/*******************************************************************************
 * Copyright (c) 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.pagedesigner.css2;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jst.pagedesigner.IHTMLConstants;
import org.eclipse.jst.pagedesigner.dtresourceprovider.DTSkinManager;
import org.eclipse.jst.pagedesigner.dtresourceprovider.IDTSkin;
import org.eclipse.wst.css.core.internal.provisional.adapters.IStyleSheetAdapter;
import org.eclipse.wst.css.core.internal.provisional.adapters.IStyleSheetListAdapter;
import org.eclipse.wst.html.core.internal.provisional.HTML40Namespace;
import org.eclipse.wst.sse.core.internal.provisional.INodeAdapter;
import org.eclipse.wst.sse.core.internal.provisional.INodeNotifier;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMElement;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.stylesheets.StyleSheet;
import org.w3c.dom.stylesheets.StyleSheetList;

/**
 * @author mengbo
 * @version 1.5
 */
public final class CSSTempUtil {
	/**
	 * the default implementation of (IStyleSheetListAdapter)
	 * docnotifier.getAdapterFor(IStyleSheetListAdapter.class) will only get
	 * those style tags under certain tags like "html", "head", etc.
	 * 
	 * But datawindow is generating style tag and is not putting them into
	 * "head". So we can't handle them using the default SSE mechanism.
	 * 
	 * We have another problem: currently the converted element is also using
	 * the original document, not generating another document, and these
	 * elements is not really adding into the document, so they can't be reached
	 * from the document.
	 * 
	 * @param element
	 * @return the list
	 * see org.eclipse.wst.html.core.htmlcss.HTMLDocumentAdapter#addStyleSheet(org.w3c.dom.Element)
	 */
	public static List getStyleSheets(Element element) {
		List styleSheets = new ArrayList();
		INodeNotifier docnotifier = (INodeNotifier) element.getOwnerDocument();
		IStyleSheetListAdapter adapter = (IStyleSheetListAdapter) docnotifier
				.getAdapterFor(IStyleSheetListAdapter.class);

		StyleSheetList ssl = (adapter == null ? null : adapter.getStyleSheets());

		if (ssl != null) {
			for (int i = 0, numStyles = ssl.getLength(); i < numStyles; i++) {
				// loop for styles (<style> and <link>)
				org.w3c.dom.stylesheets.StyleSheet ss = ssl.item(i);
				styleSheets.add(ss);
			}
		}

		// now is our work-around part for support datawindow.
		Node parent = element.getParentNode();
		Element rootEle = element;
		while (parent != null && parent instanceof Element) {
			rootEle = (Element) parent;
			parent = parent.getParentNode();
		}
		addStyleSheet(rootEle, styleSheets);

		//add stylesheets from any active IDTSkin instances
		if (element instanceof IDOMNode) {
			List<IDTSkin> dtSkins =
				DTSkinManager.getInstance((IDOMNode)element).getCurrentSkins();
			for (IDTSkin dtSkin: dtSkins) {
				if (dtSkin != null) {
					styleSheets.addAll(dtSkin.getStyleSheets());
				}
			}
		}

		return styleSheets;
	}

	/**
	 */
	private static void addStyleSheet(Element node, List result) {
		IDOMElement element = (IDOMElement) node;
		String tagName = element.getTagName();
		if (tagName == null) {
			return;
		}
		boolean isContainer = false;

		if (element.isCommentTag()) {
			Node parent = element.getParentNode();
			if (parent == element.getOwnerDocument()) {
				// This condition is too severe, actually do not work for JSF
				// template.
				// But above (! globalTag() && isContainer()) cover JSF template
				// + tpl template
				isContainer = true;
			} else if (parent.getNodeType() == Node.ELEMENT_NODE) {
				tagName = ((Element) parent).getTagName();
				if (tagName != null
						&& tagName
								.equalsIgnoreCase(HTML40Namespace.ElementName.HEAD)) {
					isContainer = true;
				}
			}
		} else {
			INodeNotifier notifier = element;

			// (lium) Increase performance: since this method is called tooooo
			// many times,
			// and getAdapterFor() is slow, so add a check on the tagName to
			// filter
			// those stylesheet stuff first.
			if (IHTMLConstants.TAG_LINK.equalsIgnoreCase(tagName)
					|| IHTMLConstants.TAG_STYLE.equalsIgnoreCase(tagName)) {
				INodeAdapter adapter = notifier
						.getAdapterFor(IStyleSheetAdapter.class);
				if (adapter instanceof IStyleSheetAdapter) {
					StyleSheet sheet = ((IStyleSheetAdapter) adapter).getSheet();
                    if (sheet != null)
                    {
                        result.add(sheet);
                    }
				}
			}

			isContainer = true;
		}
		if (isContainer) {
			for (Node child = element.getFirstChild(); child != null; child = child
					.getNextSibling()) {
				if (child.getNodeType() != Node.ELEMENT_NODE)
					continue;
				addStyleSheet((Element) child, result);
			}
		}
	}
	
	private CSSTempUtil()
	{
	    //  util class, no instantiation
	}
}