/**********************************************
    * Copyright (C) 2009 Lukas Laag
    * This file is part of lib-gwt-svg-samples.
    * 
    * libgwtsvg-samples is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * libgwtsvg-samples is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with libgwtsvg-samples.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.svg.samples.client.xpath;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import org.vectomatic.dom.svg.impl.Attr;
  import org.vectomatic.dom.svg.impl.NamedNodeMap;
  import org.vectomatic.dom.svg.ui.SVGImage;
  import org.vectomatic.dom.svg.ui.SVGResource;
  import org.vectomatic.dom.svg.ui.SVGResource.Validated;
  import org.vectomatic.dom.svg.utils.DOMHelper;
  import org.vectomatic.dom.svg.utils.SVGConstants;
  import org.vectomatic.dom.svg.utils.SVGPrefixResolver;
  import org.vectomatic.svg.samples.client.Main;
  import org.vectomatic.svg.samples.client.Main.MainBundle;
  import org.vectomatic.svg.samples.client.SampleBase;
  
  import com.google.gwt.core.client.GWT;
  import com.google.gwt.dom.client.Document;
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.Node;
  import com.google.gwt.dom.client.NodeList;
  import com.google.gwt.dom.client.PreElement;
  import com.google.gwt.dom.client.SpanElement;
  import com.google.gwt.dom.client.Text;
  import com.google.gwt.event.dom.client.ClickEvent;
  import com.google.gwt.event.dom.client.KeyUpEvent;
  import com.google.gwt.resources.client.ClientBundle;
  import com.google.gwt.resources.client.CssResource;
  import com.google.gwt.uibinder.client.UiBinder;
  import com.google.gwt.uibinder.client.UiField;
  import com.google.gwt.uibinder.client.UiHandler;
  import com.google.gwt.user.client.ui.Button;
  import com.google.gwt.user.client.ui.CheckBox;
  import com.google.gwt.user.client.ui.HTML;
  import com.google.gwt.user.client.ui.Label;
  import com.google.gwt.user.client.ui.TabLayoutPanel;
  import com.google.gwt.user.client.ui.TextBox;
  
  /**
   * Class to demonstrate the use of XPaths to navigate in SVG documents
   * @author laaglu
   */
  public class XPathSample extends SampleBase {
  	interface XmlCssResource extends CssResource {
  		public String element();
  		public String attribute();
  		public String text();
  		public String comment();
  		public String markup();
  		public String selected();
  		public String root();
  	}
  	interface XPathBundle extends ClientBundle {
  		public static XPathBundle INSTANCE = GWT.create(XPathBundle.class);
  		@Source("xml.css")
  		public XmlCssResource css();
  		@Validated(validated=false)
  		@Source("pizza_pepperoni_bw.svg")
  		public SVGResource pizza();
  	}
  	
  	interface XPathSampleBinder extends UiBinder<TabLayoutPanel, XPathSample> {
  	}
  	private static XPathSampleBinder binder = GWT.create(XPathSampleBinder.class);
  
  	@UiField(provided=true)
  	public static XPathBundle xpathBundle = XPathBundle.INSTANCE;	
  	@UiField(provided=true)
  	public static MainBundle mainBundle = Main.mainBundle;
  	/**
  	 * A Text box to enter XPath expressions
  	 */
  	@UiField
  	TextBox xpathBox;
  	/**
  	 * A button to request evaluation of the xpath expression
  	 */
  	@UiField
 	Button evaluateButton;
 	/**
 	 * Checkbox to request continuous evaluation of xpath expressions
 	 * as they are typed
 	 */
 	@UiField
 	CheckBox evaluateCheckBox;
 	/**
 	 * A label to display XPath parsing error message
 	 */
 	@UiField
 	Label errorLabel;
 	/**
 	 * A sample SVG image
 	 */
 	@UiField
 	SVGImage svgImage;
 	/**
 	 * A colorized version of the SVG source XML text
 	 */
 	@UiField
 	HTML xmlContainer;
 	
 	/**
 	 * The root document
 	 */
 	private Document doc = Document.get();
 	/**
 	 * The CSS used to colorize text
 	 */
 	private XmlCssResource css = xpathBundle.css();
 	/**
 	 * Maps SVG nodes to bits of XML colorized text
 	 */
 	private Map<Node, SpanElement> nodeToSpan = new HashMap<Node, SpanElement>();
 	/**
 	 * The bits of XML colorized text corresponding to the SVG
 	 * nodes selected by the XPath expression
 	 */
 	private List<Element> xpathSpans;
 	/**
 	 * The SVG elements selected by the XPath expression
 	 */
 	private List<Element> svgElements;
 	/**
 	 * To resolve namespace prefixes
 	 */
 	private SVGPrefixResolver resolver;
 
 	@Override
 	public TabLayoutPanel getPanel() {
 		if (tabPanel == null) {
 			tabPanel = binder.createAndBindUi(this);
 			tabPanel.setTabText(0, "XPath");
 			createCodeTabs("XPathSample");
 			
 			css.ensureInjected();
 			xpathSpans = new ArrayList<Element>();
 			svgElements = new ArrayList<Element>();
 			PreElement pre = doc.createPreElement();
 			visit(svgImage.getElement(), pre);
 			pre.addClassName(css.root());
 			xmlContainer.getElement().appendChild(pre);
 			resolver = new SVGPrefixResolver() {
 				{
 					prefixToUri.put("i", "http://ns.adobe.com/AdobeIllustrator/10.0/");
 					prefixToUri.put("cc", "http://web.resource.org/cc/");
 					prefixToUri.put("dc", "http://purl.org/dc/elements/1.1/");
 					prefixToUri.put("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
 				}
 			};
 			evaluate();
 		}
 		return tabPanel;
 	}
 	
 	@UiHandler("evaluateButton")
 	public void evaluate(ClickEvent event) {
 		evaluate();
 	}
 
 	@UiHandler("evaluateCheckBox") 
 	public void checkbox(ClickEvent event) {
 		evaluateButton.setEnabled(!evaluateCheckBox.getValue());
 	}
 	
 	@UiHandler("xpathBox") 
 	public void keyUp(KeyUpEvent event) {
 		if (evaluateCheckBox.getValue()) {
 			evaluate();
 		}
 	}
 	
 	public void evaluate() {
 		String error = "";
 		try {
 			for (Element span : xpathSpans) {
 				span.removeClassName(css.selected());
 			}
 			xpathSpans.clear();
 			for (Element svgElement : svgElements) {
 				svgElement.setAttribute(SVGConstants.SVG_FILL_ATTRIBUTE, "#FFFFFF");
 			}
 			svgElements.clear();
 			
 			String expr = xpathBox.getText();
 			GWT.log(expr);
 			Iterator<Node> iterator = DOMHelper.evaluateNodeListXPath(svgImage.getElement(), expr, resolver);
 			while (iterator.hasNext()) {
 				Node node = iterator.next();
 				if (node.getNodeType() == Node.ELEMENT_NODE) {
 					svgElements.add(node.<Element>cast());
 				}
 				Element span = nodeToSpan.get(node);
 				xpathSpans.add(span);
 			}
 			for (Element span : xpathSpans) {
 				span.addClassName(css.selected());
 			}
 			for (Element svgElement : svgElements) {
 				svgElement.setAttribute(SVGConstants.SVG_FILL_ATTRIBUTE, "green");
 			}
 		} catch(Throwable t) {
 			error = t.getMessage();
 		}	
 		errorLabel.setText(error);
 	}
 
 	private SpanElement createMarkup(String markup) {
 		SpanElement markupSpan = doc.createSpanElement();
 		markupSpan.addClassName(css.markup());
 		markupSpan.appendChild(doc.createTextNode(markup));
 		return markupSpan;
 	}
 	
 	private void visit(Node node, Element parentSpan) {
 		SpanElement span = doc.createSpanElement();
 		nodeToSpan.put(node, span);
 		
 		parentSpan.appendChild(span);
 		NodeList<Node> childNodes = node.getChildNodes();
 		switch(node.getNodeType()) {
 			case Node.ELEMENT_NODE:
 				{
 					Element element = node.<Element>cast();
 					span.addClassName(css.element());
 					
 					// Populate the span with a start tag
 					span.appendChild(createMarkup("<"));
 					String tagName = element.getTagName();
 					int index = tagName.indexOf(":");
 					if (index != -1) {
 						span.appendChild(doc.createTextNode(tagName.substring(0, index)));
 						span.appendChild(createMarkup(":"));
 						span.appendChild(doc.createTextNode(tagName.substring(index + 1)));
 					} else {
 						span.appendChild(doc.createTextNode(tagName));
 					}
 
 					// Create the attribute nodes spans
 					NamedNodeMap<Attr> attributes = DOMHelper.getAttributes(element);
 					for (int i = 0, length = attributes.getLength(); i < length; i++) {
 						span.appendChild(doc.createTextNode(" "));
 
 						SpanElement attrSpan = doc.createSpanElement();
 						attrSpan.addClassName(css.attribute());
 						span.appendChild(attrSpan);
 						Attr attr = attributes.item(i);
 						nodeToSpan.put(attr, attrSpan);
 						
 						String attrName = attr.getName();
 						index = attrName.indexOf(":");
 						if (index != -1) {
 							attrSpan.appendChild(doc.createTextNode(attrName.substring(0, index)));
 							attrSpan.appendChild(createMarkup(":"));
 							attrSpan.appendChild(doc.createTextNode(attrName.substring(index + 1)));
 						} else {
 							attrSpan.appendChild(doc.createTextNode(attrName));
 						}
 						attrSpan.appendChild(createMarkup("=\""));
 						attrSpan.appendChild(doc.createTextNode(attr.getValue()));
 						attrSpan.appendChild(createMarkup("\""));
 					}
 					span.appendChild(createMarkup(childNodes.getLength() > 0 ? ">" : "/>"));
 				}
 				break;
 			case Node.TEXT_NODE:
 				{
 					// Populate span with text
 					Text text = node.<Text>cast();
 					span.addClassName(css.text());
 					span.appendChild(doc.createTextNode(text.getData()));
 				}
 				break;
 		}
 
 		for (int i = 0, count = node.getChildCount(); i < count; i++) {
 			visit(childNodes.getItem(i), span);
 		}
 		
 		if (childNodes.getLength() > 0 && node.getNodeType() == Node.ELEMENT_NODE) {
 			Element element = node.<Element>cast();
 			span.addClassName(css.element());
 			
 			// Populate the span with a close tag
 			span.appendChild(createMarkup("</"));
 			String tagName = element.getTagName();
 			int index = tagName.indexOf(":");
 			if (index != -1) {
 				span.appendChild(doc.createTextNode(tagName.substring(0, index)));
 				span.appendChild(createMarkup(":"));
 				span.appendChild(doc.createTextNode(tagName.substring(index + 1)));
 			} else {
 				span.appendChild(doc.createTextNode(tagName));
 			}
 			span.appendChild(createMarkup(">"));
 		}
 	}
 
 }