#!/bin/sh

# -------
# File:        lliurex-grub2-default
# Description: LliureX simple updater for /etc/default/grub
# 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

DIVERT_FILES="grub"
USR_DIR="/usr/share/grub/default"
ETC_DIR="/etc/default"
PNAME="lliurex-grub2"
LLIUREX_DIR="/usr/share/$PNAME/default"
HASH_FILE="/var/lib/ucf/hashfile"

is_diverted(){
   if [ "$(dpkg-divert --truename "$1")" = "$1" ] ; then
      return 1
   fi
   return 0

}

do_divert(){
   for f in $DIVERT_FILES ; do
      F="$USR_DIR/${f}"
      if ! is_diverted "$F" ; then
         dpkg-divert --package "$PNAME" --rename --quiet --add --divert "$F.orig" "$F" ||  echo "Unable to divert file \"$F\"" >&2
      fi
      cp "$LLIUREX_DIR/$f" "$F"
      do_etc_sync "$f"
      fix_ucf "$f"
   done
}

undo_divert(){
   for f in $DIVERT_FILES ; do
      F="$USR_DIR/${f}"
      if is_diverted "$F" ; then
         rm -f "$F"
         dpkg-divert --package "$PNAME" --rename --quiet --remove "$F" ||  true
      fi
      do_etc_sync "$f"
      fix_ucf "$f"
   done
}

do_etc_sync(){
   cp "$USR_DIR/$1" "$ETC_DIR/$1"
}

fix_ucf(){
   # look in ucf
   if grep -q "[[:blank:]]$ETC_DIR/$1$" "$HASH_FILE" ; then
      TEMPFILE="$(tempfile)"
      cp -a "$HASH_FILE" "$TEMPFILE"
      sed -i -e "\%[[:blank:]]$ETC_DIR/$1$%d" "$TEMPFILE"
      md5sum "$ETC_DIR/$1" >> "$TEMPFILE"
      mv "$TEMPFILE" "$HASH_FILE"
   fi
}

do_update(){
   grub-mkconfig -o /boot/grub/grub.cfg || true
}

# main

case "$1" in
   divert)
      do_divert
      ;;
   undivert)
      undo_divert
      ;;
   *)
      echo "Usage: $0 {divert|undivert}" >&2
      exit 1
      ;;
esac

do_update
exit 0