#!/usr/bin/env bash


working_dir="$(dirname $(realpath $0))"
conf_file="${working_dir}/conf/bind.conf"

log_file="$(mktemp)"

backup_date="$(date +%Y-%m-%d-%H%M)"

_serial_new="$(date +%Y%m%d01)"

comment=";; - IPv6 disabled "


#---------------------------------------
#-----------------------------
# Base Function(s)
#-----------------------------
#---------------------------------------

clean_up() {

   # Perform program exit housekeeping
   rm $log_file
   exit $1
}

echononl(){
   echo X\\c > /tmp/shprompt$$
   if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
      echo -e -n "$*\\c" 1>&2
   else
       echo -e -n "$*" 1>&2
   fi
   rm /tmp/shprompt$$
}

fatal(){
   echo ""
   echo -e "[ \033[31m\033[1mError\033[m ]: $*"
   echo ""
   echo -e "\t\033[31m\033[1mScript is canceled\033[m\033[m"
   echo ""
   clean_up 1
}

warn (){
   echo ""
   echo -e "\t[ \033[33m\033[1mWarning\033[m ]: $*"
   echo ""
}

info (){
   echo ""
   echo -e "\t[ \033[33m\033[1mInfo\033[m ]: $*"
   echo ""
}

ok (){
   echo ""
   echo -e "\t[ \033[36m\033[1mOk\033[m ]: $*"
   echo ""
}

error(){
   echo ""
   echo -e "\t[ \033[31m\033[1mFehler\033[m ]: $*"
   echo ""
}

echo_ok() {
   echo -e "\033[75G[ \033[32mok\033[m ]"
}
echo_done() {
   echo -e "\033[75G[ \033[32mdone\033[m ]"
}
echo_failed(){
   echo -e "\033[75G[ \033[1;31mfailed\033[m ]"
}
echo_skipped() {
   echo -e "\033[75G[ \033[33m\033[1mskipped\033[m ]"
}

containsElement () {
   local e
   for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
   return 1
}

trap clean_up SIGHUP SIGINT SIGTERM



#---------------------------------------
#-----------------------------
# Setting Defaults
#-----------------------------
#---------------------------------------

DEFAULT_CONF_FILE_DIR="/etc/bind"
DEFAULT_BIND_CACHE_DIR="/var/cache/bind"



#---------------------------------------
#-----------------------------
# Load default values from bind.conf
#
# Overwrites the settings above
# 
#-----------------------------
#---------------------------------------

#clear
echo ""
echo ""
echononl "   Loading default Configuration values from $(basename ${conf_file}).."
if [[ ! -f "$conf_file" ]]; then
   echo_skipped
else
   source "${conf_file}" > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      fatal "$(cat $log_file)"
   fi
fi

[[ -n "$CONF_FILE_DIR" ]] && DEFAULT_CONF_FILE_DIR="$CONF_FILE_DIR"

[[ -n "$BIND_CACHE_DIR" ]] && DEFAULT_BIND_CACHE_DIR="$BIND_CACHE_DIR"

if [[ -n "$ZONE_FILE_MASTER_DIR" ]] ; then
   DEFAULT_ZONE_FILE_MASTER_DIR="$ZONE_FILE_MASTER_DIR"
else
   DEFAULT_ZONE_FILE_MASTER_DIR="${DEFAULT_CONF_FILE_DIR}/master"
fi

if [[ -n "$ZONE_FILE_SLAVE_DIR" ]] ; then
   DEFAULT_ZONE_FILE_SLAVE_DIR="$ZONE_FILE_SLAVE_DIR"
else
   DEFAULT_ZONE_FILE_SLAVE_DIR="$DEFAULT_BIND_CACHE_DIR"
fi

if [[ -n "$ZONES_DECLARATION_FILE" ]] ; then
   DEFAULT_ZONES_DECLARATION_FILE="$ZONES_DECLARATION_FILE"
else
   DEFAULT_ZONES_DECLARATION_FILE="${CONF_FILE_DIR}/named.conf.local"
fi



echo ""
echo "Insert directory containing the bind configuration files."
echo ""
CONF_FILE_DIR=""
if [[ -n "$DEFAULT_CONF_FILE_DIR" ]] ; then
   echononl "Bind Configuration Directory [${DEFAULT_CONF_FILE_DIR}]: "
   read CONF_FILE_DIR
   if [[ "X$CONF_FILE_DIR" = "X" ]]; then
      CONF_FILE_DIR="$DEFAULT_CONF_FILE_DIR"
   fi
else
   echononl "Bind Configuration Directory: "
   read CONF_FILE_DIR
   while [ "X$CONF_FILE_DIR" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Bind Configuration Directory' is required!\033[m\n"
      echononl "Bind Configuration Directory: "
      read CONF_FILE_DIR
   done
fi

[[ -n "$ZONES_DECLARATION_FILE" ]] || DEFAULT_ZONES_DECLARATION_FILE="${CONF_FILE_DIR}/named.conf.local"


echo ""
echo -e "\033[32m--\033[m"

echo ""
echo "Insert zones declaration file."
echo ""
ZONES_DECLARATION_FILE=""
if [[ -n "$DEFAULT_ZONES_DECLARATION_FILE" ]] ; then
   echononl "Zones Declaration File [${DEFAULT_ZONES_DECLARATION_FILE}]: "
   read ZONES_DECLARATION_FILE
   if [[ "X$ZONES_DECLARATION_FILE" = "X" ]]; then
      ZONES_DECLARATION_FILE="$DEFAULT_ZONES_DECLARATION_FILE"
   fi
else
   echononl "Zones Declaration File: "
   read ZONES_DECLARATION_FILE
   while [ "X$ZONES_DECLARATION_FILE" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Zones Declaration File' is required!\033[m\n"
      echononl "Zones Declaration File: "
      read ZONES_DECLARATION_FILE
   done
fi


echo ""
echo -e "\033[32m--\033[m"

echo ""
echo "Insert the directory, where your zone-files resides."
echo ""
echo ""
ZONE_FILE_MASTER_DIR=""
if [[ -n "$DEFAULT_ZONE_FILE_MASTER_DIR" ]] ; then
   echononl "Zone File Directory (master) [${DEFAULT_ZONE_FILE_MASTER_DIR}]: "
   read ZONE_FILE_MASTER_DIR
   if [[ "X$ZONE_FILE_MASTER_DIR" = "X" ]]; then
      ZONE_FILE_MASTER_DIR="$DEFAULT_ZONE_FILE_MASTER_DIR"
   fi
else
   echononl "Zone File Directory (master): "
   read ZONE_FILE_MASTER_DIR
   while [ "X$ZONE_FILE_MASTER_DIR" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Zone File Directory (master)' is required!\033[m\n"
      echononl "Zone File Directory (master): "
      read ZONE_FILE_MASTER_DIR
   done
fi



clear
echo ""
echo ""
echo -e "\033[21G\033[32mDisable IPv6 for  all (master) Zones\033[m"
echo ""

echo ""
echo "Bind Configuration Directory......: $CONF_FILE_DIR"
echo "Zones Declaration File............: $ZONES_DECLARATION_FILE"
echo "Zone File Directory (master)......: $ZONE_FILE_MASTER_DIR"

echo ""
OK=
while [ "$OK" != "yes" -o "$OK" != "no" ] ; do
   echononl "Parameters ok? [yes/no]: "
   read OK
   ## - To lower case
   OK=${OK,,}
   if [ "X$OK" = "X" ]; then
      echo -e "\n\t\033[33m\033[1mAn entry is required!\033[m\n"
      OK=""
      continue
   fi
   if [ "$OK" = "yes" -o "$OK" = "no" ] ; then
      break
   else
      OK=""
      continue
   fi
   echo -e "\n\t\033[33m\033[1mWrong entry!\033[m\n"
done
[[ $OK = "yes" ]] || fatal Repeat execution with different parameters

echo ""

echononl "\tBackup directory '${ZONE_FILE_MASTER_DIR}'.."
cp -a "${ZONE_FILE_MASTER_DIR}" "${ZONE_FILE_MASTER_DIR}.${backup_date}" > $log_file 2>&1
if [[ $? -eq 0 ]]; then
   echo_ok
else
   echo_failed
   fatal "$(cat $log_file)"
fi


_found=false
_is_master=false
zonefiles_arr=()
zone_file=""
regex_master="type[[:space:]]+master"
regex_file="^[[:space:]]*file"
while IFS='' read -r _line || [[ -n $_line ]] ; do

   if [[ $_line  =~ ^[[:space:]]*zone[[:space:]]+ ]]; then
      _found=true
      zone="$(echo $_line | awk '{print$2}')"
      shopt -s extglob
      if [[ $zone =~ \; ]]; then
         zone=${zone%%*(\;)}
      fi
      if [[ $zone =~ ^\" ]]; then
         zone=${zone##*(\")}
         zone=${zone%%*(\")}
      fi
      shopt -u extglob
   fi
   if $_found ; then
      if [[ $_line  =~ $regex_file ]]; then
         zone_file=$(echo $_line | awk '{print$2}')
         shopt -s extglob
         if [[ $zone_file =~ \; ]]; then
            zone_file=${zone_file%%*(\;)}
         fi
         if [[ $zone_file =~ ^\" ]]; then
            zone_file=${zone_file##*(\")}
            zone_file=${zone_file%%*(\")}
         fi
         shopt -u extglob
      fi
      if [[ $_line  =~ $regex_master ]]; then
         _is_master=true
      fi
      if [[ "$_line"  =~ ^[[:space:]]*\}[[:space:]]*\; ]]; then
         if $_is_master && [[ -n "$zone_file" ]]; then
            if $(grep -q -E "^[^;].*\s*AAAA" "$zone_file" 2> /dev/null) ; then


               echo -e "\tEditing \033[1m$zone_file\033[m .."
      
               _replaced=false

               echononl "\t   Comment all IPv6 AAAA Records"
               perl -i -n -p -e "s/^([^;]+.*\s+AAAA\s+.*)$/${comment}\1/" "$zone_file" > $log_file 2>&1
               if [[ $? -eq 0 ]]; then
                  echo_ok
                  _replaced=true
               else
                  echo_failed
               fi

               # - Calculate new serial
               # -
               echononl "\t   Calculate new serial"
               if $_replaced ; then
                  declare -i __serial=`grep -e "[0-9]\{10\}" $zone_file | grep serial | awk '{print$1}'`
                  while [ ! $_serial_new -gt $__serial ]; do
                     let _serial_new++
                  done
                  echo_done
               else
                  echo_skipped
               fi


               # - Set new serial
               # -
               echononl "\t   Increase serial"
               if $_replaced ; then
                  perl -i -n -p -e "s#^(\s*)\s$__serial(.*)#\1 $_serial_new\2#" $zone_file > /dev/null 2>&1
                  if [ "$?" = "0" ]; then
                     echo_ok
                  else
                     echo_failed
                     error "$(cat $log_file)"
                  fi
               else
                  echo_skipped
               fi


               # - Reload Zone
               # -
               echononl "\t   Reload zone '${zone}'"
               if $_replaced ; then
                  /usr/sbin/rndc reload $zone > $log_file 2>&1
                  if [[ $? -gt 0 ]]; then
                     echo_failed
                     error "$(cat $log_file)"
                  else
                     echo_ok
                  fi
               else
                  echo_skipped
               fi

               echo

            fi
         fi
         _is_master=false
         _found=false
         zone_file=""
      fi
   fi
done < "$ZONES_DECLARATION_FILE"


if [[ -d "${ZONE_FILE_MASTER_DIR}.${backup_date}" ]] ; then
   diff -Nur "${ZONE_FILE_MASTER_DIR}" "${ZONE_FILE_MASTER_DIR}.${backup_date}" > /dev/null 2>&1
   if [[ $? -eq 0 ]]; then
      info "No zone file has changed.\n\t          Removing previously created backup"
      echononl "\tDelete '${ZONE_FILE_MASTER_DIR}.${backup_date}'.."
      rm -rf "${ZONE_FILE_MASTER_DIR}.${backup_date}" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
      fi
   fi
fi



echo ""
clean_up 0