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/*
 * 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,
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package com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

Iterators of this kind use a CurrentNodeListFilter to filter a subset of
nodes from a source iterator. For each node from the source, the boolean
method CurrentNodeListFilter.test() is called.
All nodes from the source are read into an array upon calling setStartNode()
(this is needed to determine the value of last, a parameter to
CurrentNodeListFilter.test()). The method getLast() returns the last element
after applying the filter.
Author:
Jacek Ambroziak, Santiago Pericas-Geertsen, Morten Jorgensen/**
 * Iterators of this kind use a CurrentNodeListFilter to filter a subset of
 * nodes from a source iterator. For each node from the source, the boolean
 * method CurrentNodeListFilter.test() is called.
 *
 * All nodes from the source are read into an array upon calling setStartNode()
 * (this is needed to determine the value of last, a parameter to
 * CurrentNodeListFilter.test()). The method getLast() returns the last element
 * after applying the filter.
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */

public final class CurrentNodeListIterator extends DTMAxisIteratorBase {
    
A flag indicating if nodes are returned in document order.
/**
     * A flag indicating if nodes are returned in document order.
     */
    private boolean _docOrder;

    
The source for this iterator.
/**
     * The source for this iterator.
     */
    private DTMAxisIterator _source;

    
A reference to a filter object.
/**
     * A reference to a filter object.
     */
    private final CurrentNodeListFilter _filter;

    
An integer array to store nodes from source iterator.
/**
     * An integer array to store nodes from source iterator.
     */
    private IntegerArray _nodes = new IntegerArray();

    
Index in _nodes of the next node to filter.
/**
     * Index in _nodes of the next node to filter.
     */
    private int _currentIndex;

    
The current node in the stylesheet at the time of evaluation.
/**
     * The current node in the stylesheet at the time of evaluation.
     */
    private final int _currentNode;

    
A reference to the translet.
/**
     * A reference to the translet.
     */
    private AbstractTranslet _translet;

    public CurrentNodeListIterator(DTMAxisIterator source,
                                   CurrentNodeListFilter filter,
                                   int currentNode,
                                   AbstractTranslet translet)
    {
        this(source, !source.isReverse(), filter, currentNode, translet);
    }

    public CurrentNodeListIterator(DTMAxisIterator source, boolean docOrder,
                                   CurrentNodeListFilter filter,
                                   int currentNode,
                                   AbstractTranslet translet)
    {
        _source = source;
        _filter = filter;
        _translet = translet;
        _docOrder = docOrder;
        _currentNode = currentNode;
    }

    public DTMAxisIterator forceNaturalOrder() {
        _docOrder = true;
        return this;
    }

    public void setRestartable(boolean isRestartable) {
        _isRestartable = isRestartable;
        _source.setRestartable(isRestartable);
    }

    public boolean isReverse() {
        return !_docOrder;
    }

    public DTMAxisIterator cloneIterator() {
        try {
            final CurrentNodeListIterator clone =
                (CurrentNodeListIterator) super.clone();
            clone._nodes = (IntegerArray) _nodes.clone();
            clone._source = _source.cloneIterator();
            clone._isRestartable = false;
            return clone.reset();
        }
        catch (CloneNotSupportedException e) {
            BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
                                      e.toString());
            return null;
        }
    }

    public DTMAxisIterator reset() {
        _currentIndex = 0;
        return resetPosition();
    }

    public int next() {
        final int last = _nodes.cardinality();
        final int currentNode = _currentNode;
        final AbstractTranslet translet = _translet;

        for (int index = _currentIndex; index < last; ) {
            final int position = _docOrder ? index + 1 : last - index;
            final int node = _nodes.at(index++);        // note increment

            if (_filter.test(node, position, last, currentNode, translet,
                             this)) {
                _currentIndex = index;
                return returnNode(node);
            }
        }
        return END;
    }

    public DTMAxisIterator setStartNode(int node) {
        if (_isRestartable) {
            _source.setStartNode(_startNode = node);

            _nodes.clear();
            while ((node = _source.next()) != END) {
                _nodes.add(node);
            }
            _currentIndex = 0;
            resetPosition();
        }
        return this;
    }

    public int getLast() {
        if (_last == -1) {
            _last = computePositionOfLast();
        }
        return _last;
    }

    public void setMark() {
        _markedNode = _currentIndex;
    }

    public void gotoMark() {
        _currentIndex = _markedNode;
    }

    private int computePositionOfLast() {
        final int last = _nodes.cardinality();
        final int currNode = _currentNode;
        final AbstractTranslet translet = _translet;

        int lastPosition = _position;
        for (int index = _currentIndex; index < last; ) {
            final int position = _docOrder ? index + 1 : last - index;
            int nodeIndex = _nodes.at(index++);         // note increment

            if (_filter.test(nodeIndex, position, last, currNode, translet,
                             this)) {
                lastPosition++;
            }
        }
        return lastPosition;
    }
}