#!/usr/bin/env bash
##
# Copyright (C) 2013-2016 Janek Bevendorff
# Website: http://www.refining-linux.org/
# 
# Set up a backup user.
# 
# The MIT License (MIT)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
##
if [ "$1" == "" ] || [ "$2" == "" ]; then
	. rs-version
	echo "Usage: $(basename $0) <remote host> <remote username> [<ssh public key file>]"
	exit
fi

. /etc/rs-backup/server-config

remote_hostname="$1"
remote_username="$2"
ssh_key_file="$3"
local_username="${remote_hostname}-${remote_username}"

# config template variables
USERNAME="${local_username}"
GROUPNAME="${local_username}"
HOME_DIR="${BACKUP_ROOT}/${local_username}"

# Detect distribution
distribution=$(rs-detect-distribution)

# Synology DSM
if [[ "Synology" == ${distribution} ]]; then
	GROUPNAME="users"
	
	# Create group if it does not exist
	synogroup --get "${USER_GROUP}" > /dev/null 2>&1
	if [ $? -ne 0 ]; then
		synogroup --add "${USER_GROUP}" > /dev/null
		synogroup --descset "${USER_GROUP}" "rs-backup group" > /dev/null
	fi

	# Create (disabled) user 
	synouser --add "${USERNAME}" "" "" 1 "" 0
	sed -i "s:^\(${USERNAME/./\\.}\)\:[^\:]*\::\1\:*\::" /etc/shadow

	# Re-enable user, set description
	synouser --modify "${USERNAME}" "rs-backup user" 0 ""

	# Add user to group (Synology Y U so complicated?!)
	members=$(synogroup --get "${USER_GROUP}" | grep -o "^[0-9]\+:\[.\+\]\$" | sed "s/[0-9]\+:\[\(.\+\)\]/\1/g")
	synogroup --member "${USER_GROUP}" "${USERNAME}" ${members} > /dev/null

	# Set correct home dir and shell
	sed -i "s:^\(${USERNAME/./\\.}\:.\+\:\)[^\:]\+\:/sbin/nologin\$:\1${HOME_DIR//:/\:}\:/bin/ash:" /etc/passwd

	# Create home dir
	rmdir "/var/services/homes/${USERNAME}"
	cp -R /etc/rs-skel "${HOME_DIR}"
	chmod 0700 "${HOME_DIR}"
	chown -R "${USERNAME}:${GROUPNAME}" "${HOME_DIR}"

# "Normal" Linux systems
else
	# Create group if it does not exist
	if ! grep -q "^${USER_GROUP}:" /etc/group; then
		groupadd "${USER_GROUP}"
	fi
	useradd -G "${USER_GROUP}" -b "${BACKUP_ROOT}" -m -k /etc/rs-skel -p '*' -s /bin/bash -c "rs-backup user" "${local_username}"
fi

rs-update-passwd

if $SET_QUOTA; then
	rs-setquota "${local_username}"
fi

# Generate config files from templates
rsync_conf="$(cat /etc/rs-backup/rsync.conf.template)"
rsnapshot_conf="$(cat /etc/rs-backup/rsnapshot.conf.template)"

rsync_conf=$(eval "cat << EOF
${rsync_conf}
EOF")

rsnapshot_conf=$(eval "cat << EOF
${rsnapshot_conf}
EOF")

echo "${rsync_conf}" > "${HOME_DIR}/rsync.conf"
echo "${rsnapshot_conf}" > "${HOME_DIR}/rsnapshot.conf"

# Protect config files
chown root:root "${HOME_DIR}/rsync.conf"
chmod 0644 "${HOME_DIR}/rsync.conf"
chown root:root "${HOME_DIR}/rsnapshot.conf"
chmod 0644 "${HOME_DIR}/rsnapshot.conf"

# Set permissions for backup directory
chown -R "${USERNAME}:${GROUPNAME}" "${HOME_DIR}/${FILES_DIR}"
chmod -R 0755 "${HOME_DIR}/${FILES_DIR}"

# If SSH key file has been specified
if [ "${ssh_key_file}" != "" ]; then
	rs-add-ssh-key "${remote_hostname}" "${remote_username}" "${ssh_key_file}"
fi