#!/usr/bin/env bash

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

LOCK_DIR="$(mktemp -d)"
log_file="${LOCK_DIR}/${script_name%%.*}.log"

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

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

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 ] $*"
   else
      echo -e "   [ Fatal ] $*"
   fi
   echo ""
   if $terminal ; then
      echo -e "             \033[1mScript terminated\033[m.."
   else
      echo -e "             Script terminated.."
   fi
   echo ""
   rm -rf $LOCK_DIR
   exit 1
}

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

warn (){
   if $LOGGING || $terminal ; then
      echo ""
      if $terminal ; then
         echo -e "   [ \033[33m\033[1mWarn\033[m ]  $*"
      else
         echo "   [ Warn ]  $*"
      fi
      echo ""
   fi
}

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

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

echo_done() {
   if $terminal ; then
      echo -e "\033[75G[ \033[32mdone\033[m ]"
   fi
}
echo_ok() {
   if $terminal ; then
      echo -e "\033[75G[ \033[32mok\033[m ]"
   fi
}
echo_failed(){
   if $terminal ; then
      echo -e "\033[75G[ \033[1;31mfailed\033[m ]"
   fi
}
echo_skipped() {
   if $terminal ; then
      echo -e "\033[75G[ \033[33m\033[1mskipped\033[m ]"
   fi
}
blank_line() {
   if $terminal ; then
      echo ""
   fi
}
echo_wait(){
   if $terminal ; then
      echo -en "\033[75G[ \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"
}

get_openssl_version() {

   OPENSSL_VERSION="$(openssl version|awk '{print $2}' | grep -o -E "[0-9]+\.[0-9]+\.[0-9]+[a-zA-Z]?")"

   OPENSSL_MAIN_VERSION=`echo $OPENSSL_VERSION | cut -d '.' -f1,2`
   OPENSSL_MAJOR_VERSION=`echo $OPENSSL_VERSION | cut -d '.' -f1`
   OPENSSL_MINOR_VERSION=`echo $OPENSSL_VERSION | cut -d '.' -f2`
   OPENSSL_PATCH_LEVEL=`echo $OPENSSL_VERSION | cut -d '.' -f3`

   if [[ -n "${OPENSSL_VERSION}" ]] ; then
      return 0
   else
      return 1
   fi
}

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

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

# Detect OpenSSL version
#
get_openssl_version
if [[ $? -ne 0 ]] ; then

   error "Cannot detect OpenSSL Version."

fi


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

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


# ==========
# - Begin Main Script
# ==========

# ----------
# - Headline
# ----------

if $terminal ; then
   echo ""
   echo -e "\033[1m----------\033[m"
   echo -e "\033[32m\033[1mRunning script \033[m\033[1m$script_name\033[32m .. \033[m"
   echo -e "\033[1m----------\033[m"
fi

restart_nginx_service=false

if [[ ! -d "/etc/nginx" ]] ; then
   fatal "No Nginx installation found!"
fi

if [[ ${OPENSSL_MAJOR_VERSION} -gt 1 ]]; then

   if [[ -f "/etc/nginx/ssl/dhparam.pem" ]]; then

      echononl "Stop Nginx WebsService"
      systemctl stop nginx > "$log_file" 2>&1
      if [[ $? -ne 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi

      echononl "Backup existing 'dhparam.pem' file.."
      mv "/etc/nginx/ssl/dhparam.pem" "/etc/nginx/ssl/dhparam.pem.${backup_date}" > ${log_file}  2>&1
      if [[ $? -ne 0 ]] ; then
         echo_failed
         error "$(cat $log_file)"
      else
         restart_nginx_service=true
         echo_ok
      fi
   fi
   echononl "Generate a dhparam.pem file - \033[5m\033[1mmay take a lon time\033[m .."
   openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048 > ${log_file}  2>&1
   if [[ $? -ne 0 ]] ; then
      echo_failed
      error "$(cat $log_file)"
   else
      echo_ok
   fi

   if $restart_nginx_service ; then

      echononl "Start Nginx WebsService"
      systemctl start nginx > "$log_file" 2>&1
      if [[ $? -ne 0 ]]; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok
      fi
   fi

elif [[ -f "/etc/nginx/ssl/dhparam.pem" ]]; then
   echononl "Generate a dhparam.pem file .."
   echo_skipped
else
   echononl "Cretae directory '/etc/nginx/ssl'.."
   if [[ ! -d "/etc/nginx/ssl" ]] ; then
      mkdir /etc/nginx/ssl > ${log_file}  2>&1
      if [[ $? -ne 0 ]] ; then
         echo_failed
         error "$(cat $log_file)"
      else
         echo_ok

         echononl "Generate a dhparam.pem file with parameter '-dsaparam'.."
         openssl dhparam -dsaparam -out /etc/nginx/ssl/dhparam.pem 2048 >> ${log_file}  2>&1
         if [[ $? -ne 0 ]] ; then
            _failed=true
         fi
         if $_failed ; then
            echo_failed
            error "$(cat $log_file)"
         else
            echo_ok
         fi

      fi
   else
      echo_skipped
   fi
fi

clean_up 0