#!/bin/ksh

#
# Script for adding/removing dependancies from a SysV PKG file
# Written by Philip Brown
#
# Version @(#) pkgdepend.ksh 1.2@(#)

usage(){
	print "Usage:"
	print " pkg-depends: file.pkg PKGone [...PKGtwo]"
	print " pkg-depends -r file.pkg"
	print ""
	print "This script changes the dependancies of a package"
	print "You can give a list of packages, and it will change the package"
	print "file dependancies. This is overwrite, not add"
	print "Or, you can give the -r option, which will remove all dependancies"
	print ""
	print "BUGS:"
	print "  This also only handles 'depends on', not other depend stuff"
	print "  You cannot specify versions of packages with this script."
	print "  (but on the brighter side, pkg-get will eventually try "
	print "  to grab the 'latest' version when it sees a depend)"
	print "SEE ALSO:"
	print "    pkgreloc.ksh"
	
}

if [ $# -lt 2 ] ; then
	usage
	exit 1
fi

if [ "$1" == "-r" ] ; then
	removedepend=1
	shift
fi

############################################################
# Subroutine section

#I'm highly ashamed of this. There should be a better way to calculate
# the durn SysV pkg checksum of a file. But I dont know it yet.
# So make an empty package, for the sole purpose of calculating a checksum
# assumes "depend" file is in current directory
hackdependchecksum() {
	print Doing nasty checksum hack >/dev/fd/2
	
	HACKDIR=/tmp/hack.$$
	mkdir $HACKDIR

	(print "PKG=fakepkg";print "NAME=fakepkg";print "CATEGORY=system"
	 )>$HACKDIR/pkginfo
	(print "i depend";print "i pkginfo") >$HACKDIR/prototype
	cp depend $HACKDIR
	(cd $HACKDIR && pkgmk -d . )
	if [ $? -ne 0 ] ; then
		print ERROR: checksum generation failed
		exit 1
	fi

	line=`grep depend $HACKDIR/fakepkg/pkgmap`

	if [ $? -ne 0 ] ; then
		print ERROR: checksum generation failed
		exit 1
	fi

	rm -r /tmp/hack.$$
	print "$line"
}

############################################################

ORGPKGFILE="$1"
shift


case $ORGPKGFILE in
	*/*)
		print "Sorry, this script has to run in same directory as pkg"
		exit 1
		# because I dont want to have to deal with
		# doing basename on top of everything else
		# See comment on pkgtrans at bottom
	;;
	*.gz)
		PKGFILE=${ORGPKGFILE%.gz}
		print "gunzipping, in preparation for modification"
		gunzip -c $ORGPKGFILE >$PKGFILE
	;;
	*)
	PKGFILE=$ORGPKGFILE
	;;
esac


head -1 $PKGFILE | grep 'PaCkAgE DaTaStReAm' >/dev/null
if [[ $? -ne 0 ]] ; then
        print $PKGFILE is not a SysV PKG file.
	if [ "$PKGFILE" != "$ORGPKGFILE" ] ; then
		rm $PKGFILE
	fi
        exit 1
fi

PKGNAME=`awk 'NR==2 {print $1; exit;}' $PKGFILE`

TDIR=/tmp/pkg.$$
mkdir $TDIR

print Extracting pkg files for modification
pkgtrans $PKGFILE $TDIR $PKGNAME

ORIGDIR=$PWD

cd $TDIR/$PKGNAME
if [ $? -ne 0 ] ; then
	print ERROR: something went wrong with extraction
	exit 1
fi

# skip any existing depend line
#egrep -v ' i depend|^: ' pkgmap >pkgmap.tmp
egrep -v 'i depend[ $]' pkgmap >pkgmap.tmp

if [ "$removedepend" != "-r" ] ; then
	# in case it isnt there already
	mkdir install 2>/dev/null
	while [ $# -gt 0 ] ; do
		print "P $1" >>depend
		shift
	done
	dependline=`hackdependchecksum`
	echo "$dependline" >>pkgmap.tmp
	mv depend install/depend
fi
mv pkgmap.tmp pkgmap

cd $ORIGDIR

print renaming original pkg file to $ORGPKGFILE.old
mv $ORGPKGFILE ${ORGPKGFILE}.old

print Reassembling pkg file

pkgtrans $TDIR $PKGFILE $PKGNAME
# Wierd thing about pkgtrans. It makes the PKGFILE in TDIR, NOT
# in your current directory
#
mv $TDIR/$PKGFILE .


if [ "$PKGFILE" != "$ORGPKGFILE" ] ; then
	print "Adjustment done. Gzipping..."
	gzip $PKGFILE
	print "done"
fi