<?php
// Own namespace
namespace CoreFramework\Handler\Task;

// Import framework stuff
use CoreFramework\Handler\DataSet\HandleableDataSet;
use CoreFramework\Task\Taskable;

/**
 * A HandleableTask interface
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.shipsimu.org
 * @todo		HandleableDataSet looks strange here
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
interface HandleableTask extends HandleableDataSet {
	/**
	 * Searches a task by given instance
	 *
	 * @param	$taskInstanc	An instanceof a Taskable class
	 * @return	$taskName		Name of the task as used while registration
	 */
	function searchTask (Taskable $taskInstance);

	/**
	 * Registers a task with a task handler.
	 *
	 * @param	$taskName		A task name to register the task on
	 * @param	$taskInstance	The instance we should register as a task
	 * @return	void
	 */
	function registerTask ($taskName, Visitable $taskInstance);

	/**
	 * Checks whether tasks are left including idle task
	 *
	 * @return	$tasksLeft	Whether there are tasks left to handle
	 */
	function hasTasksLeft ();

	/**
	 * Handles all tasks by checking if they should startup or if it is their
	 * turn to run. You should use this method in a while() loop in conjuntion
	 * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
	 * which will attempt to remove all tasks from the task handler.
	 *
	 * @return	void
	 */
	function handleTasks ();

	/**
	 * Shuts down all tasks and the task handler itself. This method should be
	 * called from a corresponding filter class.
	 * 
	 * @return	void
	 */
	function doShutdown ();

}