/*******************************************************************************
 * Copyright (c) 2008 Standards for Technology in Automotive Retail
 * 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
 *
 * Contributors:
 *     David Carver - STAR - bug 224197 - initial API and implementation
 *                    based on work from Apache Xalan 2.7.0
 *******************************************************************************/
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed 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.
 */
/*
 * $Id: KeyManager.java,v 1.2 2008/03/28 02:38:16 dacarver Exp $
 */
package org.eclipse.wst.xsl.core.internal.compiler.xslt10.transformer;

import java.util.Vector;

import org.apache.xalan.templates.ElemTemplateElement;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xml.utils.QName;
import org.apache.xml.utils.XMLString;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XNodeSet;

/**
 * This class manages the key tables.
 */
public class KeyManager {

	/**
	 * Table of tables of element keys.
	 * 
	 * @see org.apache.xalan.transformer.KeyTable
	 */
	private transient Vector m_key_tables = null;

	/**
	 * Given a valid element key, return the corresponding node list.
	 * 
	 * @param xctxt
	 *            The XPath runtime state
	 * @param doc
	 *            The document node
	 * @param name
	 *            The key element name
	 * @param ref
	 *            The key value we're looking for
	 * @param nscontext
	 *            The prefix resolver for the execution context
	 * 
	 * @return A nodelist of nodes mathing the given key
	 * 
	 * @throws javax.xml.transform.TransformerException
	 */
	public XNodeSet getNodeSetDTMByKey(XPathContext xctxt, int doc, QName name,
			XMLString ref, PrefixResolver nscontext)
			throws javax.xml.transform.TransformerException {

		XNodeSet nl = null;
		ElemTemplateElement template = (ElemTemplateElement) nscontext; // yuck
																		// -sb

		if ((null != template)
				&& null != template.getStylesheetRoot().getKeysComposed()) {
			boolean foundDoc = false;

			if (null == m_key_tables) {
				m_key_tables = new Vector(4);
			} else {
				int nKeyTables = m_key_tables.size();

				for (int i = 0; i < nKeyTables; i++) {
					KeyTable kt = (KeyTable) m_key_tables.elementAt(i);

					if (kt.getKeyTableName().equals(name)
							&& doc == kt.getDocKey()) {
						nl = kt.getNodeSetDTMByKey(name, ref);

						if (nl != null) {
							foundDoc = true;

							break;
						}
					}
				}
			}

			if ((null == nl) && !foundDoc /* && m_needToBuildKeysTable */) {
				KeyTable kt = new KeyTable(doc, nscontext, name, template
						.getStylesheetRoot().getKeysComposed(), xctxt);

				m_key_tables.addElement(kt);

				if (doc == kt.getDocKey()) {
					foundDoc = true;
					nl = kt.getNodeSetDTMByKey(name, ref);
				}
			}
		}

		return nl;
	}
}