#!/bin/bash

#check for strings exit if missing
command -v strings &>/dev/null || { echo "pastab requires binutils to be installed but it's not. Aborting." >&2; exit 1; }

while [[ $1 = * ]]; do
  case "$1" in
    -g|--generate)
      #check for directory .pastab in user home directory, create one if it's not exists
      [ -d $HOME/.pastab ] || mkdir $HOME/.pastab
      #check if key file with that name exists - if so exit doing nothing
      [ -e $HOME/.pastab/$2.key ] && exit 3
      dd status=noxfer if=/dev/urandom of=$HOME/.pastab/$2.key bs=1024 count=10 > /dev/null 2>&1
      shift 2
      exit 0
      ;;
    -p|--print)
      #check if key file exists if not exit doing nothing
      [ ! -e $HOME/.pastab/$2.key ] && exit 4
      alph=$(echo {a..z} | sed 's/ //g')
      line=$(for i in $(seq 26); do echo -n '-'; done)
      echo -e "NE|$alph|NW\n--+$line+--"
      key=$(cat $HOME/.pastab/$2.key | strings | tr -d '* \t\n')
      echo ${key:0:260} | awk 'BEGIN{n=1;nn=0}{while(substr($0,n,26)){print nn " |" substr($0,n,26) "| " nn;n+=26;nn+=1}}'
      echo -e "--+$line+--\nSE|$alph|SW"
      shift 2
      exit 0
      ;;
    *)
      echo "Usage: $0 [-p|--print || -g|--generate] passtab_name"
      exit 5
  esac
done
exit 0