#!/bin/bash

pdf="$1"
size=$(pdfinfo "$pdf" | awk '/^Page size:/{
	a = $3
	b = $5
	if (a >= 419  && a <= 421  && b >= 594  && b <= 596 ) print "a5"
	if (a >= 594  && a <= 596  && b >= 419  && b <= 421 ) print "a5"
	if (a >= 594  && a <= 596  && b >= 841  && b <= 843 ) print "a4"
	if (a >= 841  && a <= 843  && b >= 594  && b <= 596 ) print "a4"
	if (a >= 841  && a <= 843  && b >= 1189 && b <= 1191) print "a3"
	if (a >= 1189 && a <= 1191 && b >= 841  && b <= 843 ) print "a3"
}')
pages=$(pdfinfo "$pdf" | awk '/Pages:/{print $2}')
output=$(mktemp --dry-run /dev/shm/XXXXXXXX.pdf)
recto=$(mktemp --directory /dev/shm/XXXXXXXX)
verso=$(mktemp --directory /dev/shm/XXXXXXXX)

if test "${size,,}" != "a5"; then
    gs -o $output -sDEVICE=pdfwrite -sPAPERSIZE=a5 -dFIXEDMEDIA -dPDFFitPage -dCompatibilityLevel=1.6 "$pdf"
else
    cp "$pdf" $output
fi
pdfjam --paper a4paper --nup '2x1' --landscape --outfile $recto -- "$output" 1 "$output" 1
if test $pages -eq 2; then
    pdfjam --paper a4paper --nup '2x1' --landscape --outfile $verso -- "$output" 2 "$output" 2
    pdftk A=$(find $recto -name "*pdf") B=$(find $verso -name "*pdf") cat A B output "$output"
else
    mv $(find $recto -name "*pdf") $output
fi
mv $output "${pdf%/*}/massicotable-${pdf##*/}"
rm -fr $recto $verso $output