/*
 * Copyright 2013 Hewlett-Packard Development Company, L.P
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hp.alm.ali.idea.services;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class WeakListenersTest {

    private WeakListeners<Listener> weakListeners;
    private Semaphore semaphore;

    @Before
    public void prepare() {
        weakListeners = new WeakListeners<Listener>();
        semaphore = new Semaphore(0);
    }

    @Test
    public void testAddAndFire() throws InterruptedException {
        Listener listener = new Listener() {
            @Override
            public void exec() {
                semaphore.release(1);
            }
        };
        weakListeners.add(listener);
        weakListeners.add(new Listener() {
            @Override
            public void exec() {
                semaphore.release(1);
            }
        }, false);
        weakListeners.fire(new WeakListeners.Action<Listener>() {
            @Override
            public void fire(Listener listener) {
                listener.exec();
            }
        });
        Assert.assertTrue(semaphore.tryAcquire(2, 2000, TimeUnit.MILLISECONDS));
    }

    @Test
    public void testRemove() throws InterruptedException {
        Listener listener = new Listener() {
            @Override
            public void exec() {
                Assert.fail("Should have been removed");
            }
        };
        weakListeners.add(listener);
        weakListeners.remove(listener);
        weakListeners.fire(new WeakListeners.Action<Listener>() {
            @Override
            public void fire(Listener listener) {
                listener.exec();
            }
        });
    }

    @Test
    public void testWeakListener() throws InterruptedException {
        weakListeners.add(new Listener() {
            @Override
            public void exec() {
                Assert.fail("Should have been garbage collected");
            }
        }, true);
        weakListeners.add(new Listener() {
            @Override
            public void exec() {
                semaphore.release(1);
            }
        }, false);
        System.gc();
        weakListeners.fire(new WeakListeners.Action<Listener>() {
            @Override
            public void fire(Listener listener) {
                listener.exec();
            }
        });
        Assert.assertTrue(semaphore.tryAcquire(1, 2000, TimeUnit.MILLISECONDS));
    }

    @Test
    public void testIsRegistered() {
        Listener listener = new Listener() {
            @Override
            public void exec() {
            }
        };
        Assert.assertFalse(weakListeners.isRegistered(listener));
        weakListeners.add(listener, false);
        Assert.assertTrue(weakListeners.isRegistered(listener));
    }

    private static interface Listener {

        void exec();

    }
}