#!/bin/bash

# Copyright (C) 2010-2011 by Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
#
# This 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 3 of the License, or
# (at your option) any later version.
#
# This 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.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA

set -xe

CHECKOUT=${1:-master}

[ -d .git ] && {

	TIMESTAMP=$(date +%s)
	CURRENT_BRANCH=$(git branch | grep "*" | awk '{print $2}')

	# switch to branch given as $CHECKOUT, if it does not exist locally, create it...
	git checkout $CHECKOUT &>/dev/null || git checkout -b $CHECKOUT >/dev/null

	# switch to a tmp branch...
	git checkout -b tmp-$TIMESTAMP &>/dev/null

	# pull $CHECKOUT from origin into the tmp branch
	LANG=en_US.UTF-8 git pull origin $CHECKOUT 2>/dev/null | egrep "^Already up-to-date.$" &>/dev/null && {
		# drop the tmp branch
		git checkout $CURRENT_BRANCH &>/dev/null
		git branch -D tmp-$TIMESTAMP >/dev/null
		exit 1
	} || {
		# drop the tmp branch
		git checkout $CURRENT_BRANCH &>/dev/null
		git branch -D tmp-$TIMESTAMP >/dev/null
		exit 0
	}
} || exit 0
