/*****************************************************************************
 * Copyright (C) PicoContainer Organization. All rights reserved.            *
 * ------------------------------------------------------------------------- *
 * The software in this package is published under the terms of the BSD      *
 * style license a copy of which has been included with this distribution in *
 * the LICENSE.txt file.                                                     *
 *                                                                           *
 * Original code by                                                          *
 *****************************************************************************/
package org.picocontainer.adapters;

import org.picocontainer.Behavior;
import org.picocontainer.PicoContainer;
import org.picocontainer.LifecycleStrategy;
import org.picocontainer.ComponentMonitor;
import org.picocontainer.PicoCompositionException;
import org.picocontainer.adapters.AbstractAdapter;

/**
 * <p>
 * Component adapter which wraps a component instance.
 * </p>
 * <p>
 * This component adapter supports both a {@link Behavior Behavior} and a
 * {@link org.picocontainer.LifecycleStrategy LifecycleStrategy} to control the lifecycle of the component.
 * The lifecycle manager methods simply delegate to the lifecycle strategy methods 
 * on the component instance.
 * </p>
 * 
 * @author Aslak Hellesøy
 * @author Paul Hammant
 * @author Mauro Talevi
 * @version $Revision: 3633 $
 */
public final class InstanceAdapter extends AbstractAdapter implements Behavior, LifecycleStrategy {
    private final Object componentInstance;
    private final LifecycleStrategy lifecycleStrategy;

    public InstanceAdapter(Object componentKey, Object componentInstance, LifecycleStrategy lifecycleStrategy, ComponentMonitor componentMonitor) throws PicoCompositionException {
        super(componentKey, getInstanceClass(componentInstance), componentMonitor);
        this.componentInstance = componentInstance;
        this.lifecycleStrategy = lifecycleStrategy;
    }

    private static Class getInstanceClass(Object componentInstance) {
        if (componentInstance == null) {
            throw new NullPointerException("componentInstance cannot be null");
        }
        return componentInstance.getClass();
    }

    public Object getComponentInstance(PicoContainer container) {
        return componentInstance;
    }
    
    public void verify(PicoContainer container) {
    }

    public void start(PicoContainer container) {
        start(componentInstance);
    }

    public void stop(PicoContainer container) {
        stop(componentInstance);
    }

    public void dispose(PicoContainer container) {
        dispose(componentInstance);
    }

    public boolean componentHasLifecycle() {
        return hasLifecycle(componentInstance.getClass());
    }

    // ~~~~~~~~ LifecycleStrategy ~~~~~~~~
    
    public void start(Object component) {
        lifecycleStrategy.start(componentInstance);
    }

    public void stop(Object component) {
        lifecycleStrategy.stop(componentInstance);
    }

    public void dispose(Object component) {
        lifecycleStrategy.dispose(componentInstance);
    }

    public boolean hasLifecycle(Class type) {
        return lifecycleStrategy.hasLifecycle(type);
    }

}