#!/bin/bash

#
# Wrapper script to use FileMerge to resolve Subversion conflicts
#

FM="$(which filemerge)"
FMDIFF="$(basename $0)"
GN="/usr/local/bin/growlnotify"

# Resolve symlinks leading to FileMerge
while [ -L "$FM" ]; do
	FM_DIR="$(dirname "$FM")"
	FM="$(readlink "$FM")"
	[[ $FM == /* ]] || FM="$FM_DIR/$FM"
done

function lookup {
	local info=$1
	local wantedkey=$2
	local key
	local value
	# Split lines in info through word splitting
	local IFS=$'\n'
	for line in $info; do
		key=${line%%: *}
		value=${line#*: }
		if [ $key == $wantedkey ]; then
			RETVAL=$value
			return 0
		fi
	done
	return 1
}

while [ $# != 0 ]; do
	case $1 in
		-*)
			echo "Unknown option: $1" 1>&2
			exit 2
		;;
		*)
			if [ -z "$conflictfile" ]; then
				conflictfile=$1
			else
				echo "Too many files to resolve" 1>&2
				exit 2
			fi
	esac
	shift
done

if [ -z "$conflictfile" ]; then
	echo "Usage: $FMDIFF [options] conflictfile" 1>&2
	exit 2
fi

filedir=`dirname "$conflictfile"`
info=`svn info "$conflictfile"`
lookup "$info" "Conflict Current Base File" && leftfile=$RETVAL
lookup "$info" "Conflict Previous Working File" && rightfile=$RETVAL
lookup "$info" "Conflict Previous Base File" && ancestorfile=$RETVAL
mergefile=`basename "$conflictfile"`

if [ -z "$leftfile" ] || [ -z "$rightfile" ] || [ -z "$ancestorfile" ]; then
	echo "Can't obtain conflict info for $conflictfile" 1>&2
	exit 2
fi

function labels {
	echo Ancestor: $ancestorfile
	echo     Left: $leftfile
	echo    Right: $rightfile
}

echo Starting FileMerge... 1>&2
labels 1>&2
if [ -x "$GN" ]; then
	labels | "$GN" -a FileMerge -n "$FMDIFF" "Starting FileMerge"
fi

exec "$FM" -left "${filedir}/${leftfile}" -right "${filedir}/${rightfile}" \
	-ancestor "${filedir}/${ancestorfile}" -merge "${filedir}/${mergefile}"
