/*
    * The SmartConfig Library
    * Copyright (C) 2004-2006
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
    *
   * This library 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   *
   * For further informations on the SmartConfig Library please visit
   *
   *                        http://smartconfig.sourceforge.net
   */
  package net.smartlab.config;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import org.xml.sax.Attributes;
  
  /**
   * @author rlogiacco
   */
  public class Node extends Element {
  
  	/**
  	 * The node sub elements.
  	 * 
  	 * @link aggregation
  	 * @associates <{Element}>
  	 */
  	protected List children;
  
  	/**
  	 * The node attributes.
  	 * 
  	 * @link aggregation
  	 * @associates <{Attribute}>
  	 */
  	protected Map attributes = new HashMap();
  
  	/**
  	 * The node direct contents.
  	 * 
  	 * @uml.property name="content"
  	 */
  	protected String content;
  
  	/**
  	 * Marks this node as already resolved for references.
  	 */
  	protected boolean resolved;
  
  
  	/**
  	 * Constructs a generic empty node.
  	 * 
  	 * @param parent the node containing this node.
  	 * @param name a name associated to this node.
  	 * @param attributes a set of attributes associated with this node.
  	 */
  	protected Node(Node parent, String name, Attributes attributes) {
  		super(parent, name);
  		this.children = new ArrayList();
  		if (attributes != null) {
  			for (int i = 0; i < attributes.getLength(); i++) {
  				this.attributes.put(attributes.getQName(i), attributes.getValue(i));
  			}
  		}
  	}
  
  	/**
  	 * @see net.smartlab.config.Element#getId()
  	 */
  	public String getId() {
  		return (String)attributes.get(Reference.IDENTIFIER);
  	}
  
  	/**
  	 * @see net.smartlab.config.Element#getElements()
  	 */
  	public Collection getElements() {
  		return Collections.unmodifiableCollection(children);
  	}
  
 	/**
 	 * @see net.smartlab.config.Element#getElements(java.lang.String)
 	 */
 	public Collection getElements(String name) {
 		List result = new ArrayList();
 		if (name != null) {
 			Iterator children = this.children.iterator();
 			while (children.hasNext()) {
 				Element child = (Element)children.next();
 				if (name.equals(child.getName())) {
 					result.add(child);
 				}
 			}
 		}
 		return Collections.unmodifiableCollection(result);
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#getElement(java.lang.String,
 	 *      java.lang.String, java.lang.String)
 	 */
 	public Element getElement(String name, String attribute, String value) throws ConfigurationException {
 		Iterator children = this.children.iterator();
 		while (children.hasNext()) {
 			Element child = (Element)children.next();
 			if (name != null && name.equals(child.name)) {
 				if (attribute != null) {
 					String found = child.getAttribute(attribute);
 					if (found != null) {
 						if (value != null) {
 							if (value.equals(found)) {
 								return child;
 							}
 						} else {
 							return child;
 						}
 					}
 				} else {
 					return child;
 				}
 			}
 		}
 		return null;
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#getAttributeNames()
 	 */
 	public Collection getAttributeNames() {
 		return Collections.unmodifiableCollection(attributes.keySet());
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#getAttributes()
 	 */
 	public Collection getAttributes() {
 		return Collections.unmodifiableCollection(attributes.entrySet());
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#getAttribute(java.lang.String)
 	 */
 	public String getAttribute(String name) {
 		return (String)attributes.get(name);
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#getContent()
 	 * @uml.property name="content"
 	 */
 	public String getContent() {
 		return content;
 	}
 
 	/**
 	 * Sets the content.
 	 * 
 	 * @param content the content to set
 	 */
 	protected void setContent(String content) {
 		if (content.replace('\n', ' ').replace('\t', ' ').trim().length() > 0) {
 			this.content = content;
 		}
 	}
 
 	/**
 	 * @see net.smartlab.config.Element#resolve()
 	 */
 	public void resolve() throws ConfigurationException {
 		if (!resolved) {
 			Iterator elements = children.iterator();
 			while (elements.hasNext()) {
 				((Element)elements.next()).resolve();
 			}
 			resolved = true;
 		}
 	}
 
 	/**
 	 * Resolves the requested reference through its children nodes or,
 	 * recursively in the parent node children.
 	 * 
 	 * @param name the referenced element name.
 	 * @param id the referenced element identifier.
 	 * @return the referenced element.
 	 * @throws ConfigurationException if the referenced element cannot be found
 	 *         in the wntire configuration tree.
 	 */
 	protected Node resolve(String name, String id) throws ConfigurationException {
 		Iterator children = this.children.iterator();
 		while (children.hasNext()) {
 			Element child = (Element)children.next();
 			if (child instanceof Node && name.equals(child.name) && id.equals(child.getId())) {
 				return (Node)child;
 			}
 		}
 		return parent.resolve(name, id);
 	}
 }