/*
 * Copyright 2005 the original author or authors.
 * 
 * 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 org.wamblee.observer;

import static org.easymock.EasyMock.createControl;
import static org.easymock.EasyMock.createMock;
import static org.easymock.EasyMock.createStrictMock;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.verify;

import java.util.ArrayList;
import java.util.List;

import junit.framework.TestCase;

import org.easymock.IMocksControl;

/**
 * Test of the observer pattern implementation.
 * 
 * @author Erik Brakkee
 */
public class ObservableTest extends TestCase {

	private static final int SUBSCRIBER_COUNT = 100;

	private static final String UPDATE = "send";

	private Integer _observed;
	private Observable<Integer, String> _observable;

	/*
	 * (non-Javadoc)
	 * 
	 * @see junit.framework.TestCase#setUp()
	 */
	@Override
	protected void setUp() throws Exception {
		super.setUp();
		_observed = new Integer(1);
		_observable = new Observable<Integer, String>(_observed,
				new DefaultObserverNotifier());
	}

	/**
	 * Tests subscription and notification of one subscriber.
	 */
	public void testOneObserver() {
		final Observer mockObserver = createStrictMock(Observer.class);
		long subscription = _observable.subscribe(mockObserver);

		assertEquals(1, _observable.getObserverCount());

		final String message = "hallo";
		mockObserver.send(_observed, message);
		replay(mockObserver);

		_observable.send(message);
		verify(mockObserver);

		_observable.unsubscribe(subscription);
		assertEquals(0, _observable.getObserverCount());

		_observable.send(message);

	}

	/**
	 * Subscribes many susbcribers and sends notifications to subscribers.
	 * Verifies that unique subscription number are returned. Also verifies that
	 * the correct subscribers are notfied.
	 */
	public void testManySubscribers() {
		final int nsubscribers = SUBSCRIBER_COUNT;
		final Observer[] mocks = new Observer[nsubscribers];

		IMocksControl control = createControl();

		List<Long> subscriptions = new ArrayList<Long>();
		for (int i = 0; i < nsubscribers; i++) {
			mocks[i] = control.createMock("mock" + i, Observer.class);
			long subscription = _observable.subscribe(mocks[i]);
			assertTrue(subscriptions.add(subscription));
		}

		assertEquals(nsubscribers, _observable.getObserverCount());

		final String message = "hallo";

		for (int i = 0; i < nsubscribers; i++) {
			mocks[i].send(_observed, message);
		}
		control.replay();

		_observable.send(message);
		control.verify();

		for (int i = nsubscribers / 2; i < nsubscribers; i++) {
			_observable.unsubscribe(subscriptions.get(i));
		}
		assertEquals(nsubscribers - (nsubscribers - nsubscribers / 2),
				_observable.getObserverCount());

		control.reset();
		final String message2 = "blabla";

		for (int i = 0; i < nsubscribers / 2; i++) {
			mocks[i].send(_observed, message2);
		}
		control.replay();

		_observable.send(message2);
		control.verify();
	}

	/**
	 * Subscribes and then unsubscribes with a wrong id. Verifies that
	 * IllegalArgumentException is thrown.
	 * 
	 */
	public void testUnsubscribeWithWrongSubscription() {
		Observer<Integer, String> observer = createMock(Observer.class);
		replay(observer);
		
		long subscription = _observable.subscribe(observer);

		assertEquals(1, _observable.getObserverCount());

		try {
			_observable.unsubscribe(subscription + 1);
		} catch (IllegalArgumentException e) {
			return; // ok
		}
		fail();
	}
}