use strict;
use warnings;

use Tk;
use Crypt::CBC;
use Crypt::DES;

my($key);

my $mw = new MainWindow;
$mw->geometry('800x600');

my $menu = $mw->Menu(-menuitems => &menubar_menuitems() );
$mw->configure(-menu => $menu);

my $tpfrme = $mw->Frame;
my $mdfrme = $mw->Frame(-height => '60');
my $bmfrme = $mw->Frame;

my($text1)         = $tpfrme->Scrolled('TextUndo',
                                       -height => '1',
                                       -width => '1',
                                       -scrollbars => 'osoe',
                                      );

my $encrypt_button = $mdfrme->Button(-text=>"Encrypt",
                                     -height=>'1',
                                     -command=>[\&OnEncrypt]
                                     );

my $get_key_button = $mdfrme->Button(-text=>"Set Encryption Key",
                                     -height=>'1',
                                     -command=>[\&get_key]
                                     );

my $decrypt_button = $mdfrme->Button(-text=>"Decrypt",
                                     -height=>'1',
                                     -command=>[\&OnDecrypt]
                                     );

my($text2)         = $bmfrme->Scrolled('TextUndo',
                                      -height => '1',
                                      -width => '1',
                                      -scrollbars => 'osoe',
                                      );



$mw->bind('Tk::TextUndo', '<Control-Key-o>',
      sub { OnFileLoad(); }
      );

$mw->bind('Tk::TextUndo', '<Control-Key-s>',
      sub { OnFileSave(); }
      );

$mw->bind('<Control-Key-q>',
      sub { OnExit(); }
      );

$mw->bind('Tk::TextUndo', '<Control-Key-s>',
      sub { OnEncrypt(); }
      );

$mw->bind('Tk::TextUndo', '<Control-Key-s>',
      sub { OnDecrypt(); }
      );

$mw->bind('<Control-Key-a>',
      sub { OnAbout(); }
      );



$tpfrme        ->pack(qw/-side top    -fill both -expand 1               /);
$mdfrme        ->pack(qw/-side top    -fill both -expand 0               /);
$bmfrme        ->pack(qw/-side bottom -fill both -expand 1               /);
$text1         ->pack(qw/-side top    -fill both -expand 1               /);
$encrypt_button->pack(qw/-side left                                      /);
$get_key_button->pack(qw/                                  -anchor center/);
$decrypt_button->pack(qw/-side right                                     /);
$text2         ->pack(qw/-side top    -fill both -expand 1               /);

MainLoop;

sub menubar_menuitems{
 return
 [ map
   ['cascade', $_->[0], -tearoff=> 0,
    -menuitems => $_->[1]],

   ['~File',    &file_menuitems()   ],
   ['~Actions', &actions_menuitems()],
   ['~Help',    &help_menuitems()   ],
 ];
}

sub file_menuitems
{
 return
     [
     [qw/command ~Open  -accelerator Ctrl-o/,
      -command=>[\&OnFileLoad]],
     [qw/command ~Save  -accelerator Ctrl-s/,
      -command=>[\&OnFileSave]],
     '',
     [qw/command ~Exit  -accelerator Ctrl-q/,
      -command=>[\&OnExit]]
     ];
}



sub actions_menuitems
{
 return
     [
     [qw/command ~Encrypt  -accelerator Ctrl-e/,
      -command=>[\&OnEncrypt]],
     [qw/command ~Decrypt  -accelerator Ctrl-d/,
      -command=>[\&OnDecrypt]],
     ];
}


sub help_menuitems
{
 return
     [
     [qw/command ~About -accelerator Ctrl-a/,
      -command=>[\&OnAbout]
     ]
     ];
}

sub OnFileLoad
{
 $text1->FileLoadPopup();
}

sub OnFileSave
{
 $text2->FileSaveAsPopup();
}

sub OnExit
{
 exit 0;
}

sub OnEncrypt
{
 my $text           = $text1->get(0.1, 'end')   ;
 my $encrypted_data = encrypt_string($text)     ;
 my $widget         = $text2->Subwidget("text") ;
 tie *STDOUT, ref $widget, $widget;
 print $encrypted_data;
}

sub OnDecrypt
{
 my $text           = $text1->get(0.1, 'end')   ;
 my $decrypted_data = decrypt_string($text)     ;
 my $widget         = $text2->Subwidget("text") ;
 tie *STDOUT, ref $widget, $widget;
 print $decrypted_data;
}

sub encrypt_string
{
 my $cipher      = new_cipher()             ;
 my $string      = shift                    ;
 my $encryp_data = $cipher->encrypt($string);
 $cipher         = ""                       ;
 return $encryp_data                        ;
}

sub decrypt_string
{
 my $cipher      = new_cipher()             ;
 my $string      = shift                    ;
 my $decryp_data = $cipher->decrypt($string);
 $cipher         = ""                       ;
 return $decryp_data                        ;
}

sub new_cipher
{
 my $key    = get_key();
 my $cipher = Crypt::CBC->new( {'key'             => "$key",
                             'cipher'          => 'DES',
                             'iv'              => '$KJh#(}q',
                             'regenerate_key'  => 0,   # default true
                             'padding'         => 'space',
                             'prepend_iv'      => 0
                           });
 return $cipher;
}

sub get_key
{
 my $getkeybox = $mw->DialogBox(-title=>"Set Encryption Key",
                                -buttons=>["OK"]
                                );

 $getkeybox->add('Label',
                 -anchor  => 'w',
                 -justify => 'left',
                 -text    => qq(Please enter your Encryption Key))->pack(qw/-side top -anchor w/);
 
 my $keybox = $getkeybox->add('Scrolled',
                             'TextUndo',
                              -height     => '10'
                              )->pack(qw/-side top -fill both -expand 1 -anchor w/);

 my $result = $getkeybox->show();
 $key = $keybox->get(0.1, 'end') unless(undef $result);
}