#!/bin/bash
#
# editdiff - simple wrapper around rediff
# Copyright (C) 2001-2002, 2011 Tim Waugh <twaugh@redhat.com>

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

version() {
  echo "editdiff - patchutils version 0.3.3"
}

usage() {
  echo "usage: editdiff FILE"
}

while [ "$#" -gt 0 ]
do
  case "$1" in
  --help)
	usage
	exit 0
	;;
  --version)
	version
	exit 0
	;;
  --)
	shift || { usage; exit 1; }
	if [ -z "$FILE" ]
	then
	  FILE="$1"
	fi
	shift
	[ "$#" -gt 0 ] && { usage; exit 1; }
	;;
  *)
	if [ -z "$FILE" ]
	then
	  FILE="$1"
	fi
	shift
	;;
  esac
done
[ "$#" -gt 0 ] && { usage; exit 1; }
[ -n "$FILE" ] || { usage; exit 1; }

TMPD="$(mktemp -d /tmp/editdiff.XXXXXX)" || \
	{ echo >&2 "Failed to create temporary directory"; exit 1; }
trap 'rm -rf "${TMPD}"' EXIT
NAME="$(basename "${FILE}")"
filterdiff -v --format=unified <"${FILE}" >"${TMPD}/${NAME}.orig" || exit 1
cp "${TMPD}/${NAME}.orig" "${TMPD}/${NAME}" || exit 1
${EDITOR:-${VISUAL:-vi}} "${TMPD}/${NAME}" || \
	{ echo >&2 "Editor exited with non-zero exit status"; exit 1; }
cmp -s "${TMPD}/${NAME}" "${TMPD}/${NAME}.orig" && \
	{ echo >&2 "No changes" ; exit 0; }
mv "${FILE}" "${FILE}.orig"
rediff "${TMPD}/${NAME}.orig" "${TMPD}/${NAME}" > "${FILE}" || \
	{ cat "${TMPD}/${NAME}" > "${FILE}"; \
	  echo 1>&2 "rediff failed."
	  echo 1>&2 "Unedited patch is in ${FILE}.orig, edited patch is in ${FILE}";
	  exit 1; }