#!/bin/sh

# Copyright (C) 2015
# Thomas Schmitt <scdbackup@gmx.net>, libburnia-project.org
# Provided under BSD license: Use, modify, and distribute as you like.

echo >&2
echo "frontend/grub-mkrescue-sed.sh manipulating xorriso arguments" >&2
echo >&2

# This script may be handed by its absolute path to grub-mkrescue
# via option --xorriso= . E.g.
#
#   mkdir minimal
#   touch minimal/empty-file.txt
#   grub-mkrescue -o output.iso minimal \
#         --xorriso=/home/thomas/xorriso-1.4.3./frontend/grub-mkrescue-sed.sh
#
# It will manipulate the xorriso arguments before
# they get executed by the neighboring ../../xorriso/xorriso program.
#
# In its current form it implements an experiment which should be
# accompanied by a xorriso from
#   export CPPFLAGS="-DLibisofs_mjg_boot_for_grub2" 
#   ./configure && make clean && make

# Variation settings:

# First argument of -append_partition
partno=1

# Replacement for option --protective-msdos-label
protective="--protective-msdos-label"

# "yes" make the script very verbous
debug=no

if test "$debug" = yes
then
  # Show arguments
  echo "$0" >&2
  for i in "$@"
  do
    echo "|""$i""|" >&2
  done
fi

# Look for the name of the /tmp directory with the GRUB2 files.
# It is the next argument after -r.
next_is_dir=0
dir="."
for i in "$@"
do
  if test x"$i" = x"-r"
  then
    next_is_dir=1
  elif test $next_is_dir = 1
  then
    next_is_dir=0
    dir="$i"
  fi
done

if test "$debug" = yes
then
  # Show files on disk
  find "$dir"
fi

# Exchange arguments for the experimental GRUB2 mjg layout
x=$(echo " $*" | sed \
    -e "s/-efi-boot-part --efi-boot-image/-no-pad -append_partition $partno 0xef \/tmp\/$(basename "$dir")\/efi.img/" \
    -e "s/--efi-boot efi\.img/-eltorito-alt-boot -e efi.img -no-emul-boot -isohybrid-gpt-basdat/" \
    -e "s/--protective-msdos-label/$protective/" \
     )

if test "$debug" = yes
then
  echo "+ converted xorriso arguments:" >&2
  echo "  $x" >&2
fi

# Run neighboring xorriso binary with the altered arguments
self_dir=$(dirname $(dirname "$0") )
"$self_dir"/xorriso/xorriso $x