#!/bin/bash
# CUPS PDF writer
#
# Copyright (C) 2009, Christopher J. Cox
# Copyright (C) 2009, Sterling Commerce, Inc.
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

#
# This program tries really hard to always be successful... even when
# it isn't.  Certain things have NOT been well tested, for example,
# I have not tested a ps2pdf failure condition yet.
#

# 
# If you run the cups daemon as something other than root, this program
# has to be able to write as that user (e.g. lp) into PDFDIR.  If 
# PDFDIR is NOT set below, then PDFDIR defaults to a per-user directory
# inside the user's home directory. The filename written defaults to
# the <cups_title>-<date_stamp>.pdf.  If PDFDIR is set,
# then it defaults to <cups_user>-<cups_title>-<date_stamp>.pdf.
#
#
# Set PDFDIR is you want all results written to a common directory.
# How a user gets to their PDF output in that directory is left
# up to the administrator.  Otherwise, output goes to the user's
# home directory under pdfdirname.
#PDFDIR="/var/spool/pdf"
# Directory created in user's home dir if PDFDIR not set.
#
pdfdirname="CUPS-PDF"

# Add an extra debug logger line or two with this set
#
pdf_writer_debug=1

# Find the ps2pdf program (sometimes people override the default)
#
ps2pdf_exe=`/usr/bin/which ps2pdf`

# Date stamp for semi-unique file naming and when run info.
#
date_stamp=`/bin/date +%Y%m%d%H%M%S`

# What uid am I running as?  Assume 0 is root and can do chown/chmod.
# Note: if running as root but without an effective pdf output directory
# that root cannot operate in... NFS for example, then hardcode uid
# here to something other than 0.  It is only used for checking if root
# or not.
#
uid=`/usr/bin/id -u`

# CUPS will pass these arguments to us.
#
cups_jobnum="$1"
cups_user="$2"
cups_title="$3"
cups_copies="$4"
cups_options="$5"
cups_file="$6"

#
# General note, I always return 0 on exit, to make sure the cups printer
# doesn't go down.
#

if [ "${cups_jobnum}" = "" ]; then
	if [ -x "${ps2pdf_exe}" ]; then
		echo "network pdf-writer:/var/spool/pdf \"unknown\" \"pdf writer\" " 
		rc=0  
	else
		echo "Error: $0 - ps2pdf is not available!"      
		logger "pdf-writer: ERROR: ps2pdf is not available!"      
		rc=1 
		exit 0
	fi 
fi

if [ "${pdf_writer_debug}" ]; then
	/bin/logger "pdf-writer started: job:[${cups_jobnum}] user:[${cups_user}] title:[${cups_title}] copies:[${cups_copies}] options:[${cups_options}] file:[${cups_file}]"
fi

# Check number of command line arguments
#
if [ $# -ne 5 -a $# -ne 6 ]; then
	echo "Usage: $0 jobnum user title copies options [file]"
	/bin/logger "pdf-writer: CRITICAL: Printer stopped !"      
	rc=2
	exit 0
fi

# get directory from device URI
#
pdfpath=${DEVICE_URI#pdf-writer:}

# Check for cups_user
#
if [ ! "${cups_user}" ]; then
	/bin/logger "pdf-writer: ERROR: no user!"      
	rc=3
	exit 0
fi

if [ ! "${PDFDIR}" ]; then
	# Check for cups_users home dir
	#
	homedir=`/usr/bin/getent passwd ${cups_user} | cut -f6 -d:`
	if [ ! "${homedir}" ]; then
		/bin/logger "pdf-writer: ERROR: No home directory for user, ${cups_user}!"      
		rc=4
		exit 0
	fi

	pdfdir="${homedir}/${pdfdirname}"
	pdfuser=""
else
	pdfdir="${PDFDIR}"
	pdfuser="${cups_user}"
fi

# Check for writable CUPS-PDF directory
#
if [ ! -w "${pdfdir}" ]; then
	/bin/logger "pdf-writer(${cups_jobnum}): ERROR: PDF dir: ${pdfdir} not writable!"      
	rc=5
	exit 0
fi

# Create filename for pdf output.
#
pdffilename="${pdfdir}/${pdfuser}${pdfuser:+-}${cups_title}${cups_title:+-}${date_stamp}.pdf"

if [ ${uid} -ne 0 ]; then
	# No umask, so the user can remove the pdf file this creates ideally.
	#
	umask 0
fi

# Create PDF file.
#
if [ $# -eq 6 ]; then
        pdferr=`${ps2pdf_exe} $6 "${pdffilename}"`
else
        pdferr=`${ps2pdf_exe} - "${pdffilename}"`
fi

if [ $? -ne 0 ]; then
	/bin/logger "pdf-writer(${cups_jobnum}): ERROR: ${ps2pdf_exe}, message was: ${pdferr}"      
	rc=6
	exit 0
else
	#Change ownership if possible
	#
	if [ ${uid} -eq 0 ]; then
		/bin/chown "${cups_user}" "${pdffilename}"
		/bin/chmod u+rw "${pdffilename}"
	fi
fi

exit 0