#!/usr/bin/env bash
#=============================================================================
# Copyright 2010-2015 Kitware, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#=============================================================================

# Run this script to set up the local Git repository to use the
# preferred upstream repository URLs.

# Project configuration instructions:
#
# - Populate adjacent "config" file with:
#    upstream.url = Preferred fetch url for upstream remote
#    upstream.remote = Preferred name for upstream remote, if not "origin"

die() {
	echo 1>&2 "$@" ; exit 1
}

# Make sure we are inside the repository.
cd "${BASH_SOURCE%/*}" &&

# Load the project configuration.
url=$(git config -f config --get upstream.url) &&
remote=$(git config -f config --get upstream.remote ||
	 echo 'origin') ||
die 'This project is not configured to use a preferred upstream repository.'

# Get current upstream URLs.
fetchurl=$(git config --get remote."$remote".url || echo '') &&
pushurl=$(git config --get remote."$remote".pushurl || echo '') &&

if test "$fetchurl" = "$url"; then
	echo 'Remote "'"$remote"'" already uses recommended upstream repository.'
	exit 0
fi

upstream_recommend='
We recommended configuring the "'"$remote"'" remote to fetch from upstream at

  '"$url"'
'

# Tell user about current configuration.
if test -n "$fetchurl"; then
	echo 'Remote "'"$remote"'" is currently configured to fetch from

  '"$fetchurl"'
' &&
	if test -n "$pushurl"; then
		echo 'and push to

  '"$pushurl"
	fi &&
	echo "$upstream_recommend" &&
	if test -n "$pushurl"; then
		echo 'and to never push to it directly.
'
	fi &&

	read -ep 'Reconfigure "'"$remote"'" remote as recommended? [y/N]: ' ans &&
	if [ "$ans" == "y" ] || [ "$ans" == "Y" ]; then
		setup=1
	else
		setup=''
	fi
else
	echo 'Remote "'"$remote"'" is not yet configured.' &&
	echo "$upstream_recommend" &&
	read -ep 'Configure "'"$remote"'" remote as recommended? [Y/n]: ' ans &&
	if [ "$ans" == "n" ] || [ "$ans" == "N" ]; then
		exit 0
	else
		setup=1
	fi
fi &&

# Perform setup if necessary.
if test -n "$setup"; then
	if test -z "$fetchurl"; then
		git remote add "$remote" "$url"
	else
		git config remote."$remote".url "$url" &&
		if old=$(git config --get remote."$remote".pushurl); then
			git config --unset remote."$remote".pushurl ||
			echo 'Warning: failed to unset remote.'"$remote"'.pushurl'
		fi
	fi &&
	echo 'Remote "'"$remote"'" is now configured to fetch from

  '"$url"'
'
fi