#!/bin/sh
# -------
# File:        pe
# Description: very simple script to run a program as root
#              using op, gksu or sudo (in this order)
# Author:      Luis Garcia Gisbert <garcia_luigis@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

PATH="/usr/sbin:/usr/bin:/sbin:/bin"
# library
LLX_COMMONLIB="/usr/share/lliurex/llxcfg-common/llxcfg-common.sh"
[ -f "${LLX_COMMONLIB}" ] || exit 1
. ${LLX_COMMONLIB}


# functions
usage() {
  CMD_NAME="$(basename "$0")"
  echo "Usage: $CMD_NAME [options] COMMAND [ ARGUMENTS ...]" >&2
  echo "       options: --no-interactive\n\
                --test\n\
                --list\n\
                --update" >&2
}

op_file(){
   BASE_CMD="$(basename "$1")"
   echo "$OP_PATH/pe-$BASE_CMD.conf"
}

pe_default_template(){
   llxcfg-config read "$PE_CONF_DEFAULT"
   return 0
}

pe_update(){
   # write new files
   for PE_CMD in $(find "$PE_CFG_PATH" -maxdepth 1 -mindepth 1 -xtype d -printf "%P\n") ; do
      CMD_FILE="$(find "$PE_CFG_PATH/$PE_CMD" -xtype f -name "*.${PE_EXT_CMD}" |head -1)"
      if [ -r "$CMD_FILE" ] ; then
         PE_FULLCMD="$(cat $CMD_FILE)"
         if [ "$PE_FULLCMD" ] ; then
            PE_USERS="$(find "$PE_CFG_PATH/$PE_CMD" "$PE_ADMIN_PATH" -xtype f -name "*.${PE_EXT_USERS}" -exec cat {} \; |tr "\n" "," |sort -u)"
            PE_USERS="${PE_USERS%,}"
            PE_GROUPS="$(find "$PE_CFG_PATH/$PE_CMD" "$PE_ADMIN_PATH" -xtype f -name "*.${PE_EXT_GROUPS}" -exec cat {} \; |tr "\n" "," |sort -u)"
            PE_GROUPS="${PE_GROUPS%,}"
            TMP_FILE="$(tempfile)"
            llxcfg-config read "$PE_CONF/$PE_CMD" || pe_default_template > "$TMP_FILE"
            export PE_CMD PE_FULLCMD PE_USERS PE_GROUPS
            OP_FILE="$(op_file "$PE_FULLCMD")"
            llxcfg-template "$TMP_FILE" |llxcfg-install --mode=600 - "$OP_FILE"
            rm -f "$TMP_FILE"
            unset PE_CMD PE_FULLCMD PE_USERS PE_GROUPS
         fi
      fi
   done
   # remove old files
   for PE_FILE in $(find "$OP_PATH" -maxdepth 1 -mindepth 1 -xtype f -name "pe-*.conf") ; do
      PE_CMD="$(basename "$PE_FILE" ".conf")"
      PE_CMD="${PE_CMD#pe-}"
      [ -d "$PE_CFG_PATH/$PE_CMD" ] || rm -f "$PE_FILE"
   done
   return 0
}

pe_purge(){
   find "$OP_PATH" -maxdepth 1 -mindepth 1 -xtype f -name "pe-*.conf" --exec rm {} \;
}

op_grep(){
   if op -l |grep -q "^${1}\b"; then
      echo "${1}"
      return 0
   fi
   # try in the help (assume help is just the full path of command)
   CMD="$(op -l |sed -ne "\%[[:blank:]]${1}[[:blank:]]*$%{s%[[:blank:]].*$%%;p}")"
   if [ "$CMD" ] ; then
      echo "$CMD"
      return 0
   fi
   return 1
}

op_test(){
      # 1. try command "as is"
      ! op_grep "$1" || return 0
      # 2. try basename of command
      CMD="$(basename "$1")"
      ! op_grep "$CMD" || return 0
      # 3. Last chance ... may be the command is just a link of other command, so try basename of readlink -f
      CMD="$(readlink -f "$1")"
      ! op_grep "$(basename "$CMD")" || return 0
      return 1
}

# ----
# main
# ----
NO_INTERACTIVE=""

# check option(s)
case "$1" in
   --no-interactive)
      NO_INTERACTIVE="Y"
      shift
      ;;
   --test)
      shift
      if [ -z "$1" ] ; then
         usage
         exit 1
      fi
      ! op_test "$1" >/dev/null || exit 0
      exit 1
      ;;
   --list)
      rc=0
      op -l || rc =$?
      exit $rc
      ;;
   --update)
      rc=0
      pe_update || rc =$?
      exit $rc
      ;;
   --*)
      usage
      exit 1
      ;;
esac

if [ -z "$1" ] ; then
   usage
   exit 1
fi

CMD="$1"
shift

# 1. am I root?
[ $(id -u) -ne 0 ] || exec "$CMD" "$@"

# 2. can I use op?
if OP_CMD="$(op_test "$CMD")" ; then
   exec op "$OP_CMD" "$@"
fi

[ -z "$NO_INTERACTIVE" ] || exit 1

# 3. running under graphical environment and gksu is available?
[ -z "$DISPLAY" ] || [ ! -x /usr/bin/gksu ] || exec gksu "$CMD" "$@"

# 4. sudo is our last chance to escale privileges 
exec sudo "$CMD" "$@"