#! /bin/sh
# patchview, Copyright (C) 2005 Randy Dunlap <rdunlap@xenotime.net>
# License:  GPL v2.
#
# uses patchutils (lsdiff) and tkdiff

# returns 'base'
function strip_filename()
{
	fn=$1
	len=${#fn}
	fx=$((len - 1))
	base=""
	while [ 1 -eq 1 ]; do
		if [ ${fn:$fx:1} == "/" ]; then
			##fx=$((fx - 1))
			base=${fn:0:$fx}
			break
		fi
		fx=$((fx - 1))
		if [ $fx -eq 0 ]; then
			break
		fi
	done
}

force=0
patchfile=$1
srctree=$2
VIEWER="tkdiff"
# or maybe "sh -c colordiff" would work

if [ "$patchfile" == "-f" ]; then
	force=1
	patchfile=$2
	srctree=$3
fi

if [ "$patchfile" = "" -o "$srctree" = "" ]; then
	echo "usage: patchview [-f] patchfile srctree"
	echo "  -f : force tkdiff even if 'patch' has errors"
	exit 1
fi

# setup temp working directory
if [ -d ~/tmp ]; then
	TMPDIR=~/tmp
else
	TMPDIR=/tmp
fi
WORKDIR=`mktemp -d -p ${TMPDIR}/XXXXXX` || echo "failed mktemp for patch files dir."

pfiles=`lsdiff --strip 1 $patchfile`

for pf in $pfiles ; do
	strip_filename $pf	# sets 'base'
	##echo pf: $pf + basename: $base
	if [ "$base" != "" ]; then
		if [ ! -e $WORKDIR/$base ]; then
			mkdir -p $WORKDIR/$base
		fi
	fi
	cp -a $srctree/$pf $WORKDIR/$pf
done

patch -p1 -bs -d $WORKDIR < $patchfile
sts=$?
if [ $sts -ne 0 ] && [ $force -eq 0 ]; then
	echo "patch errors, use 'patchview -f' to force continuation"
	rm -rf $WORKDIR
	exit 1
fi

for pf in $pfiles ; do
	$VIEWER $WORKDIR/$pf.orig $WORKDIR/$pf &
done

wait # for all viewers to exit

rm -rf $WORKDIR