#!/home/merlyn/bin/perl -Tw
use strict;
$|++;
use LWP::Simple qw/get/;
use URI::URL;
use CGI qw/:form :html param header/;

## configure
my $TOP = "http://www.unitedmedia.com/comics/dilbert/archive/";
my $HTML_RE = '/comics/dilbert/archive/dilbert\d+.html';
my $GIF_RE = '/comics/dilbert/archive/images/dt\d+_\d+\.gif';
my $KEEP = 99;
## end configure

## return $_[0] encoded for HTML entities
sub ent {
  local $_ = shift;
  $_ =~ s/["<&>"]/"&#".ord($&).";"/ge;  # entity escape
  $_;
}
sub td_center { td({ align => "center" }, @_); }

BEGIN {
  my $notes = "";
  sub add_note { $notes .= join "", @_; }
  sub get_notes { $notes; }
  sub get_ent_notes { ent $notes; }
}

print header, start_html("Dilbert"), h1("Recent Dilberts"), "\n";
my $max = param("max");
if (defined $max and $max =~ /^\d+$/) {
  $max = $KEEP if $max > $KEEP;
  my $top = get $TOP;
  my @gif_urls = ();
  if (not defined $top) {
    add_note "cannot get $TOP";
  } else {
    my @old_urls = map url($_,$TOP)->abs, $top =~ m!($HTML_RE)!og;

    @old_urls = @old_urls[-$max..-1] if @old_urls > $max;

    for my $url (@old_urls) {
      my $content = get $url or (add_note "cannot get $url\n"), next;
      my ($gif) = $content =~ m!($GIF_RE)!o;
      push @gif_urls, url($gif,$url)->abs;
    }
  }

  print table(
              (map { TR(td_center($_)) }
               map { table(TR(td_center(ent $_)),
                           TR(td_center(img{-src => $_})))
                   } @gif_urls),
              p(get_ent_notes())
             );
} else {
  print hr, start_form;
  print p(submit("get this many days of back-images:"),
          popup_menu("max", [1..45], "14"));
  print end_form, hr;
}
print "\n", end_html;