#!/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/${script_name%%.*}.LOCK"
log_file="${LOCK_DIR}/${script_name%%.*}.log"

# Sending alert messages
#
declare -a alert_email_arr=()

declare -a potential_critical_msg_file=()
declare -a tmp_potential_critical_msg_file=()

tmp_spool_msg_folder_exists=false


# -------------
# - Some functions
# -------------

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
}

warn_only_terminal () {
   if $terminal ; then
      echo ""
      echo -e "\t[ \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"
}

# 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
}

# Check if directory is empty
#
is_empty_directory () {

   # Set the variable for bash behavior
   shopt -s nullglob
   shopt -s dotglob

   # Die if no dir name was provided on command line
   if [[ $# -eq 0 ]]; then 
      error "Wrong call of function 'is_empty_directory ()'. 

              Usage: is_empty_directory <dir-name>"

      echo ""
      return 1
   fi

   chk_empty_dir=(${1}/*)

   # Unset the variable  for bash behavior
   shopt -u nullglob
   shopt -u dotglob

   if (( ${#chk_empty_dir[*]} )) ; then

      # Files found in $1 directory (send false)
      return 1
   else

      # Directory $1 is empty. (send true)
      return 0
   fi
   
}

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


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

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


# ----------
#  Read Configurations from $conf_file
# ----------


# - Give your default values here
# -
if [[ -d "/usr/local/sympa/spool/msg" ]] ; then
   DEFAULT_SYMPA_SPOOL_MSG_DIR="/usr/local/sympa/spool/msg"
else
   DEFAULT_SYMPA_SPOOL_MSG_DIR=""
fi
DEFAULT_TMP_SPOOL_MSG_DIR="/tmp/usr_local_sympa_spool_msg"

DEFAULT_CONFLICTING_SCRIPTS=""

DEFAULT_COMPANY="O.OPEN"
DEFAULT_CONTENT_TYPE='Content-Type: text/plain;\n charset="utf-8"'
DEFAULT_SENDER_ADDRESS="${script_name%%.*}@$(hostname -f)"
DEFAULT_ALERT_EMAIL_ADDRESSES="ckubu@oopen.de"

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


[[ -n "$TMP_SPOOL_MSG_DIR" ]] || TMP_SPOOL_MSG_DIR="${DEFAULT_TMP_SPOOL_MSG_DIR}"
[[ -n "$SYMPA_SPOOL_MSG_DIR" ]] || SYMPA_SPOOL_MSG_DIR="${DEFAULT_SYMPA_SPOOL_MSG_DIR}"
if [[ ! -d "${SYMPA_SPOOL_MSG_DIR}" ]]; then
   fatal "Given Sympa's spool message dir \033[1m${SYMPA_SPOOL_MSG_DIR}\033[m does not exist."
fi

[[ -n "$CONFLICTING_SCRIPTS" ]] || CONFLICTING_SCRIPTS="${DEFAULT_CONFLICTING_SCRIPTS}"

[[ -n "$(trim $alert_email_addresses)" ]] ||  alert_email_addresses=("${DEFAULT_ALERT_EMAIL_ADDRESSES[@]}")

if [[ ${#alert_email_addresses} -gt 0 ]] ; then
   for _email in $alert_email_addresses ; do
      alert_email_arr+=("$_email")
   done
fi

[[ -n "$sender_address" ]] || sender_address="${DEFAULT_SENDER_ADDRESS}"
[[ -n "$content_type" ]] || content_type="${DEFAULT_CONTENT_TYPE}"
[[ -n "$company" ]] || company="${DEFAULT_COMPANY}"


# -------------
# - Job is already running?
# -------------

# - If job already runs, stop execution..
# -
if mkdir "$LOCK_DIR" 2> /dev/null ; then

   ## - Remove lockdir when the script finishes, or when it receives a signal
   trap "clean_up 1" SIGHUP SIGINT SIGTERM

else

   datum="$(date +"%d.%m.%Y %H:%M")"

   msg="[ Error ]: A previos instance of \"`basename $0`\" seems already be running.\n\n           Exiting now.."

   echo ""
   echo "[ Error ]: A previos instance of that script \"`basename $0`\" seems already be running."
   echo ""
   echo -e "           Exiting now.."
   echo ""

   for _email in ${alert_email_arr[@]} ; do
      echo -e "To:${_email}\n${content_type}\nSubject:Error cronjob `basename $0` -- $datum\n${msg}\n" \
         | sendmail -F "Error `hostname -f`" -f $sender_address $_email
   done

   exit 1

fi


# - Stop here, if these give scripts are running
# -
if [[ ${#CONFLICTING_SCRIPTS} -gt 0 ]] ; then

   # - Try using a random start delay to prevent (or at least have a small chance) that
   # - conflicting scripts will both/all abort if they start at the same time.
   # -
   # - !! Notice !!
   # - This only makes sense if a fixed LOCK directory is used, otherwise the process list
   # - (and NOT the LOCK-directory) is used to look for scripts running in parallel.
   # -
   # - Skip delay if running in an terminal (from copnsole)
   # -
   if ! $terminal ; then
      if [[ "$LOCK_DIR" = "/tmp/${script_name%%.*}.LOCK" ]]; then
         _shift="$(( $RANDOM % 10 + 1 ))"
         sleep  $(( $RANDOM % 25 + $_shift ))
      fi
   fi

   _stop_running=false
   for _val in $CONFLICTING_SCRIPTS ; do

      IFS=':' read -a _val_arr <<< "${_val}"

      _script_name="$(basename ${_val_arr[0]})"

      if [[ -n "${_val_arr[1]}" ]] ; then

         if [[ "${_val_arr[1]}" = "CHECK_PROCESS_LIST" ]] ; then

            check_string_ps="${_val_arr[0]}"
            if ps -e f | grep -E "\s+${check_string_ps}" | grep -v grep | grep -v -E "\s+vim\s+" > /dev/null ; then
               _stop_running=true
            fi

         elif [[ -d "${_val_arr[1]}" ]] ; then
            _stop_running=true
         fi

      elif [[ -d "/tmp/${_script_name%%.*}.LOCK" ]]; then
         _stop_running=true
      fi

      if $_stop_running ; then

         warn_only_terminal "\033[1m${_script_name}\033[m is currently running, but it conflicts with this script.

                      Exiting now.."

         clean_up 1

      fi # if $_stop_running ; then

   done # for _val in $CONFLICTING_SCRIPTS ; do

fi # if [[ ${#CONFLICTING_SCRIPTS} -gt 0 ]] ; then

# ----------
# - Some pre-script tasks ..
# ----------

if $terminal ; then
   echo ""
   echo ""
   echo -e "   \033[1mDoing some pre-script tasks ..\033[m"
   echo ""
fi

echononl "Gather all files 'sympa@*' from folder \033[1m${SYMPA_SPOOL_MSG_DIR}\033[m.."

CUR_IFS="$IFS"
while IFS=" " read -r -d '' _file ; do
   potential_critical_msg_file+=("$(basename ${_file})")
done < <(find "${SYMPA_SPOOL_MSG_DIR}" -mindepth 1 -maxdepth 1 -type f -name "sympa@*" -print0)
echo_ok

if [[ ${#potential_critical_msg_file[@]} -lt 1 ]] ; then
   blank_line
   info "No critical message(s) in folder \033[1m${SYMPA_SPOOL_MSG_DIR}\033[m found.

             \033[1mAll is fine.\033[m - Script ends here."

   if [[ -d "${TMP_SPOOL_MSG_DIR}" ]] ; then
      rm -rf "${TMP_SPOOL_MSG_DIR}"

      if ! $terminsl ; then
         echo ""
         echo -e "   [ Info ]: No critical message(s) in folder '${SYMPA_SPOOL_MSG_DIR}' found.

             ."
         echo ""
      fi
   fi
   clean_up 0
else
   blank_line
   if $terminal ; then
      error "Found some critical file(s) in \033[1m${SYMPA_SPOOL_MSG_DIR}\033[m!"
   else
      error "Found some critical file(s) in ${SYMPA_SPOOL_MSG_DIR}!"
   fi
   blank_line
fi
IFS="$CUR_IFS"

#blank_line
#for _file in ${potential_critical_msg_file[@]} ; do
#   echo $_file
#done
#blank_line

echononl "Create Folder \033[1m${TMP_SPOOL_MSG_DIR}\033[m if not exists.." 
if [[ ! -d ${TMP_SPOOL_MSG_DIR} ]] ; then
   mkdir -p "${TMP_SPOOL_MSG_DIR}"
   if [[ $? -lt 1 ]] ; then
      echo_done
   else
      echo_failed
   fi
else
   echo_skipped

   tmp_spool_msg_folder_exists=true

   echononl "Gather all files 'sympa@*' from folder \033[1m${TMP_SPOOL_MSG_DIR}\033[m.."
   while IFS=" " read -r -d '' _file ; do
      tmp_potential_critical_msg_file+=("$(basename ${_file})")
   done < <(find "${TMP_SPOOL_MSG_DIR}" -mindepth 1 -maxdepth 1 -type f -name "sympa@*" -print0)
   echo_ok

   #blank_line
   #for _file in ${tmp_potential_critical_msg_file[@]} ; do
   #   echo $_file
   #done
   #blank_line

fi



# ----------
# - Main part of script
# ----------

if $terminal ; then
   echo ""
   echo ""
   echo -e "   \033[1mMain part of script \033[32m${script_name}\033[m\033[1m ..\033[m"
   echo ""
fi

_found_file_second_time=false
if ! $tmp_spool_msg_folder_exists ; then
   for _file in ${potential_critical_msg_file[@]} ; do
      echononl "Copy file \033[1m${_file}\033[m into ${TMP_SPOOL_MSG_DIR}.."
      cp -a "${SYMPA_SPOOL_MSG_DIR}/${_file}" "${TMP_SPOOL_MSG_DIR}/" > $log_file 2>&1
      if [[ $? -lt 1 ]] ; then
         echo_done
      else
         echo_failed

         error "$(cat $log_file)"
      fi
   done

   #clean_up 0
else

   for _file in ${potential_critical_msg_file[@]} ; do

      if containsElement "$_file"  "${tmp_potential_critical_msg_file[@]}" ; then

         _found_file_second_time=true

         blank_line
         echononl "Remove \033[1m${_file}\033[m from directory \033[1m${SYMPA_SPOOL_MSG_DIR}\033[m.."
         rm "${SYMPA_SPOOL_MSG_DIR}/${_file}" > $log_file 2>&1
         if [[ $? -lt 1 ]] ; then
            echo_done
         else
            echo_failed

            error "$(cat $log_file)"
         fi

         echononl "Remove \033[1m${_file}\033[m from directory \033[1m${TMP_SPOOL_MSG_DIR}\033[m.."
         rm "${TMP_SPOOL_MSG_DIR}/${_file}" > $log_file 2>&1
         if [[ $? -lt 1 ]] ; then
            echo_done
         else
            echo_failed

            error "$(cat $log_file)"
         fi

      else

         blank_line
         echononl "Copy file \033[1m${_file}\033[m into ${TMP_SPOOL_MSG_DIR}.."
         cp -a "${SYMPA_SPOOL_MSG_DIR}/${_file}" "${TMP_SPOOL_MSG_DIR}/" > $log_file 2>&1
         if [[ $? -lt 1 ]] ; then
            echo_done
         else
            echo_failed

            error "$(cat $log_file)"
         fi

      fi

   done
fi

if ! $_found_file_second_time ; then

   if $terminal ; then
      blank_line
      info "Right now there is nothing more to do as the critical files have been found for the first time."
   else
      echo ""
      echo -e "   [ Info ]: Right now there is nothing more to do as the critical files have been found 
             for the first time."
      echo ""
   fi

else

   # ----------
   # - Some post-script tasks ..
   # ----------

   if $terminal ; then
      echo ""
      echo ""
      echo -e "   \033[1mDoing some post-script tasks ..\033[m"
      echo ""
   else
      echo ""
      echo -e "   [ Info ]: Critical files have been removed from the spool directory. '${SYMPA_SPOOL_MSG_DIR}'" 
      echo ""
   fi


   # If directory ${TMP_SPOOL_MSG_DIR} is empty remove it.
   #
   echononl "Remove directory \033[1m${TMP_SPOOL_MSG_DIR}\033[m.."
   if $(is_empty_directory "${TMP_SPOOL_MSG_DIR}") ; then

      rmdir "${TMP_SPOOL_MSG_DIR}" > $log_file 2>&1
      if [[ $? -lt 1 ]] ; then
         echo_done

         if $terminal ; then
            echononl "Try to (re)start sympa service.."
         else
            echo ""
            echo "   [ Info ]: Try restarting sympa service now.."
            echo ""
         fi
         systemctl restart sympa > $log_file 2>&1
         if [[ $? -lt 1 ]] ; then
            echo_done
         else
            echo_failed

            error "$(cat $log_file)"
         fi

      else
         echo_failed

         error "$(cat $log_file)"
      fi
   else
      echo_skipped

      if $terminal ; then
         warn "Directory \033[1m${TMP_SPOOL_MSG_DIR}\033[m is not empty!"
      else
         echo ""
         echo "   [ Warn ]: Directory '${TMP_SPOOL_MSG_DIR}' is not empty.
             Now, awaiting next run of this script.."
         echo ""
      fi
   fi
fi


clean_up 0