/*******************************************************************************
 * Copyright (c) 2007 Chase Technology Ltd - http://www.chasetechnology.co.uk
 * 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:
 *     Doug Satchwell (Chase Technology Ltd) - initial API and implementation
 *     David Carver (STAR) - bug 214235 - Node List expansion
 *******************************************************************************/
package org.eclipse.wst.xsl.launching.model;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.model.IDebugTarget;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.model.IVariable;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class XSLValue extends XSLDebugElement implements IValue
{
	private static final String NODESET = "nodeset"; //$NON-NLS-1$
	private static final String EMPTY_NODESET = "<EMPTY NODESET>"; //$NON-NLS-1$
	private String fValue;
	private String type;
	private boolean hasVariables;
	private Node actualNode;

	/**
	 * @since 1.0
	 */
	public XSLValue(IDebugTarget target, String type, Node node) {
		super(target);
		actualNode = node;
		String value = ""; //$NON-NLS-1$
		if (node.getNodeValue() != null) {
			value = node.getNodeValue();
		}
		init(target, type, value);
	}
	public XSLValue(IDebugTarget target, String type, String value)
	{
		super(target);
		init(target, type, value);
	}
	
	private void init(IDebugTarget target, String type, String value) {
		this.type = type;
		fValue = value;
	}
	

	public String getReferenceTypeName() throws DebugException
	{
		return type;
	}

	public String getValueString() throws DebugException
	{
		if ("string".equals(type)) //$NON-NLS-1$
			return "'"+fValue+"'"; //$NON-NLS-1$ //$NON-NLS-2$
		return fValue;
	}

	public boolean isAllocated() throws DebugException
	{
		return true;
	}

	public IVariable[] getVariables() throws DebugException
	{
		List<IVariable> variableList = new ArrayList<IVariable>();
		if (actualNode != null) {
			if (actualNode.hasAttributes()) {
				getAttributes(variableList, actualNode);
			}
			variableList.addAll(getNodeListVariables(actualNode.getChildNodes()));
		}
		if (type.equals(NODESET) && !(fValue.equals(EMPTY_NODESET))) { 
			createNodeSetVariables(variableList);
		}
		IVariable[] variables = new IVariable[variableList.size()];
		variableList.toArray(variables);
		return variables;
	}
	private void createNodeSetVariables(List<IVariable> variableList) {
		DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
		NodeList nodeList = null;
		try {
			DocumentBuilder builder = builderFactory.newDocumentBuilder();
			String nodeSet = "<nodeset>" + fValue + "</nodeset>"; //$NON-NLS-1$ //$NON-NLS-2$
			InputStream is = new ByteArrayInputStream(nodeSet.getBytes());
			Document doc = builder.parse(is);
			Node firstChild = doc.getFirstChild();
			nodeList = firstChild.getChildNodes();
			variableList.addAll(getNodeListVariables(nodeList));
		} catch (ParserConfigurationException e) {
			e.printStackTrace();
		} catch (SAXException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	private List<IVariable> getNodeListVariables(NodeList nodeList) {
		List<IVariable> variableList = new ArrayList<IVariable>();
		if (nodeList != null) {
			for (int i = 0; i < nodeList.getLength(); i++) {
				Node node = nodeList.item(i);
				IVariable variable = new NodeListVariable(getDebugTarget(), node);
				variableList.add(variable);
			}
		}
		return variableList;
	}
	private void getAttributes(List<IVariable> variableList, Node node) {
		NamedNodeMap nodeMap = node.getAttributes();
		for (int item = 0; item < nodeMap.getLength(); item++) {
			Attr attribute = (Attr) nodeMap.item(item);
			IVariable variable = new NodeListVariable(getDebugTarget(), attribute);
			variableList.add(variable);
		}
	}

	public boolean hasVariables() throws DebugException
	{
		hasVariables = false;
		if (actualNode != null) {
			hasVariables = actualNode.hasChildNodes();
		} else 	if (type.equals(NODESET)) { 
			hasVariables = true;
		} else {
			hasVariables = false;
		}
		if (fValue.equals(EMPTY_NODESET)) {
			hasVariables = false;
		}
		
		return hasVariables; 
	}
}