#!/usr/bin/env bash

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

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

log_file="$(mktemp)"
random_prefix="$(head -c 300 /dev/urandom | tr -cd 'a-zA-Z0-9' | head -c  8)"

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


# =============
# --- Some Variables
# =============

declare -a lx_container_arr=()
declare -a lx_running_container_arr=()


# =============
# --- Some Functions
# =============

clean_up() {


   if [[ -f "$_backup_crontab_file" ]]; then

      blank_line
      echononl "   (Re)Install Crontab from previously saved crontab file
      '$_backup_crontab_file'.."

      crontab $_backup_crontab_file >> $log_file 2>&1

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

   fi

   # Perform program exit housekeeping
   rm -f $log_file
   rm -rf /tmp/*.${random_prefix}
   blank_line
   exit $1
}

echononl(){
   if $terminal ; then
      echo X\\c > /tmp/shprompt$$
      if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
         echo -e -n "[ \033[5m\033[1m....\033[m ]\033[13G$*\\c" 1>&2
      else
         echo -e -n "[ \033[5m\033[1m....\033[m ]\033[13G$*" 1>&2
      fi
      rm /tmp/shprompt$$
   fi
}
echo_print_command() {
   if $terminal ; then
      echo X\\c > /tmp/shprompt$$
      if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
         echo -e -n "\n\033[13G\033[1m$*\\c\033[m" 1>&2
      else
         echo -e -n "\n\033[13G\033[1m$*\033[m" 1>&2
      fi
      rm /tmp/shprompt$$
   fi
}
echo_done() {
   if $terminal ; then
      echo -e "\033[1G[ \033[1;32mdone\033[m ]"
   fi
}
echo_ok() {
   if $terminal ; then
      echo -e "\033[1G[ \033[1;32mok\033[m ]"
   fi
}
echo_ignore() {
   if $terminal ; then
      echo -e "\033[1G[ \033[1;33mignore\033[m ]"
   fi
}
echo_warning() {
   if $terminal ; then
      echo -e "\033[1G[ \033[1;33m\033[1mwarn\033[m ]"
   fi
}
echo_failed(){
   if $terminal ; then
      echo -e "\033[1G[ \033[1;31mfail\033[m ]"
   fi
}
echo_skipped() {
   if $terminal ; then
      echo -e "\033[1G[ \033[1;37mskip\033[m ]"
   fi
}
echo_wait(){
   if $terminal ; then
      echo -en "\033[1G[ \033[5m\033[1m...\033[m ]"
   fi
}


fatal (){
   blank_line
   if $terminal ; then
      echo -e "[ \033[31m\033[1mFatal\033[m ] \033[13G\033[37m\033[1m$*\033[m"
      echo ""
      echo -e " \033[13G\033[31m\033[1mScript will be interrupted..\033[m\033[m"
   else
      echo "fatal: $*"
      echo "Script will be interrupted.."
   fi
   clean_up 1
}
error(){
   blank_line
   if $terminal ; then
      echo -e "[ \033[31m\033[1mFehler\033[m ]\033[13G$*"
   else
      echo ""
      echo "[ Error ]: $*"
      echo ""
   fi
   blank_line
}

warn (){
   if $terminal ; then
      echo ""
      echo -e "[ \033[33m\033[1mWarning\033[m ]\033[13G$*"
      echo ""
   fi
}
info (){
   if $terminal ; then
      echo ""
      echo -e "[ \033[32m\033[1mInfo\033[m ]\033[13G$*"
      echo ""
   fi
}

## - Check if a given array (parameter 2) contains a given string (parameter 1)
## -
containsElement () {
   local e
   for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
   return 1
}

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
}

usage() {
   if [ -n "$1" ];then
      echo -e "\n   [ Error ]: $1"
   fi

cat<<EOF

   Usage: $(basename $0) YYYY-MM-DD

   $(basename $0) - Scripts shuts down this machine if the given date is the actual date.

                         The most common practice is, to use this script as cronjob.

EOF

clean_up 1
}

isValidDate() {
    DATE="${1}"

    # Autorized separator char ['space', '/', '.', '_', '-']
    SEPAR="([ \/._-])?"

    # Date format day[01..31], month[01,03,05,07,08,10,12], year[1900..2099]
    DATE_1="((([123][0]|[012][1-9])|3[1])${SEPAR}(0[13578]|1[02])${SEPAR}(19|20)[0-9][0-9])"

    # Date format day[01..30], month[04,06,09,11], year[1900..2099]
    DATE_2="(([123][0]|[012][1-9])${SEPAR}(0[469]|11)${SEPAR}(19|20)[0-9][0-9])"

    # Date format day[01..28], month[02], year[1900..2099]
    DATE_3="(([12][0]|[01][1-9]|2[1-8])${SEPAR}02${SEPAR}(19|20)[0-9][0-9])"

    # Date format day[29], month[02], year[1904..2096]
    DATE_4="(29${SEPAR}02${SEPAR}(19|20(0[48]|[2468][048]|[13579][26])))"

    # Date 29.02.2000
    DATE_5="(29${SEPAR}02${SEPAR}2000)"

    # Match the date in the Regex

    if [[ "${DATE}" =~ ^(${DATE_1}|${DATE_2}|${DATE_3}|${DATE_4}|${DATE_5})$ ]] ; then
      return 0
    else
      return 1
   fi
}



# =============
# --- Jobhandling
# =============

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



# =============
# --- Some Checks
# =============

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


[ $# -ne "1" ] && usage "Wrong number of arguments"

_date=$1

IFS='-' read -a _val_arr <<< "$_date"

__year=${_val_arr[0]}
__month=${_val_arr[1]}
__day=${_val_arr[2]}

if ! isValidDate "${__day}-${__month}-${__year}" ; then
	usage "Invalid date: ${_date}"
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"
   echo ""
fi


if [[ "$(/bin/date +%Y-%m-%d)" != "$_date" ]] ; then

   info "Shutdown Date \\033[1m${_date} \033[mis NOT today. So nothing to do.."

   clean_up 1
fi


if $(dpkg -l 2> /dev/null | grep -q "lxc" 2> /dev/null) \
   || $(systemctl list-unit-files | grep -q "lxc"); then

   echononl "Get List of \033[1mall existing\033[m LX Contaoner.."

   _failed=false
   for _container in $(lxc-ls) ; do
      lx_container_arr+=("$_container")
      [[ $? -gt 0 ]] && _falied=true
   done
   if $_failed ; then
      echo_failed
      fatal "Getting list of \033[1mall\033[m LX-Container failed!"
   else
      echo_done
   fi


   _failed=false
   echononl "Get List of \033[1mrunning\033[m LX Contaoner.."
   for _container in $(lxc-ls --running) ; do
      lx_running_container_arr+=("$_container")
      [[ $? -gt 0 ]] && _falied=true
   done
   if $_failed ; then
      echo_failed
      fatal "Getting list of \033[1mrunning\033[m LX-Container failed!"
   else
      echo_done
   fi


   if [[ ${#lx_container_arr[@]} -gt 0 ]]; then

      for _lx_container in "${lx_container_arr[@]}" ; do

         echononl "Stopping Container ${_lx_container}.."

         if containsElement "$_lx_container"  "${lx_running_container_arr[@]}" ; then

            lxc-stop -n ${_lx_container} > $log_file 2>&1

            if [[ $? -gt 0 ]]; then
               echo_failed
               fatal "$(cat $log_file)"
            else
               echo_done
            fi
         else
            echo_skipped
         fi
      done
   fi


else

   info "NO LX Container on this Host"

fi



if $terminal ; then
   echo ""
   echo ""
   echo -e "\033[13G\033[1mGoing to power off the system ..\033[m"
   echo ""
else

   from_address="power-off@$(hostname -f)"
   to_address="root"
   content_type='Content-Type: text/plain;\n charset="utf-8"'
   subject="Power OFF System $(hostname -f).."
   msg="    Going to power off system '$(hostname -f)' .."

   echo -e "To:${to_address}\n${content_type}\nSubject:$subject\n\n${msg}\n" \
         | /usr/sbin/sendmail -F "Webservice Monitor" -f $from_address $to_address

fi

/sbin/poweroff

exit 0