#! /bin/bash -eu
# Version 1.01
# Last updated 11 March 2011
#
# DEFAULTS
#
SCANNER_MODE="col"   # try  "lin", "bin",  "gr", or "col" 
SCANNER_RES=300
PDF_QUALITY=70
PDF_FORCE="colour"
#PDF_FORCE="monochrome"
PAGE_X=210
PAGE_Y=297
DESTFILE=$(pwd)
DM=`date +%d%b%y_%H%M%S`
DESTFILE="$DESTFILE/scan_$DM.pdf"
#
# CHECK COMMAND LINE PARAMS
#
p=0
for PARAM in "$@"
do
    p=$(( $p + 1 ))
    case "$PARAM" in
     "--file")
			#value is p+1
			v=$(( $p + 1 ))
			DESTFILE=${!v}     # note the ! = INDIRECT EXPANSION OF VARIABLES
           ;;
     "--resolution")
			#value is p+1
			v=$(( $p + 1 ))
			SCANNER_RES=${!v}     # note the ! = INDIRECT EXPANSION OF VARIABLES
			;;
     "--mode")
			#value is p+1
			v=$(( $p + 1 ))
			SCANNER_MODE=${!v}     # note the ! = INDIRECT EXPANSION OF VARIABLES
			;;
     "--quality")
           #value is p+1
			v=$(( $p + 1 ))
			PDF_QUALITY=${!v}     # note the ! = INDIRECT EXPANSION OF VARIABLES
			;;
     "--force")
			#value is p+1
			v=$(( $p + 1 ))
			PDF_FORCE=${!v}     # note the ! = INDIRECT EXPANSION OF VARIABLES
			;;
     "--pagesize")
			# A4 [DEFAULT] = 210 x 297
			# 6by4 = 152 x 101
			# 4by6 = 101 x 152
			#letter = 215.9 x 279.4
           #value is p+1
			v=$(( $p + 1 ))
			case ${!v} in
				"A4")
					PAGE_X=210
					PAGE_Y=297
					;;
				"6by4")
					PAGE_X=152
					PAGE_Y=101
					;;
				"4by6")
					PAGE_X=101
					PAGE_Y=152
					;;
				"letter")
					PAGE_X=216
					PAGE_Y=280
					;;
				*)
					echo "Unrecognised page size! Valid options are: A4, 6by4, 4by6 and letter"
					exit
					;;
			esac
			;;
     "--help")
           echo -e "This will scan one or more pages, convert it to a PDF and save it in the present
directory. Possible switches are:
	--help 				- this message
	--file ./somefile.pdf		- set a custom file name
	--resolution 300		- set scanning resolution
	--mode	greyscale		- set scanning mode 
					(lineart, binary, greyscale or color)
	--quality 70			- set PDF jpeg compression factor 
					(1-100, higher number better quality)
	--pagesize	A4		- set the page size, options are A4, 
					6by4, 4by6 or letter (A4 is the default)

Lineart and Binary are equivalent, which term you use depends on your driver. 
Note that some of these options may not work as it depends on your hardware and driver compatibility. See http://www.sane-project.org/sane-mfgs.html for more
information.

For devices that do not support '--mode lineart' or '--mode binary', if you 
wish to make a black and white PDF (e.g. for archival or OCR purposes) then use 
the following switch:

	--force monochrome"
			exit
           ;;
     esac  
done
#
# Check that a scanner is attached
#
SCANNER_TEST=`scanimage -f %d`
if [ ${#SCANNER_TEST} == 0 ]
then
	echo -e "No scanner detected! Is the device plugged in and powered on?
Run 'scanimage -L' or 'sane-find-scanner' for further assistance"
	exit 1
fi
#
# check that we can write to destination file
#
if [ ! -w ${DESTFILE%/*} ]
then
	echo "Unable to write to ${DESTFILE%/*}"
	exit 1
fi
#
#
# Test for required programs.
if [[ -z $( type -p scanimage ) ]]; then echo -e "Error! scanimage (sane-utils) is not installed!";exit ;fi
if [[ -z $( type -p tiffcp ) ]]; then echo -e "Error! tiffcp (libtiff-tools) is not installed!";exit ;fi
if [[ -z $( type -p tiff2pdf ) ]]; then echo -e "Error! tiff2pdf (libtiff-tools) is not installed!";exit ;fi
#
# check for optional requirements - ImageMagick?
#
if [ $PDF_FORCE == "monochrome" ];
then
	if [[ -z $( type -p convert ) ]]; then echo -e "Error! convert (imagemagick) is not installed!";exit ;fi
fi
#
#
# create a temporary directory
TEMP_FLDR=`mktemp -d`
i=0
CONTINUE="Y"
while [ $CONTINUE == "Y" ] || [ $CONTINUE == "y" ]; do 
	i=$(expr $i + 1)
	echo "Scanning page $i"
	scanimage --mode $SCANNER_MODE --format tiff --resolution $SCANNER_RES -x $PAGE_X -y $PAGE_Y > $TEMP_FLDR/out$i.tif
	#[scan an image, output to $TEMP_FLDR/out1.tif]
	# could also use batch or batch-prompt to do multiple page scans and or use ADF
	read -p "Do you wish to scan another page (Y or N)?  " -n 1 -e CONTINUE
done
if [ $i -gt 0 ]
then
	#is force monochrome set?
	if [ $PDF_FORCE == "monochrome" ];
	then
		FILES=$TEMP_FLDR/out*.tif
		for f in $FILES
		do
			convert "$f" -monochrome "$f"
		done
	fi
	# join tiff files together
	echo -e "Combining $i tiff files..." 
	tiffcp -c lzw $TEMP_FLDR/out*.tif $TEMP_FLDR/output.tif 
	#Convert the tiff to PDF
	echo -e "Creating $DESTFILE"
	tiff2pdf -j -q $PDF_QUALITY $TEMP_FLDR/output.tif > "$DESTFILE"
	#delete temp folder
else
	#nothing to do
	echo "No Pages scanned!"
fi
rm -rf $TEMP_FLDR
echo -e "Done."