#!/bin/bash

#
# pdfattach --- embed specified file(s) in a specified PDF file
# Requires pdfLaTeX and attachfile.sty package to run
# Returns 0 on success or >0 on error
#
# Written by Tigran Aivazian <tigran@bibles.org.uk>
#

progname=$(basename $0)

function escape_tex_specialchars()
{
	local txt=$1
	local res=$(echo "$txt" | sed -e "s%_%\\\_%g" -e "s%&%\\\&%g")
	echo "$res"
}

function usage()
{
	echo "Usage: $progname -o file.pdf [-a author] file1.djvu [file2.mp3] ..."
	exit 1
}

if (! getopts ":o:" opt); then
	echo "$progname: Missing options." >&2
	usage
fi

if ! type pdflatex > /dev/null 2>&1 ; then
	echo "$progname: pdfLaTeX program is required." >&2
	exit 1
fi

if ! kpsewhich attachfile.sty > /dev/null 2>&1 ; then
	echo "$progname: attachfile.sty package is required." >&2
	exit 1
fi

declare outfile=""
declare -a infiles=()
declare -a infiles_texclean=()
declare -a infilesize=()
declare -i infcount=0 outfcount=0 totalsize=0
declare author=""

while getopts ":o:a:" opt; do
	case $opt in
	a)
		author="$OPTARG"
		;;
	o)
		outfile=$(readlink -f "$OPTARG")
		((outfcount++))
		;;
	\?)
		echo "$progname: Invalid option: -$OPTARG" >&2
		usage
		;;
	:)
		echo "$progname: Option -$OPTARG requires an argument." >&2
		usage
		;;
	esac
done

shift $((OPTIND-1))

numargs=$#
for ((i=1 ; i <= $numargs ; i++))
do
	fullname=$(readlink -f "$1")
	if [ ! -r "$fullname" ] ; then
		echo "$progname: cannot access the file \"$fullname\"" >&2
		usage
	fi
	infiles[$infcount]="$fullname"
	infiles_texclean[$infcount]=$(escape_tex_specialchars $(basename "${infiles[$infcount]}"))
	infilesize[$infcount]=$(stat --print="%s" "$fullname")
	((totalsize=totalsize+${infilesize[$infcount]}))
	((infcount++))
	shift
done

if ((infcount == 0)) ; then
	echo "$progname: No input file(s) specified." >&2
	usage
fi

if ((outfcount != 1)) ; then
	echo "$progname: One (and only one) output file must be specified." >&2
	usage
fi

workdir=$(mktemp --tmpdir -d pdfattach.XXXXXX)
cd $workdir
> tmp.tex
# emit TeX preamble
echo -E "\documentclass{book}" >> tmp.tex
echo -E "\usepackage[margin={1mm},papersize={9cm,12cm}]{geometry}" >> tmp.tex
echo -E "\usepackage{hyperref,attachfile}" >> tmp.tex
if [ ! -z "$author" ] ; then
	echo -E "\AtBeginDocument{\hypersetup{pdfauthor={$author}}}" >> tmp.tex
fi
echo -E "\begin{document}" >> tmp.tex
echo -E "\tolerance=10000\pagestyle{empty}\fontsize{7}{13}\selectfont" >> tmp.tex

# emit the list of all files
for ((i = 0 ; i < ${#infiles[*]} ; i++));
do
	echo -E "\noindent \hyperlink{L$i}{$((i+1))/${infcount}} \texttt{${infiles_texclean[$i]}} (${infilesize[$i]} bytes)" >> tmp.tex
	echo >> tmp.tex
done
echo -E "\noindent Total size $totalsize bytes\newpage" >> tmp.tex

# now emit all the attachments, one per page
for ((i = 0 ; i < ${#infiles[*]} ; i++));
do
	echo -E "\noindent\hypertarget{L$i}$((i+1))/${infcount}\\\\\texttt{${infiles_texclean[$i]}} (\textattachfile[color={0 0 0}]{${infiles[$i]}}{${infilesize[$i]} bytes})\newpage" >> tmp.tex
done
echo -E "\end{document}" >> tmp.tex
pdflatex -halt-on-error tmp.tex > /dev/null && mv tmp.pdf "$outfile"
cd - > /dev/null
rm -rf $workdir