#! /bin/bash
set -x

if ! [ -d kernel -a -d Documentation ]
then
    echo >&2 "Not in kernel top level directory. Exiting"
    exit 1
fi
TOPPATCHDIR=/usr/src/kernel-patches/lustre
ARCHITECTURE=`dpkg --print-installation-architecture`

QUILT="quilt --quiltrc /dev/null"
export QUILT_PATCHES="$TOPPATCHDIR/patches"

if ! [ -f debian/APPLIED_all_lustre ]; then
  echo >&2 "Lustre patch not applied."
  exit 0
fi
VERSION=$(grep ^VERSION Makefile 2>/dev/null | \
        sed -e 's/[^0-9]*\([0-9]*\)/\1/')
PATCHLEVEL=$( grep ^PATCHLEVEL Makefile 2>/dev/null | \
        sed -e 's/[^0-9]*\([0-9]*\)/\1/')
SUBLEVEL=$(grep ^SUBLEVEL Makefile 2>/dev/null | \
        sed -e 's/[^0-9]*\([0-9]*\)/\1/')
#EXTRAVERSION=$(grep ^EXTRAVERSION Makefile | head -1 2>/dev/null | \
#        sed -e 's/EXTRAVERSION =[       ]*\([^  ]*\)$/\1/')
#KERNELBRANCHLET=${VERSION}.${PATCHLEVEL}.${SUBLEVEL}
#KERNELRELEASE=${KERNELBRANCHLET}${EXTRAVERSION}
KERNELRELEASE=${VERSION}.${PATCHLEVEL}.${SUBLEVEL}

# Check for depends on lustre
if grep -l "^DEPENDS=.*[' ]all/unpatch/lustre[' ]" debian/APPLIED_* >/dev/null 2>/dev/null; then
    # There are patches depending on this one, to be removed before.
    # the dep will be removed by the last of those other patches.
    echo >&2 "NOT unpatching \"Lustre Filesystem patch for the Linux kernel\" since other patches still rely on it"
    exit 0
fi

if ! [ -d debian/APPLIED_all_lustre_tmp/.pc.lustre ]; then
  cat >&2 <<EOF
ERROR: .pc directory missing for unpatching. I strongly suggest
you remove this kernel tree and unpack a clean one.
EOF
  exit 1
fi

if ! [ -e debian/APPLIED_all_lustre_tmp/series.lustre ]; then
  cat >&2 <<EOF
ERROR: series file missing for unpatching. I strongly suggest
you remove this kernel tree and unpack a clean one.
EOF
  exit 1
fi

cleanup() {
  echo >&2 Cleaning up
  if [ -e series ]; then
    echo >&2 Removing series file
    rm series
  fi
  if [ -e debian/APPLIED_all_lustre_tmp/series.orig ]; then
    echo >&1 Restoring orig series file
    mv debian/APPLIED_all_lustre_tmp/series.orig series
  fi
  if [ -e .pc ]; then
    echo >&2 Removing .pc dir
    rm -r .pc
  fi
  if [ -e debian/APPLIED_all_lustre_tmp/.pc.orig ]; then
    echo >&2 Restoring orig .pc dir
    mv debian/APPLIED_all_lustre_tmp/.pc.orig .pc
  fi
}

if [ -e series ]; then
  echo >&2 Preserving existing series file
  mv series debian/APPLIED_all_lustre_tmp/series.orig
fi
if [ -e .pc ]; then
  echo >&2 Preserving existing .pc dir
  mv .pc debian/APPLIED_all_lustre_tmp/.pc.orig
fi

trap cleanup EXIT

echo >&2 Restoring lustre quilt
mv debian/APPLIED_all_lustre_tmp/series.lustre series
mv debian/APPLIED_all_lustre_tmp/.pc.lustre .pc

echo >&2 Unpatching lustre patches
$QUILT pop -a
ERR=$?
if ! [ $ERR = 0 ]; then
  cat >&2 <<EOF
ERROR: Lustre patches failed to unpatch. I strongly suggest
you remove this kernel tree and unpack a clean one.
EOF
  cleanup
  exit $ERR
fi

echo >&2 Removing lustre quilt
rm -rf .pc series
cleanup
rm debian/APPLIED_all_lustre debian/image.d/register-lustre

echo >&2 "\"Lustre Filesystem patch for the Linux kernel\" patch for $KVERSION removed successfully"

echo >&2 "Removing empty files:"
# make an exception for ./debian, or else the stamp files will go too.
find . -path ./debian -prune -o \
       -type f -size 0 ! -name 'APPLIED*' -exec rm {} \; -print
echo >&2 "Done."

rmdir debian/image.d debian/APPLIED_all_lustre_tmp || true

echo >&2 "END unpatching lustre patch"