#!/bin/bash

# Copyright (C) 2008-2018 Richard Kimberly Heck

# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

# Updates etc should be available from:
# https://gitlab.com/rikiheck/text

# Change log

# Version 0.3: Add ability to embed text so djvu's are searchable.

# Version 0.2: Add ability to merge two pages into one. Mostly, this is
# due to my starting to use the fantastic ScanTailor program, which can
# be found at http://scantailor.sourceforge.net/.

# Version 0.1: First public release

# TODO
# Implement losslevel
# convert input files to bitonal

PROG=`basename $0`;

function printUsage {
cat <<EOF
USAGE: $PROG [options] FILE1 [FILE2 ....]
$PROG takes a set of tiff images---say, scans of pages---and creates a 
DJVU file from them. It will also create a PDF, if requested.

Input files must be bitonal.

Options:
-a: Make a PDF, too.
-A: Also make a PDF with split pages.
-b: Batch mode: Make a separate file for each page.
-c: Rotate pages clockwise.
-C: Crop all pages to WxH+X+Y (as ImageMagick).
    Note that this is done before rotation, if rotation is done.
-d: Don't do anything, just say what we'd do.
-D: Don't create DJVU.
-f: Crop left side of first page (after rotation).
    Intended for the case where the text starts on an odd page.
-h: Print this message.
-k: Keep intermediate files.
-l: Crop right side of last page (after rotation).
    Intended for the case where the text starts on an even page.
-o: Output filename, without extension [defaults to tiff2djvu-$$]
-q: Be quiet.
-r: Rotate pages ARG degrees.
-t: Put two pages on one page.
-T: Embed ocr'd text in djvu to make it searchable.
-v: Be verbose.
-w: Rotate pages counterclockwise.

Prerequisite:
- We use convert, from ImageMagick, for page manipulation.
- We use tesseract for OCR.
EOF
}

function crop {
	FILE=$1;
	SIDE=$2;
	if [ -z "$SIDE" ]; then
		echo "Function crop must be given three arguments.";
		exit 1;
	fi

	# get image size data, and figure out how to crop
	DATA=`identify $FILE | cut -d' ' -f 3`;
	WIDTH=${DATA%x*};
	HEIGHT=${DATA#*x};
	NEWHT=$(($HEIGHT / 2));
	NEWDT=$(($WIDTH / 2));
	if [ "$SIDE" = "N" ]; then
		RECT="0,0 $WIDTH,$NEWHT";
	elif [ "$SIDE" = "S" ]; then
		RECT="0,$NEWHT $WIDTH,$HEIGHT";
	elif [ "$SIDE" = "W" ]; then
		RECT="0,0 $NEWDT,$HEIGHT";
	elif [ "$SIDE" = "E" ]; then
		RECT="$NEWDT,0 $WIDTH,$HEIGHT";
	else
		echo "Missing directional argument in crop()";
		exit 1;
	fi

	TMP=$FILE.$$.tiff;
	cp $FILE $TMP;
	# crop it
	#$DEBUG convert $TMP -fill white -draw "rectangle $RECT" -type Bilevel -colors 2 -threshold 127,127,127 $FILE;
	$DEBUG convert $TMP -fill white -draw "rectangle $RECT" -type Grayscale $FILE;
}


DEBUG="";

BATCH="";
PDF="";
EXT="tiff"; # this could be generalized, but it can lead to problems
            # with cropping, because the djvu programs expect the files
            # in a very particular format.
KEEP="";
QUIET="";
ROTATE="";
MKDJVU="YES";
CROPFIRST="";
CROPLAST="";
CROPDIMS="";
TWOINONE="";
DOOCR="";
OUTFILE="tiff2djvu-$$";
VERBOSE="";

while getopts ":aAbcC:dDfklo:qr:tTvw" opt; do
	case $opt in
		a )   PDF="YES";;
		A )   PDFSPLIT="YES";;
		b )   BATCH="YES";;
		c )   ROTATE="90";;
		C )   CROPDIMS="$OPTARG";;
		d )   DEBUG="echo ";;
		D )   MKDJVU="";;
		f )   CROPFIRST="TRUE";;
		k )   KEEP="echo ";;
		l )   CROPLAST="TRUE";;
		o )   OUTFILE="$OPTARG";
		      OUTFILE=${OUTFILE%.djvu};;
		q )   QUIET="TRUE"; VERBOSE="";;
		r )   ROTATE="$OPTARG";;
		R )   ROTATE="";;
		t )   TWOINONE="TRUE";;
		T )   DOOCR="TRUE";;
		v )   VERBOSE="TRUE"; QUIET="";;
		w )   ROTATE="270";;
		\? )  printUsage; exit 1;;
	esac
done

shift $(($OPTIND - 1));

CVT=`which convert 2>/dev/null`;
if [ -z "$CVT" ]; then 
	echo "This script uses the convert utility from the ImageMagick package. It does not appear to be in your path.";
	exit 1;
fi

# Get filename we're looking for
if [ -z "$1" ]; then
	echo "No input files given.";
	printUsage;
	exit 1;
fi

FIRSTFILE="";
LASTFILE="";
FILES="";

echo "Copying original files";
while [ -n "$1" ]; do
	fil="$1";
	shift;
	echo -n ".";
	NEWFILE="tiff2djvu-$$-$fil.$EXT";
	$DEBUG cp $fil $NEWFILE;
	if [ -z "$FILES" ]; then 
		FILES="$NEWFILE"; 
	else
		FILES="$FILES
$NEWFILE";
	fi
	if [ -z "$FIRSTFILE" ]; then FIRSTFILE="$NEWFILE"; fi;
	LASTFILE="$NEWFILE";
done
echo "done.";

GENFILES="$FILES";

# Crop pages if requested
if [ -n "$CROPDIMS" ]; then
	echo "Cropping to $CROPDIMS";
	for fil in $FILES; do
		echo -n ".";
		CFIL="precrop-$fil";
		if [ -z "$DEBUG" ]; then mv $fil $CFIL; fi
		$DEBUG convert $CFIL -crop $CROPDIMS +repage $fil;
		$DEBUG $KEEP rm $CFIL;
	done
	echo "done.";
fi

# Rotate pages if requested
if [ -n "$ROTATE" ]; then
	echo "Rotating pages";
	for fil in $FILES; do
		echo -n ".";
		RFIL="prerot-$fil";
		if [ -z "$DEBUG" ]; then mv $fil $RFIL; fi
		$DEBUG convert -rotate $ROTATE $RFIL $fil;
		$DEBUG $KEEP rm $RFIL;
	done
	echo "done.";
fi

# Crop first and last pages if requested
if [ -n "$CROPFIRST$CROPLAST" ]; then
	echo -n "Cropping";
	if [ -n "$CROPFIRST" ]; then 
		echo -n " first page";
		crop $FIRSTFILE "W";
	fi
	if [ -n "$CROPLAST" ]; then
		if [ -n "$CROPFIRST" ]; then echo -n " and"; fi
		if [ -z "$QUIET" ]; then echo " last page."; fi
		crop $LASTFILE "E";
	else
		echo ".";
	fi
fi

# Are we doing 2 in 1?
if [ -n "$TWOINONE" ]; then
	echo "Merging pages";
	PAGE="";
	NUM=0;
	NEWPAGES="";
	for FIL in $FILES; do 
		if [ -z "$VERBOSE" ]; then echo -n "."; fi
		# If we don't yet have a first page, this one is it.
		if [ "$PAGE" = "" ]; then 
			PAGE="$FIL"; 
		# Otherwise we have the first page, so...
		else 
			NUM=$(($NUM + 1)); #just a counter to form filenames
			# normalize it
			if (($NUM < 10)); then P="0$NUM"; else P=$NUM; fi; 
			NEWPAGE="tiff2djvu-$$-$OUTFILE-$P.$EXT";
			if [ -n "$VERBOSE" ]; then 
				echo "Creating page $NEWPAGE from $PAGE and $FIL"; 
			fi
			$DEBUG montage -geometry +0+0 $PAGE $FIL $NEWPAGE;
			#No first page any more.
			PAGE="";
			NEWPAGES="$NEWPAGES $NEWPAGE";
			GENFILES="$GENFILES $NEWPAGE";
		fi; 
  done

  #If there were an odd number of pages, then one page will be left over, so...
  if [ -n "$PAGE" ]; then
		if [ -z "$VERBOSE" ]; then echo -n "."; fi
		#...we use ImageMagick to create an empty page...
		EMPTYPAGE="emptyPage-$$.$EXT";
		#...of the same size as the other pages...
		SIZE=`identify -format '%wx%h' $PAGE`;
		NUM=$(($NUM + 1)); 
		if (($NUM < 10)); then P="0$NUM"; else P=$NUM; fi; 
		if [ -n "$VERBOSE" ]; then 
			echo "Creating empty page $EMPTYPAGE at $SIZE"; 
		fi;
		$DEBUG convert -size $SIZE xc:white $EMPTYPAGE;
		GENFILES="$GENFILES $EMPTYPAGE";
		NEWPAGE="tiff2djvu-$$-$OUTFILE-$P.$EXT";
		if [ -n "$VERBOSE" ]; then 
			echo "Creating page $NEWPAGE from $PAGE and $EMPTYPAGE"; 
		fi;
		#...and collate the last page with the empty page.
		$DEBUG montage -geometry +0+0 $PAGE $EMPTYPAGE $NEWPAGE;
		NEWPAGES="$NEWPAGES $NEWPAGE";
		GENFILES="$GENFILES $NEWPAGE";
  fi
	echo "done.";

	# so now we're working with these...
	FILES="$NEWPAGES";
fi

DJVUFILES="";
PDFFILES="";
PDFSPLIT=""; # not yet implemented

RMFILS="";
echo "Converting....";
WORKING=1;
for i in $FILES; do 
	echo Page $WORKING;
	WORKING=$(($WORKING + 1));
	if [ -n "$MKDJVU" ]; then
		DJVUFIL="djvu-$$-$i";
		GENFILES="$GENFILES $DJVUFIL";
		if identify $i | grep -q Bilevel; then
			ln -s $i "$DJVUFIL";
		else
			$DEBUG convert $i -depth 1 "$DJVUFIL";
		fi
		NEWFIL="${i%$EXT}djvu"

		# create djvu page
		$DEBUG cjb2 "$DJVUFIL" $NEWFIL; 

		GENFILES="$GENFILES $NEWFIL";
		if [ -n "$DOOCR" ]; then
			$DEBUG tesseract "$DJVUFIL" "$DJVUFIL" makebox >/dev/null 2>&1;
			$DEBUG tesseract "$DJVUFIL" "$DJVUFIL" >/dev/null 2>&1;
			$DEBUG mv "$DJVUFIL.box" temp.box;
			$DEBUG box2box.pl temp.box "$DJVUFIL.box";
			$DEBUG box2sed.pl "$DJVUFIL.box" "$DJVUFIL.txt" > "$DJVUFIL.djvutxt";
			GENFILES="$GENFILES $DJVUFIL.box $DJVUFIL.txt $DJVUFIL.djvutxt";
			# the page may not have any text, which would upset djvused
			# generally that seems to mean a single line file
			TMP=$(cat $DJVUFIL.djvutxt | wc -l);
			if [ $TMP -ge 2 ]; then
				$DEBUG djvused -e "select 1; set-txt \"$DJVUFIL.djvutxt\"; save" $NEWFIL;
				# GENFILES="$GENFILES $DJVUFIL.djvutxt";
			fi
		fi

		DJVUFILES="$DJVUFILES $NEWFIL";
	fi

	if [ -n "$PDF" ]; then
		if [ -n "$DOOCR" ]; then 
			echo "Not implemented."
			exit 1;
		fi
		PNGFIL="${i%$EXT}png";
		PDFFIL="${i%$EXT}pdf";
		$DEBUG convert $i "$PNGFIL";
		if [ -n "$BATCH" ]; then
			$DEBUG convert "$PNGFIL" "$PDFFIL";
		else
			PDFFILES="$PDFFILES $PNGFIL";
		fi
		GENFILES="$GENFILES $PNGFIL";
	fi

	if [ -n "$PDFSPLIT" ]; then
		echo "Need to check if we need to collect filenames here, as well.";
		exit 1;
		DATA=`identify $i | cut -d' ' -f 3`;
		WIDTH=${DATA%x*};
		HEIGHT=${DATA#*x};
		NEWDT=$(($WIDTH / 2));
		NEWHT=$(($HEIGHT / 2));
		if [ "$i" != "$FIRSTFILE" -o -z "$CROPFIRST" ]; then
			#$DEBUG convert $i -resize ${NEWDT}x$NEWHT +repage -type Grayscale +compress $i;
			#NEWDT=$(($NEWDT / 2));
			$DEBUG convert $i -crop ${NEWDT}x$HEIGHT+0+0 +repage -type Grayscale -depth 4 +compress SPLIT-$$-$i.1.png;
			GENFILES="$GENFILES SPLIT-$$-$i.1.png";
		fi
		if [ "$i" != "$LASTFILE" -o -z "$CROPLAST" ]; then
			#$DEBUG convert $i -resize ${NEWDT}x$NEWHT +repage -type Grayscale +compress $i;
			#NEWDT=$(($NEWDT / 2));
			$DEBUG convert $i -crop ${NEWDT}x$HEIGHT+${NEWDT}+0 +repage -type Grayscale -depth 4 +compress SPLIT-$$-$i.2.png;
			GENFILES="$GENFILES SPLIT-$$-$i.2.png";
		fi
	fi
done
echo "done.";

if [ -z "$BATCH" ]; then
	if [ -n "$MKDJVU" ]; then
		echo -n "Creating DJVU...";
		$DEBUG djvm -c x$OUTFILE.djvu $DJVUFILES;
		$DEBUG mv x$OUTFILE.djvu $OUTFILE.djvu
		echo "done.";
	fi
	if [ -n "$PDF" ]; then
		echo -n "Creating PDF...";
		$DEBUG convert tiff2djvu-$$*png $OUTFILE.pdf
		echo "done.";
	fi
	if [ -n "$PDFSPLIT" ]; then
		echo -n "Creating single-page PDF...";
		if [ -z "$PDF" ]; then 
			PDFNAME=$OUTFILE.pdf; 
		else 
			PDFNAME=$OUTFILE-split.pdf;
		fi
		$DEBUG convert SPLIT-$$-*.png $PDFNAME;
		echo "done.";
	fi
fi

$DEBUG $KEEP rm $GENFILES;