/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.apache.cxf.bus;

import java.util.Collection;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.cxf.Bus;
import org.apache.cxf.BusFactory;
import org.apache.cxf.buslifecycle.BusLifeCycleManager;
import org.apache.cxf.feature.AbstractFeature;
import org.apache.cxf.interceptor.AbstractBasicInterceptorProvider;

public class CXFBusImpl extends AbstractBasicInterceptorProvider implements Bus {    
    
    protected final Map<Class, Object> extensions;
    private String id;
    private BusState state;      
    private Collection<AbstractFeature> features;
    private ExtensionFinder finder;
    
    public CXFBusImpl() {
        this(null);
    }

    public CXFBusImpl(Map<Class, Object> extensions) {
        if (extensions == null) {
            extensions = new ConcurrentHashMap<Class, Object>();
        } else {
            extensions = new ConcurrentHashMap<Class, Object>(extensions);
        }
        this.extensions = extensions;
        
        state = BusState.INITIAL;
        
        CXFBusFactory.possiblySetDefaultBus(this);
    }

    protected void setState(BusState state) {
        this.state = state;
    }
    
    public void setExtensionFinder(ExtensionFinder f) {
        finder = f;
    }
    
    public void setId(String i) {
        id = i;
    }

    public final <T> T getExtension(Class<T> extensionType) {
        Object obj = extensions.get(extensionType);
        if (obj == null && finder != null) {
            obj = finder.findExtension(extensionType);
        }
        if (null != obj) {
            return extensionType.cast(obj);
        }
        return null;
    }
    
    public <T> void setExtension(T extension, Class<T> extensionType) {
        extensions.put(extensionType, extension);
    }
     
    public String getId() {        
        return null == id ? DEFAULT_BUS_ID + Integer.toString(this.hashCode()) : id;
    }

    public void run() {
        synchronized (this) {
            if (state == BusState.RUNNING) {
                // REVISIT
                return;
            }
            state = BusState.RUNNING;

            while (state == BusState.RUNNING) {

                try {
                    wait();
                } catch (InterruptedException ex) {
                    // ignore;
                }
            }
        }
    }

    public void initialize() {
        initializeFeatures();
    }

    private void initializeFeatures() {
        if (features != null) {
            for (AbstractFeature f : features) {
                f.initialize(this);
            }
        }
    }

    public void shutdown(boolean wait) {
        BusLifeCycleManager lifeCycleManager = this.getExtension(BusLifeCycleManager.class);
        if (null != lifeCycleManager) {
            lifeCycleManager.preShutdown();
        }
        synchronized (this) {
            state = BusState.SHUTDOWN;
            notifyAll();
        }
        if (null != lifeCycleManager) {
            lifeCycleManager.postShutdown();
        }
        if (BusFactory.getDefaultBus(false) == this) { 
            BusFactory.setDefaultBus(null);
        }
    }

    protected BusState getState() {
        return state;
    }

    public Collection<AbstractFeature> getFeatures() {
        return features;
    }

    public synchronized void setFeatures(Collection<AbstractFeature> features) {
        this.features = features;
        
        if (state == BusState.RUNNING) {
            initializeFeatures();
        }
    }
    
    public interface ExtensionFinder {
        <T> T findExtension(Class<T> cls);
    }
}
