package com.felhr.utils;

public class HexData 
{
	private static final String HEXES = "0123456789ABCDEF";
	private static final String HEX_INDICATOR = "0x";
	private static final String SPACE = " ";
	
	private HexData()
	{
		
	}
	
	public static String hexToString(byte[] data)
	{
		if(data != null)
		{
			StringBuilder hex = new StringBuilder(2*data.length);
			for(int i=0;i<=data.length-1;i++)
			{
				byte dataAtIndex = data[i];
				hex.append(HEX_INDICATOR);
				hex.append(HEXES.charAt((dataAtIndex & 0xF0) >> 4))
	            .append(HEXES.charAt((dataAtIndex & 0x0F)));
				hex.append(SPACE);
			}
			return hex.toString();
		}else
		{
			return null;
		}
	}
	
	public static byte[] stringTobytes(String hexString)
	{
		String stringProcessed = hexString.trim().replaceAll("0x", "");
		stringProcessed = stringProcessed.replaceAll("\\s+","");
		byte[] data = new byte[stringProcessed.length()/2];
		int i = 0;
		int j = 0;
		while(i <= stringProcessed.length()-1)
		{
			byte character = (byte) Integer.parseInt(stringProcessed.substring(i, i+2), 16);
			data[j] = character;
			j++;
			i += 2;
		}
		return data;
	}
	
	public static String hex4digits(String id)
	{
		if(id.length() == 1) return "000" + id;
		if(id.length() == 2) return "00" + id;
		if(id.length() == 3) return "0" + id;
		else return id;
	}
}