#!/bin/sh
# -*- coding:utf-8;mode:shell-script;mode:font-lock -*-

##
# Resolve Subversion conflicts using FileMerge.
#
# (FileMerge is a graphical diff tool in the Mac OS X Developer
# Tools.)
#
# In your working copy, do (for example):
#
#   svn-resolve .
#
# FileMerge will open a window for each file that is in a conflict
# state, showing you diffs with the left/right arrows pointing to the
# side of each change that is selected.  Diffs with gray outlines are
# automatically resolved.  Diffs with red outlines are the conflicts.
# Find those and select which side you want, or pull up the split view
# at he bottom and edit the text to what it should be.
##
# Copyright (c) 2002 Wilfredo Sanchez Vega <wsanchez@wsanchez.net>.
# All rights reserved.
#
# Permission to use, copy, modify, and distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice, this permission, and the following
# disclaimer notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
# AUTHORS BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
# WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
##

set -e
set -u

##
# Handle command line
##

usage ()
{
  program=$(basename "$0");

  if [ $# != 0 ]; then echo "$@"; echo ""; fi;

  echo "${program}: usage:";
  echo "    ${program} file1 [file2 ...]";
}

# Process arguments
while [ $# != 0 ]; do
  case "$1" in
    --help)
      usage;
      exit 0;
      ;;
    --|*) break; ;;
  esac;
done;

##
# Do The Right Thing
##

#
# If opendiff isn't installed, you can't launch FileMerge.
# If we're not in the OS X Terminal, we probably can't run FileMerge
#
if ! type opendiff >& /dev/null || [ "${TERM_PROGRAM:=}" != "Apple_Terminal" ]; then
    diff "$@";
    exit $?;
fi;

find_ancestor ()
{
    local conflict="$1";
    local    which="$2";

    n=$(ls -1 "${conflict}.merge-${which}.r"* 2>/dev/null | wc -l);

    if [ "${n}" -eq 0 ]; then
        echo "ERROR: No ${which} ancenstor found."
        return 1;
    fi;

    if [ "${n}" -gt 1 ]; then
        echo "ERROR: Multible ${which} ancenstors found:"
        ls -1 "${conflict}.merge-left.r"*
        return 1;
    fi;

    ls "${conflict}.merge-${which}.r"*
}

resolve ()
{
    local conflict="$1";

    local revision="$(svn info "${conflict}" | grep '^Revision: ' | sed 's|^Revision: ||')";

    local     left="${conflict}.working";
    local    right="$(find_ancestor "${conflict}" right)";
    local ancestor="$(find_ancestor "${conflict}" left )";

    for file in "${left}" "${right}" "${ancestor}"; do
        if [ ! -f "${file}" ]; then
            echo "ERROR: Missing file: ${file}";
            return 1;
        fi;
    done;

    opendiff "${left}" "${right}" -ancestor "${ancestor}" -merge "${conflict}";
}

for file in "$@"; do
    for conflict in $(svn status . | grep '^C' | sed 's|^C......||'); do
        resolve "${conflict}";
    done;
done;