#!/bin/sh

GVF=$1
APP=$2
DEF_VER=UNKNOWN

# First see if there is a version file (included in release tarballs),
# then try git-describe, then default.
if test -f version
then
	VN=$(cat version)
elif test -d .git
then
	VN=$(git describe 2>/dev/null) && git update-index -q --refresh
	HEAD=$(git rev-parse --verify --short HEAD 2>/dev/null)

	if [ -n "$VN" ] ; then
	    VN="$VN-$HEAD"
	else
	    VN="none-$HEAD"
	fi

	test -z "$(git diff-index --name-only HEAD --)" || VN="$VN-dirty"
else
	VN="$DEF_VER"
fi

#VN=$(expr "$VN" : v*'\(.*\)')

echo "$VN"

if test -r $GVF
then
	VC=$(grep SYSTEM_VERSION $GVF | sed -e 's/^#define SYSTEM_VERSION //')
	VM=$(grep SYSTEM_APP $GVF | sed -e 's/^#define SYSTEM_APP //')
else
	VC=unset
fi
if [ -n "$APP" ] ; then
    APP="-$APP"
fi

test "\"$VN\"" = "$VC" -a "\"$APP\"" = "$VM" || {
	echo "#define SYSTEM_VERSION \"$VN\"" >$GVF
	echo "#define SYSTEM_APP \"$APP\"" >>$GVF

}