/*
 * Copyright (c) 2015, 2017 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.controller.config.facade.xml.mapping.attributes.toxml;

import com.google.common.base.Preconditions;
import java.util.List;
import java.util.Map;
import org.opendaylight.controller.config.facade.xml.util.Util;
import org.w3c.dom.Document;

public class SimpleUnionAttributeWritingStrategy extends SimpleAttributeWritingStrategy {

    public SimpleUnionAttributeWritingStrategy(final Document document, final String key) {
        super(document, key);
    }

    @Override
    protected Object preprocess(final Object value) {
        Util.checkType(value, Map.class);
        Preconditions.checkArgument(((Map<?, ?>) value).size() == 1, "Unexpected number of values in %s, expected 1",
                value);
        Object listOfStrings = ((Map<?, ?>) value).values().iterator().next();
        Util.checkType(listOfStrings, List.class);

        StringBuilder builder = new StringBuilder();
        for (Object character : (List<?>) listOfStrings) {
            Util.checkType(character, String.class);
            builder.append(character);
        }
        return builder.toString();
    }
}