/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.tools.ant.taskdefs.optional.ejb;

import java.io.File;
import java.io.FileInputStream;
import java.io.ObjectInputStream;

import javax.ejb.deployment.DeploymentDescriptor;

/**
 * A helper class which performs the actual work of the ddcreator task.
 *
 * This class is run with a classpath which includes the weblogic tools and the home and remote
 * interface class files referenced in the deployment descriptors being built.
 *
 * @author <a href="mailto:conor@cortexebusiness.com.au">Conor MacNeill</a>, Cortex ebusiness Pty Limited
 */
public class DDCreatorHelper {
    /**
     * The root directory of the tree containing the textual deployment desciptors. 
     */
    private File descriptorDirectory;
    
    /**
     * The directory where generated serialised desployment descriptors are written.
     */
    private File generatedFilesDirectory;

    /**
     * The descriptor text files for which a serialised descriptor is to be created.
     */
    String[] descriptors; 

    /**
     * The main method.
     *
     * The main method creates an instance of the DDCreatorHelper, passing it the 
     * args which it then processes.
     */    
    public static void main(String[] args) throws Exception {
        DDCreatorHelper helper = new DDCreatorHelper(args);
        helper.process();
    }
  
    /**
     * Initialise the helper with the command arguments.
     *
     */
    private DDCreatorHelper(String[] args) {
        int index = 0;
        descriptorDirectory = new File(args[index++]);
        generatedFilesDirectory = new File(args[index++]);
        
        descriptors = new String[args.length - index];
        for (int i = 0; index < args.length; ++i) {
            descriptors[i] = args[index++];
        }
    }
    
    /**
     * Do the actual work.
     *
     * The work proceeds by examining each descriptor given. If the serialised
     * file does not exist or is older than the text description, the weblogic
     * DDCreator tool is invoked directly to build the serialised descriptor.
     */    
    private void process() throws Exception {
        for (int i = 0; i < descriptors.length; ++i) {
            String descriptorName = descriptors[i];
            File descriptorFile = new File(descriptorDirectory, descriptorName);

            int extIndex = descriptorName.lastIndexOf(".");
            String serName = null;
            if (extIndex != -1) {
                serName = descriptorName.substring(0, extIndex) + ".ser";
            }
            else {
                serName = descriptorName + ".ser";
            }
            File serFile = new File(generatedFilesDirectory, serName);
                
            // do we need to regenerate the file
            if (!serFile.exists() || serFile.lastModified() < descriptorFile.lastModified()
                || regenerateSerializedFile(serFile)) {
                
                String[] args = {"-noexit", 
                                 "-d", serFile.getParent(),
                                 "-outputfile", serFile.getName(),
                                 descriptorFile.getPath()};
                try {
                    weblogic.ejb.utils.DDCreator.main(args);
                }
                catch (Exception e) {
                    // there was an exception - run with no exit to get proper error
                    String[] newArgs = {"-d", generatedFilesDirectory.getPath(),
                                 "-outputfile", serFile.getName(),
                                 descriptorFile.getPath()};
                    weblogic.ejb.utils.DDCreator.main(newArgs);
                }
            }
        }
    }

    /**
     * EJBC will fail if the serialized descriptor file does not match the bean classes.
     * You can test for this by trying to load the deployment descriptor.  If it fails,
     * the serialized file needs to be regenerated because the associated class files
     * don't match.
     */
    private boolean regenerateSerializedFile(File serFile) {
        try {

            FileInputStream fis = new FileInputStream(serFile);
            ObjectInputStream ois = new ObjectInputStream(fis);
            DeploymentDescriptor dd = (DeploymentDescriptor) ois.readObject();
            fis.close();

            // Since the descriptor read properly, everything should be o.k.
            return false;

        } catch (Exception e) {
            
            // Weblogic will throw an error if the deployment descriptor does 
            // not match the class files.
            return true;

        }
    }
}