AsyncEventDelegate.php

<?php

/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */

declare(strict_types=1);

namespace pocketmine\event;

use pocketmine\promise\Promise;
use pocketmine\promise\PromiseResolver;
use pocketmine\utils\ObjectSet;
use function array_shift;
use function count;

final class AsyncEventDelegate extends Event{
	/** @phpstan-var ObjectSet<Promise<null>> $promises */
	private ObjectSet $promises;

	public function __construct(
		private AsyncEvent&Event $event
	){
		$this->promises = new ObjectSet();
	}

	/**
	 * @phpstan-return Promise<null>
	 */
	public function callAsync() : Promise{
		$this->promises->clear();
		return $this->callDepth($this->callAsyncDepth(...));
	}

	/**
	 * @phpstan-return Promise<null>
	 */
	private function callAsyncDepth() : Promise{
		/** @phpstan-var PromiseResolver<null> $globalResolver */
		$globalResolver = new PromiseResolver();

		$priorities = EventPriority::ALL;
		$testResolve = function () use (&$testResolve, &$priorities, $globalResolver){
			if(count($priorities) === 0){
				$globalResolver->resolve(""); // TODO: see #6110
			}else{
				$this->callPriority(array_shift($priorities))->onCompletion(function() use ($testResolve) : void{
					$testResolve();
				}, function () use ($globalResolver) {
					$globalResolver->reject();
				});
			}
		};

		$testResolve();

		return $globalResolver->getPromise();
	}

	/**
	 * @phpstan-return Promise<null>
	 */
	private function callPriority(int $priority) : Promise{
		$handlers = HandlerListManager::global()->getListFor($this->event::class)->getListenersByPriority($priority);

		/** @phpstan-var PromiseResolver<null> $resolver */
		$resolver = new PromiseResolver();

		$nonConcurrentHandlers = [];
		foreach($handlers as $registration){
			if($registration instanceof RegisteredAsyncListener){
				if($registration->canBeCallConcurrently()){
					$this->promises->add($registration->callAsync($this->event));
				}else{
					$nonConcurrentHandlers[] = $registration;
				}
			}else{
				$registration->callEvent($this->event);
			}
		}

		$testResolve = function() use (&$nonConcurrentHandlers, &$testResolve, $resolver){
			if(count($nonConcurrentHandlers) === 0){
				$this->waitForPromises()->onCompletion(function() use ($resolver){
					$resolver->resolve(""); // TODO: see #6110
				}, function() use ($resolver){
					$resolver->reject();
				});
			}else{
				$this->waitForPromises()->onCompletion(function() use (&$nonConcurrentHandlers, $testResolve){
					$handler = array_shift($nonConcurrentHandlers);
					if($handler instanceof RegisteredAsyncListener){
						$this->promises->add($handler->callAsync($this->event));
					}
					$testResolve();
				}, function() use ($resolver) {
					$resolver->reject();
				});
			}
		};

		$testResolve();

		return $resolver->getPromise();
	}

	/**
	 * @phpstan-return Promise<array<int, null>>
	 */
	private function waitForPromises() : Promise{
		$array = $this->promises->toArray();
		$this->promises->clear();

		return Promise::all($array);
	}
}