/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.as.server.deployment.module;

import org.jboss.as.server.deployment.Attachments;
import org.jboss.as.server.deployment.DeploymentPhaseContext;
import org.jboss.as.server.deployment.DeploymentUnit;
import org.jboss.as.server.deployment.DeploymentUnitProcessingException;
import org.jboss.as.server.deployment.DeploymentUnitProcessor;
import org.jboss.modules.Module;

import java.lang.instrument.ClassFileTransformer;

/**
 * A {@link DeploymentUnitProcessor} that instantiates {@link ClassFileTransformer}s defined in the
 * <code>jboss-deployment-structure.xml</code> file.
 *
 * @author Marius Bogoevici
 */
public class ClassFileTransformerProcessor implements DeploymentUnitProcessor {

    @Override
    public void deploy(DeploymentPhaseContext phaseContext) throws DeploymentUnitProcessingException {
        try {
            DeploymentUnit deploymentUnit = phaseContext.getDeploymentUnit();
            DelegatingClassFileTransformer transformer = deploymentUnit.getAttachment(DelegatingClassFileTransformer.ATTACHMENT_KEY);
            // some modules do not install a transformer (e.g. OSGi)
            if (transformer != null) {
                Module module = deploymentUnit.getAttachment(Attachments.MODULE);
                ModuleSpecification moduleSpecification = deploymentUnit.getAttachment(Attachments.MODULE_SPECIFICATION);
                for (String transformerClassName : moduleSpecification.getClassFileTransformers()) {
                    transformer.addTransformer((ClassFileTransformer) module.getClassLoader().loadClass(transformerClassName).newInstance());
                }
                // activate transformer only after all delegate transformers have been added
                // so that transformers themselves are not instrumented
                transformer.setActive(true);
            }
        } catch (Exception e) {
            throw new DeploymentUnitProcessingException("Failed to instantiate a ClassFileTransformer: ", e);
        }
    }

    @Override
    public void undeploy(DeploymentUnit context) {
    }
}
