#!/bin/bash
#set -x

NR=0

set -e
function ver
{
	eval `cat Makefile | head -4  | perl -pe 's/ //g'`
	echo $VERSION.$PATCHLEVEL.$SUBLEVEL$EXTRAVERSION
}
function gitaddnew
{
	git ls-files -o --exclude-standard | xargs --no-run-if-empty git add 
}
VER=$(ver)
if ! [ -d .git ]; then
	echo first patch run?? >&2
	echo ver: $VER
	CDIR="$HOME/rpm2git-linux.git"
	if ! [ -d "$CDIR" ]; then
		git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-2.6-stable.git $CDIR
	fi 
	ln -s $CDIR/.git .git
	git remote update
	git fetch --tags
	echo adding...
	gitaddnew
	echo diffing...
	if ! git diff v$VER | head -100 | diffstat | grep '^ 0 files changed'; then
		echo unable to find starting git revision
		exit 1
	fi
	git reset v$(ver)
	echo diffstat:
	git diff v$VER | head -100 | diffstat
	git describe
	echo sleeping...
	sleep 10
	VER=""
fi
PATCHNEXT=false
PATCH="$(readlink /proc/self/fd/0)"
for arg in "$@"; do
	if $PATCHNEXT; then
		PATCH="$arg"	
		break;
	fi
	if [ "$arg" == "-i" ]; then
		PATCHNEXT=true
	fi;
done
echo PATCH: "'$PATCH'"
{ 
	echo my stdin is from \"`readlink /proc/self/fd/0`\"
	echo PATCH: "'$PATCH'"
	echo args: "$@"
}	>> ~/logs/patch.log

function cherry_pick
{
	PATCH="$1"
	COMMIT=$(formail -x Commit-ID < "$PATCH")
	if [ -z "$COMMIT" ]; then
		return -1;
	fi
	# TODO: check that the patch in git is the
	# same as the one in the RPM.  They are
	# not always
	echo cherry picking commit: "'$COMMIT'"
	if ! git cherry-pick $COMMIT; then
		echo aborting bad cherry pick
		git reset --hard HEAD
		return -2
	fi
	return 0
}
function git_am {
	if ! git am "$PATCH"; then
		git am --skip
		git reset --hard HEAD
		return -2
	fi
	return 0;
}
# Cherry picking seems like it would be nice to use
# but it appears that at least openSUSE rpms have
# patches with a 'Commit-ID:' in them that are not
# quite the same as the commit in git with that id.
# Oh, well.
#
#if cherry_pick "$PATCH"; then
#	echo cherry picked patch
#el
if git_am "$PATCH"; then
	echo am\'d patch
elif /usr/bin/patch "$@"; then
	gitaddnew
	git commit -a -m "fill me in"
fi;

# there is almost certainly a better way of doing this
#

RET=$?
VER2=$(ver)
if [ "$VER" == "$VER2" ]; then
	echo done, `git describe`
	exit $RET
fi
echo changing ver from $VER to $VER2
VER=$VER2
#set -x
git describe
gitaddnew
# back out the patch
git reset --hard HEAD^
#COMMIT=`git rev-list v$VER -n 1`
git merge v$VER
git describe
exit $RET