#!/bin/bash

#SMOKEPING_VERSION="2.8.3"
SMOKEPING_PIDFILE="/run/smokeping/smokeping.pid"
SMOKEPING_USER=@SMOKEPING_USER@
SMOKEPING_PATH=@SMOKEPING_PATH@
SMOKEPING_CONFIG_PATH=@SMOKEPING_CONFIG_PATH@
SMOKEPING_LOG_PATH="/var/log/smokeping.nosyslog.log"

get_child_pids() {
  if [[ -z "$1" ]]; then echo "get_child_pids:error: \$1 is empty " 1>&2 ; exit 1 ; fi
  local parent_pid=$1
  ps -o pid --no-headers --ppid $parent_pid
}

# Function to recursively get all descendant PIDs
get_descendant_pids() {
  if [[ -z "$1" ]]; then echo "get_descendant_pids:error: \$1 is empty " 1>&2 ; exit 1 ; fi
  local parent_pid=$1
  local child_pids=$(get_child_pids $parent_pid)
  for pid in $child_pids; do
    echo $pid
    get_descendant_pids $pid
  done
}

function start
{
  export LC_ALL=C
  # no idea why this is required
  # https://github.com/oetiker/SmokePing/issues/29
  cd /var/lib/smokeping

  mkdir -p /run/smokeping/
  chown $SMOKEPING_USER /run/smokeping/

  touch "$SMOKEPING_LOG_PATH"
  chown $SMOKEPING_USER "$SMOKEPING_LOG_PATH"
  
  if [[ -e $SMOKEPING_PIDFILE && ( "" == "$(cat $SMOKEPING_PIDFILE)" ) ]]
  then
    printf "Pid file is empty: %s\n" "$SMOKEPING_PIDFILE" 1>&2
  elif [[ -e $SMOKEPING_PIDFILE && ( "" != "$(cat $SMOKEPING_PIDFILE)" ) ]]
  then
    PID=$(cat "$SMOKEPING_PIDFILE")
    printf "PID=%s\n" "$PID"
    if ps --pid "$PID"
    then
      printf "Smokeping already running with pid %d.\n" "$PID" 1>&2
      return 1
    else
      printf "You have bogus pid file!\n" 1>&2
      rm "$SMOKEPING_PIDFILE"
    fi
  fi

  /sbin/setcap 'CAP_NET_RAW+eip CAP_NET_ADMIN+eip'  /usr/sbin/fping
  if ! su smokeping -s/bin/sh -c "$SMOKEPING_PATH --config=$SMOKEPING_CONFIG_PATH --logfile=$SMOKEPING_LOG_PATH"
  then
    printf "Smokeping failed to start!\n" 1>&2
    return 2
  fi

  if [[ ! -e $SMOKEPING_PIDFILE ]]
  then
    printf "Smokeping pidfile missing!\n" 1>&2
    return 3
  elif [[ "" == $(cat $SMOKEPING_PIDFILE  | tr -d '\n' ) ]]
  then
    printf "Pid file %s empty.\n" $(cat $SMOKEPING_PIDFILE) 1>&2
  else
    PID=$(cat "$SMOKEPING_PIDFILE")
    if ps --pid "$PID"
    then
      :
    else
      printf "Smokeping created pidfile, but is not running!\n" 1>&2
      return 4
    fi
  fi
  rm -f /run/smokeping-fcgi.sock
  /usr/bin/spawn-fcgi -u $SMOKEPING_USER -s /run/smokeping-fcgi.sock -M 660 -U $SMOKEPING_USER -- /var/www/htdocs/smokeping/smokeping.fcgi
  return 0
}

function stop()
{
  if [[ ! -e "$SMOKEPING_PIDFILE" ]];  then
    printf "Pid file %s does not exist!\n" "$SMOKEPING_PIDFILE"
    return 6
  elif [[ "" == "$(cat "$SMOKEPING_PIDFILE")" ]] ;  then
    printf "Pid file %s empty!\n" "$SMOKEPING_PIDFILE"
    return 6
  fi
  child_pids=$(get_descendant_pids $(cat  "$SMOKEPING_PIDFILE"))
  printf "Full pid list (smokeping+children):%s\n" "$(cat "$SMOKEPING_PIDFILE") $child_pids"
  /bin/kill --timeout 3000 TERM --timeout 1000 KILL --signal QUIT $(cat "$SMOKEPING_PIDFILE") $child_pids

  rm -f "$SMOKEPING_PIDFILE"

  if pgrep -f 'bin/smokeping ' -la >/dev/null 2>&1 # the space is important
  then
    printf "Killing smokeping failed!\n" 1>&2
    pgrep -f 'bin/smokeping' -la
  fi
  /bin/kill --timeout 3000 TERM --timeout 1000 KILL --signal QUIT $(/usr/sbin/ss -f unix -l -p | grep /run/smokeping-fcgi.sock | sed -E 's/.*pid=([[:digit:]]+),.*/\1/g')
  rm /run/smokeping-fcgi.sock
}

case "$1" in
  start)
    printf "case up\n"
    start
    exit "$?"
    ;;
  stop)
    printf "case down\n"
    stop
    exit "$?"
    ;;
  status)
    if [[ -e "$SMOKEPING_PIDFILE" && "" != $(cat  "$SMOKEPING_PIDFILE") ]] ; then
      pstree -s -p $(cat  "$SMOKEPING_PIDFILE")
    else
      printf "smokeping is not running or not running from this service.\n"
    fi
    cgi_pid=$(/usr/sbin/ss -f unix -l -p | grep /run/smokeping-fcgi.sock | sed -E 's/.*pid=([[:digit:]]+),.*/\1/g' 2>/dev/null)
    if [[ "" == "$cgi_pid" ]] ; then
      printf "smokeping_cgi is not running or not running from this service.\n"
    else
      pstree -s -p "$cgi_pid"
    fi
    ;;
  restart)
    if ! stop
    then
      exit "$?"
    fi
    if ! start
    then
      exit "$?"
    fi
    ;;
  *) printf "usage: {up,down,restart,status}\n"
esac