#!/usr/bin/perl

# ylink.pl - create <link> elements from directory structure to make it
#            easier to browse big document hierarchies

# 1.0.0 - 2004-07-02 - Morten Wulff <wulff@psyke.org>

use strict;
use warnings;

$|++;

use File::Find;

# config ----------------------------------------------------------------------

my @input_dirs = qw(
	d:/projekter/psyke.org/source/main/about
	d:/projekter/psyke.org/source/main/articles
	d:/projekter/psyke.org/source/main/bookstore
	d:/projekter/psyke.org/source/main/coping
	d:/projekter/psyke.org/source/main/faqs
	d:/projekter/psyke.org/source/main/personal
	d:/projekter/psyke.org/source/main/pictures
	d:/projekter/psyke.org/source/main/poetry
);

#	d:/projekter/psyke.org/source/mirror/download
#	d:/projekter/psyke.org/source/mirror/forum
#	d:/projekter/psyke.org/source/mirror/pictures

my @exclude = qw(^_ img \.tmpl$ ~$);

my $link_file = 'link-browse.tmpl';
my $link_file_prev = 'nav-trail-prev.tmpl';
my $link_file_next = 'nav-trail-next.tmpl';

# init ------------------------------------------------------------------------

my $depth = 0;
my @paths = ();

# main ------------------------------------------------------------------------

foreach my $input_dir (@input_dirs) {
	$depth = 0;
	@paths = ();

	print "$input_dir\n";

	find(
		{
			preprocess  => \&preprocess,
			wanted      => \&wanted,
			postprocess => \&postprocess
		},
		$input_dir
	);

	foreach my $path ( @paths ) {
		$path->{name} =~ s/$input_dir//;
		$path->{name} =~ s/\/$//;
		$path->{name} =~ s/^\///;
	}

	foreach my $i ( 0 .. $#paths ) {
		my $rel_next = $i < $#paths
			? '../' x $paths[$i]->{depth} . $paths[$i+1]->{name}
			: '';
		my $rel_prev = $i > 0
			? '../' x $paths[$i]->{depth} . $paths[$i-1]->{name}
			: '';

		my $file = join '/', $input_dir, "$paths[$i]->{name}", $link_file;

		open(OUT, ">$file") or die "Can't open file '$file': $!";
		print OUT "\t<link rel=\"Prev\" href=\"$rel_prev\" />\n" if $rel_prev ne '';
		print OUT "\t<link rel=\"Next\" href=\"$rel_next\" />" if $rel_next ne '';
		close(OUT);

		$rel_prev .= '/' unless $rel_prev =~ /\/$/;
		$rel_next .= '/' unless $rel_next =~ /\/$/;

		$file = join '/', $input_dir, "$paths[$i]->{name}", $link_file_prev;
		open(OUT, ">$file") or die "Can't open file '$file': $!";
		if ($rel_prev ne '') {
			print OUT "<li class=\"prev\"><a href=\"$rel_prev\">&laquo;&nbsp;Prev</a></li>";
		}
		else {
			print OUT '';
		}
		close(OUT);

		$file = join '/', $input_dir, "$paths[$i]->{name}", $link_file_next;
		open(OUT, ">$file") or die "Can't open file '$file': $!";
		if ($rel_next ne '') {
			print OUT "<li class=\"next\"><a href=\"$rel_next\">Next&nbsp;&raquo;</a></li>";
		}
		else {
			print OUT '';
		}
		close(OUT);
	}
}

# subs ------------------------------------------------------------------------

sub preprocess {
    my @files = sort { $a cmp $b } @_;

    my $dir = $File::Find::dir;

    ### remove unwanted elements from the file list
    @files = grep {
        my $file = $_;
        my $path = join '/', $dir, $file;
        !/^\.{1,2}/ and
        !grep {$file =~ /$_/ or $path =~ /$_/} @exclude
    } @files;

    $depth++;
    return reverse @files;
}

sub wanted {
	return unless -d;

	push @paths, { name => $File::Find::name, depth => $depth };
}

sub postprocess {
	$depth--;
}