+ $_ eq $style ? 'stylesheet' : 'alternate stylesheet', "/$_.css?1.17", $_
+ ) } @avail;
+}
+
+sub checkmodified {
+ my $lastmod = 0;
+ for (@_) {
+ my $mod = stat $_ or next;
+ $mod = $mod->mtime or next;
+ $lastmod = $mod if $mod gt $lastmod;
+ }
+
+ for ($ENV{HTTP_IF_MODIFIED_SINCE} || ()) {
+ next if str2time($_) < $lastmod;
+ $header{status} = '304 Same old';
+ exit;
+ }
+
+ $header{'Last-Modified'} = time2str($lastmod);
+}
+
+sub Data {
+ my ($filename) = @_;
+ my @data = eval {
+ open my $cache, '<:raw', "data/$filename.json"
+ or return do "./$filename.inc.pl"; # silent fallback to original code
+ require JSON;
+ local $/; # slurp
+ return JSON::decode_json(readline $cache);
+ };
+ if ($@ or !@data or !$data[0]) {
+ die ['Table data not found', $@ || $!];
+ }
+ if (@data == 1 and ref $data[0] eq 'HASH' and not %{$data[0]}) {
+ die ['Table data missing'];
+ }
+ return wantarray ? @data : $data[0]; # list compatibility like do does
+}
+
+sub Html {
+ my ($meta) = @_;
+
+ unless ($meta->{nocache}) {
+ # announce and check data modification
+ checkmodified(
+ $ENV{SCRIPT_FILENAME},
+ (grep { /\bShiar_/ } values %INC),
+ $meta->{data} ? @{ $meta->{data} } : (),
+ );
+ $header{'Cache-Control'} = 'max-age='.(24*60*60);
+ }
+
+ # default fallbacks
+ $meta->{stylesheet} ||= [qw( light dark circus mono red )];
+ $meta->{charset} ||= 'utf-8';
+ $meta->{lang} ||= 'en';
+
+ # convert options to arrays
+ ref $_ eq 'ARRAY' or $_ = [$_]
+ for grep {$_} $meta->{raw}, $meta->{description}, $meta->{keywords};
+
+ # document headers before output
+ $header{content_type} = "text/html; charset=$meta->{charset}"
+ unless $PLP::sentheaders;
+ exit if $ENV{REQUEST_METHOD} eq 'HEAD';
+ unshift @{ $meta->{raw} }, stylesheet($meta->{stylesheet});
+
+ push @{ $meta->{raw} }, (
+ '<link rel="stylesheet" type="text/css" media="monochrome" href="/mono.css?1.11" title="light">',
+ );
+
+ if (my $img = $meta->{image}) {
+ my $proto = sprintf('http%s://', !!$ENV{HTTPS} && 's');
+ my $url = "$proto$ENV{HTTP_HOST}/$img";
+ push @{ $meta->{raw} }, (
+ qq(<meta property="og:image" content="$url" />),
+ );
+ }
+
+ my ($file) = $ENV{SCRIPT_FILENAME} =~ m{ ([^/]+) \.plp$ }x;
+
+ if (my $url = $meta->{canonical} // "/$file/$Request") {
+ $url = "https://sheet.shiar.nl$url";
+ push @{ $meta->{raw} }, qq(<link rel="canonical" href="$url" />);
+ }
+
+ PLP_START {
+ # leading output
+ say '<!DOCTYPE html>';
+ say qq(<html lang="$meta->{lang}">);
+ say '';
+ say '<head>';
+ say sprintf '<meta http-equiv="content-type" content="%s">', $_
+ for $header{content_type};
+ say sprintf '<title>%s</title>', $meta->{title};
+ say sprintf '<meta name="description" content="%s">', EscapeHTML($_)
+ for join(' ', @{ $meta->{description} // [] }) || ();
+ say sprintf '<meta name="keywords" content="%s">', EscapeHTML($_)
+ for join(', ', @{ $meta->{keywords} // [] }) || ();
+ say '<meta name="viewport" content="width=device-width, initial-scale=1">';
+ say '<link rel="icon" type="image/png" href="/clip.png">';
+ say for map { @{$_} } $meta->{raw} || ();
+ say '<meta name="robots" content="noindex">' if $Dev;
+ say '</head>';
+ say '';
+ say sprintf '<body id="%s">', $file;
+
+ # development version indicator
+ printf '<p style="%s">beta</p>', join('; ',
+ 'position: fixed',
+ 'right: 1em',
+ 'opacity: .5',
+ 'border: 1ex solid red',
+ 'border-width: 1ex 0',
+ 'z-index: 1',
+ 'background: inherit',
+ ) if $Dev;
+ };
+
+ # prepare trailing output
+ PLP_END {
+ print <<"EOT";
+<p class="footer">
+ <a href="/" rel="start">sheet.shiar.nl</a>/$file.<a href="/source/$file.plp"
+ rel="source" title="Written in Perl">plp</a>
+ version <a href="http://git.shiar.nl/sheet.git/history/HEAD:/$file.plp"
+ rel="vcs-git" title="Git repository">$meta->{version}</a>
+ created by <a href="http://shiar.nl/" rel="author">Shiar</a> •
+ <a href="http://www.fsf.org/licensing/licenses/agpl-3.0.html"
+ title="Licensed under the GNU Affero General Public License, version 3"
+ rel="license">AGPLv3</a>
+EOT
+ our $Time;
+ say sprintf '• %.3fs', Time::HiRes::tv_interval($Time) if $Dev and $Time;
+ say '</p>';
+ say '';
+ say '</html>';
+ };
+}
+
+BEGIN {
+ $PLP::ERROR = sub {
+ my ($message, $html) = @_;
+ if (ref $message) {
+ warn join ': ', @{$message};
+ $html = shift @{$message};
+ }
+ else {
+ warn $message;
+ $message = [];
+ }
+ unless ($PLP::sentheaders) {
+ Html({nocache => 1});
+ say '<h1>Page unavailable</h1>';
+ }
+ Alert("Fatal error: $html.", @{$message});
+ };
+}
+
+sub showlink {
+ my ($title, $href, $selected) = @_;
+ EscapeHTML($title);
+ return $title if not $href;
+ return "<strong>$title</strong>" if $selected;
+ return sprintf '<a href="%s">%s</a>', EscapeHTML($href), $title;