//usr/bin/env jbang "$0" "$@" ; exit $?

//SOURCES dev/datastar/*.java

//DEPS io.vertx:vertx-web:5.0.1

//JAVAC_OPTIONS -parameters

import dev.datastar.Datastar;

import dev.datastar.VertxDatastar;

import io.vertx.core.Vertx;

import io.vertx.ext.web.Router;

import io.vertx.ext.web.RoutingContext;

import io.vertx.ext.web.handler.StaticHandler;

public class helloworld {

public static void main(String[] args) {

var vertx = Vertx.vertx();

var server = vertx.createHttpServer();

var router = Router.router(vertx);

router.get("/hello-world").handler(context -> {

var signals = VertxDatastar.readSignals(context.request());

var delay = signals.getLong("delay").longValue();

VertxDatastar.prepareResponse(context.response());

context.vertx().setTimer(delay, tick -> {

sendSubstring(1, "Hello, world!", delay, context);

});

});

router.route().handler(StaticHandler.create("."));

server.requestHandler(router).listen(8080);

}

private static void sendSubstring(int currentStep, String hello, long delay, RoutingContext context) {

if (currentStep > hello.length()) {

context.end();

return;

}

VertxDatastar.send(context.response(), Datastar.patchElements().replace("""

<div id="message">%s</div>

""".formatted(hello.substring(0, currentStep))));

context.vertx().setTimer(delay, id -> {

sendSubstring(currentStep + 1, hello, delay, context);

});

}

}