#!/bin/bash

## Author Luis@32768.org at 2012-02-14
## Check HP LaserJet 1020 is plugged in or not every 6 seconds
## If pluged, make a 1 flag to /tmp/hplj1020
## If unpluged, remove /tmp/hplj1020
## If not pluged, do nothing

CHECKFILE=/proc/bus/usb/devices
FLAGCHECK='HP LaserJet 1020'
FLAGFILE=/tmp/hplj1020
FIRMWARE=/root/sihp1020.dl
PRINTER=/dev/usb/lp0

DEBUG=0

rm -rf $FLAGFILE

while(true)
do
	printeronline=0
	flagfileexist=0
	firmwareloaded=0

	## check printer is online or not
	pscnt=`cat ${CHECKFILE} | grep "${FLAGCHECK}" | wc -l`
	if [ $pscnt -gt 0 ]
	then
		## HP LaserJet 1020 is online
		printeronline=1;
		
		## DEBUG
		if [ $DEBUG -eq 1 ]
		then
			echo "Printer is online"
		fi
	else
		## DEBUG
		if [ $DEBUG -eq 1 ]
		then
			echo "Printer is NOT online"
		fi
	fi
	
	## check flag file
	if [ -f $FLAGFILE ]
	then
		## flag file is exist
		flagfileexist=1;
		
		## DEBUG
		if [ $DEBUG -eq 1 ]
		then
			echo "Flag file exist"
		fi
		
		## check the content
		firmwareloaded=`cat ${FLAGFILE}`
		
		## DEBUG
		if [ $DEBUG -eq 1 ]
		then
			echo "Firmware loaded: $firmwareloaded"
		fi
	else
		## DEBUG
		if [ $DEBUG -eq 1 ]
		then
			echo "Flag file NOT exist"
		fi
	fi
	
	## now we get all three flag
	
	## No priniter, clear flag file
	if [ $printeronline -eq 0 ]
	then
		if [ -f $FLAGFILE ]
		then
			rm -rf $FLAGFILE
		
			## DEBUG
			if [ $DEBUG -eq 1 ]
			then
				echo "Remove flag file"
			fi
		fi
	fi
	
	## Check printer online or NOT
	if [ $printeronline -eq 1 ]
	then
		## Printer exist, load firmware if NOT load
		if [ $firmwareloaded -lt 1 ]
		then
			## Load firmware first
			cat $FIRMWARE > $PRINTER
			
			## DEBUG
			if [ $DEBUG -eq 1 ]
			then
				echo "Load firmware to printer"
			fi
			
			## Flag it
			if [ $flagfileexist -eq 1 ]
			then
				## Flag file exist, flag it
				echo "1" > $FLAGFILE
				
				## DEBUG
				if [ $DEBUG -eq 1 ]
				then
					echo "Flag the exist of printer"
				fi
			else
				## Flag file NOT exist, touch it and flag it
				touch $FLAGFILE
				echo "1" > $FLAGFILE
				
				## DEBUG
				if [ $DEBUG -eq 1 ]
				then
					echo "Create flag file and flag it"
				fi
			fi
		fi
	fi
	
	sleep 2;
done