working

lib/Unshorten.pm

@@ -0,0 +1,54 @@
+use MooseX::Declare;
+use Unshorten::Model;
+use POE;
+use HTTP::Engine::Role; # for type constraints
+use feature 'say';
+
+class Unshorten with MooseX::Getopt with MooseX::Runnable with HTTP::Engine::Role {
+    has '_engine_type' => ( is => 'ro', default => 'POE' );
+
+    has 'dsn' => (
+        is            => 'ro',
+        isa           => 'Str',
+        required      => 1,
+        default       => 'hash',
+        documentation => 'DSN of the KiokuDB',
+    );
+
+    has 'model' => (
+        traits     => ['NoGetopt'],
+        is         => 'ro',
+        isa        => 'Unshorten::Model',
+        lazy_build => 1,
+    );
+
+    method _build_model() {
+        return Unshorten::Model->new( dsn => $self->dsn );
+    }
+
+    method handle_request(HTTP::Engine::Request $req){
+
+        my $short = URI->new(substr $req->uri->path, 1);
+
+        my $long = eval { $self->model->unshorten($short) };
+        if(!$long || $@){
+            return HTTP::Engine::Response->new(
+                code         => 500,
+                content_type => 'text/plain',
+                body         => "An error occurred while shortening '$short': $@",
+            );
+        }
+
+        return HTTP::Engine::Response->new(
+            content_type => 'text/plain',
+            body         => $long,
+        );
+    }
+
+    method run() {
+        $self->engine->run;
+        say "Starting server on port ". $self->port;
+        POE::Kernel->run;
+    }
+
+};

lib/Unshorten/Model.pm

@@ -0,0 +1,45 @@
+use MooseX::Declare;
+
+class Unshorten::Model extends KiokuX::Model {
+    use Moose::Util::TypeConstraints;
+    use MooseX::Types::URI qw(Uri);
+
+    use AnyEvent::HTTP qw(http_head);
+
+    method unshorten(Uri $url) {
+        return $self->_lookup_or_cache($url, sub {
+            $self->_lookup(@_),
+        });
+    }
+
+    method _lookup(Uri $url) {
+        my $done = AnyEvent->condvar;
+
+        http_head $url, sub {
+            my ($data, $headers) = @_;
+            my $long_url = eval { URI->new($headers->{URL}) };
+            confess 'Failed to get a URL' unless $url;
+            $done->send($long_url);
+        };
+
+        return $done->recv;
+    }
+
+    method _lookup_or_cache(Uri $url, CodeRef $shortener) {
+        my $scope = $self->new_scope;
+        my $shortened = $self->lookup("$url");
+        return $shortened if $shortened;
+
+        $shortened = $shortener->($url);
+
+        # "Unknown reason" because the shortener should die if it knows
+        # the reason
+        confess "Unable to shorten '$url': Unknown reason"
+          unless $shortened;
+
+        $self->store("$url" => $shortened);
+
+        return $shortened;
+    }
+
+};