#!/usr/bin/env bash

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

log_file="$(mktemp)"

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

usage() {
   echo 
      [ -n  "$1" ] && echo -e "Error: $1\n"

      cat<<EOF

   Usage: $(basename $0) [Options]

      Script removes a domain from bind (slave) nameservice.

      If running in a terminal and NOT '-q' is used, script acts in
      interactive mode. Script uses defaults either reading from file
      ${conf_file}, or if not present, bei hardcoded default settings.
      You will be asked to confirm or override the default setting.

      If not running in a terminal (i.e. used as cronjob) or flag '-q' (and 
      within '-d') is set, all configurations are read from file '${conf_file}'.
   

      Options:

      -d <domain>
            The name of the domain, which is requested for deletion.

      -h    
            Prints this help.

      -q
            Be quiet. If '-q' is used, also a domain must be given using
            parameter '-d'.

EOF
clean_up 1
}


clean_up() {

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

trim() {
    local var="$*"
    var="${var#"${var%%[![:space:]]*}"}"   # remove leading whitespace characters
    var="${var%"${var##*[![:space:]]}"}"   # remove trailing whitespace characters
    echo -n "$var"
}

echononl(){
   if $terminal && $LOGGING ; then
      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$$
   fi
}

fatal(){
   echo ""
   if $terminal ; then
      echo -e "[ \033[31m\033[1mError\033[m ]: $*"
      echo ""
      echo -e "\t\033[31m\033[1mScript was interupted\033[m!"
   else
      echo "   [ Fatal ]: $*"
      echo ""
      echo "              Script was terminated...."
   fi
   echo ""
   clean_up 1
}

info (){
   if $terminal && $LOGGING ; then
      echo ""
      echo -e "\t[ \033[32m\033[1mInfo\033[m ]: $*"
      echo ""
   else
      if $LOGGING ; then
         echo ""
         echo "Info: $*"
         echo ""
      fi
   fi
}

warn (){
   echo ""
   if $terminal ; then
      echo -e "\t[ \033[33m\033[1mWarning\033[m ]: $*"
   else
      echo "Warning: $*"
   fi
   echo ""
}

error (){
   echo ""
   if $terminal ; then
      echo -e "\t[ \033[31m\033[1mError\033[m ]: $*"
   else
      echo "Error: $*"
   fi
   echo ""
}

echo_done() {
   if $terminal && $LOGGING ; then
      echo -e "\033[75G[ \033[32mdone\033[m ]"
   else
      if $LOGGING ; then
         echo " [ done ]"
      fi
   fi
}
echo_ok() {
   if $terminal && $LOGGING ; then
      echo -e "\033[75G[ \033[32mok\033[m ]"
   else
      if $LOGGING ; then
         echo " [ ok ]"
      fi
   fi
}
echo_failed(){
   if $terminal && $LOGGING ; then
      echo -e "\033[75G[ \033[1;31mfailed\033[m ]"
   else
      if $LOGGING ; then
         echo " [ failed ]"
      fi
   fi
}
echo_skipped() {
   if $terminal && $LOGGING ; then
      echo -e "\033[75G[ \033[33m\033[1mskipped\033[m ]"
   else
      if $LOGGING ; then
         echo " [ skipped ]"
      fi
   fi
}

trap clean_up SIGHUP SIGINT SIGTERM



#---------------------------------------
#-----------------------------
# Check some prerequisites
#-----------------------------
#---------------------------------------

if [[ -t 1 ]] ; then
   terminal=true
   LOGGING=true
else
   terminal=false
   LOGGING=false
fi

while getopts d:hq opt ; do
   case $opt in
      d) DOMAIN_REQUESTED_TO_REMOVE="$OPTARG"
         ;;
      q) LOGGING=false
         ;;
      h) usage
          ;;
      *) usage
   esac
done

shift $(expr $OPTIND - 1)

# - Parameter "check" can be used, to test whether this script
# - is accessable (e.g. from a script on a remote host)
# -
if [[ "$1" = "check" ]]; then
   info "Script \033[1m$(basename $0)\033[m was successfully invoked, but its only a test."
   clean_up 0
fi


if ! $LOGGING && [[ -z "$DOMAIN_REQUESTED_TO_REMOVE" ]] ; then
   usage "Giving Domain for deletion (option '-d') is required if using option '-q'."
fi



#---------------------------------------
#-----------------------------
# 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
# 
#-----------------------------
#---------------------------------------

if $LOGGING ; then
   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
   [[ -n "$ZONES_DECLARATION_FILE" ]] && DEFAULT_ZONES_DECLARATION_FILE="$ZONES_DECLARATION_FILE"


   echo ""


   if [[ -z "$DOMAIN_REQUESTED_TO_REMOVE" ]] ;then
      echo ""
      echo -e "\033[32m--\033[m"
      echo ""
      echo "Insert domain which you want to be removed from bind nameservice."
      echo ""
      DOMAIN_REQUESTED_TO_REMOVE=""
      echononl "Remove Domain: "
      read DOMAIN_REQUESTED_TO_REMOVE
      while [ "X$DOMAIN_REQUESTED_TO_REMOVE" = "X" ] ; do
         echo -e "\n\t\033[33m\033[1mSetting 'Remove Domain' is required!\033[m\n"
         echononl "Remove Domain: "
         read DOMAIN_REQUESTED_TO_REMOVE
      done
   fi


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


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


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



   echo ""
   echo ""
   echo -e "\033[1;32mSettings for \033[1;37mRemove Domain\033[m Script"
   echo ""
   echo -e   "\tDomain requested to remove..........: $DOMAIN_REQUESTED_TO_REMOVE"
   echo ""
   echo -e   "\tBind Configuration Directory........: $CONF_FILE_DIR"
   echo -e   "\tZones Declaration File..............: $ZONES_DECLARATION_FILE"
   echo -e   "\tZone File Directory (slave).........: $ZONE_FILE_SLAVE_DIR"

   echo ""
   info "Remove Domain \033[37m\033[1m${DOMAIN_REQUESTED_TO_REMOVE}\033[m.."
   echo -n "To continue type uppercase 'YES': "
   read OK
   echo ""
   if [[ "$OK" != "YES" ]] ; then
      fatal "Abort by user request - Answer as not 'YES'"
   fi

else # if $LOGGING

   #if [[ ! -f "$conf_file" ]]; then
   #   fatal "Configuration file '$conf_file' not found!"
   #else
   if [[ -f "$conf_file" ]]; then
      echononl "   Loading default Configuration values from $(basename ${conf_file}).."
      source "${conf_file}" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
         fatal "$(cat $log_file)"
      fi
   fi

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

   if [[ -z "$CONF_FILE_DIR" ]]; then
      fatal "Directory contaning bind configurations not set (see CONF_FILE_DIR)!"
   fi

   [[ -n "$ZONES_DECLARATION_FILE" ]] || ZONES_DECLARATION_FILE="${CONF_FILE_DIR}/named.conf.local"
   [[ -n "$ZONE_FILE_MASTER_DIR" ]] || ZONE_FILE_MASTER_DIR="${CONF_FILE_DIR}/master"
   [[ -n "$ZONE_FILE_SLAVE_DIR" ]] || ZONE_FILE_SLAVE_DIR="${DEFAULT_BIND_CACHE_DIR}"

fi

if [[ ! -f "$ZONES_DECLARATION_FILE" ]]; then
   fatal "Zone declaration file '${ZONES_DECLARATION_FILE}' not found!"
fi

if [[ ! -d "$ZONE_FILE_SLAVE_DIR" ]]; then
   fatal "Zone File Directory '${ZONE_FILE_SLAVE_DIR}' (slave zones) not found!"
fi

if ! grep -q -E "^\s*zone\s+\"?${DOMAIN_REQUESTED_TO_REMOVE}\"?\s+\{" $ZONES_DECLARATION_FILE 2> /dev/null ; then
   fatal "No decleration for domain '${DOMAIN_REQUESTED_TO_REMOVE}' found!"
fi

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

echononl "   Backup '$ZONES_DECLARATION_FILE'.."
if [[ -f "${ZONES_DECLARATION_FILE}.$backup_date" ]] ; then
   echo_skipped
else
   cp -a "$ZONES_DECLARATION_FILE" "${ZONES_DECLARATION_FILE}.$backup_date" > $log_file 2>&1
   if [[ $? -gt 0 ]]; then
      echo_failed
      error "$(cat $log_file)"
   else
      echo_ok
   fi
fi

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


declare -i line_number=0

_found=false
_is_slave=false
declare -i _first_line=0
declare -i _last_line=0
while IFS='' read -r _line || [[ -n $_line ]] ; do
   let line_number++
   if [[ "$_line"  =~ ^[[:space:]]*zone[[:space:]]+\"?${DOMAIN_REQUESTED_TO_REMOVE}\"?[[:space:]]+\{ ]]; then
      _found=true
      _first_line=$line_number
   fi
   if $_found ; then
      if [[ "$_line"  =~ ^[[:space:]]*file[[:space:]]+\"? ]]; 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"  =~ type[[:space:]]+slave ]]; then
         _is_slave=true
      fi

      if $_is_slave && [[ "$_line"  =~ ^[[:space:]]*zone[[:space:]]+\"? ]]; then
         _found=false
         _last_line=$((line_number - 1))
      fi
   fi
   if [[ $_last_line -gt 0 ]] && $_is_slave ; then
      break;
   fi

done < "$ZONES_DECLARATION_FILE"

# - if zone declaration was the last one in file "$ZONES_DECLARATION_FILE"
# -
if $_found && [[ $_last_line -eq 0 ]]; then
   _last_line=$line_number
   _found=false
fi


if $_found ; then
   fatal "Configuration for zone '${DOMAIN_REQUESTED_TO_REMOVE}' was found, but cannot be deleted."
fi


$LOGGING && echo ""
echononl "   Delete zone declaration for domain '${DOMAIN_REQUESTED_TO_REMOVE}'"
sed -i "${_first_line},${_last_line}d" "$ZONES_DECLARATION_FILE" > $log_file 2>&1
if [[ $? -gt 0 ]]; then
   echo_failed
   error "$(cat $log_file)"
else
   echo_ok
fi

$LOGGING && echo ""
echononl "   Create directory '$(dirname ${zone_file})/DELETED'.."
if [[ ! -d "$(dirname ${zone_file})/DELETED" ]] ; then
   mkdir "$(dirname ${zone_file})/DELETED"  > $log_file 2>&1
   if [[ $? -gt 0 ]]; then
      echo_failed
      error "$(cat $log_file)"
   else
      echo_ok
   fi
else
   echo_skipped
fi

echononl "   Move zone file '$(basename $zone_file)' into directory 'DELETED'"
if [[ ! -f "$zone_file" ]] ; then
   echo_failed
   error "Concerning zone file '$zone_file' not found!"
else
   mv "${zone_file}" "$(dirname ${zone_file})/DELETED"  > $log_file 2>&1
   if [[ $? -gt 0 ]]; then
      echo_failed
      error "$(cat $log_file)"
   else
      echo_ok
   fi
fi

while IFS='' read -r -d '' _file ; do
   echononl "   Move file '$(basename $_file)' into directory 'DELETED'"
   mv "$_file" "$(dirname ${zone_file})/DELETED"  > $log_file 2>&1
   if [[ $? -gt 0 ]]; then
      echo_failed
      #error "$(cat $log_file)"
   else
      echo_ok
   fi
done < <(find $(dirname ${zone_file}) -mindepth 1 -maxdepth 1 -type f -name "${DOMAIN_REQUESTED_TO_REMOVE}.*" -print0)


if [[ -n "$key_directory" ]]; then

   $LOGGING && echo ""

   if [[ "$(dirname ${key_directory})" != "$CONF_FILE_DIR" ]]; then
      backup_key_dir="$(dirname ${key_directory})"
      echononl "   Backup directory '${backup_key_dir}'.."
      cp -a "${backup_key_dir}" "${backup_key_dir}.${backup_date}" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
         fatal "$(cat $log_file)"
      fi
   fi

   _dir="$(dirname ${key_directory})/DELETED"
   echononl "   Create directory '${_dir}'.."
   if [[ ! -d "${_dir}" ]] ; then
      mkdir "${_dir}" > $log_file 2>&1
      if [[ $? -gt 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi
   else
      echo_skipped
   fi

   _dir="$(dirname ${key_directory})/DELETED/$(basename ${key_directory})"
   echononl "   Create directory '${_dir}'.."
   if [[ ! -d "${_dir}" ]] ; then
      mkdir "${_dir}" > $log_file 2>&1
      if [[ $? -gt 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi
   else
      echo_skipped
   fi

   while IFS='' read -r -d '' _file ; do
      echononl "   Move file '$(basename $_file)' into directory 'DELETED'"
      mv "$_file" "$(dirname ${key_directory})/DELETED/$(basename ${key_directory})" > $log_file 2>&1
      if [[ $? -gt 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi
   done < <(find $key_directory -mindepth 1 -maxdepth 1 -type f -name "K${DOMAIN_REQUESTED_TO_REMOVE}.*" -print0)

   if [[ ! "$(ls -A $key_directory)" ]] ; then
      echononl "   Remove empty key directory '$(basename $key_directory)'.."
      rmdir $key_directory > $log_file 2>&1
      if [[ $? -gt 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi
   fi
fi


if [[ -f "${ZONES_DECLARATION_FILE}.$backup_date" ]]; then
   diff "$ZONES_DECLARATION_FILE" "${ZONES_DECLARATION_FILE}.$backup_date" > /dev/null 2>&1
   if [[ $? -eq 0 ]]; then
      info "Zone declaration file $(basename $ZONES_DECLARATION_FILE) has not changed.\n\t          Removing previously created backup now."
      echononl "\tDelete '${ZONES_DECLARATION_FILE}.$backup_date'.."
      rm "${ZONES_DECLARATION_FILE}.$backup_date" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
      fi
   fi
fi
      

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 [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
         error "$(cat $log_file)"
      fi
   fi
fi

if [[ -d "${backup_key_dir}.${backup_date}" ]] ; then
   diff -Nur "${backup_key_dir}" "${backup_key_dir}.${backup_date}" > /dev/null 2>&1
   if [[ $? -eq 0 ]]; then
      info "Key directory '${backup_key_dir}' has not changed.\n\t          Removing previously created backup now."
      echononl "\tDelete '${backup_key_dir}.${backup_date}'.."
      rm -rf "${backup_key_dir}.${backup_date}" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
         error "$(cat $log_file)"
      fi
   fi
fi



$LOGGING && echo ""

echononl "   Reeload bind configuration"
rndc reconfig  > $log_file 2>&1
if [[ $? -gt 0 ]]; then
   echo_failed
   error "$(cat $log_file)"
else
   echo_done
fi


#echo "zone file: $zone_file"
#echo "$line_number - $_first_line , $_last_line"


$LOGGING && echo ""
clean_up 0