/*
 * #%L
 * BroadleafCommerce Common Libraries
 * %%
 * Copyright (C) 2009 - 2013 Broadleaf Commerce
 * %%
 * 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.
 * #L%
 */
package org.broadleafcommerce.common.extensibility.jpa.copy;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;

import java.lang.instrument.IllegalClassFormatException;
import java.security.ProtectionDomain;

/**
 * Based on a Spring property value resolving to a boolean, this ClassTransformer will optionally perform
 * bytecode transformations.
 *
 * @author Jeff Fischer
 */
public class OptionalDirectCopyClassTransformer extends DirectCopyClassTransformer implements BeanFactoryAware {

    protected String propertyName;
    protected ConfigurableBeanFactory beanFactory;

    public OptionalDirectCopyClassTransformer(String moduleName) {
        super(moduleName);
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        this.beanFactory = (ConfigurableBeanFactory) beanFactory;
    }

    /**
     * Will return null if the Spring property value defined in {@link #propertyName} resolves to false, or if
     * an exception occurs while trying to determine the value for the property.
     *
     * @param loader
     * @param className
     * @param classBeingRedefined
     * @param protectionDomain
     * @param classfileBuffer
     * @return
     * @throws IllegalClassFormatException
     */
    @Override
    public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined,
            ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {

        Boolean shouldProceed;
        try {
            String value = beanFactory.resolveEmbeddedValue("${" + propertyName + ":false}");
            shouldProceed = Boolean.parseBoolean(value);
        } catch (Exception e) {
            shouldProceed = false;
        }
        if (!shouldProceed) {
            return null;
        }

        return super.transform(loader, className, classBeingRedefined, protectionDomain, classfileBuffer);
    }

    public String getPropertyName() {
        return propertyName;
    }

    public void setPropertyName(String propertyName) {
        this.propertyName = propertyName;
    }
}