Sleep() problem

i used sleep to wait 1 second in interact event but it wait and then use all code

PHP:

public function onInteract(PlayerInteractEvent $event)
{
    $block = $event->getBlock();
    $player = $event->getPlayer();
    $inventory = $player->getInventory();
    if ($block->getId() === Block::CHEST) {
        if ($inventory->contains(new Emerald(0, 1))) {
            $event->setCancelled();
            $player->sendMessage("§6[MineDox] §aOpening crate chest...");
            sleep(1);
            $player->sendMessage("§a3");
            sleep(1);
            $player->sendMessage("§a2");
            sleep(1);
            $player->sendMessage("§a1");
            $level = $player->getLevel();
            $x = $block->getX();
            $y = $block->getY();
            $z = $block->getZ();
            $r = 0;
            $g = 255;
            $b = 255;
            $center = new Vector3($x + 1, $y, $z);
            $radius = 0.5;
            $count = 100;
            $particle = new DustParticle($center, $r, $g, $b, 1);
            for ($yaw = 0, $y = $center->y; $y < $center->y + 4; $yaw += (M_PI * 2) / 20, $y += 1 / 20) {
                $x = -sin($yaw) + $center->x;
                $z = cos($yaw) + $center->z;
                $particle->setComponents($x, $y, $z);
                $level->addParticle($particle);

 

YAAY
another post to be moved to facepalm
http://php.net/manual/en/function.sleep.php READ!
D E L A Y S execution. That means everything else also gets stopped. Events aren't in another thread. Please search the forums on how to create Delayed/Repeating tasks.