#!/bin/bash

CONFDIR="$HOME/.config/ssh-tunnelier"
CONF="$CONFDIR/config"
MAGIC_TIME=873749328

function _helpexit() {
  echo "SSH tunnel manager
Runs and monitors preconfigured background ssh tunnels, with the ability
to kill existing ssh processes. You don't need to keep the program on
to remember connected sessions.

Configuration stored in: $CONF
"
  exit 0
}

for (( i=1; i<=$#; i++ )); do 
  [[ ${!i} = "-h" ]] && _helpexit
  [[ ${!i} = "--help" ]] && _helpexit
done


[[ -f "$CONF" ]]  || {
  echo No config file.
  echo "$CONF" each line like:
  echo -L 8888:localhost:8888 servername
  mkdir -p "$CONFDIR"
  echo -e "# example:\n -L 8888:localhost:8888 servername" > "$CONF"
}
number_re='^[0-9]+$'

colZ="\033[0m"
colTitle="\033[0;1;32m"
colRow="\033[0;1m"
colMenu="\033[0;33m"
colWarn="\033[0;1;31m"

function fpgrep() { 
  pgrep -x -u $UID "$@" | xargs --no-run-if-empty ps -o pid,bsdstart,args; 
  test ${PIPESTATUS[0]} -ne 0 && echo '----'
}

function get_id() {
  id=$( printf "%s" "$line" | base64 -w 0 )
  echo -n $id
}

function get_command() {
  switches=$( echo "$1" | base64 -d )
  echo -n "ssh -f -n $switches \"sleep $MAGIC_TIME; echo tunneler $1\""
}

function get_pid() {
  pgrep -f "$MAGIC_TIME.*echo tunneler $1" | head -n 1
}

function list_all_ssh() {
  printf "\n${colTitle}=============================================\n"
  printf "${colTitle}                List of SSH:${colZ}\n"
  printf "${colTitle}Enter PID to kill, empty to return $colZ\n"
  printf "${colTitle}Outgoing SSH processes\n"
  printf "${colTitle}=============================================\n${colRow}"
  fpgrep ssh 
  printf "${colTitle}Incoming SSH processes\n"
  printf "${colTitle}=============================================\n${colRow}"
  fpgrep sshd 
  read -t 600 inputpid

  [[ "$inputpid" =~ $number_re ]] && {
    kill $inputpid
  }
}

function read_config() {
  while read line; do
    id=$( get_id "$line" )
    pid=$( get_pid "$id" )
    printf "%-3d %-7s %s\n" $i "$pid" "$line"
    ids+=( $id )
    i=$(( i + 1 ))
  done < <( grep -v ^# "$CONF" | grep '[a-zA-Z]' )
}

function run_command() {
  eval $( get_command "$1" )
}

while true; do
  ids=()
  i=1
  printf "\n${colTitle}=============================================\n"
  printf "${colTitle}              List of tunnels:${colZ}\n" 
  printf "${colTitle} (q)uit (e)dit (l)ist ssh             [%s]${colZ}\n" $( date +%H:%M )
  printf "${colTitle}=============================================\n"
  printf "${colRow}ID  PID     command\n"
  read_config
  printf "$colZ"
  read -t 600 input

  [[ "$input" = "q" ]] && exit 0
  [[ "$input" = "e" ]] && vim "$CONF"
  [[ "$input" = "l" ]] && list_all_ssh
  [[ "$input" = "0" ]] && continue
  [[ "$input" =~ $number_re ]] && {
    j=$(( $input - 1 ))
    [[ $j -gt $(( $i - 1 )) ]] && { 
        printf  "${colWarn}No such tunnel number${colZ}\n"
        continue
    }
    
    printf "\n${colTitle}Tunnel command: %s${colZ}\n" "$( echo  "${ids[$j]}" | base64 -d )" 
    this_pid="$( get_pid "${ids[$j]}" )"
    [[ -n "$this_pid" ]] && {
	  # PID exists, ask to kill
	  printf "\n  ${colRow}k kill?${colZ}\n"
      read -t 600 input2
      [[ "$input2" = "k" ]] && kill $( get_pid "${ids[$j]}" )
  	}
	  [[ -z "$this_pid" ]] && {
	  # PID empty, run
      run_command "${ids[$j]}"
      sleep 1
    }
  }
done