/* * *************************************************
 *      COMPRESS IPv6 ADDRESS
 *     .project: tutorial about IPv6 Address
 *      Eli pentser
 *  ************************************************* */


import java.awt.*;
import java.awt.event.*;
import java.text.*;


import javax.swing.*;


public class Ipv6 extends JApplet
   implements ActionListener, KeyListener
 {
// objects
  private JLabel colon[];
   private JTextField octet[];
   private JButton comp,clear;
   private JTextArea output;
   private int i, count;



   String display = "";

   // set up applet's GUI
   public void init()
   {
     count=0;
      // get content pane and set its layout to FlowLayout
      Container container = getContentPane();
      container.setLayout( new FlowLayout() );
      container.setBackground(Color.white);

      colon=new JLabel[7];
      octet=new JTextField[8];

      for(i=0;i<7;i++)
      {
      colon[i]=new JLabel(":");
      octet[i] = new JTextField( 4 );
      octet[i].setText("");
      container.add( octet[i] );
      container.add(colon[i]);
      octet[i].addKeyListener(this);
      }
      octet[0].requestFocus(true);

       octet[i] = new JTextField( 4 );
       octet[i].setText("");
      container.add( octet[i] );
      octet[i].addKeyListener(this);



      output=new JTextArea(6,30);
      output.setForeground(new Color(255,128,64));

      output.setText("\nEnter unabbreviated  IPv6 Address.\nnote: in an unabbreviated IPv6 Address, each octet has 4 HEXA DIGITS.\nHEXA DIGIT: 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f (Lower Case).\n");
      output.setEditable(false);

           container.add(output);


       comp=new JButton("Compress IP address");
       comp.setBackground(new Color(128,0,128));
       comp.setForeground(Color.white);
       comp.addActionListener(this);
        container.add(comp);

        clear=new JButton("Clear");
       clear.setBackground(new Color(128,0,128));
       clear.setForeground(Color.white);
       clear.setEnabled(false);
       clear.addActionListener(this);
        container.add(clear);

   }


   public void actionPerformed( ActionEvent actionEvent )
   {

       int  i;
       String str;
     if( (actionEvent.getSource())==comp)
     {
         comp.setEnabled(false);
         clear.setEnabled(true);

       output.setText("");

       if  (getInfo())
       {

           compress();
       }

     }
     else if(actionEvent.getSource()==clear)
     {
         clear.setEnabled(false);
         comp.setEnabled(true);
          for(i=0;i<8;i++)
          {
             octet[i].setText("");
            if(octet[i].getBackground()==Color.red)
                    octet[i].setBackground(Color.white);
          }
           output.setText("\nEnter unabbreviated  IPv6 Address.\nnote: in an unabbreviated IPv6 Address, each octet has 4 HEXA DIGITS\nHEXA DIGIT: 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f (Lower Case)\n");
           octet[0].requestFocus(true);
     }
   }  // end method actionPerformed

/** *******************************************************************************************
 *      getInfo method:
 *      cheak  the given Ipv6 if the address are ligal?
 *      if the address are ligal- return true.
 *     if the address are not ligal- return false
 **********************************************************************************************/


 public  boolean getInfo()
 {
     int i,j,k;
     boolean flag;
     String str;
     String ligal="0123456789abcdef";
     for(i=0;i<8;i++)
     {

       str=octet[i].getText();
         if(str.length()!=4)
         {
             octet[i].setBackground(Color.red);
             output.append("\nEach Octet must be 16 bits! (4 HEXA DIGITS)\n");
             return false;
         }
         for(j=0;j<str.length();j++)
         {
             flag=false;
             for(k=0;k<ligal.length();k++)
             {
                 if(str.charAt(j)==ligal.charAt(k))
                 {
                         flag=true;
                         break;
                 }
             }
                 if (!flag)
                 {
                      octet[i].setBackground(Color.red);
                      output.append("\nMUST BE HEXA DIGIT: 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f (Lower Case).\n");
                      return false;
                 }

             }
     }

 output.setText("\nYour unabbreviated form:\t");
  for(i=0;i<7;i++)
       {
               str=octet[i].getText();
               output.append(str + ':');
       }
  str=octet[i].getText();
  output.append(str + "\n\n");
 return true;

 }

 /** **************************************************************************************************************
  *     compress method:
  *     the method make the compress IPv6 address by parsing the origenal Ipv6 address.
  *     two steps of parsing:
  *    1)  parsing the data string and delete  leading "zero"  from each octet..(0028 will be 28, 0000 will be null)
  *    2) the parser find the first group of Zero octet and compress them, and finaly display the
  *       compressed string
  * ***************************************************************************************************************/

 public void compress()
 {

     int i,j,k;


     int count=0;
     String str[]=new String[8];
     String display="";
     String temp="";
     boolean flag=false;
     int first;


     //on this loop we parsing the given string and "delete" leading zeros
     for(i=0;i<8;i++)
     {
        j=0;
        str[i]=octet[i].getText();

                while(j<str[i].length()&&str[i].charAt(j)== '0' )
                     j++;

                if(j==str[i].length())
                    str[i]="";
                else
                {

                    for(;j<str[i].length();j++)
                    {

                           temp+=str[i].charAt(j);
                    }
                        str[i]=temp;
                        temp="";
                    }
                }

           flag=false;
           count=0;
     //*************************************************************************
    // in the folowing loop we make the compressing
     for(i=0;i<8 ;i++)
     {
       if( str[i].equals("") && !flag)             // if the octet are null (mean-0000 and thus the first Appearance
       {
           first=i;
            while( i<8 && str[i].equals("") )      // count null octet antil non null octet.
            {
                count++;
                i++;
            }
          if(count==1)                                           // if only one null Appearance present only 0:
          {
              display+='0';
              display+=':';
              count=0;
          }
          else
          {

             if (first==0)                                               // if more then one null Appearance present  double colon
              {
                  display+=':';
                  display+=':';
                  if(i==8)
                     break;
              }
          }
      if(first!=0 && count>1)
         display+=':';
      i--;
      if(count>1)
          flag=true;
       }

       else if( str[i].equals("") && flag )                                  // if null Appearance and we got before null group.
       {
            while( i<7 && str[i].equals("")  )
            {
                display+='0';
                display+=':';
                 i++;
            }
            if(i==7 && str[i].equals("") )
            {
               display+='0';
               break;
            }
            i--;
       }
       else                                                      // if not null Appearance we present the number.
       {
           while( i<7 && !str[i].equals("") )
           {
               display+=str[i];
               display+=':';
               i++;
           }
           if(i==7)
           {
              if( !str[i].equals("") )
                   display+=str[i];
              else if (str[i].equals("") )
                  display+='0';
              break;
           }
            i--;
       }

   }
    // display the Compress address.
     output.append("The compressed form:\t"+ display +"\n");


 }


 public void keyPressed(KeyEvent evt){

       int i=0;
       count++;

       if(count == 4)
       {
           for (;i < 8 ;i++)
           {
             if (evt.getComponent().equals(octet[i])){
               if (i < 7)
                 octet[i + 1].requestFocus(true);
                if(i==7)
                 comp.requestFocus(true);
             }

           }
          count=0;

       }
 }

 public void keyReleased(KeyEvent evt) {

      }


 public void keyTyped(KeyEvent evt)  {


      }



}  // end class Ipv6

/*****************************************************************************
/* all rights belong to Eli pentser:
 * Hadassah college - department of computer science
 *Class D2
 ****************************************************************************/