/*******************************************************************************
 * Copyright (c) 2007 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: XSLProcessorContext.java,v 1.2 2008/03/28 02:38:18 dacarver Exp $
 */
package org.eclipse.wst.xsl.core.internal.compiler.xslt10.extensions;

import javax.xml.transform.TransformerException;

import org.eclipse.wst.xsl.core.internal.compiler.xslt10.templates.Stylesheet;
import org.eclipse.wst.xsl.core.internal.compiler.xslt10.transformer.ClonerToResultTree;
import org.eclipse.wst.xsl.core.internal.compiler.xslt10.transformer.TransformerImpl;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMAxisIterator;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xalan.serialize.SerializerUtils;
import org.apache.xml.serializer.SerializationHandler;
import org.apache.xml.utils.QName;
import org.apache.xpath.XPathContext;
import org.apache.xpath.axes.DescendantIterator;
import org.apache.xpath.axes.OneStepIterator;
import org.apache.xpath.objects.XBoolean;
import org.apache.xpath.objects.XNodeSet;
import org.apache.xpath.objects.XNumber;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XRTreeFrag;
import org.apache.xpath.objects.XString;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.traversal.NodeIterator;

// import org.apache.xalan.xslt.*;

/**
 * Provides transformer context to be passed to an extension element.
 * 
 * @author Sanjiva Weerawarana (sanjiva@watson.ibm.com)
 * @xsl.usage general
 */
public class XSLProcessorContext {

	/**
	 * Create a processor context to be passed to an extension. (Notice it is a
	 * package-only constructor).
	 * 
	 * @param transformer
	 *            non-null transformer instance
	 * @param stylesheetTree
	 *            The owning stylesheet
	 */
	public XSLProcessorContext(TransformerImpl transformer,
			Stylesheet stylesheetTree) {

		this.transformer = transformer;
		this.stylesheetTree = stylesheetTree;
		// %TBD%
		org.apache.xpath.XPathContext xctxt = transformer.getXPathContext();
		this.mode = transformer.getMode();
		this.sourceNode = xctxt.getCurrentNode();
		this.sourceTree = xctxt.getDTM(this.sourceNode);
	}

	/** An instance of a transformer */
	private TransformerImpl transformer;

	/**
	 * Get the transformer.
	 * 
	 * @return the transformer instance for this context
	 */
	public TransformerImpl getTransformer() {
		return transformer;
	}

	/** The owning stylesheet for this context */
	private Stylesheet stylesheetTree;

	/**
	 * Get the Stylesheet being executed.
	 * 
	 * @return the Stylesheet being executed.
	 */
	public Stylesheet getStylesheet() {
		return stylesheetTree;
	}

	/** The root of the source tree being executed. */
	private org.apache.xml.dtm.DTM sourceTree;

	/**
	 * Get the root of the source tree being executed.
	 * 
	 * @return the root of the source tree being executed.
	 */
	public org.w3c.dom.Node getSourceTree() {
		return sourceTree.getNode(sourceTree.getDocumentRoot(sourceNode));
	}

	/** the current context node. */
	private int sourceNode;

	/**
	 * Get the current context node.
	 * 
	 * @return the current context node.
	 */
	public org.w3c.dom.Node getContextNode() {
		return sourceTree.getNode(sourceNode);
	}

	/** the current mode being executed. */
	private QName mode;

	/**
	 * Get the current mode being executed.
	 * 
	 * @return the current mode being executed.
	 */
	public QName getMode() {
		return mode;
	}

	/**
	 * Output an object to the result tree by doing the right conversions. This
	 * is public for access by extensions.
	 * 
	 * 
	 * @param stylesheetTree
	 *            The owning stylesheet
	 * @param obj
	 *            the Java object to output. If its of an X<something> type
	 *            then that conversion is done first and then sent out.
	 * 
	 * @throws TransformerException
	 * @throws java.io.FileNotFoundException
	 * @throws java.io.IOException
	 * @throws java.net.MalformedURLException
	 */
	public void outputToResultTree(Stylesheet stylesheetTree, Object obj)
			throws TransformerException, java.net.MalformedURLException,
			java.io.FileNotFoundException, java.io.IOException {

		try {
			SerializationHandler rtreeHandler = transformer
					.getResultTreeHandler();
			XPathContext xctxt = transformer.getXPathContext();
			XObject value;

			// Make the return object into an XObject because it
			// will be easier below. One of the reasons to do this
			// is to keep all the conversion functionality in the
			// XObject classes.
			if (obj instanceof XObject) {
				value = (XObject) obj;
			} else if (obj instanceof String) {
				value = new XString((String) obj);
			} else if (obj instanceof Boolean) {
				value = new XBoolean(((Boolean) obj).booleanValue());
			} else if (obj instanceof Double) {
				value = new XNumber(((Double) obj).doubleValue());
			} else if (obj instanceof DocumentFragment) {
				int handle = xctxt.getDTMHandleFromNode((DocumentFragment) obj);

				value = new XRTreeFrag(handle, xctxt);
			} else if (obj instanceof DTM) {
				DTM dtm = (DTM) obj;
				DTMIterator iterator = new DescendantIterator();
				// %%ISSUE%% getDocument may not be valid for DTMs shared by
				// multiple
				// document trees, eg RTFs. But in that case, we shouldn't be
				// trying
				// to iterate over the whole DTM; we should be iterating over
				// dtm.getDocumentRoot(rootNodeHandle), and folks should have
				// told us
				// this by passing a more appropriate type.
				iterator.setRoot(dtm.getDocument(), xctxt);
				value = new XNodeSet(iterator);
			} else if (obj instanceof DTMAxisIterator) {
				DTMAxisIterator iter = (DTMAxisIterator) obj;
				DTMIterator iterator = new OneStepIterator(iter, -1);
				value = new XNodeSet(iterator);
			} else if (obj instanceof DTMIterator) {
				value = new XNodeSet((DTMIterator) obj);
			} else if (obj instanceof NodeIterator) {
				value = new XNodeSet(new org.apache.xpath.NodeSetDTM(
						((NodeIterator) obj), xctxt));
			} else if (obj instanceof org.w3c.dom.Node) {
				value = new XNodeSet(xctxt
						.getDTMHandleFromNode((org.w3c.dom.Node) obj), xctxt
						.getDTMManager());
			} else {
				value = new XString(obj.toString());
			}

			int type = value.getType();
			String s;

			switch (type) {
			case XObject.CLASS_BOOLEAN:
			case XObject.CLASS_NUMBER:
			case XObject.CLASS_STRING:
				s = value.str();

				rtreeHandler.characters(s.toCharArray(), 0, s.length());
				break;

			case XObject.CLASS_NODESET: // System.out.println(value);
				DTMIterator nl = value.iter();

				int pos;

				while (DTM.NULL != (pos = nl.nextNode())) {
					DTM dtm = nl.getDTM(pos);
					int top = pos;

					while (DTM.NULL != pos) {
						rtreeHandler.flushPending();
						ClonerToResultTree.cloneToResultTree(pos, dtm
								.getNodeType(pos), dtm, rtreeHandler, true);

						int nextNode = dtm.getFirstChild(pos);

						while (DTM.NULL == nextNode) {
							if (DTM.ELEMENT_NODE == dtm.getNodeType(pos)) {
								rtreeHandler.endElement("", "", dtm
										.getNodeName(pos));
							}

							if (top == pos)
								break;

							nextNode = dtm.getNextSibling(pos);

							if (DTM.NULL == nextNode) {
								pos = dtm.getParent(pos);

								if (top == pos) {
									if (DTM.ELEMENT_NODE == dtm
											.getNodeType(pos)) {
										rtreeHandler.endElement("", "", dtm
												.getNodeName(pos));
									}

									nextNode = DTM.NULL;

									break;
								}
							}
						}

						pos = nextNode;
					}
				}
				break;
			case XObject.CLASS_RTREEFRAG:
				SerializerUtils.outputResultTreeFragment(rtreeHandler, value,
						transformer.getXPathContext());
				// rtreeHandler.outputResultTreeFragment(value,
				// transformer.getXPathContext());
				break;
			}
		} catch (org.xml.sax.SAXException se) {
			throw new TransformerException(se);
		}
	}

	/**
	 * I need a "Node transformNode (Node)" method somewhere that the user can
	 * call to process the transformation of a node but not serialize out
	 * automatically. ????????????????
	 * 
	 * Does ElemTemplateElement.executeChildTemplates() cut it? It sends results
	 * out to the stream directly, so that could be a problem.
	 */
}