/*
 * $Id$
 *
 * 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.struts2.spring;

import javax.servlet.ServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.StrutsConstants;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.spring.SpringObjectFactory;



/**
 * Struts object factory that integrates with Spring.
 * <p/>
 * Spring should be loaded using a web context listener
 * <code>org.springframework.web.context.ContextLoaderListener</code> defined in <code>web.xml</code>.
 *
 */
public class StrutsSpringObjectFactory extends SpringObjectFactory {
    private static final Log log = LogFactory.getLog(StrutsSpringObjectFactory.class);
    
    private String autoWire;
    private boolean useClassCache = true;
    
    @Inject(value=StrutsConstants.STRUTS_OBJECTFACTORY_SPRING_AUTOWIRE,required=false)
    public void setAutoWire(String val) {
        autoWire = val;
    }
    
    @Inject(value=StrutsConstants.STRUTS_OBJECTFACTORY_SPRING_USE_CLASS_CACHE,required=false)
    public void setUseClassCache(String val) {
        useClassCache = "true".equals(val);
    }
    
    @Inject
    public void setServletContext(ServletContext servletContext) {
        log.info("Initializing Struts-Spring integration...");

        ApplicationContext appContext = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        if (appContext == null) {
            // uh oh! looks like the lifecycle listener wasn't installed. Let's inform the user
            String message = "********** FATAL ERROR STARTING UP SPRING-STRUTS INTEGRATION **********\n" +
                    "Looks like the Spring listener was not configured for your web app! \n" +
                    "Nothing will work until WebApplicationContextUtils returns a valid ApplicationContext.\n" +
                    "You might need to add the following to web.xml: \n" +
                    "    <listener>\n" +
                    "        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>\n" +
                    "    </listener>";
            log.fatal(message);
            return;
        }

        this.setApplicationContext(appContext);

        int type = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;   // default
        if ("name".equals(autoWire)) {
            type = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;
        } else if ("type".equals(autoWire)) {
            type = AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE;
        } else if ("auto".equals(autoWire)) {
            type = AutowireCapableBeanFactory.AUTOWIRE_AUTODETECT;
        } else if ("constructor".equals(autoWire)) {
            type = AutowireCapableBeanFactory.AUTOWIRE_CONSTRUCTOR;
        }
        this.setAutowireStrategy(type);

        this.setUseClassCache(useClassCache);

        log.info("... initialized Struts-Spring integration successfully");
    }
}
