#!/bin/sh

# Copyright (C) 2008 Adalbert Prokop, adalbert.prokop(%)web.de
#
# 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 3 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/>.

#set -x # debug

declare -i WIDTH
declare -i HEIGHT
declare -i RPS # rows per strip, multiple of 16 for JPEG
RPS=16

DEBUG=

AUTHOR=
ALIGN=center
VALIGN=middle
CREATOR=
DATE=$(date +%Y%m%d%H%M%S)
KEYWORDS=
PAPER=A4
PWIDTH=21.0
PHEIGHT=29.7
QUALITY=85
SUBJECT=
TITLE=
WORKAROUND=no

function showhelp() {
	cat <<EOF
Usage: $(basename "$0") [options] directory [directories...]

Converts one or more directories with PNM files to PDF files. The final PDF
file will be named as the directory with the suffix .pdf appended.

Options:

-h|--help
	Shows this help.

-w|--workaround
	Workaround. tiff2pdf has a bug - color are wrong because of mixed color
	tables (RGB vs. CMY). This workaround uses JPEG compression for every
	converted file, before they are merged together. Unfortunatelly, at
	least XPDF complains about invalid PDF structure, but shows the
	containts nonetheless.

-a|--author <author>
	Autor for the PDF file.

-c|--creator <creator>
	Creator for the PDF file.

-d|--date YYYYMMDDHHMMSS
	Date for the PDF file. Defaults to now.

-k|--keywords <keywords>
	Keywords for the PDF file.

-s|--subject <subject>
	Subject for the PDF file.

-t|--title <title>
	Title for the PDF file.

-p|--paper [A4|A5]
	Papersize.

-q|--quality [0..100]
	JPEG compression quality. Defaults to $QUALITY.

EOF
}

if [ $# -eq 0 ]; then
	showhelp
	exit 0
fi

if [ -z "$(which python 2>/dev/null)" ]; then
	cat <<EOF
This script needs python for some calculation. Please make sure there is a
python executable. Right now none can be find.
EOF
fi

eval set -- $(getopt -o a:c:d:hk:p:q:s:t:w -l author:,creator:,date:,help,keywords:,paper:,quality:,subject:,title:,workaround -- "$@")

while [ "$1" != "--" ]; do
	case "$1" in
	-h|--help)
		showhelp
		exit 0
		;;
	-w|--workaround)
		WORKAROUND=yes
		shift
		;;
	-a|--author)
		AUTHOR="$2"
		shift 2
		;;
	-c|--creator)
		CREATOR="$2"
		shift 2
		;;
	-d|--date)
		DATE="$2"
		shift 2
		;;
	-k|--keywords)
		KEYWORDS="$2"
		shift 2
		;;
	-s|--subject)
		SUBJECT="$2"
		shift 2
		;;
	-t|--title)
		TITLE="$2"
		shift 2
		;;
	-p|--paper)
		PAPER="$2"
		shift 2
		;;
	-q|--quality)
		if [ "$2" -gt 0 -a "$2" -le 100 ]; then
			QUALITY="$2"
		else
			echo "Bad quality settings $2"
			exit 1
		fi
		shift 2
		;;
	esac
done

shift

case "$PAPER" in
	a4|A4)
		PWIDTH=21.0
		PHEIGHT=29.7
		;;
	a4|A4)
		PWIDTH=14.85
		PHEIGHT=21.0
		;;
	*)
		echo "Unknown papersize $PAPER"
		exit 1
		;;
esac

for dir in "$@"; do
	dir="${dir%/}"
	
	if [ ! -d "$dir" ]; then
		echo "There is no directory called $dir"
		continue
	fi

	echo "Processing directory $dir"
	rm -f "$dir"/*.tif

	for file in "$dir"/*.pnm; do
		WIDTHHEIGHT="$(pamfile "$file" | sed -e 's/.*, \([0-9]\+\) by \([0-9]\+\) .*/\1 \2/g')"
		WIDTH=$(echo "$WIDTHHEIGHT"|cut -d" " -f 1)
		HEIGHT=$(echo "$WIDTHHEIGHT"|cut -d" " -f 2)

		if [ $(python -c "print abs($HEIGHT.0/$WIDTH.0 - 1.4142) > 0.1") == "True" ]; then
			echo "*** Resolution ratio of $file is NOT DIN norm! ***"
		fi

		XRES=$(python -c "print '%.2f' % ($WIDTH/$PWIDTH)")
		YRES=$(python -c "print '%.2f' % ($HEIGHT/$PHEIGHT)")
		RES=$(python -c "print($XRES if $XRES > $YRES else $YRES)")

		[ "$DEBUG" ] && echo "pamtotiff -rowsperstrip=$RPS -truecolor -xresolution=$RES -yresolution=$RES -resolutionunit=centimeter $file > ${file%.pnm}.tif"
		echo -n "Converting $file (${RES}dpcm) to TIFF format... "
		pamtotiff -rowsperstrip=$RPS -truecolor -xresolution=$RES -yresolution=$RES -resolutionunit=centimeter "$file" > "${file%.pnm}.tif" && echo "done." || echo "failed."
	done

	[ "$DEBUG" ] && echo "tiffcp -r $RPS $dir/*.tif $dir.tif"
	echo -n "Creating combined TIFF... "
	tiffcp -r $RPS "$dir"/*.tif "$dir.tif" && rm -f "$dir"/*.tif && echo "done." || echo "failed."

	[ "$DEBUG" ] && echo "tiff2pdf -o $dir.pdf -j -q $QUALITY -p $PAPER $dir.tif"
	echo -n "Creating PDF from combined TIFF image... "
	tiff2pdf -o "$dir.pdf" -j -q $QUALITY -p $PAPER -f \
		${TITLE:+-t"$TITLE"} \
		${AUTHOR:+-a"$AUTHOR"} \
		${CREATOR:+-c"$CREATOR"} \
		${SUBJECT:+-s"$SUBJECT"} \
		${KEYWORDS:+-k"$KEYWORDS"} \
		${DATE:+-e"$DATE"} \
		"$dir.tif" && rm -f "$dir.tif" && echo "done." || echo "failed."
	if [ "$WORKAROUND" = "yes" ]; then
		echo "Applying workaround."
		sed -e 's#/ColorTransform 0#/ColorTransform 1#g' "$dir.pdf" > "$dir.pdf.tmp"
		mv -f "$dir.pdf.tmp" "$dir.pdf"
	fi

done