#!/usr/local/bin/perl -w

use strict;
use diagnostics;
use Tk;
use Tk::Dialog;

sub convert_main;
sub num2char;
sub char2num;
sub denary2string;
sub base2denary;
sub char2denary;

my $mw = MainWindow->new;
$mw->geometry("500x500");
$mw->minsize(qw(500 500));
$mw->maxsize(qw(500 500));
$mw->title("Mega-Converter");

my $top_frm = $mw->Frame->pack(-side => 'top', -fill => 'y', pady => 8);
my $mid_frm = $mw->Frame->pack(-side => 'top', -fill => 'x', pady => 8);
my $bottom_frm = $mw->Frame->pack(-side => 'top', -fill => 'x', pady => 8);

my $left_frm = $mid_frm->Frame->pack(-side => 'left', 
	-fill => 'y', 
	-padx => 4, 
	-expand => 1, 
	-anchor => 'center');

my $mid_frm1 = $mid_frm->Frame->pack(-side => 'left', 
	-fill => 'y', 
	-padx => 4, 
	-expand => 1, 
	-anchor => 'center');

my $right_frm = $mid_frm->Frame->pack(-side => 'left', 
	-fill => 'y',
	-padx => 4,
	-expand => 1, 
	-anchor => 'center');

my $start_text = $top_frm->Text(-background => 'white',
	-height => 13)->pack;

my $convert_btn = $mid_frm1->Button(-text => 'Convert >>',
	-command => \&convert_main)
->pack(-side => 'top', pady => 2, padx => 2, -expand => 1, -anchor => 'center');

my $label2 = $left_frm->Label(-text => 'Convert From:',
	-padx => 4)
	->pack(-side => 'top');

my $from_lb = $left_frm->Scrolled('Listbox',
	-exportselection => 0,
	-scrollbars => 'e',
	-selectmode => 'single',
	-background => 'white',
	-height => 5)->pack(-side => 'top');

$from_lb->insert('end', qw/Binary Octal Decimal Hex Char/);

my $label3 = $right_frm->Label(-text => 'Convert To:',
	-padx => 4)
	->pack(-side => 'top');

my $to_lb = $right_frm->Scrolled('Listbox',
	-exportselection => 0,
	-scrollbars => 'e',
	-selectmode => 'single',
	-background => 'white',
	-height => 5)->pack(-side => 'top');

$to_lb->insert('end', qw/Binary Octal Decimal Hex Char/);

my $end_text = $bottom_frm->Text(-background => 'white',
	-height => 13)->pack;

my $dialog = $mw->Dialog;

MainLoop;

my ($start_string, $end_string, $base_from, $base_to);
my @start_values;

sub convert_main {

	my @base_values = (2, 8, 10, 16);
	my (@from_list, @to_list);
	my $err = 0;
	
	@from_list = $from_lb->curselection();
	@to_list = $to_lb->curselection();

	$base_from = $base_values[$from_list[0]];
	$base_to = $base_values[$to_list[0]];

	$start_string = $start_text->get('1.0', 'end');
	chomp($start_string);

	# Search for invalid entries
	# Binary
	if ($from_list[0] == 0 and !($start_string =~ m/^[0-1].+$/)) {
		$err = 1;
	}
	# Octal
	if ($from_list[0] == 1 and !($start_string =~ m/^[0-7].+$/)) {
		$err = 1;
	}
	# Denary (decimal)
	if ($from_list[0] == 2 and !($start_string =~ m/^[0-9].+$/)) {
		$err = 1;
	}

	# Hex
	if ($from_list[0] == 3 and !($start_string =~ m/^[0-9a-fA-F].+$/)) {
		$err = 1;
	}

	if ($err == 1) {
		$dialog->configure(-title => 'Invalid Entry', -text => 'Invalid value.');
		$dialog->Show;
		return;
	}
	
	if ($from_list[0] == 4) {
		@start_values = split(//, $start_string);
		char2num();
	}
	else {
		@start_values = split(/ /, $start_string);
		base2denary();
	}

	if ($to_list[0] == 4) {
		num2char();		
	}
	else {
		denary2string;
	}

	$start_string = '';
	$end_string = '';
	
}

sub num2char {
	my $value = '';

	$end_string = pack('C*', @start_values);

	$end_text->delete('1.0', 'end');
	$end_text->insert('1.0', $end_string);
}

sub char2num {
	my $value1 = '';
	my $value2 = '';
	my $index1 = 0;
	my @temp;
	my @temp2;

	foreach $value1 (@start_values) {
		@temp = split(//, $value1);
		foreach $value2 (@temp) {
			$temp2[$index1] = unpack('c*', $value2);
			$index1 += 1;
		}
	}

	@start_values = @temp2;
}

sub denary2string {
	my $value1 = 0;
	my $index1 = 0;
	my $index2 = 0;
	my $temp = '';

	my %character_map = (
		'10' => 'A',
		'11' => 'B',
		'12' => 'C',
		'13' => 'D',
		'14' => 'E',
		'15' => 'F',
	);

	foreach $value1 (@start_values) {
		while ($value1 >= $base_to**$index1) {
			$a = int(($value1/($base_to**$index1)) % $base_to);

			if (defined($character_map{$a})){
				$a = $character_map{$a};
			}

			$temp = $a.$temp;

			$index1 += 1;
		}
		
		if ($index2 > 0) {
			$end_string = $end_string.' '.$temp;
		}
		else {
			$end_string = $end_string.$temp;
		}

		$index1 = 0;
		$temp = '';
		$index2 += 1;
	}
	
	$end_text->delete('1.0', 'end');
	$end_text->insert('1.0', $end_string);
}

sub base2denary {
	my $value1 = 0;
	my $value2 = 0;
	my $final_num = 0;
	my $index = 0;
	my $index2 = 0;
	my @temp = ();

	foreach $value1 (@start_values) {
		@temp = split(//, $value1);
		@temp = reverse(@temp);
		foreach $value2 (@temp) {

			$value2 =~ s/(a|A)/10/;
			$value2 =~ s/(b|B)/11/;
			$value2 =~ s/(c|C)/12/;
			$value2 =~ s/(d|D)/13/;
			$value2 =~ s/(e|E)/14/;
			$value2 =~ s/(f|F)/15/;

			$final_num = $final_num + ($value2 * ($base_from**$index));
			$index +=1;
		}
		$start_values[$index2] = $final_num;
		$index2 += 1;
		$final_num = 0;
		$index = 0;
	}
}