/*
 * 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.RequiredInterface;
import org.wamblee.system.core.SystemAssemblyException;

import java.util.List;


/**
 * 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 {
    /**
     * DOCUMENT ME!
     */
    private RequiredInterface _required;

/**
         * Constructs the bean. 
         * @param aId Id of the bean in the service registry.  
         */
    public RequiredServiceBean(String aId) {
        List<RequiredInterface> required = SpringComponent.THIS.get()
            .getRequiredInterfaces();

        for (RequiredInterface intf : required) {
            if (intf.getName().equals(aId)) {
                _required = intf;

                return;
            }
        }

        throw new SystemAssemblyException("Cannot resolve required component '"
            + aId + "'");
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws Exception DOCUMENT ME!
     */
    @Override
    public Object getObject() throws Exception {
        return SpringComponent.SCOPE.get()
        .getInterfaceImplementation(_required.getProvider(), Object.class);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    @Override
    public Class getObjectType() {
        return null;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    @Override
    public boolean isSingleton() {
        return true;
    }
}