#!/usr/bin/perl -w
use strict;
use Fcntl qw(:flock);

use constant MONTHS => qw(
	Jan Feb Mar Apr May Jun
	Jul Aug Sep Oct Nov Dec
);

use constant DATE_RX => qr#(\d+)/(\d+)/(\d+) at (\d\d:\d\d:\d\d)#;

print "Content-type: text/html\n\n";

my $boarddir = './yabb/Boards';
my $boardurl = '/cgi-bin/yabb/YaBB.pl';

chdir $boarddir
	or die "Cannot chdir to $boarddir: $!";

my @files = do {
	opendir my $dir, "."
		or die ("Cannot open Boards directory $!");
	grep /\.txt\z/, readdir $dir;
};

sub parse_time {
	require HTTP::Date;
	return unless @_ == 4;
	my $time = "$_[1] ".(MONTHS)[$_[0]-1]." $_[2] $_[3] GMT";
	return ($time, HTTP::Date::str2time($time));
}

my @data;

for my $file (@files) {
	open my $fh, "<", $file
		or die "Cannot open file $file: $!";

	flock $fh, LOCK_SH;

	my ($board) = $file =~ /(\w+)\./;

	while (<$fh>) {
		my ($id, $name, $user, $email, $datetime) = split /\|/;
		my ($time, $utime) = parse_date($datetime =~ DATE_RX);
		push @data, [ $utime, $board, $id, $name, $time ]
			if defined $utime;
	}
}

my @link = @{ sort { $a->[0] <=> $b->[0] } @data)[0] || [] };

printf
	qq{<div id="lastmbpost"><a href="%s?board=%d;action=display;num=%d;start=1">%s</a><br />was updated on %s</div>},
	$boardurl, @link[1..4];