#! /usr/bin/perl -w


use Getopt::Long qw(:config posix_default no_ignore_case gnu_compat
                            bundling auto_version auto_help); 
use Pod::Usage;
use IPC::Open2;
use POSIX qw(floor);
use strict;


=head1 NAME

pdftool.pl - a PDF swiss army knife

=head1 SYNOPSIS

B<pdftool.pl> [-s I<pages>] [-p I<paper>] [-m I<margin>] [-c] [-b]
[-n I<nup>] [-q] [I<infile> [I<outfile>]]

=head1 DESCRIPTION

I<PDFTool> combines the tools in the PSUtils bundle in a nice way. The
input should be either a Portable Document Format (PDF) file, or a
PostScript file. The output format is the same as the input one.

If no input file is given, or if a single hyphen-minus (B<->) is given as
file name, I<PDFTool> will read the PDF or PostScript data from the standard
input. In that case, and if the input data is in PDF format, an
auxiliary file will be created (since the conversion from PDF to PS
requires random access to the data), and removed afterwards.
An other auxiliary file may be created by I<PSResize2>, see its man page
for details.

If no output file is given, or if a single hyphen-minus (B<->) is given as
file name, I<PDFTool> will send the data (of the same type as the input) to
the standard output.

The document will be treated as follows:

=over 8

=item Conversion from PDF to PostScript (if necessary),

=item Selection of the page range,

=item Resizing to the given papersize, adding a margin, and croping, 

=item Rearranging pages for printing books or booklets,

=item Putting several pages per sheets,

=item Conversion from PS to PDF (if necessary).

=back

=head1 OPTIONS

=over 8

=item B<-s, --select>

Specifies the pages which are to be selected.
I<Pages> is a comma separated list of page ranges, each of which
may be a page number, or a page range of the form
I<first>-I<last>. If I<first> is omitted, the first page is assumed,
and if I<last> is omitted,  the last page is assumed.

The prefix character `_' indicates that the page number is relative
to the end of the document, counting backwards. If just this
character with no page number is used, a blank page will be inserted.

=item B<-p, --paper>

Specify the paper size of the output file.
Can be set to B<a0>, B<a1>, B<a2>, B<a3>, B<a4>, B<a5>, B<b5>,
B<letter>, B<legal>, B<tabloid>, B<statement>, B<executive>, B<folio>,
B<quarto>, or B<10x14>. The  default output paper size is B<a4>.

=item B<-m, --margin>

Add a margin to the output file. Possible units are B<pt>, B<in>, B<cm>
and B<mm>. The default unit is B<pt>. The default margin is B<1cm> if the
crop option (B<-c>) is set, and B<0> otherwise.

If the nup option (B<-n>I<nup>) is set to more than one page per sheet,
and if the booklet option (B<-b>) is not set, the margin will be the
same beetween two logical pages, and between a logical page and the
sheet border.
Otherwise, the margin beetween two logical pages will be twice bigger
the one between a logical page and the sheet border.

=item B<-c, --crop>

If this option is set, I<PSResize2> will interpret the PostScript code to
calculate the maximal effective bounding box. This operation may be quite
demanding for the CPU.

=item B<-b, --book>

Rearrange pages for printing books or booklets.

=item B<-n, --nup>

Puts multiple logical pages onto each physical sheet of paper. The inner
margin might be same as the outer one (depending on the booklet option
B<-b>), see B<-m> for details.

If I<nup> is less than 10, the option B<->I<nup> may be used as an
alternative.

=item B<-q, --quiet>

I<PDFTool> normally prints the page numbers of the pages output; this
option suppresses this.

=item B<--help>

Display a brief help.

=item B<--version>

Display the version number of the I<PDFTool> program.

=item B<--man>

Display the manual page.

=back

=head1 EXAMPLES

The following comand can be used to remotely crop a PDF file, convert it
to A4 paper, and rearrange the pages for printing a booklet: 

ssh remote pdftool.pl -cpA4 -b2 < in.pdf > out.pdf

=head1 REQUIRE

Requires PSUtils installed and available in the command line
http://www.tardis.ed.ac.uk/~ajcd/psutils/.

PSResize2 is also required, mostly for the crop option B<-c>.

=head1 AUTHOR

Public domain, (c) Guilhem Moulin.

=head1 VERSION

Version: 0.1, 25 September 2010

=cut

# TODO: inline it in the header
$main::VERSION = "0.1, 25 September 2010";



my $tmpdir   = '/tmp';

#
# Options & arguments 
#

my $select;
my $paper;
my $margin;
my $crop;
my $book;
my $nup = 1;
my $quiet;
my $man;

# TODO: choose the output type
GetOptions( "select|s=s" => \$select,
            "paper|p=s"  => \$paper,
            "margin|m=s" => \$margin,
            "crop|c"     => \$crop,
            "book|b"     => \$book,
            "nup|n=i"    => \$nup,
            "1"          => sub { $nup = 1 },
            "2"          => sub { $nup = 2 },
            "3"          => sub { $nup = 3 },
            "4"          => sub { $nup = 4 },
            "5"          => sub { $nup = 5 },
            "6"          => sub { $nup = 6 },
            "7"          => sub { $nup = 7 },
            "8"          => sub { $nup = 8 },
            "9"          => sub { $nup = 9 },
            "q|quiet"    => \$quiet,
            "man"        => \$man )
    or  pod2usage(2);

pod2usage(2)  if  ($#ARGV > 1);
pod2usage(-exitstatus => 0, -verbose => 2)  if  defined $man;

# Input and output files
my ($infile, $outfile) = @ARGV;



#
# Default values
#

# Default output papersize
$paper = "a4"  unless  defined $paper;


# Default margin
unless (defined $margin) {
    $margin = 0;
    $margin = "1cm" if defined $crop;
}

# Default unit: PostScript point
&topoints( \$margin );

# Inner and outer margins
my ($mresize, $mnup) = (0,0);
if ($nup > 1 && not defined $book) {
    $mresize = $margin/2;
    $mnup    = $mresize;
} else {
    $mresize = $margin;
}



# Open input and output files
my $infile_display;
if (defined $infile && $infile ne "-") {
    open FIN, '<', "$infile"  or  die "Can't read `$infile': $!";
    $infile_display = $infile;
} else {
    undef $infile;
    *FIN = *STDIN;
    $infile_display = "(stdin)";
}
# After the pipe, it won't be detected as seekable
my $inseek = (seek FIN, 0, 1) ? 1 : undef; 


if (defined $outfile && $outfile ne "-") {
    open FOUT, '>', "$outfile"  or  die "Can't create `$outfile': $!";
} else {
    *FOUT = *STDOUT;
}



#
# Detect filetype
#
# To avoid to seek into FIN, it gonna be copied from WRITE to READ in
# background, once the filetype has been read

# TODO: read specification to detect filetype properly
my $filetype;
pipe *READ, *WRITE  or  die "Can't pipe: $!";
while (not (defined $filetype) && defined (my $l = <FIN>)) {
    print WRITE $l  or  die "Can't close: $!";

    if (defined $l && $l =~ /^%!PS/) {
        $filetype = "PS";
    } elsif (defined $l && $l =~ /^%PDF/) {
        $filetype = "PDF";
    } 
}

die "Cannot recognise FileType"  unless  defined $filetype;

unless (my $pid = fork) {
    # Child: cat FIN > WRITE in background
    die "Can't fork: $!" unless defined $pid;
    close READ  or  die "Can't close: $!";
        
    while (<FIN>) {
        print WRITE  or  die "Can't print: $!";
    }
    exit;
}
# Parent

close WRITE  or  die "Can't close: $!";
close FIN  or  die "Can't close: $!";
        
open *FIN, "<&READ"  or  die "Can't dup: $!";



# Auxiliary files, to remove
my @auxfiles;

# Pids, to waid for
my @pids;



#
# Conversion from PDF to PS, if necessary 
#
my @cmd;
if ($filetype eq "PDF") {
    unless (defined $infile && $inseek) {
        # Need to copy the whole input to an auxiliary file, since
        # conversion from PDF to PS requires random access to the data
        
        $infile = "$tmpdir/pdftool-stdin-$$" . lc ".$filetype";

        open FINAUX, '>', "$infile"
            or die "Can't write into `$infile': $!";
        push @auxfiles, "$infile";

        # cat > $infile
        while (<FIN>) {
            print FINAUX  or  die "Can't print: $!";
        }
        close FINAUX;
    }
        

    # Convert to PS
    @cmd = ('pdftops', "$infile", '-');
    push @cmd, '-q'  if  defined $quiet;
    my $pid = open PSIN, "-|", @cmd
                  or die "Can't run `" . &printcmd (@cmd) . "'";
    push @pids, [$pid, @cmd];
} else {
    open *PSIN, "<&FIN"  or  die "Can't dup: $!";
}



#
# Select, if necessary
#
# TODO: preselection, during the conversion from pdf?
if (defined $select) {
    @cmd = ('psselect', "-p$select");
    push @cmd, '-q'  if  defined $quiet;
    my $pid = open2 *PSSELECT, "<&PSIN", @cmd;
    push @pids, [$pid, @cmd];
} else {
    *PSSELECT = *PSIN;
}



#
# Resize file to our paper
#
@cmd = ('psresize2.pl', "-p$paper", "-m$mresize");
push @cmd, "-c" if defined $crop;
push @cmd, '-q'  if  defined $quiet;

my $pid = open2 *PSRESIZE, "<&PSSELECT", @cmd;
push @pids, [$pid, @cmd];
# Note: open2 closes the filehandles for us :)



#
# PSBook
#
if (defined $book) {
    @cmd = ('psbook');
    push @cmd, '-q'  if  defined $quiet;

    my $pid = open2 *PSBOOK, "<&PSRESIZE", @cmd;
    push @pids, [$pid, @cmd];
} else {
    *PSBOOK = *PSRESIZE;
}



#
# PSNup
# 
if ($nup > 1) {
    @cmd = ('psnup', "-p$paper", "-m$mnup", "-$nup");
    push @cmd, '-q'  if  defined $quiet;

    my $pid = open2 *PSOUT, "<&PSBOOK", @cmd;
    push @pids, [$pid, @cmd];
} else {
    *PSOUT = *PSBOOK;
}



#
# Final file
#
if ($filetype eq "PDF") {
    # Convert back to PDF

    @cmd = ('ps2pdf', "-dEmbedAllFonts=true", "-sPAPERSIZE=$paper", '-', '-');
    $pid = open2 ">&FOUT", "<&PSOUT", @cmd;
    push @pids, [$pid, @cmd];
} else {
    # cat > FOUT
    while (<PSOUT>) {
        print FOUT  or  die "Can't print: $!";
    }
}


# Avoid zombies
map { my ($pid, @cmd) = @$_;
#     print STDERR "PID: ", $pid, " Cmd: `", &printcmd (@cmd), "'";
      my ($r,$v) = (waitpid ($pid, 0), $?);
      warn "Can't run `" . &printcmd (@cmd) . "'"  if  ($r != -1 and $v >> 8);
    } @pids;


map { close $_  or  die "Can't close: $!" }
    ( *READ, *FIN, *FOUT );


# Delete auxiliary files
unlink @auxfiles;




# =========================================================

#
# In-place convert the given length to PostScript points
#
sub topoints {
    my $l = $_[0];
    return unless defined $$l;
 
    $$l =~ /^([+-]?\d*\.?\d+)(\w*)$/  or  die "Unable to parse `$$l'";

    my $r = $1;
    if ($2 eq "" or $2 eq "pt") {
        # nothing
    } elsif ($2 eq "in") {
        $r *= 72;
    } elsif ($2 eq "cm") {
        $r *= 72/2.54;
    } elsif ($2 eq "mm") {
        $r *= 72/25.4;
    } else {
        die "Unknown unit: `$2'";
    }
    $$l = floor ($r + .5);
}


#
# Print a command just like you'd do in a shell
#
sub printcmd {
    my @cmd;

    for (@_) {
        my $s = $_;
        $s =~ s/"/\\"/;
        $s = "\"$s\""  if  $s =~ /[ ()';#{}*?~&|`]/;
        push @cmd, $s;
    }

    join ' ', @cmd; 
}