#!/bin/bash

mode=$1
shift

help() {
	echo ""
	echo "Usage: $0 co patch file"
	echo "       $0 ci patch file"
	echo ""
	echo "       $0 joe file"
	echo "       $0 vim file"
	echo ""
	echo "       $0 ed patch [file]"
	echo ""
	echo "       $0 filter patch command"
	echo ""
	exit 1
}

case "$mode" in
  joe)
	file="${1%.rej}"
	joe $file{,.rej}
	;;
  vim)
	file="${1%.rej}"
	vim -o $file{,.rej}
	;;
  ed)
	if [ -n "$2" ]; then
		$0 co "$1" "$2"
		$0 vim "$2"
		$0 ci "$1" "$2"
	else
		cp "$1" "$1.fixed"; vim "$1.fixed"
		diff -u "$1" "$1.fixed" > "$(dirname $1)/fixdiff_$(basename $1).part"
		touch "$(dirname $1)/fixdiff_$(basename $1)"
		mv "$(dirname $1)/$(basename $1).fixed" "$1"

		combinediff "$(dirname $1)/fixdiff_$(basename $1)" \
			"$(dirname $1)/fixdiff_$(basename $1).part" \
			> "$(dirname $1)/fixdiff_$(basename $1).new"
		mv "$(dirname $1)/fixdiff_$(basename $1).new" \
			"$(dirname $1)/fixdiff_$(basename $1)"
		rm -f "$(dirname $1)/fixdiff_$(basename $1).part"
	fi
	;;
  co)
	patch=$1; shift
	if [ ! -f "$patch" ] || [ $# -ne 1 ]; then help; fi

	for x; do
		x="${x%.rej}"
		rm -f "$x".{orig,rej}

		if [ -f "$x" ]; then cp "$x" "$x.orig"
		else touch "$x.orig"; fi

		filterdiff -i "$x" "$patch" | patch -p0
	done
	;;
  ci)
	patch=$1; shift
	if [ ! -f "$patch" ] || [ $# -ne 1 ]; then help; fi

	{
		gotit=""
		awk '/^--- / { exit; } { print; }' < "$patch"
		while read f; do
			thisisnew=0
			for x; do
				x="${x%.rej}"
				if [ "$f" = "$x" ]; then thisisnew=1; fi
			done
			if [ "$thisisnew" = "0" ]; then
				filterdiff -i "$f" "$patch"
			else
				filterdiff -i "$f" $patch | head -n 2
				diff -u "$x.orig" "$x" | tail -n +3
				gotit="$gotit $f "
			fi
		done < <( lsdiff "$patch" )
		for x; do
			x="${x%.rej}"
			if [ -n "${gotit##* $x *}" ]; then
				diff -u "$x.orig" "$x"
			fi
		done
	} > "$patch.fixed"

	diff -u "$patch" "$patch.fixed" \
		> "$(dirname $patch)/fixdiff_$(basename $patch).part"
	touch "$(dirname $patch)/fixdiff_$(basename $patch)"
	mv "$patch.fixed" "$patch"

	combinediff "$(dirname $patch)/fixdiff_$(basename $patch)" \
		"$(dirname $patch)/fixdiff_$(basename $patch).part" \
		> "$(dirname $patch)/fixdiff_$(basename $patch).new"
	mv "$(dirname $patch)/fixdiff_$(basename $patch).new" \
		"$(dirname $patch)/fixdiff_$(basename $patch)"
	rm -f "$(dirname $patch)/fixdiff_$(basename $patch).part"

	for x; do
		x="${x%.rej}"
		rm -f "$x.rej"
		mv "$x.orig" "$x"
	done
	;;
  filter)
	eval "$2" < "$1" > "$1.fixed"
	diff -u "$1" "$1.fixed" > "$(dirname $1)/fixdiff_$(basename $1).part"
	touch "$(dirname $1)/fixdiff_$(basename $1)"
	mv "$1.fixed" "$1"

	combinediff "$(dirname $1)/fixdiff_$(basename $1)" \
		"$(dirname $1)/fixdiff_$(basename $1).part" \
		> "$(dirname $1)/fixdiff_$(basename $1).new"
	mv "$(dirname $1)/fixdiff_$(basename $1).new" \
		"$(dirname $1)/fixdiff_$(basename $1)"
	rm -f "$(dirname $1)/fixdiff_$(basename $1).part"
	;;
  *)
	help
	;;
esac