#!/bin/bash
function init_interactive {
	rm watchdogjobs.pid > /dev/null 2> /dev/null
	touch watchdogjobs.pid > /dev/null 2> /dev/null
	INTERACTIVE=true
}
function wrapthekill {
trap 'exit' 1 2 3 15
}
function processor {
	HOSTUP=false
	echo "$$,$2" >> watchdogjobs.pid
	showstatus $2 offline
	while true
	do
		RAWREPLY=$(ping -c 1 $1 2> /dev/null)
		REPLY=$(echo $RAWREPLY | grep from)
		if [[ ! -z $REPLY ]] 
		then
			if [[ $HOSTUP == "false" ]]
			then
				echo -ne "\a"
				showstatus $2 online
				HOSTUP=true
			fi
		else
			if [[ $HOSTUP == "true" ]]
			then
				echo -ne "\a"
				showstatus $2 offline
				HOSTUP=false
			fi	
		fi
	done
}
function smbsolver {
	smbutil lookup $1 | grep IP | awk -F": " '{print $2}'
}
function showstatus {
	echo "[$(date) $$] Host $1 $2"
}
function action {
	processor $1 $1
}
function smb_action {
	processor $(smbsolver $1) $1
}
function this {
	case $1 in 
		-s|--smb|--netbios|--nb)
			smb_action $2
			;;
		*)
			action $*
			;;
	esac
}
function new {
	if [[ $INTERACTIVE != "true" ]]
	then
		echo "[$(date) $$] Can't use new in non-interactive mode"
	else
		if [[ ! -z $*  ]]
		then
			$0 $* &
		fi
	fi
}
function showjobs {
	if [[ $INTERACTIVE != "true" ]]
	then
		echo "[$(date) $$] Can't show jobs in non-interactive mode"
	else
		for pid in $(cat watchdogjobs.pid)
		do
			echo "Task watching $(echo $pid | awk -F, '{print $2}'), pid $(echo $pid | awk -F, '{print $1}')"
		done
	fi
}
function killjobs {
	if [[ $INTERACTIVE != "true" ]]
	then
		echo "[$(date) $$] Can't kill jobs in non-interactive mode"
	else
		echo "[$(date) $$] Send SIGKILL to all jobs..."
		for pid in $(cat watchdogjobs.pid | awk -F, '{print $1}')
		do
			kill -9 $pid
		done
		init_interactive
	fi
}
function help {
	case $1 in
		action)
			echo "Usage: action IP"
			echo "Start a new watchdog job using given IP address. It it not recommand to start job using this. You should use this action command. see help this for more informations. "
		;;
		exit)
			echo "Usage: exit [-k|--keep-jobs]"
			echo "Exit watchdog. When -k or --keep-jobs is used, the process watchdog start will not be terminate. That might cause zombie process."
		;;
		init_interactive)
			echo "Usage: init_interactive"
			echo "This is an internal function, you should not use this directly. Set the environment for interactive mode to run. If you run this command, the watchdog jobs list will be clear, without killing the running jobs. That might cause zombie process."
		;;
		killjobs)
			echo "Usage: killjobs"
			echo "Kill all running watchdog process"
		;;
		new)
			echo "Usage: new arguement [options]"
			echo "Start a new watchdog process and process given argument, argument can be any one of avaliable command"
		;;
		processor)
			echo "Usage: processor IP DISPLAY_NAME"
			echo "Start a new watchdog job using given IP addesss and Display name. It it not recommand to start job using this. You should use this action command. see help this for more informations."
		;;
		showjobs)
			echo "Usage: showjobs"
			echo "Show all jobs start by current watchdog process"
		;;
		showstatus)
			echo "Usage: showstatus HOST STATUS"
			echo "This is an internal function, you should not use this directly. Using to display online/offline of a host."
		;;
		this)
			echo "Usage: this [-s|--smb|--netbios|--nb] HOST"
			echo "Call current watchdog process to preform given job. It is not recommand to directly using this command. If you can, use new to start the job."
			echo "When option -s, --smb, --netbios or --nb is used, watchdog will first lookup IP address using smbutil."
		;;
		smb_action)
			echo "Usage: smb_action NETBIOS_NAME"
			echo "Start a new watchdog job using given NETBIOS/Samba hostname. It it not recommand to start job using this. You should use this action command. see help this for more informations."
		;;
		smbsolver)
			echo "Usage: smbsolver NETBIOS_NAME"
			echo "Resolve NETBIOS/Samba hostname to IP address."
		;;
		*)
			echo "No such help topic found."
			echo "Avaliable helps are: action, exit, help, init_interactive, killjobs, new, processor, showstatus, this, smb_action, smbslover"
		;;
	esac
}
function exit {
	case $1 in
	-k|--keep-jobs)
		echo "[$(date) $$] Send SIGKILL to self..."
		kill -9 $$
	;;
	*)
		echo "[$(date) $$] Send SIGKILL to all jobs..."
		for pid in $(cat watchdogjobs.pid | awk -F, '{print $1}')
		do
			kill -9 $pid
		done
		rm watchdogjobs.pid
		echo "[$(date) $$] Send SIGKILL to self..."
		kill -9 $$
	;;
	esac
}
wrapthekill
if [[ ! -z $* ]]
then
	$*
else
	init_interactive
	echo "Watchdog 0.1 (interactive mode) - (C) MagicNAT 2014"
	echo "Available commands: action, exit, help, init_interactive, killjobs, new, processor, showstatus, this, smb_action, smbslover"
	while true 
	do
		echo -n "[$(pwd)] watchdog-$$> "
		read cmd;$cmd;
	done
fi