#! /usr/bin/perl

use Getopt::Long; 
use IPC::Open2;
use warnings;
use strict;

Getopt::Long::Configure ("bundling");

my $pdf2ps      = 'pdftops';
my $pscrop      = 'psnup2.pl -s1 -l1';
my $psresize    = 'psresize';
my $psnup       = 'psnup';
my $psbook      = 'psbook';
my $ps2pdf      = 'ps2pdf';

my $tmpdir      = '/tmp';

my $papersize;

my $nup     = 1;
my $margin  = 1;
#TODO: units
my $crop;
my $book;

GetOptions( "nup|n=i"       => \$nup,
            "1"             => sub { $nup = 1 },
            "2"             => sub { $nup = 2 },
            "4"             => sub { $nup = 4 },
            "8"             => sub { $nup = 8 },
            "crop|c"        => \$crop,
            "book|b"        => \$book,
            "papersize|p=s" => \$papersize,
            "margin|m=s"    => \$margin );

die "I can handle only one file at the same time :P"
    if $#ARGV > 0;

die "How should I put a non-positive number of pages per sheet?"
    if $nup <= 0;

unless (defined $papersize) {
    $papersize = `paperconf` or die "Can't guess papersize";
    chomp $papersize;
}

for (my $n = $nup; $n > 1; $n /= 2) {
    die "nup should be a power of two"
        unless $n % 2 == 0;
}

my $filename = $ARGV[0];
$filename = "-" unless defined $filename;
my $filename2 = $filename;
$filename2 = "(stdin)" if $filename eq "-";


my ($mresize, $mcrop, $mnup) = (0,0,0);

if (defined $crop) {
    $mresize = 0;
    if (not defined $book && $nup > 1) {
        $mcrop = $margin/2;
        $mnup  = $mcrop;
    } else {
        $mcrop = $margin;
        $mnup  = 0;
    }
} else {
    if (not defined $book && $nup > 1) {
        $mresize = $margin/2;
        $mnup    = $mresize;
    } else {
        $mresize = $margin;
        $mnup    = 0;
    }
}




open(FILE, $filename)
    or die "Can't read `$filename'";

my $filetype;
my $fstline  = <FILE>;
if (defined $fstline && $fstline =~ /%!PS.*/) {
    $filetype = "PS";
} elsif (defined $fstline && $fstline =~ /%PDF.*/) {
    $filetype = "PDF";
} else {
    die "Can't recognize the type of `$filename2'";
}

# auxiliary files, to remove
my @auxfiles;

# auxiliary file descriptors, to close
my @auxfds;


if ($filename eq "-") {
    # Need to copy the whole input to an auxiliary file, since
    # conversion from pdf to ps requires random access to the data
    
    $filename = "$tmpdir/pdftool-stdin-" . int(rand 2**16) . lc ".$filetype";
    open(AUXFD, '>', "$filename")
        or die "Can't read write into `$filename'";
    push @auxfiles, "$filename";
    
    # cat > $filename
    print AUXFD $fstline;
    while (<FILE>) {
        print AUXFD $_;
    }
    close(AUXFD);
}
close(FILE);


# Convert to ps, or read the input file
if ($filetype eq "PDF") {
    open(PSFILE, '|-', "$pdf2ps $filename -")
        or die "Error with `$pdf2ps $filename -'";
} else {
    open(PSFILE, '<', "$filename")
        or die "Can't open `$filename'";
}
push @auxfds, fileno PSFILE;

# Resize file to our papersize
open2(*PSRESIZE, "<&PSFILE", "psresize -p$papersize")
    or die "Error with `psresize -p$papersize'";
#push @auxfds, fileno \*PSRESIZE;

open("<&PSRESIZE", "cat");
exit 0;

# pscrop
*PSCROP = *PSRESIZE;

# psbook
*PSBOOK = *PSCROP;

# psnup
# TODO: sometimes unecessary
open2(*PSNUP, "<&PSBOOK", "psnup -p$papersize -m$mnup -$nup")
    or die "Error with `psnup -p$papersize -m$mnup -$nup'";

# TODO: not always stdout
open2(">&STDOUT", "<&PSBOOK", "ps2pdf -sPAPERSIZE=$papersize - -")
    or die "Error with `ps2pdf -sPAPERSIZE=$papersize - -'";






# close auxiliary filehandles
map {close $_} @auxfds;

# delete auxiliary files
unlink @auxfiles;

#TODO: better do forget stdin, I guess
#if ($filename eq "-" && $filetype eq "PDF") {
#}

#if ($filetype eq "PDF") {
#    $command .= "$pdf2ps $filename - | "; 
#} else {
#    $command .= "cat $filename | ";
#}
#
#
##$command .= "$psresize -p$papersize /tmp/paf.ps | ";
## useless, since the argument of $pscrop has to be seekable
#
#if (defined $crop) {
#    $command .= "$pscrop -m$margin /tmp/paf.ps | ";
#} else {
#    $command .= "cat /tmp/paf.ps | ";
#}
#
#$command .= "$psnup -p$papersize -m${margin}cm -$nup | ";
#
#$command .= "$psbook | " if defined $book;
#
#$command .= "$ps2pdf -sPAPERSIZE=$papersize - - ";
#
#
#$command .= "> /tmp/pouf.pdf";
#
#print "$command", "\n";

#system $command;


#system ($pdfviewer, "/tmp/pouf.pdf");