#!/bin/bash
# -------
# File:                llxcfg-passgen
# Description:         Script to generate secrets/passwords in a LliureX environment
# (template) Author:   Ramon Onrubia Perez <onrubia_ram@gva.es>
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along 
# with this program; if not, write to the Free Software Foundation, Inc., 
# 51 Franklin St, Fifth Floor, Boston MA 02110-1301 USA
# --------

set -e

# ---------
# variables
# ---------

PATH="/usr/sbin:/usr/bin:/sbin:/bin"
# TODO: si esta ruta es definitiva, añadirla a llxcfg-runtime.dirs
PASS_STORE_PATH="/etc/lliurex-secrets/passgen"
PASS_FILE_EXT="secret"

DEFMODE="600"
DEFOWNER="root"
DEFGROUP="root"
DEFPASSLENGTH="12"

MODE="$DEFMODE"
OWNER="$DEFOWNER"
GROUP="$DEFGROUP"
PASSLENGTH="$DEFPASSLENGTH"
FORCE=""

#
# functions
# ---------
usage() {
  CMD_NAME="$(basename "$0")"
  error_message \
"Usage: $CMD_NAME [options] PASSNAME {gen|show|remove}\n\
       $CMD_NAME list \n\
       where options are: [--force ] [-l |--length=PASSLENGTH] [-m |--mode=MODE] [-o |--owner=OWNER] [-g |--group=GROUP]\n\
       Generate a password and returns the path where it is store. 
       If mode, owner or group are not passed, use $DEFMODE, $DEFOWNER:$DEFGROUP as defaults\n\
       IF PASSLENGTH is not passed, use $DEFPASSLENGTH as password length"
} 

error_message() {
   echo -e "$1" >&2
   exit 1
}
# ----
# main
# ----

declare -a ARGV
# Bash arrays are 0-based, but we like ARGC to be equal to the number of non-option arguments.
# To solve this issue, we use a "C-like" ARGV vector by setting ARGV[0] with the name of script
# ('basename' of script for arbitrary cosmetic reasons), so real arguments begin with index 1
# the array will be ARGC+1 elements
ARGC=0
ARGV[0]="$(basename "$0")"

while [ $# -ge 1 ] ; do
   case "$1" in
      --length=*)
         PASSLENGTH="${1#--length=}"
         shift
         ;;
      -l)
         # -l LENGTH as equivalent to --length=LENGTH
         [ -z "$2" ] && usage
         PASSLENGTH="$2"
         shift 2
         ;;
      --group=*)
         GROUP="${1#--group=}"
         shift
         ;;
      -g)
         # -g GROUP as equivalent to --group=GROUP
         [ -z "$2" ] && usage
         GROUP="$2"
         shift 2
         ;;
      --owner=*)
         OWNER="${1#--owner=}"
         shift
         ;;
      -o)
         # -o OWNER as equivalent to --owner=MODE
         [ -z "$2" ] && usage
         OWNER="$2"
         shift 2
         ;;
      --mode=*)
         MODE="${1#--mode=}"
         shift
         ;;
      -m)
         # -m MODE as equivalent to --mode=MODE
         [ -z "$2" ] && usage
         MODE="$2"
         shift 2
         ;;
      --force|--chucknorris)
        FORCE="Y"
        shift
        ;;
      -?*)
         # an invalid option -* or --* but not a single -
         usage
         ;;
      *)
         ARGC=$(( $ARGC +1 ))
         ARGV[$ARGC]="$1"
         shift
         ;;
     esac
done

case $ARGC in
   1)
   	  ACTION="${ARGV[1]}"
   	  ;;
   2)
     # we need 2 arguments
      PASSNAME="${ARGV[1]}"
      ACTION="${ARGV[2]}"
      PASS_FILE="${PASS_STORE_PATH}/${PASSNAME}.${PASS_FILE_EXT}"
      #echo ok
      ;;
   *)   
      usage
      ;;
esac

case "$ACTION" in 
   gen)
   		#TODO: add pwgen dependency in llxcfg control file
   		# comprobar que no existe ya la contraseña, si existe hace falta --force
   		[ -f $PASS_FILE -a -z "$FORCE" ] && error_message "Use --force to overwrite password"
		pwgen -cns $PASSLENGTH 1 |llxcfg-install --mode=$MODE --owner=$OWNER --group=$GROUP - "$PASS_FILE" || error_message "Couldn't not generate password in $PASS_FILE path"
		echo "$PASS_FILE"
		;;
   show)
   		[ -f "${PASS_FILE}" ] || error_message "There is not a PASSNAME named \"$PASSNAME\""
   		echo "$PASS_FILE"
		;;
   list)
   		find "$PASS_STORE_PATH" -xtype f|sort -u|while read line;
   		do
   			echo $(basename $line)|sed -e "s/.${PASS_FILE_EXT}//"
   		done
   		;;
   remove)
   		[ -f "${PASS_FILE}" ] || error_message "There is not a PASSNAME named \"$PASSNAME\""
   		rm -f "$PASS_FILE" || error_message "Couldn't not remove $PASS_FILE file"
   		;;
   *)
    	usage
    	;;
esac
exit 0