/*
 * Copyright 2007 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.system.spring;

import org.springframework.beans.factory.FactoryBean;
import org.wamblee.system.core.ProvidedInterface;
import org.wamblee.system.core.RequiredInterface;
import org.wamblee.system.core.SystemAssemblyException;

/**
 * Bean which adds a service required by the spring component to 
 * the application context so that other spring beans can use it.  
 *  
 * @author Erik Brakkee
 */
class RequiredServiceBean implements FactoryBean {
	
	private RequiredInterface _required; 
	
	/**
	 * Constructs the bean. 
	 * @param aId Id of the bean in the service registry.  
	 */
	public RequiredServiceBean(String aId) { 
		RequiredInterface[] required = SpringComponent.THIS.get().getRequiredServices();
		for ( RequiredInterface intf: required) { 
			if ( intf.getName().equals(aId)) { 
				_required = intf; 
				return;
			}
		}
		throw new SystemAssemblyException("Cannot resolve provided component '" + aId + "'");
	}

	@Override
	public Object getObject() throws Exception {
		return _required.getImplementation(Object.class);
	}

	@Override
	public Class getObjectType() {
		return null;
	}

	@Override
	public boolean isSingleton() {
		return true; 
	}

}