#!/bin/bash
LOCATION=/data/cisco
NUMOFRACK="1 2 3 4"
TOTALRACKNUM=`echo $NUMOFRACK | tail -c -2`

###########################################################################################################
#Sanity check on rack number and additional variable declaration.
###########################################################################################################
if [ -z $2 ]
	then 
		/bin/true
	elif  [ $2 -gt $TOTALRACKNUM ]
		then
			echo "Invalid Rack identifier select. Please use one of the following: $NUMOFRACK"
			exit
		else
			RACKNUM=$2
			RACKPID=`ps -ef | grep dyna | grep 720$RACKNUM |  tr -s [:space:] " "  | cut -d\  -f2`
			RACKUSER=`w -s -f | grep start\ $RACKNUM | tr -s [:space:] " " | cut -d\  -f1`
fi
	
###########################################################################################################
#Functions are declared here
###########################################################################################################

RACKLOG () { 
	TIME="`date +%R--%d-%m-%y`" 
	case $1 in
		start )
			echo "$TIME $USER started rack $RACKNUM" >> /data/cisco/logs/usage.log
		;;
		stop )
			echo "$TIME $USER stopped rack $RACKNUM" >> /data/cisco/logs/usage.log
		;;
	esac
}

RACKSTART () {
        $LOCATION/dynamips-0.2.8-RC2-x86.bin -H 720$RACKNUM  -l $LOCATION/$USER/dynamips.log & 
        echo "Starting Rack $RACKNUM and loading Topology please wait."
        RACKLOG start
	sleep 5
        $LOCATION/dynagen/dynagen $LOCATION/$USER.net
}

RACKKILL () { 
	DYNAPID=`ps -ef | grep dyna | grep 720$RACKNUM |  tr -s [:space:] " "  | cut -d\  -f2`
        kill  $DYNAPID 2> /dev/null && echo "Rack $RACKNUM has been stopped"
	RACKLOG stop
}

RACKRENUM () {
if [ -e $LOCATION/$USER.net ] 
	then
			echo "Reconfiguring your topology." 
	else
		echo "It appears this is your first time using the rack. Please stand by while your topology is built."
		cp $LOCATION/template.net $LOCATION/$USER.net
		mkdir $LOCATION/$USER && chmod -R 755 $LOCATION/$USER
		chmod 644 $LOCATION/$USER.net
fi

 	mv $LOCATION/$USER.net $LOCATION/$USER.net.back
  	sed -e "/\[localhost/s/720[1234]/720$RACKNUM/" -e "/udp/s/2[1234]/2$RACKNUM/"	-e "/workingdir/s/template/$USER/" -e "/console/s/2[1234]/2$RACKNUM/" $LOCATION/$USER.net.back > $LOCATION/$USER.net
	rm $USER.net.back 2> /dev/null
}

RACKLIST () {
                for i in $NUMOFRACK
                        do
                                if [ -z `ps -ef | grep dyna | grep 720$i |  tr -s [:space:] " "  | cut -d\  -f2` ]
                                        then
                                                echo Rack $i is available for use.       
                                        else
                                                STATUS="currently running"
                                                RACKUSER=`w -s -f | grep start\ $i | tr -s [:space:] " " | cut -d\  -f1`
                                                if [ -z $RACKUSER ]
                                                        then
                                                                echo "Rack $i is current running but does not seem to be in use."
                                                        else
                                                                echo "Rack $i is currenty running and in use by $RACKUSER"
                                                 fi
                                fi

        done
}

###########################################################################################################
#Control portion of script
###########################################################################################################

case "$1" in
	 start )
		if [ -z $RACKPID ]
			then
				RACKRENUM
   				RACKSTART
				RACKKILL
	 		
			else
				if [ -z $RACKUSER ]
                                	then    
                                        	echo "Rack $RACKNUM is current running but does not seem to be in use.Please try to stop this rack first, Then start it again."
                                        else    
                                                echo "The rack you have selected is currently in use. Please select another rack from the following list:"
						RACKLIST
                                fi
		fi
	;;
	 stop )
                if [ -z $RACKPID ]
			then
				echo "$RACKNUM is not currently running, so cannot stop it."
			else
				RACKKILL

		fi
	;;
	list ) 
		RACKLIST
	;; 
	* )
		echo "Please specify a valid action, (start, stop or list). Start and Stop need to be followed by a rack number"
esac