$OPTARG" -lt 1 ]
      then
        error "argument has to be greater than 0"
        exit 2
      fi
      _arg_n=$OPTARG
      _opt_n=y
      ;;
    d)
      _opt_d=y
      ;;
    \?)
      echo "Uknown option: $OPTARG" >&2
      usage
      exit 1
      ;;
  esac
done

shift $((OPTIND-1))

if [ $# -le 0 ]
then
  usage
  exit 2
fi

_LIST=$(lsblk -lnio NAME,LABEL | tr -s ' ')

for _I in "$@"
do
  if [ -n "$_opt_d" ] ; then
    _I=$(echo "$_I" | cut -d'/' -f3)
  fi
  _ret=$(echo "$_LIST" | grep "$_I" | tr -s ' ' | cut -d' ' -f2- | sed '/^[[:space:]]*$/d')
  if [ -n "$_opt_n" ] ; then
    echo "$_ret" | cut -d'\n' -f"$_arg_n"
  else
    echo "$_ret"
  fi
done

exit 0