#!/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)
# ----------

clean_up() {

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

usage() {


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


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

   $(basename $0)

\033[1mDescription\033[m

   Script lists all connected NFS client ip-addresses.

\033[1mOptions\033[m

   No Options present

\033[1mFiles\033[m

   $conf_file: Configuration file

\033[1mExample:\033[m

   List connected NFS clients

      $(basename $0)

"

   clean_up 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
         echo -e -n "   $*\\c"
      else
         #echo -e -n "   $*" 1>&2
			echo -e -n "   $*"
      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 ""
}

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

echo_skipped() {
   if $terminal ; then
      echo -e "\033[75G[ \033[37m\033[1mskipped\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
}

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

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


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

# - Print help?
# -
if [[ "$(trim $*)" = "-h" ]] || [[ "$(trim $*)" = "--help" ]] ; then
    usage
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


# Redirect all errors to $log_file
#
exec 2> "$log_file"
echononl "Redirect all errors to '\$log_file'.."
if [[ $? -eq 0 ]] ; then
	echo_ok
else
	echo_failed
fi

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


# - Give your default values here
# -
DEFAULT_NFS_SERVER_PORT="2049"

echononl "Load Configurations from file '$(basename "$conf_file")'."
if [[ -f "$conf_file" ]]; then
   source "$conf_file"
   echo_ok
else
   echo_skipped
   msg="No configuration file found. Script default values are loaded.."
   if $terminal ; then
      echo ""
      echo -e "   [ \033[33m\033[1mWarn\033[m ]  $msg"
      echo ""
   fi
fi

if [[ -z "$NFS_SERVER_IPV4" ]] ; then
   NFS_SERVER_IPV4="$(ip a | grep "inet " | grep -v "127\.0" | awk '{print$2}' | cut -d '/' -f1 | head -n 1)"
   if [[ -z "$NFS_SERVER_IPV4" ]] ; then
      fatal "Missing NFS Server IP Address."
   fi
fi
[[ -z "$NFS_SERVER_PORT" ]] && NFS_SERVER_PORT="$DEFAULT_NFS_SERVER_PORT"

# Get NFS client list
#
#	netstat -an | grep 192.168.112.10:2049 \
#    | awk '{print"   "$5}' \
#    | cut -d ':' -f1 \
#    | sort
#
echononl "Get NFS client list.."
netstat -an \
	| grep  ${NFS_SERVER_IPV4}:$NFS_SERVER_PORT \
	| awk '{print"   "$5}' \
	| cut -d ':' -f1 \
	| sort >> ${LOCK_DIR}/nfs-clients.list
if [[ -s "$log_file" ]]; then
	echo_failed
	error "$(cat "$log_file")"
	> "$log_file"
else
	echo_ok
fi


# Create array of connected clients:
#
echononl "Create array of connected clients.."
declare -a NFS_CLIENT_ARR=()
while read _nfs_client ; do
	NFS_CLIENT_ARR+=("$(trim "$_nfs_client")")
done < "${LOCK_DIR}/nfs-clients.list"
if [[ -s "$log_file" ]]; then
	echo_failed
	error "$(cat "$log_file")"
	> "$log_file"
else
	echo_ok
fi



if $terminal ; then
	echo ""
	echo ""
	echo "   ----------------------"
	echo -e "   \033[37m\033[1mConnected NFS Clients:\033[m"
	echo "   ----------------------"
	echo ""
fi

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

   if ! $terminal ; then
      echo ""
      echo "Number of connected clients: ${#NFS_CLIENT_ARR[@]}"
      echo ""
   fi

	for _nfs_client in "${NFS_CLIENT_ARR[@]}" ; do
      if $terminal ; then
		   echo -e  "   \033[33m$_nfs_client\033[m"
      else
         echo "   $_nfs_client"
      fi
	done

   if $terminal ; then
	   info "Number of connected clients: \033[1m${#NFS_CLIENT_ARR[@]}\033[m"
   fi

else
   if $terminal ; then
	   info "No NFS Client connected."
   else
      echo ""
      echo ""No NFS Client connected.
      echo ""
   fi
fi


clean_up 0