/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF 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 groovy.xml.slurpersupport;

import java.util.Iterator;
import java.util.Map;

/**
* Lazy evaluated representation of parent nodes without duplicates
*/
public class NodeParents extends NodeChildren {

    /**
     * @param parent the GPathResult prior to the application of the expression creating this GPathResult
     * @param namespaceTagHints the known tag to namespace mappings
     */
    public NodeParents(final GPathResult parent, final Map<String, String> namespaceTagHints) {
        super(parent, parent.parent.name, namespaceTagHints);
    }

    /** {@inheritDoc} */
    @Override
    public Iterator nodeIterator() {
        return new NodeIterator(this.parent.nodeIterator()) {

            private Node prev = null;

            @Override
            protected Object getNextNode(final Iterator iter) {
                while (iter.hasNext()) {
                    final Node node = ((Node)iter.next()).parent();
                    if (node != null && node != prev) {
                        prev = node;
                        return node;
                    }
                }
                return null;
            }
        };
    }

}
