use Mojolicious::Lite -signatures;
use Mojo::Pg;

helper pg => sub { state $pg = Mojo::Pg->new('postgresql://postgres@/test') };

# Use migrations to create a table during startup
app->pg->migrations->from_data->migrate;

get '/' => sub ($c) {

  my $db = $c->pg->db;
  my $ip = $c->tx->remote_address;

  # Store information about current visitor blocking
  $db->query('INSERT INTO visitors VALUES (NOW(), ?)', $ip);

  # Retrieve information about previous visitors non-blocking
  $db->query('SELECT * FROM visitors LIMIT 50' => sub ($db, $err, $results) {

    return $c->reply->exception($err) if $err;

    $c->render(json => $results->hashes->to_array);
  });
};

app->start;
__DATA__

@@ migrations
-- 1 up
CREATE TABLE visitors (at TIMESTAMP WITH TIME ZONE, ip TEXT);
-- 1 down
DROP TABLE visitors;