#!/bin/bash

#
# Copyright (C) 2018 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
#
# This script 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 2 of the License, or
# (at your option) any later version.
#
# This script 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.

TRANSFER_BASE="/skole/tjener/transfer"
TRANSFER_TEACHERS="${TRANSFER_BASE}/nur-Lehrer"
TRANSFER_STUDENTS="${TRANSFER_BASE}/Schüler+Lehrer"

GROUP_TEACHERS="teachers"
GROUP_STUDENTS="students"

FOLDERLIST_TEACHERS="t1 t2 t3 t4 t5 t6 t7 t8 t9"
FOLDERLIST_STUDENTS="s1 s2 s3 s4 s5 s6 s7 s8 s9"

if [ -f /etc/default/itzks-transfer-create ]; then
    . /etc/default/itzks-transfer-create
fi

function find_mount_point()
{
	LANG=C  mount | while read mountline; do
		mountpoint=$(echo "${mountline}" | awk '{print $3}')
		if echo $1 | grep -q "${mountpoint}"; then
			echo ${mountpoint}
		fi
	done | sort | tail -n1
}

function find_mounted_dev()
{
	echo $(LANG=C  mount | grep -E ".*on\\s$1\s" | awk '{print $1}')
}

transfer_mount_point=$(find_mount_point ${TRANSFER_BASE})
transfer_mounted_dev=$(find_mounted_dev ${transfer_mount_point})

if ! blkid "${transfer_mounted_dev}" | grep -qE '.*\sTYPE="ext[3-4]{1}"(\s|$)'; then
	echo "ERROR: Underlying filesystem of mount-point ${transfer_mount_point} (${transfer_mounted_dev}) is not an ext3/ext4 file system."
	echo "       Exiting."
	exit -1
fi

if ! cat /etc/fstab | grep "${transfer_mount_point}" | grep -qE ".*(\s|,)acl(,|\s).*"; then
	echo "WARNING: Underlying filesystem of mount-point ${transfer_mount_point} does not have ACL support. Enabling it temporarily..."
	mount -o remount,acl "${transfer_mount_point}"
fi

mkdir -p "${TRANSFER_TEACHERS}"
mkdir -p "${TRANSFER_STUDENTS}"

# create t1 - t9 for teachers
for i in ${FOLDERLIST_TEACHERS}; do
    mkdir -p "${TRANSFER_TEACHERS}/${i}"
done

# create s05 - s13 for students
for i in ${FOLDERLIST_STUDENTS}; do
    mkdir -p "${TRANSFER_STUDENTS}/${i}"
done

# ACLs for teachers' transfer folders
cd "${TRANSFER_TEACHERS}"

# ACLs
chown root:${GROUP_TEACHERS} .
chmod 0750 .

chown root:root t*
setfacl -m u::rwx t*
setfacl -m g::rwx t*
setfacl -m g:${GROUP_TEACHERS}:rwx t*
setfacl -m o::--- t*
setfacl -m d:u::rwx t*
setfacl -m d:g::rwx t*
setfacl -m d:g:${GROUP_TEACHERS}:rwx t*
setfacl -m d:o::--- t*

cd - 1>/dev/null

# ACLs for students' transfer folders
cd "${TRANSFER_STUDENTS}"

# ACLs
chown root:${GROUP_STUDENTS} .
chmod 0750 .
chown root:root s*
setfacl -m u::rwx s*
setfacl -m g::rwx s*
setfacl -m g:${GROUP_TEACHERS}:rwx s*
setfacl -m g:${GROUP_STUDENTS}:rwx s*
setfacl -m o::--- s*
setfacl -m d:u::rwx s*
setfacl -m d:g::rwx s*
setfacl -m d:g:${GROUP_TEACHERS}:rwx s*
setfacl -m d:g:${GROUP_STUDENTS}:r-x s*
setfacl -m d:o::--- s*

cd - 1>/dev/null

if ! cat /etc/fstab | grep ${transfer_mount_point} | grep -qE ".*(\s|,)acl(,|\s).*"; then
	echo "WARNING: ${transfer_mount_point} does not support ACLs. Enable ACL support in /etc/fstab."
	mount -o remount,noacl "${transfer_mount_point}"
fi

exit 0