#!/bin/sh
# vim: et sw=2 sts=2 ts=2 tw=0:
#
# Copyright 2013 Dimitris Tzemos <djemos@slackel.gr>
# Copyright 2014 Cyrille Pontvieux <jrd@salixos.org>
# 
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

initialize() {
  if [ ! -d "$TMP" ]; then
    mkdir -p "$TMP"
    chmod 700 "$TMP"
  fi
  # T_PX is the root device. Used in the Slackware installer.
  # The variable name is kept the same here, for consistence.
  if [ -n "$!" ] && [ -d "$1" ]; then
    T_PX="$1"
  elif [ -r $TMP/SeTT_PX ]; then
    T_PX=$(cat $TMP/SeTT_PX)
  else
    T_PX=/
  fi
  cd "$T_PX"
  # Determine the root partition (such as /dev/hda2)
  if [ -n "$2" ] && [ -e "$2" ]; then
    DEV="$2"
  elif [ -r $TMP/SeTrootdev ]; then
    DEV=$(cat $TMP/SeTrootdev)
  else
    DEV=$(df .|sed -rn '$s/^([^ \t]+)[ \t].*/\1/p')
  fi
  [ -n "$DEV" ] || exit 1
  # Set OS name
  # are we on a running system?
  if [ -r etc/slackware-version ]; then
    OS="Salix $(sed -e 's/^Slackware //' etc/slackware-version)"
  else
    OS="Salix"
  fi
  # Title
  BACKTITLE="$OS - GRUB Installer"
}

ask_append() {
  dialog \
    --title 'OPTIONAL GRUB_CMDLINE_LINUX_DEFAULT="<kernel parameters>" LINE' \
    --inputbox \
"Some systems might require extra parameters to be passed to the kernel. \
If you needed to pass parameters to the kernel when you booted the Slackware \
bootdisk, you'll probably want to enter the same ones here.  Most \
systems won't require any extra parameters.  If you don't need any, just \
hit ENTER to continue.\n\
" 12 72 2> $TMP/reply
  RETVAL=$?
  return $RETVAL
}

append_grub_conf() {
  ask_append;
  GRUB_CMDLINE_LINUX_DEFAULT="quiet $(cat $TMP/reply)"
  UTFVT='vt.default_utf8=1'
  sed -i "
    s/GRUB_CMDLINE_LINUX_DEFAULT=.*/GRUB_CMDLINE_LINUX_DEFAULT='$GRUB_CMDLINE_LINUX_DEFAULT'/;
    s/GRUB_CMDLINE_LINUX=.*/GRUB_CMDLINE_LINUX='$UTFVT'/;
    " etc/default/grub
}

install_grub() {
  # Setup Menu
  dialog --backtitle "$BACKTITLE" \
         --title ' INSTALL GRUB2 ' \
         --menu "\nWhere do you want to install the boot loader?" 0 0 0 \
    "MBR" "Install in $(echo "$DEV"|sed 's/[0-9]$//') (recommended) " \
    "ROOT" "Install in $DEV (Expert)" \
    "EXIT" "Quit (Do not install GRUB)" \
    2> $TMP/option_menu.txt
  OPTION="$(cat $TMP/option_menu.txt)"
  if [ "$OPTION" = "MBR" ]; then
    DEVICE="$(echo "$DEV"|sed 's/[0-9]$//')"
  elif [ "$OPTION" = "ROOT" ]; then
    DEVICE="$DEV"
  else
    clear && exit 1
  fi
  # Confirm Installation
  dialog --backtitle "$BACKTITLE" \
         --title ' CONTINUE? ' \
         --yesno "\n This will install the GRUB2 bootloader \n in $DEVICE \n " 0 0 || exit 1
  # install grub2
  TEXT="Installing bootloader in $DEVICE...\n "
  chroot "$T_PX" grub-install --target=i386-pc --boot-directory=/boot --recheck --force $DEVICE 2>&1 |\
  while read LINE; do
    TEXT="$TEXT \n$LINE"
    dialog --backtitle "$BACKTITLE" --title ' INSTALLING GRUB2 ' --infobox "$TEXT" 0 0
  done
  sleep 3
  # Update boot menu
  TEXT="Updating boot/grub/grub.cfg...\n "
  chroot "$T_PX" update-grub 2>&1 |\
  while read LINE; do
    TEXT="$TEXT \n$LINE"
    dialog --backtitle "$BACKTITLE" --title ' UPDATING GRUB2 ' --infobox "$TEXT" 0 0
  done
  sleep 1
}

# Check for root
[ $(id -u) -eq 0 ] || exit 1
# Create temporary directory
TMP=/var/log/setup/tmp
T_PX='' # passed as first argument by the installer
DEV='' # passed as second argument by the installer
BACKTITLE=''
initialize "$@"
cd "$T_PX"
append_grub_conf
install_grub
rm -f $TMP/reply $TMP/option_menu.txt 2>/dev/null || true