/*
 *    This program 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 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program 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 this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * 
 * Copyright c 2002-2004 E-Business Technology Institute
 * The University of Hong Kong,
 * Pukfulam Road, 
 * Hong Kong.
 * All Rights Reserved.
 * 
 * InputChecking - provides methods for various types of input checking.
 *
 * $Author$
 * $Date$
 * $Revision$
 *  
 */
 
package eti.bi.util;
 
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashSet;
import java.util.Vector;

/*
 *
 * A class that provides methods for various types of data type checking.
 *
 */
public class ValueValidator
{
    public static boolean debug;
    private static HashSet<String> m_SymbolList = null;
       
    static
    {
    	m_SymbolList = new HashSet<String>();
    	m_SymbolList.add("~");
    	m_SymbolList.add("`");
    	m_SymbolList.add("!");
    	m_SymbolList.add("@");
    	m_SymbolList.add("#");
    	m_SymbolList.add("$");
    	m_SymbolList.add("%");
    	m_SymbolList.add("^");
    	m_SymbolList.add("&");
    	m_SymbolList.add("*");
    	m_SymbolList.add("(");
    	m_SymbolList.add(")");
    	m_SymbolList.add("-");
    	m_SymbolList.add("_");
    	m_SymbolList.add("+");
    	m_SymbolList.add("=");
    	m_SymbolList.add("{");
    	m_SymbolList.add("[");
    	m_SymbolList.add("}");
    	m_SymbolList.add("]");
    	m_SymbolList.add("|");
    	m_SymbolList.add("\\");
    	m_SymbolList.add(":");
    	m_SymbolList.add(";");
    	m_SymbolList.add("\"");
    	m_SymbolList.add("'");
    	m_SymbolList.add("<");
    	m_SymbolList.add(",");
    	m_SymbolList.add(">");
    	m_SymbolList.add(".");
    	m_SymbolList.add("?");
    	m_SymbolList.add("/");	
    }

    /** Check whether the argument value contains space or not **/
    public static boolean containsSpace(String a_Value)
    {

        if (a_Value.indexOf(" ") != -1 || a_Value.indexOf("\t") != -1)
            return true;
        else return false;
    }
    
    /** Check whether the argument value contains alphabet only or not **/
    public static boolean isAlphabet(String a_Value)
    {
        char c;
        int valueLength = a_Value.length();
        for (int i = 0; i < valueLength; i++)
        {
            c = a_Value.charAt(i);
            if (!((c >= 65 && c <= 90) || (c >= 97 && c <= 122)))
                return false;
        }
        return true;
    }
    
    /** Check whether the argument value represents a numeric number **/
    public static boolean isDouble(String a_Value)
    {
        try
        {
            Double.parseDouble(a_Value);
        } 
        catch (NumberFormatException nfe)
        {
            if (debug)
                System.out.println(nfe.toString());
            return false;
        }
        return true;
    }
    
    /** Check whether the argument value represents a numeric number **/
    public static boolean isFloat(String a_Value)
    {
        try
        {
            Float.parseFloat(a_Value);
        } 
        catch (NumberFormatException nfe)
        {
            if (debug)
                System.out.println(nfe.toString());
            return false;
        }
        return true;
    }    
    
    /** Check whether the argument value represents a numeric number **/
    public static boolean isNumeric(String a_Value)
    {
        try
        {
            Long.parseLong(a_Value);
        } 
        catch (NumberFormatException nfe) 
        {
            if (debug)
                System.out.println(nfe.toString());
            return false;
        }
        return true;
    }
    
    public static boolean isNumber(String a_Value)
    {
        a_Value = a_Value.trim();
        for (int i=0; i<a_Value.length(); i++){
            if (a_Value.charAt(i) < '0' || a_Value.charAt(i) > '9')
                return false;
        }
        
        return true;
    }
    
    /** Check whether the argument value represents a integer number **/
    public static boolean isInteger(String a_Value)
    {
        try
        {
            Integer.parseInt(a_Value);
        } 
        catch (NumberFormatException nfe) 
        {
            if (debug)
                System.out.println(nfe.toString());
            return false;
        }
        return true;
    }
    /**
     * Checks whethe the argument a_Value represents a symbol or not.
     *
     * @param a_Value the sting to be checked.
     **/
    public static boolean isSymbol(String a_Value)
    {
    	if (a_Value.length() != 1)
    		return false;
    	
    	char symbolCharacter = a_Value.charAt(0);
    	
    	return !Character.isLetter(symbolCharacter);
    }
    
    /** Check whether the host name is valid or not (May not check for host
        existence) **/
    public static boolean isValidHost(String a_Host)
    {

        @SuppressWarnings("unused") InetAddress add;

		/** If the network does not exists or the host represents an IP address
		    , return true **/
        if (ValueValidator.isNetworkExist() == false && ValueValidator.isIPAddress(a_Host) == false)
        	return true;
        	
        try 
        {
            add = InetAddress.getByName(a_Host);
        } 
        catch (UnknownHostException ukhe)
        {
            if (debug)
                System.out.println(ukhe.toString());
            return false;
        } 
        catch (SecurityException se)
        {
            if (debug)
                System.out.println(se.toString());
            return false;
        }
        return true;
    }

	/** Check whether the network exists or not **/
	public static boolean isNetworkExist()
	{
		boolean exists = true;
		
		try
		{
			@SuppressWarnings("unused") InetAddress yahoo = InetAddress.getByName("www.yahoo.com");
		}
		catch (UnknownHostException ue)
		{
			exists = false;
		}

		try
		{
			@SuppressWarnings("unused") InetAddress google = InetAddress.getByName("www.google.com");
		}
		catch (UnknownHostException ue)
		{
			exists = false;
		}
		return exists;
	}

	/** Check whehther the input IP address is a valid IP address o not **/
	public static boolean isIPAddress(String a_IpAddress)
	{

		int start_index = 0;
		int end_index;
		
		for (int i = 0; i < 4; i++)
		{
			end_index = a_IpAddress.indexOf(".", start_index);