#!/bin/sh
#
# ircd-patch
# Copyright (C) 2002 Alex Badea <vampire@p16.pub.ro>
#
# $Id: ircd-patch,v 1.2 2002-04-02 09:42:32 isomer Exp $
#
# Experimental centralized patch system for ircu
#
# Return codes:
#   0 - success
#   1 - at least one live patch failed
#   2 - at least one simulation (dry run) failed 
#   3 - invalid arguments (i.e. no such patch)
#   4 - invalid operation (i.e. tried to apply when already applied)
#

DIFFS=patches/diffs
MARKS=patches/marks
retcode=0
force=0

[ ! -d $DIFFS ] && echo "*** Missing $DIFFS, creating it" ; mkdir -p $DIFFS
[ ! -d $MARKS ] && echo "*** Missing $MARKS, creating it" ; mkdir -p $MARKS

PLIST=""
for fname in $DIFFS/*.diff ; do
	name=`basename $fname | sed -e 's/\.diff//'`
	PLIST="$PLIST $name"
done

dry_run() {
	patch -p0 -N -t --dry-run $2 >/dev/null < $1
}

patch_list() {
	echo "Available patches (* marks applied patches):"
	for name in $PLIST ; do
		[ -f $MARKS/$name ] && echo -n " * " || echo -n "   "
		echo $name
	done
	echo "Done."
}

patch_test() {
	echo "Testing patches:"
	list="$*"
	[ -z "$list" ] && list=$PLIST
	for name in $list ; do
		fname=$DIFFS/$name.diff
		echo -ne "  $name\t"
		if [ ! -f $MARKS/$name ] ; then
			if dry_run "$fname" ; then
				echo -n " OK"
			else
				echo -n " PATCH FAILED"
				retcode=2
			fi
		else
			echo -n " APPLIED"
			if dry_run "$fname" -R ; then
				echo -n " OK"
			else
				echo -n " REVERSE FAILED"
				retcode=2
			fi
		fi
		echo
	done
	echo "Done."
}

patch_add() {
	name=$1
	fname="$DIFFS/$name.diff"
	if [ ! -f $fname ]; then
		echo "Patch $name ($fname) does not exist"
		retcode=3
		return
	fi

	if [ $force -lt 2 -a -f $MARKS/$name ] ; then
		echo "Patch $name seems already applied"
		retcode=4
		return
	fi

	if [ $force -lt 1 ]; then
		echo -n "Testing $fname... "
		if ! dry_run $fname ; then
			echo "Failed (use -f to force)."
			retcode=2
			return
		fi
		echo "seems ok."
	fi

	echo "Applying $fname..."
	if patch -p0 -N -t < $fname ; then
		touch $MARKS/$name
		echo "Done."
	else
		echo "Failed."
		retcode=1
	fi
}

patch_del() {
	name=$1
	fname="$DIFFS/$name.diff"
	if [ ! -f $fname ]; then
		echo "Patch $name ($fname) does not exist"
		retcode=3
		return
	fi

	if [ $force -lt 2 -a ! -f $MARKS/$name ] ; then
		echo "Patch $name doesn't seem to be applied"
		retcode=4
		return
	fi

	if [ $force -lt 1 ]; then
		echo -n "Testing $fname... "
		if ! dry_run $fname -R ; then
			echo "Failed (use -f to force)."
			retcode=2
			return
		fi
		echo "seems ok."
	fi
	
	echo "Reversing $fname..."
	if patch -p0 -R -t < $fname ; then
		rm -f $MARKS/$name
		echo "Done."
	else
		echo "Failed."
		retcode=1
	fi
}

do_help() {
	echo "Usage: $0 [-f [-f]] [args]"
	echo "Arguments may be:"
	echo "  help                Prints this help"
	echo "  list                List available patches"
	echo "  test [patch list]   Tests whether patches can be (un)applied correctly"
	echo "  add  <patch list>   Applies a patch"
	echo "  del  <patch list>   Reverses a patch"
	echo "The -f option forces patching even if a dry run fails (effective on 'add'"
	echo "and 'del' commands only). Using it twice will also skip checking whether"
	echo "a patch is already applied."
}

while [ "$1" == "-f" ]; do
	force=$[$force + 1]
	shift
done

case "$1" in
	add)
		shift
		for name in $* ; do
			patch_add $name
		done
		;;
	del)
		shift
		for name in $* ; do
			patch_del $name
		done
		;;
	test)
		shift
		patch_test $*
		;;
	list)
		patch_list
		;;
	*)
		do_help
		;;
esac

exit $retcode