#!/bin/sh
# -------
# File:        lliurex-vault-owner
# Description: LliureX uid+gid backup tool
# Author:      Luis Garcia Gisbert <garcia_luigis@gva.es>
#
# This program 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 program 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
# --------

do_usage(){
   echo "$0 --backup RESTORE_SCRIPT_PATH NAME_PREFIX BACKUP_DIR SOURCE..." >&2
   exit 1
}


do_gen_script(){
   cat <<EOF
#!/bin/sh
# automagically generated restore script
# -------

set -e
verify_user(){
   USER_NAME="\$1"
   USER_GROUP="\$2"
   USER_SHELL="\$3"
   USER_HOME="\$4"
   DATA_FILE="\$5"
   shift 5
   if ! getent group |grep -q "^\$USER_GROUP:" ; then
      groupadd "\$USER_GROUP"
   fi
   if getent passwd |grep -q "^\$USER_NAME:" ; then
      return 0
   fi
   USER_CMD=""
   [ -d "\$USER_HOME" ] || USER_CMD="-m -d \$USER_HOME"
   useradd \$USER_CMD -s "\$USER_SHELL" -g "\$USER_GROUP" "\$USER_NAME"
   [ "\$USER_CMD" ] || chown -R "\$USER_NAME:\$USER_GROUP" "\$USER_HOME"
   while [ "\$1" ] ; do
      if getent group |grep -q "^\$1:" ; then
         if ! groups "\$USER_NAME" |tr "\\n" " " |grep -qxF "\$1" ; then
            adduser --quiet "\$USER_NAME" "\$1"
         fi
      fi
      shift
   done
   [ -r "\$DATA_FILE" ] || return 0
   GECOS="\$(grep "^\$USER_NAME:" "\$DATA_FILE" |cut -f 2 -d ":"  |tr "\n" ":")"
   sed -i -e "/^\$USER_NAME:/s%^\\(\\([^:]*:\\)\\{4\\}\\)[^:]*:%\\1\$GECOS%" /etc/passwd
   sed -i -e "/^\$USER_NAME:/s%^[^:]*:[^:]*:%\$USER_NAME:\$(grep "^\$USER_NAME:" "\$DATA_FILE" |cut -f 3 -d ":"  |tr "\n" ":")%" /etc/shadow
}         

RC=0
[ "\$1" = "--restore" ] || exit 1

EOF
}

RC=0
AC="$1"
[ "$AC" = "--backup" ] || do_usage
shift
RESTORE_SCRIPT="$1"
[ "$RESTORE_SCRIPT" ] || do_usage
shift
PREFIX_NAME="$1"
[ "$PREFIX_NAME" ] || do_usage
shift
BACKUP_DIR="$1"
[ "$BACKUP_DIR" -a -d "$BACKUP_DIR" ] || do_usage
OUTPUT_FILE="$BACKUP_DIR/$PREFIX_NAME.user"
shift
[ "$1" ] || do_usage
rm -f "$OUTPUT_FILE"

do_gen_script > "$RESTORE_SCRIPT"

while [ "$1" ] ; do
   if [ -e "$1" ] ; then
      USER_GROUP="$(find "$1" -maxdepth 0 -mindepth 0 -printf "%u:%g")"
      USER_NAME="${USER_GROUP%%:*}"
      if [ "$USER_NAME" ] && grep -q "^$USER_NAME:" /etc/passwd && grep -q "^$USER_NAME:" /etc/shadow ; then
         USER_SELL="$(grep "^$USER_NAME:" /etc/passwd |cut -f 7 -d ":"  |tr -d "\n")"
         printf "$USER_NAME:" >> "$OUTPUT_FILE"
         USER_HOME="$(grep "^$USER_NAME:" /etc/passwd |cut -f 6 -d ":"  |tr -d "\n")"
         grep "^$USER_NAME:" /etc/passwd |cut -f 5 -d ":"  |tr "\n" ":" >> "$OUTPUT_FILE"
         grep "^$USER_NAME:" /etc/shadow |cut -f 2 -d ":"  |tr "\n" ":" >> "$OUTPUT_FILE"
         echo "verify_user \"${USER_NAME}\" \"${USER_GROUP##*:}\" \"$USER_SELL\"" "$USER_HOME" "./$PREFIX_NAME.user" "$(groups "${USER_NAME}")" >> "$RESTORE_SCRIPT"
         echo "chown -R \"$USER_GROUP\" \"$1\" || true" >> "$RESTORE_SCRIPT"
      fi
   fi
   shift
done
echo "exit 0" >> "$RESTORE_SCRIPT"
chmod +x "$RESTORE_SCRIPT"

exit 0