<?php

namespace Amp\Internal;

use Amp\Cancellation;
use Amp\CancelledException;
use Amp\ForbidCloning;
use Amp\ForbidSerialization;
use Revolt\EventLoop;

/**
 * Cancellation with public cancellation method.
 *
 * @internal
 */
final class Cancellable implements Cancellation
{
	use ForbidCloning;
	use ForbidSerialization;

	private string $nextId = "a";

	/** @var \Closure[] */
	private array $callbacks = [];
	private ?CancelledException $exception = null;
	private ?\Throwable $previous = null;
	private bool $requested = false;


	public function cancel(?\Throwable $previous = null): void
	{
		if ($this->requested) {
		    return;
		}

		$this->requested = true;
		$this->previous = $previous;

		$callbacks = $this->callbacks;
		$this->callbacks = [];

		if (empty($callbacks)) {
		    return;
		}

		$exception = $this->getException();

		foreach ($callbacks as $callback) {
		    EventLoop::queue(static fn () => $callback($exception));
		}
	}


	private function getException(): CancelledException
	{
		return $this->exception ??= new CancelledException($this->previous);
	}


	public function subscribe(\Closure $callback): string
	{
		$id = $this->nextId++;

		if ($this->requested) {
		    $exception = $this->getException();
		    EventLoop::queue(static fn () => $callback($exception));
		} else {
		    $this->callbacks[$id] = $callback;
		}

		return $id;
	}


	public function unsubscribe(string $id): void
	{
		unset($this->callbacks[$id]);
	}


	public function isRequested(): bool
	{
		return $this->requested;
	}


	public function throwIfRequested(): void
	{
		if ($this->requested) {
		    throw $this->getException();
		}
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NDIxMzc5MDQzMTk2NDI0MiA2NDE3NjkxNTU1MzM4MzQyIDE2MDkzMzI2Nzk2MTExMzM=