/**
 *  Copyright 2005-2015 Red Hat, Inc.
 *
 *  Red Hat 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 io.fabric8.commands.support;

import io.fabric8.api.FabricRequirements;
import io.fabric8.api.FabricService;
import org.apache.karaf.shell.console.AbstractAction;

/**
 */
public abstract class ChangeRequirementSupport extends AbstractAction {

    private final FabricService fabricService;

    public ChangeRequirementSupport(FabricService fabricService) {
        this.fabricService = fabricService;
    }

    public FabricService getFabricService() {
        return fabricService;
    }

    @Override
    protected Object doExecute() throws Exception {
        FabricRequirements requirements = getFabricService().getRequirements();
        if (requirements == null) {
            requirements = new FabricRequirements();
        }
        if (updateRequirements(requirements)) {
            getFabricService().setRequirements(requirements);
        }
        return null;
    }

    /**
     * Performs the updates on the requirements, returning true if the requirements are updated.
     */
    protected abstract boolean updateRequirements(FabricRequirements requirements);
}
