<?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);

/**
 * Event related classes
 */

namespace pocketmine\event;

use BadMethodCallException;
use RuntimeException;
use function assert;
use function get_class;

abstract class Event{
	private const MAX_EVENT_CALL_DEPTH = 50;
	/** @var int */
	private static $eventCallDepth = 1;

	/** @var string|null */
	protected $eventName = null;
	/** @var bool */
	private $isCancelled = false;

	final public function getEventName() : string{
		return $this->eventName ?? get_class($this);
	}

	/**
	 * @throws BadMethodCallException
	 */
	public function isCancelled() : bool{
		if(!($this instanceof Cancellable)){
			throw new BadMethodCallException(get_class($this) . " is not Cancellable");
		}

		return $this->isCancelled;
	}

	/**
	 * @throws BadMethodCallException
	 */
	public function setCancelled(bool $value = true) : void{
		if(!($this instanceof Cancellable)){
			throw new BadMethodCallException(get_class($this) . " is not Cancellable");
		}

		$this->isCancelled = $value;
	}

	/**
	 * Calls event handlers registered for this event.
	 *
	 * @throws RuntimeException if event call recursion reaches the max depth limit
	 */
	public function call() : void{
		if(self::$eventCallDepth >= self::MAX_EVENT_CALL_DEPTH){
			//this exception will be caught by the parent event call if all else fails
			throw new RuntimeException("Recursive event call detected (reached max depth of " . self::MAX_EVENT_CALL_DEPTH . " calls)");
		}

		$handlerList = HandlerList::getHandlerListFor(get_class($this));
		assert($handlerList !== null, "Called event should have a valid HandlerList");

		++self::$eventCallDepth;
		try{
			foreach(EventPriority::ALL as $priority){
				$currentList = $handlerList;
				while($currentList !== null){
					foreach($currentList->getListenersByPriority($priority) as $registration){
						$registration->callEvent($this);
					}

					$currentList = $currentList->getParent();
				}
			}
		}finally{
			--self::$eventCallDepth;
		}
	}
}
