use Mojolicious::Lite -signatures;
use JSON::Validator 'joi';
use Mojo::JSON qw(false to_json true);

post '/users' => sub ($c) {
  my $user = $c->req->json;

  # Validate input JSON document
  my @errors = joi(
    $user,
    joi->object->props(
      email    => joi->email->required,
      username => joi->string->min(1)->required,
      password => joi->string->min(12)->required,
    )
  );

  # Report back on invalid input
  return $c->render(json => {errors => \@errors}, status => 400) if @errors;

  # Handle the $user in some way
  $c->app->log->info(to_json $user);

  # Report back the status
  return $c->render(json => {accepted => true}, status => 201);
};

app->start;