#!/pro/bin/perl

use 5.14.1;
use warnings;

sub usage
{
    my $err = shift and select STDERR;
    say "usage: pod2pdf [--output=file.pdf] [input]";
    exit $err;
    } # usage

use Getopt::Long qw(:config bundling);
my $opt_o;
my $opt_t;
my $opt_c;
GetOptions (
    "help|?"     => sub { usage (0); },
    "o|output=s" => \$opt_o,
    "t|title=s"  => \$opt_t,
    "c|css=s"    => \$opt_c,
    ) or usage (1);

use Pod::Html;
use File::Temp qw( tempdir ); # Pod::Html doesn't support piped output :( :(
use HTML::TreeBuilder;

my $td = tempdir (CLEANUP => 1);
my %tf = map { $_ => "$td/pod2pdf.$_" } "html", "pdf";

my $html;
{   pod2html "--outfile=$tf{html}", @ARGV;
    # Cleanup leftover junk from Pod::Html :(
    -f $_ && unlink $_ for map { "$_/pod2htmd.tmp" } ".", $ENV{TMPDIR} // "/tmp";
    open my $fh, "<", $tf{html};
    $html = join "" => <$fh>;
    close $fh;
    }

my $css  = join "" => <DATA>;
if ($opt_c && open my $fh, "<", $opt_c) {
    $css = join "" => <$fh>;
    close $fh;
    }

my $tree = HTML::TreeBuilder->new;
$tree->parse_content ($html);
foreach my $head ($tree->look_down (_tag => "head")) {
    my $style = HTML::Element->new ("style");
    $style->attr (type => "text/css");
    $style->push_content ($css);
    $head->push_content ($style);
    }

my $pdf = do {
    open my $fh, ">", $tf{html} or die "$tf{html}: $!\n";
    print $fh $tree->as_HTML (undef, "  ", {});
    close $fh;
    my @cmd = qw( wkhtmltopdf --quiet --load-error-handling ignore );
    $opt_t and push @cmd, "--title", $opt_t;
    push @cmd, $tf{html}, $tf{pdf};
    system @cmd;
    open $fh, "<", $tf{pdf} or die "$tf{pdf}: $!\n";
    join "" => <$fh>;
    };

if ($opt_o) {
    open my $fh, ">", $opt_o or die "$opt_o: $!\n";
    print $fh $pdf;
    close $fh;
    }
else {
    print $pdf;
    }

__END__
body, p, ul, ol, h1, h2, h3 {
            font-family: "DejaVu Sans", "Nimbus Sans L",
                         Helvetica, sans-serif; }
body      { color:       Black;
            background:  White;                 }
a:link    { color:       Purple;                }
a:visited { color:       Maroon;                }
pre, tt, code {
            font-family: "DejaVu Sans Mono", "Liberation Mono",
                         LettrGothic12BT, "Lucida Console",
                         mono, monospace;       }
p, ul, ol { text-align:  left;                  }
h1        { color:       Maroon;                }
h2        { color:       Green;                 }
h3        { color:       Navy;                  }