/*  _____ _
 * |_   _| |_  _ _ ___ ___ _ __  __ _
 *   | | | ' \| '_/ -_) -_) '  \/ _` |_
 *   |_| |_||_|_| \___\___|_|_|_\__,_(_)
 *
 * Threema for Android
 * Copyright (c) 2017-2020 Threema GmbH
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

package ch.threema.app.managers;

import junit.framework.Assert;

import org.junit.Test;

public class ListenerManagerTest {

	interface TestListener {
		void call();
	}

	/**
	 * Make sure that the handle method cannot cause a deadlock.
	 */
	@Test
	public void handleDeadlock() throws InterruptedException {
		// Create a test listener manager
		final ListenerManager.TypedListenerManager<TestListener> testListeners = new ListenerManager.TypedListenerManager<>();

		// Add a listener that modifies the list of listeners
		testListeners.add(new TestListener() {
			@Override
			public void call() {
				// Add another listener from another thread
				final Thread thread = new Thread(new Runnable() {
					@Override
					public void run() {
						testListeners.add(new TestListener() {
							@Override
							public void call() {
								// No-op
							}
						});
					}
				});

				// Start thread
				thread.start();

				// Check whether thread has finished
				try {
					thread.join(500);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
				if (thread.isAlive()) {
					Assert.fail("Thread is still active: Deadlock detected!");
				}
				// Yeah, no deadlock!
			}
		});

		// Handle
		testListeners.handle(new ListenerManager.HandleListener<TestListener>() {
			@Override
			public void handle(TestListener listener) {
				listener.call();
			}
		});
	}

}
