#!/usr/bin/env bash


script_name="$(basename $(realpath $0))"
working_dir="$(dirname $(realpath $0))"

conf_file="${working_dir}/conf/${script_name%%.*}.conf"

LOCK_DIR="/tmp/$(basename $0).$$.LOCK"
log_file="${LOCK_DIR}/${script_name%%.*}.log"


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

usage() {


   [[ -n  "$1" ]] && error "$1"


   [[ $terminal ]] && echo -e "
\033[1mUsage:\033[m

   $(basename $0) [OPTION [OPTION ..

\033[1mDescription\033[m

   <Some Description>

\033[1mOptions\033[m

   <List Options>

\033[1mFiles\033[m

   $conf_file: Configuration file

\033[1mExample:\033[m

   <description example>

      $(basename $0) .. <comand example>

   <description another example>

      $(basename $0) .. <command another example>

"

   clean_up 1

}

clean_up() {

   # Perform program exit housekeeping
   rm -rf "$LOCK_DIR"
   blank_line
   exit $1
}

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

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

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

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

ok (){
   if $terminal ; then
      echo ""
      echo -e "   [ \033[32m\033[1mOk\033[m ]    $*"
      echo ""
   fi
}

echo_done() {
   if $terminal ; then
      echo -e "\033[95G[ \033[32mdone\033[m ]"
   fi
}
echo_ok() {
   if $terminal ; then
      echo -e "\033[95G[ \033[32mok\033[m ]"
   fi
}
echo_warn() {
   if $terminal ; then
      echo -e "\033[95G[ \033[33mwarn\033[m ]"
   fi
}
echo_failed(){
   if $terminal ; then
      echo -e "\033[95G[ \033[1;31mfailed\033[m ]"
   fi
}
echo_skipped() {
   if $terminal ; then
      echo -e "\033[95G[ \033[90m\033[1mskipped\033[m ]"
   fi
}
echo_wait(){
   if $terminal ; then
      echo -en "\033[95G[ \033[5m\033[1m...\033[m ]"
   fi
}

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

blank_line() {
   if $terminal ; then
      echo ""
   fi
}



# ----------
# - Jobhandling
# ----------

# - Run 'clean_up' for signals SIGHUP SIGINT SIGTERM
# -
trap clean_up SIGHUP SIGINT SIGTERM

# - Create lock directory '$LOCK_DIR"
#
mkdir "$LOCK_DIR"



# ----------
# - Some checks ..
# ----------

# - Running in a terminal?
# -
if [[ -t 1 ]] ; then
   terminal=true
else
   terminal=false
fi



# -------------
# - Default values
# -------------

# - Give your default values here
# -
DEFAULT_DNS_DKIM_ZONE_MASTER_SERVER="b.ns.oopen.de"
DEFAULT_TTL="3600"
DEFAULT_KEY_ALGO="hmac-sha256"
DEFAULT_KEY_NAME="update-dkim"
DEFAULT_DKIM_TYPE="DKIM1"
DEFAULT_KEY_TYPE="rsa"

DEFAULT_DKIM_SELECTOR=""



if [[ -f "$conf_file" ]]; then
   source "$conf_file"
else
   warn "No configuration file '$conf_file' present.\n
             Loading default values.."
fi


if [[ -n "$(trim "$DNS_DKIM_ZONE_MASTER_SERVER")" ]] ; then
   DEFAULT_DNS_DKIM_ZONE_MASTER_SERVER="${DNS_DKIM_ZONE_MASTER_SERVER}"
   DNS_DKIM_ZONE_MASTER_SERVER=""
fi

if [[ -n "$(trim "$KEY_ALGO")" ]] ; then
   DEFAULT_KEY_ALGO="${KEY_ALGO}"
   KEY_ALGO=""
fi

if [[ -n "$(trim "$KEY_NAME")" ]] ; then
   DEFAULT_KEY_NAME="${KEY_NAME}"
   KEY_NAME=""
fi

if [[ -n "$(trim "$KEY_SECRET")" ]] ; then
   DEFAULT_KEY_SECRET="${KEY_SECRET}"
   KEY_SECRET=""
fi


if $terminal ; then

   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert a domain name for which DKIM support should be configured."
   echo ""
   echo ""
   echononl "   DKIM domain: "
   read DKIM_DOMAIN
   while [ "X$DKIM_DOMAIN" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
      echononl "   DKIM domain: "
      read DKIM_DOMAIN
   done


   DEFAULT_DKIM_UPDATE_ZONE="_domainkey.${DKIM_DOMAIN}"

   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert zone which should be updated with the new DKIM key."
   echo ""
   echo ""
   echononl "   DKIM Zone [${DEFAULT_DKIM_UPDATE_ZONE}]: "
   read DKIM_UPDATE_ZONE
   if [[ "X$DKIM_UPDATE_ZONE" = "X" ]] ; then
      DKIM_UPDATE_ZONE="${DEFAULT_DKIM_UPDATE_ZONE}"
   fi


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert DKIM selector"
   echo ""
   echo ""
   echononl "   DKIM selector: "
   read DKIM_SELECTOR
   while [ "X$DKIM_SELECTOR" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
      echononl "   DKIM selector: "
      read DKIM_SELECTOR
   done


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert DKIM Key"
   echo ""
   echo ""
   echononl "   DKIM Key: "
   read DKIM_KEY
   while [ "X$DKIM_KEY" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
      echononl "   DKIM Key: "
      read DKIM_KEY
   done


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo -e "   Insert DNS master server for domain \033[1m$DKIM_UPDATE_ZONE\033[m"
   echo ""
   echo ""

   if [[ -n "${DEFAULT_DNS_DKIM_ZONE_MASTER_SERVER}" ]] ; then
      echononl "   DNS master server [${DEFAULT_DNS_DKIM_ZONE_MASTER_SERVER}]: "
      read DNS_DKIM_ZONE_MASTER_SERVER
      if [[ "X$DNS_DKIM_ZONE_MASTER_SERVER" = "X" ]] ; then
         DNS_DKIM_ZONE_MASTER_SERVER="${DEFAULT_DNS_DKIM_ZONE_MASTER_SERVER}"
      fi
   else
      echononl "   DNS master server: "
      read DNS_DKIM_ZONE_MASTER_SERVER
      while [[ "X$DNS_DKIM_ZONE_MASTER_SERVER" = "X" ]] ; do
         echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
         echononl "   DNS master server: "
         read KEY_SECRET
      done
   fi



   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert Key name"
   echo ""
   echo ""
   echononl "   Key name [${DEFAULT_KEY_NAME}]: "
   read KEY_NAME
   if [[ "X$KEY_NAME" = "X" ]] ; then
      KEY_NAME="${DEFAULT_KEY_NAME}"
   fi


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert Key secret"
   echo ""
   echo ""

   if [[ -n "${DEFAULT_KEY_SECRET}" ]] ; then
      echononl "   Key secret [${DEFAULT_KEY_SECRET}]: "
      read KEY_SECRET
      if [[ "X$KEY_SECRET" = "X" ]] ; then
         KEY_SECRET="${DEFAULT_KEY_SECRET}"
      fi
   else
      echononl "   Key secret: "
      read KEY_SECRET
      while [[ "X$KEY_SECRET" = "X" ]] ; do
         echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
         echononl "   Key secret: "
         read KEY_SECRET
      done
   fi


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Specifies the algorithm to use for the TSIG key."
   echo ""
   if [[ "hmac-md5" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [1] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [1] hmac-md5"
   fi
   if [[ "hmac-sha1" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [2] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [2] hmac-sha1"
   fi
   if [[ "hmac-sha224" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [3] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [3] hmac-sha224"
   fi
   if [[ "hmac-sha256" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [4] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [4] hmac-sha256"
   fi
   if [[ "hmac-sha384" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [5] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [5] hmac-sha384"
   fi
   if [[ "hmac-sha512" = "${DEFAULT_KEY_ALGO}" ]] ; then
      echo -e "   [6] \033[37m\033[1m${DEFAULT_KEY_ALGO}\033[m"
   else
      echo "   [6] hmac-sha512"
   fi

   echo ""
   echo "   Type a number or press <RETURN> to choose highlighted value"
   echo ""
   echononl "   Key algorithm [${DEFAULT_KEY_ALGO}]: "

   while [[ "$KEY_ALGO" != "hmac-md5" ]] \
         &&  [[ "$KEY_ALGO" != "hmac-sha1" ]] \
         &&  [[ "$KEY_ALGO" != "hmac-sha224" ]] \
         &&  [[ "$KEY_ALGO" != "hmac-sha256" ]] \
         &&  [[ "$KEY_ALGO" != "hmac-sha384" ]] \
         &&  [[ "$KEY_ALGO" != "hmac-sha512" ]] ; do
      read OPTION
      case $OPTION in
         1)    KEY_ALGO="hmac-md5" ;;
         2)    KEY_ALGO="hmac-sha1" ;;
         3)    KEY_ALGO="hmac-sha224" ;;
         4)    KEY_ALGO="hmac-sha256" ;;
         5)    KEY_ALGO="hmac-sha384" ;;
         6)    KEY_ALGO="hmac-sha512" ;;
         '')   KEY_ALGO="${DEFAULT_KEY_ALGO}" ;;
         *) echo ""
            echo -e "      \033[33m\033[1mFalsche Eingabe ! [ 1 = hmac-md5 | 2 = hmac-sha1 | .. ]\033[m"
            echo ""
            echononl "   Key algorithm [hmac-sha256]:"
            ;;
      esac
   done


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert DKIM Type (i.e. 'DKIM1')"
   echo ""
   echo ""
   echononl "   Key name [${DEFAULT_DKIM_TYPE}]: "
   read DKIM_TYPE
   if [[ "X$DKIM_TYPE" = "X" ]] ; then
      DKIM_TYPE="${DEFAULT_DKIM_TYPE}"
   fi


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert Key Type (i.e. 'rsa')"
   echo ""
   echo ""
   echononl "   Key type [${DEFAULT_KEY_TYPE}]: "
   read KEY_TYPE
   if [[ "X$KEY_TYPE" = "X" ]] ; then
      KEY_TYPE="${DEFAULT_KEY_TYPE}"
   fi


   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echo "   Insert TTL for dns entry"
   echo ""
   echo ""
   echononl "   TTL [${DEFAULT_TTL}]: "
   read TTL
   if [[ "X$TTL" = "X" ]] ; then
      TTL="${DEFAULT_TTL}"
   fi
fi



if [[ -z "$(trim "${DKIM_DOMAIN}")" ]]; then
   fatal "Variable \033[1mDKIM_DOMAIN\033[m not set!"
fi

if [[ -z "$(trim "${DKIM_UPDATE_ZONE}")" ]]; then
   fatal "Variable \033[1mDKIM_UPDATE_ZONE\033[m not set!"
fi

if [[ -z "$(trim "${DKIM_SELECTOR}")" ]]; then
   fatal "Variable \033[1mDKIM_SELECTOR\033[m not set!"
fi

if [[ -z "$(trim "${DKIM_KEY}")" ]]; then
   fatal "\033[1mDKIM_KEY\033[m not given!"
fi

if [[ -z "$(trim "${KEY_SECRET}")" ]]; then
   fatal "Variable \033[1mKEY_SECRET\033[m not set!"
fi


blank_line
blank_line

declare -i length_dkim_key=${#DKIM_KEY}

_intro="v=${DKIM_TYPE}; k=${KEY_TYPE}; p="
declare -i length_intro=${#_intro}

declare -i total_length=$((length_intro + length_dkim_key))


echononl "Create (splitted) 'p' value of DNS record.."
if [[ ${total_length} -gt 255 ]] ; then

   TMP_DKIM_KEY="$DKIM_KEY"

   p_val=""

   _length=64
   declare -i index=1

   while [ -n "$TMP_DKIM_KEY" ]; do
      if [[ index -eq 1 ]]; then
         p_val="\"${TMP_DKIM_KEY:0:$_length}\""
      else
         p_val+=" \"${TMP_DKIM_KEY:0:$_length}\""
      fi

      TMP_DKIM_KEY="${TMP_DKIM_KEY:$_length}"

      (( ++index ))

   done
   echo_done


   txt_val="\"v=${DKIM_TYPE}; k=${KEY_TYPE}; s=email; p=\" ${p_val}"

else
   echo_skipped
   p_val="${DKIM_KEY}"
   txt_val="\"${_intro}${p_val}\""
fi



if $terminal ; then
   echo ""
   echo ""
   echo -e "   \033[1m----------\033[m"
   echo "   DKIM Domain......................: $DKIM_DOMAIN"
   echo "   DKIM Selector....................: $DKIM_SELECTOR"
   echo "   DKIM Key.........................: ${DKIM_KEY:0:15}..${DKIM_KEY:$(expr ${#DKIM_KEY} - 15)}"
   echo ""
   echo "   Domain used for DKIM TXT record..: $DKIM_UPDATE_ZONE"
   echo "   Secret for the update key........: $KEY_SECRET"
   echo "   Algorithm used for the TSIG key..: $KEY_ALGO"
   echo "   Name of the TSIG key.............: $KEY_NAME"
   echo ""
   echo "   DNS Master Server................: $DNS_DKIM_ZONE_MASTER_SERVER"
   if [[ -z "$TTL" ]] || [[ "${TTL,,}" = "none" ]] ; then
      echo -e "   TTL for the DKIM TXT Record......: \033[33m- Not set -\033[m"
   else
      echo "   TTL for the DKIM TXT Record......: $TTL"
   fi
   echo ""
   echo "   DKIM Type........................: $DKIM_TYPE"
   echo "   Key Type.........................: $KEY_TYPE"
   echo "   DKIM Key.........................: $DKIM_KEY"
   echo -e "   \033[1m----------\033[m"
   echo ""
   echo -e "   DNS Record to add:\n\n\033[33m${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}. ${TTL} IN TXT ${txt_val}\033[m"
   echo ""
   echo -e "\n\n   The following 'nsupdate'command will be used:"
   cat <<END

cat <<EOF | nsupdate -v -L3
server $DNS_DKIM_ZONE_MASTER_SERVER
zone $DKIM_UPDATE_ZONE
key ${KEY_ALGO}:$KEY_NAME $KEY_SECRET
update delete ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}.
update add ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}. $TTL IN TXT ${txt_val}
send
EOF

END

   echo ""
   echo -n "   Type upper case 'YES' to start: "
   read OK
   if [[ "$OK" != "YES" ]] ; then
      fatal "Abort by user request - Answer iwas not 'YES'"
   fi
   echo ""
fi

if $terminal ; then
   echo ""
   echo -e  "   \033[32mUpdate Zone \033[37m\033[1m${DKIM_UPDATE_ZONE}\033[m\033[32m DNS Server \033[37m\033[1m${DNS_DKIM_ZONE_MASTER_SERVER}\033[m"
   echo ""
fi


echononl "   Add DKIM entry for domain \033[1m${DKIM_DOMAIN}\033[m with selector \033[1m${DKIM_SELECTOR} .."
cat <<EOF | nsupdate -v -L3 > $log_file 2>&1
server $DNS_DKIM_ZONE_MASTER_SERVER
zone $DKIM_UPDATE_ZONE
key ${KEY_ALGO}:$KEY_NAME $KEY_SECRET
update delete ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}.
update add ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}. ${TTL} IN TXT ${txt_val}
send
EOF
if [[ $? -eq 0 ]] ; then
   echo_ok
else
   echo_failed

   cat <<END

Command was:

cat <<EOF | nsupdate -v -L3
server $DNS_DKIM_ZONE_MASTER_SERVER
zone $DKIM_UPDATE_ZONE
key ${KEY_ALGO}:$KEY_NAME $KEY_SECRET
update delete ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}.
update add ${DKIM_SELECTOR}.${DKIM_UPDATE_ZONE}. $TTL IN TXT ${txt_val}
send
EOF
END

   error "$(cat $log_file)"
fi


info "Flush update data from .jnl files of domain \033[1m${DKIM_UPDATE_ZONE}\033[m back to the zone file:

             rndc freeze <zone>  -  \033[1mrndc freeze ${DKIM_UPDATE_ZONE}\033[m
             rndc thaw <zone     -  \033[1mrndc thaw ${DKIM_UPDATE_ZONE}\033[m"


clean_up 0