use Tk;
use IPC::Open3;
use Hash::Util (lock_keys);

use strict;
use warnings;

$main::self = {};
$main::self->{OPEN_FILE} = undef;
$main::self->{MAIN_WINDOW} = new MainWindow(title => "My Program - Untiled");

my $tools_frame = $main::self->{MAIN_WINDOW}
                             ->Frame(border => 1,
                                     relief => "sunken")
                             ->pack(fill => "x",
                                    padx => 5,
                                    pady => 5,
                                    side => "top");
my $run = $tools_frame->Button(text => "Run",
                               background => "light blue",
                               activebackground => "pink",
                               command => \&run)
                      ->pack(side => "left",
                             padx => 5,
                             pady => 5);
$tools_frame->Button(text => "New",
                               background => "light blue",
                               activebackground => "pink",
                     command => \&new_file)
            ->pack(side => "left",
                   pady => 5);
$tools_frame->Button(text => "Open",
                               background => "light blue",
                               activebackground => "pink",
                     command => \&open_file)
            ->pack(side => "left",
                   pady => 5);
$tools_frame->Button(text => "Save",
                               background => "light blue",
                               activebackground => "pink",
                     command => \&save)
            ->pack(side => "left",
                   pady => 5);
$tools_frame->Button(text => "Save As",
                               background => "light blue",
                               activebackground => "pink",
                     command => \&save_as)
            ->pack(side => "left",
                   pady => 5);
$main::self->{PROGRAM_TEXT} = $main::self->{MAIN_WINDOW}
                            ->Scrolled("Text",
                                       font => ["Times", 16],
                                       -scrollbars => "e",
                                       background => "cyan",
                                       width => 70,
                                       height => 20)
                            ->pack(side => "top",
                                   fill => "x");
lock_keys(%{$main::self});
$main::result = $main::self->{MAIN_WINDOW}
                           ->Scrolled("Text",
                                      font => ["Times", 16],
                                      -scrollbars => "e",
                                      background => "light green",
                                      width => 70,
                                      height => 8)
                           ->pack(side => "top",
                                  fill => "x");
$main::self->{PROGRAM_TEXT}->focus();

MainLoop;
              
sub run {
    my $program = $main::self->{PROGRAM_TEXT}->get("1.0", "end");
    open(PROGRAM, ">", "program.pl");
    print PROGRAM $program;
    close(PROGRAM);
    open3(\*WRITER, \*READER, \*READER, "perl", "-w", "program.pl");
    $main::result->delete("1.0", "end");
    while (my $content = <READER>) {
        $main::result->insert("end", $content);
    } 
}

sub save_file {
    open(FILE, ">", $main::self->{OPEN_FILE});
    my $program = $main::self->{PROGRAM_TEXT}->get("1.0", "end");
    print FILE $program;
    close(FILE);
}

sub save {
    if ($main::self->{OPEN_FILE}) {
        save_file();
    } else {
        save_as();
    }
}

sub save_as {
    my $file_name = $main::self->{MAIN_WINDOW}->getSaveFile();
    if ($file_name ne "") {
        $main::self->{OPEN_FILE} = $file_name;
        save_file();
        display_file_name();
    }
}

sub open_file {
    if ($main::self->{OPEN_FILE} = $main::self->{MAIN_WINDOW}->getOpenFile()) {
        open(FILE, "<", $main::self->{OPEN_FILE});
        local $/;
        my $program = <FILE>;
        close(FILE);
        $main::self->{PROGRAM_TEXT}->delete("1.0", "end");
        $main::self->{PROGRAM_TEXT}->insert("end", $program);
        display_file_name();
    }
}

sub new_file {
    $main::self->{OPEN_FILE} = undef;
    $main::self->{PROGRAM_TEXT}->delete("1.0", "end");
    display_file_name();
}

sub display_file_name {
    if ($main::self->{OPEN_FILE}) {
        $main::self->{MAIN_WINDOW}
                   ->configure("title",
                               "My Porgram - $main::self->{OPEN_FILE}");
    } else {
        $main::self->{MAIN_WINDOW}
                   ->configure("title",
                               "My Porgram - Untiled");
    }
}