/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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 com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;

import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;

import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

/**

 * @author Jacek Ambroziak

 * @author Morten Jorgensen

 */

public final class NthIterator extends DTMAxisIteratorBase {

    // ...[N]

    private DTMAxisIterator _source;

    private final int _position;

    private boolean _ready;

    public NthIterator(DTMAxisIterator source, int n) {

        _source = source;

        _position = n;

    }

    public void setRestartable(boolean isRestartable) {

        _isRestartable = isRestartable;

        _source.setRestartable(isRestartable);

    }

    public DTMAxisIterator cloneIterator() {

        try {

            final NthIterator clone = (NthIterator) super.clone();

            clone._source = _source.cloneIterator();    // resets source

            clone._isRestartable = false;

            return clone;

        }

        catch (CloneNotSupportedException e) {

            BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,

                                      e.toString());

            return null;

        }

    }

    public int next() {

        if (_ready) {

            _ready = false;

            return _source.getNodeByPosition(_position);

        }

        return DTMAxisIterator.END;

        /*

        if (_ready && _position > 0) {

            final int pos = _source.isReverse()

                                       ? _source.getLast() - _position + 1

                                       : _position;

            _ready = false;

            int node;

            while ((node = _source.next()) != DTMAxisIterator.END) {

                if (pos == _source.getPosition()) {

                    return node;

                }

            }

        }

        return DTMAxisIterator.END;

        */

    }

    public DTMAxisIterator setStartNode(final int node) {

        if (_isRestartable) {

            _source.setStartNode(node);

            _ready = true;

        }

        return this;

    }

    public DTMAxisIterator reset() {

        _source.reset();

        _ready = true;

        return this;

    }

    public int getLast() {

        return 1;

    }

    public int getPosition() {

        return 1;

    }

    public void setMark() {

        _source.setMark();

    }

    public void gotoMark() {

        _source.gotoMark();

    }

}