/*******************************************************************************
 * Copyright (c) 2008 Standards for Technology in Automotive Retail and others.
 * 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 - initial API and implementation
 *     
 *******************************************************************************/

package org.eclipse.wst.xsl.core.internal.parser;

import org.eclipse.wst.sse.core.internal.ltk.parser.BlockTokenizer;
import org.eclipse.wst.sse.core.internal.ltk.parser.RegionParser;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegionContainer;
import org.eclipse.wst.sse.core.internal.util.Debug;
import org.eclipse.wst.xml.core.internal.parser.XMLSourceParser;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;

public class XSLSourceParser extends XMLSourceParser {


	public XSLSourceParser() {
		super();
	}
	
	@Override
	public RegionParser newInstance() {
		XSLSourceParser newInstance = new XSLSourceParser();
		newInstance.setTokenizer(getTokenizer().newInstance());
		return newInstance;
	}
	@Override
	protected void setTokenizer(BlockTokenizer newTokenizer) {
		// TODO Auto-generated method stub
		super.setTokenizer(newTokenizer);
	}
	
	@Override
	protected IStructuredDocumentRegion parseNodes() {
		// regions are initially reported as complete offsets within the
		// scanned input
		// they are adjusted here to be indexes from the currentNode's start
		// offset
		IStructuredDocumentRegion headNode = null;
		IStructuredDocumentRegion lastNode = null;
		ITextRegion region = null;
		IStructuredDocumentRegion currentNode = null;
		String type = null;

		while ((region = getNextRegion()) != null) {
			type = region.getType();
			// these types (might) demand a IStructuredDocumentRegion for each
			// of them
			
			if (type == DOMRegionContext.BLOCK_TEXT) {
				if (currentNode != null && currentNode.getLastRegion().getType() == DOMRegionContext.BLOCK_TEXT) {
					// multiple block texts indicated embedded containers; no
					// new IStructuredDocumentRegion
					currentNode.addRegion(region);
					currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
					region.adjustStart(-currentNode.getStart());
					// DW 4/16/2003 regions no longer have parents
					// region.setParent(currentNode);
				}
				else {
					// not continuing a IStructuredDocumentRegion
					if (currentNode != null) {
						// ensure that any existing node is at least
						// terminated
						if (!currentNode.isEnded()) {
							currentNode.setLength(region.getStart() - currentNode.getStart());
							// fCurrentNode.setTextLength(region.getStart() -
							// fCurrentNode.getStart());
						}
						lastNode = currentNode;
					}
					fireNodeParsed(currentNode);
					currentNode = createStructuredDocumentRegion(type);
					if (lastNode != null) {
						lastNode.setNext(currentNode);
					}
					currentNode.setPrevious(lastNode);
					currentNode.setStart(region.getStart());
					currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
					currentNode.setEnded(true);
					region.adjustStart(-currentNode.getStart());
					currentNode.addRegion(region);
					// DW 4/16/2003 regions no longer have parents
					// region.setParent(currentNode);
				}
			}
			// the following contexts OPEN new StructuredDocumentRegions
			else if ((currentNode != null && currentNode.isEnded()) || (type == DOMRegionContext.XML_CONTENT) || (type == DOMRegionContext.XML_CHAR_REFERENCE) || (type == DOMRegionContext.XML_ENTITY_REFERENCE) || (type == DOMRegionContext.XML_PI_OPEN) || (type == DOMRegionContext.XML_TAG_OPEN) || (type == DOMRegionContext.XML_END_TAG_OPEN) || (type == DOMRegionContext.XML_COMMENT_OPEN) || (type == DOMRegionContext.XML_CDATA_OPEN) || (type == DOMRegionContext.XML_DECLARATION_OPEN)) {
				if (currentNode != null) {
					// ensure that any existing node is at least terminated
					if (!currentNode.isEnded()) {
						currentNode.setLength(region.getStart() - currentNode.getStart());
						// fCurrentNode.setTextLength(region.getStart() -
						// fCurrentNode.getStart());
					}
					lastNode = currentNode;
				}
				fireNodeParsed(currentNode);
				currentNode = createStructuredDocumentRegion(type);
				if (lastNode != null) {
					lastNode.setNext(currentNode);
				}
				currentNode.setPrevious(lastNode);
				currentNode.setStart(region.getStart());
				currentNode.addRegion(region);
				currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
				region.adjustStart(-currentNode.getStart());
				// DW 4/16/2003 regions no longer have parents
				// region.setParent(currentNode);
			}
			// the following contexts neither open nor close
			// StructuredDocumentRegions; just add to them
			else if ((type == DOMRegionContext.XML_TAG_NAME) || (type == DOMRegionContext.XML_TAG_ATTRIBUTE_NAME) || (type == DOMRegionContext.XML_TAG_ATTRIBUTE_EQUALS) || (type == DOMRegionContext.XML_TAG_ATTRIBUTE_VALUE) || (type == DOMRegionContext.XML_COMMENT_TEXT) || (type == DOMRegionContext.XML_PI_CONTENT) || (type == DOMRegionContext.XML_DOCTYPE_INTERNAL_SUBSET)) {
				currentNode.addRegion(region);
				currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
				region.adjustStart(-currentNode.getStart());
				// DW 4/16/2003 regions no longer have parents
				// region.setParent(currentNode);
			}
			// the following contexts close off StructuredDocumentRegions
			// cleanly
			else if ((type == DOMRegionContext.XML_PI_CLOSE) || (type == DOMRegionContext.XML_TAG_CLOSE) || (type == DOMRegionContext.XML_EMPTY_TAG_CLOSE) || (type == DOMRegionContext.XML_COMMENT_CLOSE) || (type == DOMRegionContext.XML_DECLARATION_CLOSE) || (type == DOMRegionContext.XML_CDATA_CLOSE)) {
				currentNode.setEnded(true);
				currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
				currentNode.addRegion(region);
				region.adjustStart(-currentNode.getStart());
				// DW 4/16/2003 regions no longer have parents
				// region.setParent(currentNode);
			}
			// this is extremely rare, but valid
			else if (type == DOMRegionContext.WHITE_SPACE) {
				ITextRegion lastRegion = currentNode.getLastRegion();
				// pack the embedded container with this region
				if (lastRegion instanceof ITextRegionContainer) {
					ITextRegionContainer container = (ITextRegionContainer) lastRegion;
					container.getRegions().add(region);
					// containers must have parent set ...
					// setting for EACH subregion is redundent, but not sure
					// where else to do, so will do here for now.
					container.setParent(currentNode);
					// DW 4/16/2003 regions no longer have parents
					// region.setParent(container);
					region.adjustStart(container.getLength() - region.getStart());
				}
				currentNode.getLastRegion().adjustLength(region.getLength());
				currentNode.adjustLength(region.getLength());
			}
			else if (type == DOMRegionContext.UNDEFINED && currentNode != null) {
				// skip on a very-first region situation as the default
				// behavior is good enough
				// combine with previous if also undefined
				if (currentNode.getLastRegion() != null && currentNode.getLastRegion().getType() == DOMRegionContext.UNDEFINED) {
					currentNode.getLastRegion().adjustLength(region.getLength());
					currentNode.adjustLength(region.getLength());
				}
				// previous wasn't undefined
				else {
					currentNode.addRegion(region);
					currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
					region.adjustStart(-currentNode.getStart());
				}
			}
			else {
				// if an unknown type is the first region in the document,
				// ensure that a node exists
				if (currentNode == null) {
					currentNode = createStructuredDocumentRegion(type);
					currentNode.setStart(region.getStart());
				}
				currentNode.addRegion(region);
				currentNode.setLength(region.getStart() + region.getLength() - currentNode.getStart());
				region.adjustStart(-currentNode.getStart());
				// DW 4/16/2003 regions no longer have parents
				// region.setParent(currentNode);
				if (Debug.debugTokenizer)
					System.out.println(getClass().getName() + " found region of not specifically handled type " + region.getType() + " @ " + region.getStart() + "[" + region.getLength() + "]"); //$NON-NLS-4$//$NON-NLS-3$//$NON-NLS-2$//$NON-NLS-1$
				//$NON-NLS-3$//$NON-NLS-2$//$NON-NLS-1$
			}

			// these regions also get their own node, so close them cleanly
			// NOTE: these regions have new StructuredDocumentRegions created
			// for them above; it may
			// be more readable if that is handled here as well, but the
			// current layout
			// ensures that they open StructuredDocumentRegions the same way
			if ((type == DOMRegionContext.XML_CONTENT) || (type == DOMRegionContext.XML_CHAR_REFERENCE) || (type == DOMRegionContext.XML_ENTITY_REFERENCE)) {
				currentNode.setEnded(true);
			}
			if (headNode == null && currentNode != null) {
				headNode = currentNode;
			}
		}
		if (currentNode != null) {
			fireNodeParsed(currentNode);
			currentNode.setPrevious(lastNode);
		}
		// fStringInput = null;
		primReset();
		return headNode;
	}
	
}