# Helper library for update-grub
# Copyright (C) 2007,2008  Free Software Foundation, Inc.
#
# GRUB 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 3 of the License, or
# (at your option) any later version.
#
# GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.

transform="@program_transform_name@"

prefix=@prefix@
exec_prefix=@exec_prefix@
datarootdir=@datarootdir@
datadir=@datadir@
sbindir=@sbindir@
pkgdatadir=${datadir}/`echo @PACKAGE_TARNAME@ | sed "${transform}"`

grub_probe=${sbindir}/`echo grub-probe | sed ${transform}`

make_system_path_relative_to_its_root ()
{
  path=$1
  # abort if file doesn't exist
  if test -e $path ; then : ;else
    return 1
  fi

  # canonicalize
  if path=`readlink -f $path` ; then : ; else
    return 1
  fi

  # if not a directory, climb up to the directory containing it
  if test -d $path ; then
    dir=$path
  else
    dir=`echo $path | sed -e "s,/[^/]*$,,g"`
  fi

  num=`stat -c %d $dir`

  # this loop sets $dir to the root directory of the filesystem we're inspecting
  while : ; do
    parent=`readlink -f $dir/..`
    if [ "x`stat -c %d $parent`" = "x$num" ] ; then : ; else
      # $parent is another filesystem; we found it.
      break
    fi
    if [ "x$dir" = "x/" ] ; then
      # / is our root.
      break
    fi
    dir=$parent
  done

  # This function never prints trailing slashes (so that its output can be
  # appended a slash unconditionally).  Each slash in $dir is considered a
  # preceding slash, and therefore the root directory is an empty string.
  if [ "$dir" = "/" ] ; then
    dir=""
  fi

  echo $path | sed -e "s,^$dir,,g"
}

is_path_readable_by_grub ()
{
  path=$1

  # abort if path doesn't exist
  if test -e $path ; then : ;else
    return 1
  fi

  # abort if file is in a filesystem we can't read
  if ${grub_probe} -t fs $path > /dev/null 2>&1 ; then : ; else
    return 1
  fi

  return 0
}

convert_system_path_to_grub_path ()
{
  path=$1

  echo "Warning: convert_system_path_to_grub_path() is deprecated.  Use prepare_grub_to_access_device() instead." >&2

  # abort if GRUB can't access the path
  if is_path_readable_by_grub ${path} ; then : ; else
    return 1
  fi

  if drive=`${grub_probe} -t drive $path` ; then : ; else
    return 1
  fi

  if relative_path=`make_system_path_relative_to_its_root $path` ; then : ; else
    return 1
  fi

  echo ${drive}${relative_path}
}

prepare_grub_to_access_device ()
{
  device=$1

  # Abstraction modules aren't auto-loaded.
  abstraction="`${grub_probe} --device ${device} --target=abstraction`"
  if [ "x${abstraction}" = "x" ] ; then : ; else
    echo "insmod ${abstraction}"
  fi

  # If there's a filesystem UUID that GRUB is capable of identifying, use it;
  # otherwise set root as per value in device.map.
  echo "set root=`${grub_probe} --device ${device} --target=drive`"
  if fs_uuid="`${grub_probe} --device ${device} --target=fs_uuid 2> /dev/null`" ; then
    echo "search --fs-uuid --set ${fs_uuid}"
  fi
}

font_path ()
{
  for dir in ${pkgdatadir} /boot/grub /usr/share/grub ; do
    # FIXME: We prefer ascii because loading complete fonts is too slow (and
    # we don't yet provide the gettext magic that would make unicode useful).
    for basename in ascii unicode unifont ; do
      path="${dir}/${basename}.pff"
      if is_path_readable_by_grub ${path} > /dev/null ; then
        echo "${path}"
        return 0
      fi
    done
  done

  return 1
}

grub_file_is_not_garbage ()
{
  if test -f "$1" ; then
    case "$1" in
      *.dpkg-dist|*.dpkg-old|*.dpkg-tmp) return 1 ;; # debian dpkg
    esac
  else
    return 1
  fi
  return 0
}