#!/bin/bash
#Ryan Pisani - March, 20th 2010
#Please give feedback to mythdora@thepisanis.com

PATH=/bin:/sbin:/usr/sbin:/usr/bin

#Incoming options
ISO="$1" 
COUNT="$2"
SCRIBE="3"

if [[ ! -e $ISO || -z $COUNT ]]; then

	echo "Usage: $0 /path/to/image.iso count"
	exit

fi

#Get basename of the iso file to use in caches
ISONAME=$(basename $ISO)

#Determine how many writers we have
DRIVES=($(ls /dev/sr* | grep -v sr0))
#DRIVES=($(ls /dev/sr*))
DRIVECOUNT=$(echo $DRIVES | wc -w)

#Check to see if there is a cache file setup already for the iso
if [[ ! -d "$HOME/.bulk-burn" ]]; then

	mkdir -p $HOME/.bulk-burn

fi

#Check to see if the cache exists for this iso, if not we create one
if [[ ! -e "$HOME/.bulk-burn/$ISONAME.isosum" ]]; then

        #echo that we're generating md5sums
	echo -e "\nGenerating md5sum & block counts for the ISO. This may take a bit..\n"
	#First get md5 information on the target iso to be used later in verification
	ISOSUM=$(md5sum $ISO | awk '{print $1}')
	ISOBLKS=$(ls -l $ISO | awk '{print $5}') 
	BLKCNT=$(echo $[ISOBLKS / 2048])

	echo "$ISOSUM" >$HOME/.bulk-burn/$ISONAME.isosum
	echo "$BLKCNT" >$HOME/.bulk-burn/$ISONAME.blkcnt

else

	#Retrieve the existing values
	ISOSUM=$(cat $HOME/.bulk-burn/$ISONAME.isosum)
	BLKCNT=$(cat $HOME/.bulk-burn/$ISONAME.blkcnt)

fi

echo -e "\nMD5SUM: $ISOSUM BLOCKS: $ISOBLKS BLKCNT: $BLKCNT\n"

#lets start burning the images
while [[ $COUNT -gt 0 ]]; do 

  for DRIVE in ${DRIVES[@]}; do 	
            
	if [[ $COUNT -gt 0 ]]; then

		DRV=$(basename $DRIVE)

		#Check to see if a disk is there already
		if ! ( lshal | grep -A1 volume_empty_dvd_r | grep block.device | grep $DRIVE ); then

			echo "Please insert a blank disk into $DRIVE"
			eject $DRIVE

			read -p "Press enter to continue"

		fi

		until [[ ! -e "/var/tmp/lock.$DRV" ]]; do 

			echo "Waiting for $DRIVE to be free"
			sleep 30

		done

		#Write the disk and background it so we can move on to another disk		
		(touch /var/tmp/lock.$DRV;
                growisofs -Z $DRIVE=$ISO;  

		echo -e "\nVerifying burned disk.. this may take a few minutes\n"

		BRNSUM=$(dd if=$DRIVE bs=2048 count=$BLKCNT 2>/dev/null| md5sum | awk '{print $1}');

		echo -e "$DRIVE:\nISO:$ISOSUM\nDisk:$BRNSUM\n"
		if [[ $BRNSUM != $ISOSUM ]]; then 

			echo "Burn on drive $DRIVE failed to verify" 

		fi 
                rm -rf /var/tmp/lock.$DRV; eject $DRIVE) #& #uncomment ampersan to allow concurrent background writing on multiple drives
	
	fi

	sleep 30;
	let COUNT="$COUNT - 1"	

  done

done
#Lets wait for child processes to exit before we exit
wait
#TARGET=$(lshal -u /org/freedesktop/Hal/devices/volume_empty_dvd_r | grep block.device | awk -F"'" '{print $2}' | awk -F"'" '{print $1}')