/*
 * 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 java.util.ArrayList;
import java.util.List;

import org.jmock.Mock;
import org.jmock.cglib.MockObjectTestCase;

/**
 * Test of the observer pattern implementation. 
 */
public class ObservableTest extends MockObjectTestCase {
    
    private static final String UPDATE = "send";
    

    private Observable<ObservableTest, String> _observable; 
  
    /* (non-Javadoc)
     * @see junit.framework.TestCase#setUp()
     */
    @Override
    protected void setUp() throws Exception {
        super.setUp();
        
        _observable = new Observable<ObservableTest, String>(this, new DefaultObserverNotifier());
    }
    
    /**
     * Tests subscription and notification of one subscriber.
     */
    public void testOneObserver() { 
        Mock mockObserver = mock(Observer.class);
        Observer<ObservableTest,String> observer = (Observer<ObservableTest,String>)mockObserver.proxy();        
        long subscription = _observable.subscribe(observer);
        
        assertEquals(1, _observable.getObserverCount()); 
        
        String message = "hallo";
        mockObserver.expects(once()).method(UPDATE).with(same(this), eq(message)); 
       
        _observable.send(message);
        _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() { 
        int nsubscribers = 100; 
        Mock[] mocks = new Mock[nsubscribers];
 
        List<Long> subscriptions = new ArrayList<Long>();
        for (int i = 0; i < nsubscribers; i++) { 
            Mock mockObserver = mock(Observer.class);
            Observer<ObservableTest,String> observer = (Observer<ObservableTest,String>)mockObserver.proxy();        
            long subscription = _observable.subscribe(observer);
            
            mocks[i] = mockObserver;
            assertTrue( subscriptions.add(subscription));  
        }
        
        assertEquals(nsubscribers, _observable.getObserverCount());
       
        String message = "hallo";
        for (int i = 0; i < nsubscribers; i++) { 
           mocks[i].expects(once()).method(UPDATE).with(same(this), eq(message));
        }
        
        _observable.send(message);
       
        for (int i = nsubscribers/2; i < nsubscribers; i++) { 
            _observable.unsubscribe(subscriptions.get(i));    
        }
        assertEquals(nsubscribers - ( nsubscribers - nsubscribers/2), _observable.getObserverCount());
     
        message = "blabla"; 
        for (int i = 0; i < nsubscribers/2; i++) { 
            mocks[i].expects(once()).method(UPDATE).with(same(this), eq(message));
        }
        _observable.send(message);
    }

}