package org.hwo.bitfields;

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

import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class BitField {
	private List<Field> fields;
	private List<ChangeListener> changeListeners;

	public BitField()
	{
		this.fields = new ArrayList<Field>();
		initialize();
	}

	public BitField(Element fieldsNode)
	{
		this.fields = new ArrayList<Field>();
		this.initialize();
		this.clear();
		
		if (fieldsNode != null)
		{
			fieldsFromXML(fieldsNode);
		}
	}
	
	private void initialize()
	{
		this.changeListeners = new LinkedList<ChangeListener>();
		
		for (int i=0;i<4;i++)
			this.fields.add(new Field(this, i, 1));
	}

	public void addChangeListener(ChangeListener listener){
		this.changeListeners.add(listener);
	}
	public void removeChangeListener(ChangeListener listener){
		this.changeListeners.remove(listener);
	}

	public void fireStateChanged(){
		ChangeEvent ce = new ChangeEvent(this);
		for (ChangeListener listener: this.changeListeners){
			listener.stateChanged(ce);
		}
	}

	public void fieldsFromXML(Node fieldsNode){
		NodeList fields = ((Element)fieldsNode).getElementsByTagName("Field");
		for (int i=0;i<fields.getLength();i++)
		{
			Element fieldNode = (Element)fields.item(i);
			int start = 0,
				len = 1;
			
			if (!fieldNode.getAttribute("len").equals(""))
				len = Integer.decode(fieldNode.getAttribute("len"));
			if (!fieldNode.getAttribute("start").equals(""))
				start = Integer.decode(fieldNode.getAttribute("start"));
			
			this.fields.add(new Field(this,start,len,fieldNode.getTextContent()));
		}		
	}
	
	public synchronized String toText(Integer value)
	{
		StringBuilder sb = new StringBuilder();
		
		if (value != null)
		{
			for (Field field:this.fields)
			{
				String st = field.toText(value);
				if (st != null)
				{
					if (sb.length() > 0)
						sb.append(", ");
					sb.append(st);
				}
			}
		}
		return sb.toString();
	}
	
	public Field[] getFields()
	{
		return this.fields.toArray(new Field[0]);
	}
	
	public void clear(){
		this.fields.clear();
	}
	
	public void addField(Field field){
		this.fields.add(field);
	}
	
	public void removeField(Field field){
		this.fields.remove(field);
	}

	public void initialize32Bit(){
		this.clear();
		
		for (int i=0;i<4;i++)
			this.fields.add(new Field(this, i, 1));
	}
	
	
/*	public synchronized void setValue(int value,int start,int len)
	{
		if (this.value == null)
			this.value = 0;
		
		this.value &= ~((-1 >> (Integer.SIZE - len)) << start);
		this.value |= (value & (-1 >> (Integer.SIZE - len))) << start;
	}
*/
	
}