#!/bin/bash
#
#############################################################################
#
# This CUPS backend provides a mechanism to browse local HELIOS queues and
# to print into these. Every queue that is configured as "tcp/ip printer"
# will be published (the 'chooser' name will be displayed).
#
# To use it, save this script renamed as "helios" in CUPS' backend folder
# e.g. /usr/libexec/cups/backend (on MacOS X)
#
#############################################################################
#
# author: Thomas Kaiser <mailto:print-to-pdf@kaiser-edv.de>
# license: GPL - http://www.gnu.org/copyleft/gpl.html
# url: http://users.phg-online.de/tk/helios/scripts/cups-backend.sh
# date: Sat Apr  5 16:57:09 CEST 2003 (v.0.0.5)
#
#############################################################################
#
# CHANGES:
#
# 0.0.5: - force CUPS to reread its ppds.dat database after we copied
#          PPDs to the model dir
#        - some code cleanups
#
# 0.0.4: - added support for copying the HELIOS PPDs to CUPS' model dir
#
# 0.0.3: - some code cleanups
#        - append the CUPS OWNER string as the For: string in the PS header
#
# 0.0.2: - supply a printer model based on the "*ModelName" entry in the
#          queue's PPD file
#        - changed the "device class" from "direct" to "file"
#
#############################################################################
#
# Non-Warranty: 
# This script comes with absolutely no warranty.
#
# Use at your own risk!
#
#############################################################################
#
# Custom settings:
#
# if you define this path and it is pointing to a directory then the backend
# will copy the queue's PPDs inside and force CUPS to update its PPD database

PPD_DIR=/usr/share/cups/model/helios

# administrative settings
 
PROTOCOL=`basename ${0}`
TMP_FILE="${TMPDIR:=/tmp}/${PROTOCOL}-$$.ps"
while [ -e "${TMP_FILE}" ]; do TMP_FILE="${TMP_FILE}x"; done

#############################################################################
#
# some functions

main()
{
	# Check prerequisits
	
	CheckHELIOS
	
	# Let's start to process the CUPS requests
	
	if [ ${#} = 0 ]; then 
	
		# CUPS is calling us to determine which services we can provide
	
		# check whether we should copy the queue's PPDs over to CUPS
		if [ -d "${PPD_DIR}" ]; then      
			CopyPPD=TRUE
		else
			CopyPPD=FALSE
		fi
	
		# let's parse the Helios config for available 'tcp/ip printers'
	
		${HELIOSDIR}/bin/prefdump | tr -d "\012" | sed 's|\[\]|\\|g' | \
		tr "\\" "\n" | grep "\[TCPPublish\]" | while read PRINTER; do 
			IsTCPPrinter=`echo ${PRINTER} | cut -d"=" -f4`
			if [ ${IsTCPPrinter} = "TRUE" ]; then 
				PrinterName=`echo ${PRINTER} | cut -d"[" -f3 | tr -d "]"`
				
				# Try to get the macintosh chooser name
				PAPName=`${HELIOSDIR}/bin/prefdump | tr -d "\012" | \
					sed 's|\[\]|@|g' | tr "@" "\n" | \
					grep "\[Printers\]\[${PrinterName}\]\[papname\]" | \
					cut -d"]" -f5`
				if [ "X${PAPName}" = "X" ]; then
					PAPName=${PrinterName}
				fi
				
				# Try to get the model name of the printer
				PPD=${HELIOSDIR}/var/spool/qmeta/${PrinterName}/PPD
				TYPE="\"Unknown\""
				if [ -r ${PPD} ]; then
					PPDTYPE=`grep "^*ModelName:" ${PPD} | cut -d"\"" -f2`
					test "X${PPDTYPE}" = "X" || TYPE="\"${PPDTYPE}\""
					
					# test whether we should copy the PPD to CUPS
					if [ ${CopyPPD} = "TRUE" -a ! -f "${TMP_DIR}/update_ppds" ]; then
						cp "${PPD}" "${PPD_DIR}/${PrinterName}"
					fi
					
				fi
				
				echo "file ${PROTOCOL}://${PrinterName} ${TYPE} \"HELIOS Queue '${PAPName}'\""
			fi
		done
	
		# let CUPS eventually update its PPD database
		
		ForcePPDUpdate
	
	else
		# Let's print the job...
		
		PRINTER=`echo ${DEVICE_URI} | awk -F"://" '{print $2}'`
		TITLE="${3}"
		OWNER="${2}"
	
		echo "INFO: Sending job to HELIOS" >&2
		(echo -e "%!PS\n%%For: (${OWNER})"; cat $6) | ${LPR} -P${PRINTER} -T"${TITLE}"
		echo "PAGE: 1 1" >&2
	
	fi
}

CheckHELIOS()
{
	if [ -r /etc/HELIOSInstallPath ]; then
		read HELIOSDIR </etc/HELIOSInstallPath
		DT="${HELIOSDIR}/bin/dt"
		LPR="${HELIOSDIR}/bin/lpr"
	else
		echo "ERROR: Cannot locate HELIOS installation dir" >&2
		exit 1
	fi
}

ForcePPDUpdate()
{
	if [ -f "${TMP_DIR}/update_ppds" ]; then
		rm "${TMP_DIR}/update_ppds"
		return 0
	else
		touch "${TMP_DIR}/update_ppds"
	fi

	case `uname -s` in
	AIX|HP-UX|OSF1|SunOS|IRIX*)
		CUPSPID=`ps -e | grep cupsd | awk -F' ' '{print $1}'`
		;;
	Darwin|Linux)
		CUPSPID=`ps ax | grep cupsd | awk -F' ' '{print $1}'`
		;;
	*)
		echo "ERROR: unable to check system architecture" >&2
		return 1
		;;
	esac
	
	if [ -z "${CUPSPID}" ]; then
		echo "ERROR: unable to get CUPS PID" >&2
		return 1
	fi
	
	kill -HUP ${CUPSPID}
}


#############################################################################
#
# let's go

main "$@"