/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2016, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file 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.clustering.controller;

import java.util.Optional;

import org.jboss.as.controller.OperationContext;
import org.jboss.as.controller.OperationFailedException;
import org.jboss.as.controller.OperationStepHandler;
import org.jboss.as.controller.PathAddress;
import org.jboss.dmr.ModelNode;

/**
 * A read-attribute operation handler that translates a value from another attribute
 * @author Paul Ferraro
 */
public class ReadAttributeTranslationHandler implements OperationStepHandler {

    private final Attribute targetAttribute;
    private final AttributeValueTranslator translator;

    public ReadAttributeTranslationHandler(AttributeTranslation translation) {
        this(translation.getTargetAttribute(), translation.getReadTranslator());
    }

    public ReadAttributeTranslationHandler(Attribute targetAttribute, AttributeValueTranslator translator) {
        this.targetAttribute = targetAttribute;
        this.translator = translator;
    }

    @Override
    public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {
        ModelNode targetOperation = Operations.createReadAttributeOperation(context.getCurrentAddress(), this.targetAttribute);
        String targetName = this.targetAttribute.getName();
        // If attribute has no read handler, synthesize one
        Optional.ofNullable(context.getResourceRegistration().getAttributeAccess(PathAddress.EMPTY_ADDRESS, targetName).getReadHandler()).orElse((ctx, op) -> {
            ModelNode model = ctx.readResource(PathAddress.EMPTY_ADDRESS).getModel();
            ModelNode result = ctx.getResult();
            if (model.hasDefined(targetName)) {
                result.set(model.get(targetName));
            } else if (Operations.isIncludeDefaults(op)) {
                result.set(this.targetAttribute.getDefinition().getDefaultValue());
            }
        }).execute(context, targetOperation);
        ModelNode result = context.getResult();
        result.set(this.translator.translate(context, result));
    }
}