#!/usr/bin/env bash
#=============================================================================
# Copyright 2010-2012 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 push to
# a Gerrit Code Review instance for this project.

# Project configuration instructions:
#
# - Run a Gerrit Code Review server
#
# - Populate adjacent "config" file with:
#    gerrit.site = Top Gerrit URL (not project-specific)
#    gerrit.project = Name of project in Gerrit
#    gerrit.pushurl = Review site push URL with "$username" placeholder
#    gerrit.remote = Gerrit remote name, if not "gerrit"
#    gerrit.url = Gerrit project URL, if not "$site/p/$project"
#                 optionally with "$username" placeholder

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

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

# Load the project configuration.
site=$(git config -f config --get gerrit.site) &&
project=$(git config -f config --get gerrit.project) &&
remote=$(git config -f config --get gerrit.remote ||
	 echo "gerrit") &&
fetchurl_=$(git config -f config --get gerrit.url ||
	    echo "$site/p/$project") &&
pushurl_=$(git config -f config --get gerrit.pushurl ||
	   git config -f config --get gerrit.url) ||
die 'This project is not configured to use Gerrit.'

# Get current gerrit push URL.
pushurl=$(git config --get remote."$remote".pushurl ||
	  git config --get remote."$remote".url || echo '') &&

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

  '"$pushurl"'
' &&
	read -ep 'Reconfigure Gerrit? [y/N]: ' ans &&
	if [ "$ans" == "y" ] || [ "$ans" == "Y" ]; then
		setup=1
	else
		setup=''
	fi
else
	echo 'Remote "'"$remote"'" is not yet configured.

'"$project"' changes must be pushed to our Gerrit Code Review site:

  '"$site/p/$project"'

Register a Gerrit account and select a username (used below).
You will need an OpenID:

  http://openid.net/get-an-openid/
' &&
	read -ep 'Configure Gerrit? [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
	echo 'Sign-in to Gerrit to get/set your username at

  '"$site"'/#/settings

Add your SSH public keys at

  '"$site"'/#/settings/ssh-keys
' &&
	read -ep "Gerrit username? [$USER]: " gu &&
	if test -z "$gu"; then
		gu="$USER"
	fi &&
	fetchurl="${fetchurl_/\$username/$gu}" &&
	if test -z "$pushurl"; then
		git remote add "$remote" "$fetchurl"
	else
		git config remote."$remote".url "$fetchurl"
	fi &&
	pushurl="${pushurl_/\$username/$gu}" &&
	if test "$pushurl" != "$fetchurl"; then
		git config remote."$remote".pushurl "$pushurl"
	fi &&
	echo 'Remote "'"$remote"'" is now configured to push to

  '"$pushurl"'
'
fi &&

# Optionally test Gerrit access.
if test -n "$pushurl"; then
	read -ep 'Test access to Gerrit (SSH)? [y/N]: ' ans &&
	if [ "$ans" == "y" ] || [ "$ans" == "Y" ]; then
		echo -n 'Testing Gerrit access by SSH...'
		if git ls-remote --heads "$pushurl" >/dev/null; then
			echo 'passed.'
		else
			echo 'failed.' &&
			die 'Could not access Gerrit.  Add your SSH public keys at

  '"$site"'/#/settings/ssh-keys
'
		fi
	fi
fi &&

# Set up GerritId hook.
hook=$(git config --get hooks.GerritId || echo '') &&
if test -z "$hook"; then
	echo '
Enabling GerritId hook to add a "Change-Id" footer to commit
messages for interaction with Gerrit.  Run

  git config hooks.GerritId false

to disable this feature (but you will be on your own).' &&
	git config hooks.GerritId true
else
	echo 'GerritId hook already configured to "'"$hook"'".'
fi