#!/usr/local/bin/perl
##########################################################################################################
##########################################################################################################
#This is a program that simulates some of the tasks of posting and previewing a node at PerlMonks.       #
# I thought of making such a program for the following reasons:                                          #
#                    01-Practice the Tk module to a decent level or mastery.                             #
#                    02-Make a GUI that could enable Perl newbies to post nodes quicker without          #
#   using some of the deprecated tags like <pre> and.                                                    #
#                    03-Participate at the Monastery by contributing something that can also be used     #
#   by everyone who wants a speedier approach to posting a node with some of the following advantages:   #
#                  *The lengthoverhead of the preview button response is minimized.                      #
#                  *Minimizing the clutter of the most used tags at your personalized node dispatcher.   #
#                  *Giving an insight into the MarkUp of the Monastery that is visualizable.             #
#                  *presenting wpl.exe to newbies and how it allows a program to run without console.    #
#                  *Some other advantages and ideas like checking the module availablity, strictures..etc#
#                   04- Improve my coding style and entertain constructive criticism from all.           #
##########################################################################################################
##########################################################################################################


                ###Checking whether the required modules are installed before everything else###

@modules=("use Tk", "require Tk::BrowseEntry", "require Tk::DialogBox","require Tk::Dialog");
foreach(@modules){
        eval;
        if($@){
                $_=~/\w+\W(\S+)/;
                print "Module $1 does not exist, please install it first!\n";
                }
        };
use strict;
use warnings;
use Tk;

                ## Declaring Main, side Panel, Top Panel, Text Area, preview Area and Two menus##
my ($main, $menuBar, $sideBar, $textBar,$textArea, $prevArea);
my ($fileMenu, $editMenu);
$main = MainWindow->new();
$main->title('PM HTML Encoder (BioHisham@gmail.com) ');
$menuBar=$main->Frame()->pack(-side=>'top',-fill=>'x');
$sideBar=$main->Frame()->pack(-side=>'left', -expand=>1, -fill=>'both');
$textBar=$main->Frame()->pack();
$fileMenu=$menuBar->Menubutton(-text=>'File', -relief=>'raised')->pack(-side=>'left');
$editMenu=$menuBar->Menubutton(-text=>'Edit', -relief=>'raised')->pack(-side=>'left');
$textArea=$textBar->Scrolled(           #text Area, the width is not the default 70 like the PM's,
                'Text',                 #because my screen width doesn't allow that.
                -scrollbars=>'ow',      #the o let's the scrollbar show when necessary.
                -width=>'50',
                -height=>'30'
                )->pack(-side=>'left');
$prevArea=$textBar->Scrolled(            #preview Area.
                'Text',
                -scrollbars=>'ow',
                -width=>'50',
                -height=>'30'
                )->pack(-side=>'right');



                      ## Populating the File menu and setting behavior ##
                   ## I dont know what else to place on these menus however :( ##

my $exitCmd=$fileMenu->command(
        -label=>'exit',
        -accelerator=>'(Alt + F4)',
        -command=>sub{exit;}
        );
$main->bind('<Alt - F4>'=>sub{exit;});

                     ########################################
                     ###     Buttons FOR:                 ###
                     ###    CODE, Paragraph,              ###
                     ###    preview, Read More,           ###
                     ###    Internal Links,               ###
                     ###    External Links,               ###
                     ###    Lists invocation and Preview  ###
                     ######################################

my ($codeTag, $html_var,$listTag,$readTag,$internLink, $extLink,$lineTag,$prevTag,$paraTag, $listButton, $resetAll);     #Buttons
$codeTag=$sideBar->Button(
        -text=>   'CODE',
        -relief=>'ridge',
        -height=> 2,
        -width=>  10,
        -command=>\&CodeIt)->pack();

$paraTag=$sideBar->Button(
        -text=>  'PARAGRAPH',
        -relief=>'ridge',
        -height=> 2,
        -width=>  10,
        -command=>\&ParaIt)->pack();


#$lineTag=$sideBar->Button(     #this is the <br> not deployed yet
#        -text=>'Line Break',
#        -relief=>'ridge',
#        -height=> 2,
#        -width=>10,
#         -command=>\&LineIt
#         )->pack();


$readTag=$sideBar->Button(
         -text=>   'Read More',   #Not sure I presented this the right way though cuz it confused me
         -relief=> 'ridge',
         -height=> 2,
         -width=>  10,
         -command=>\&LinkIt
         )->pack();

$internLink=$sideBar->Button(
        -text=>  'Internal link',
        -relief=> 'ridge',
        -height=> 2,
        -width=>  10,
        -command=>\&linkIt_Intern,
        )->pack();

$extLink=$sideBar->Button(
        -text=>   'External Link',
        -relief=> 'ridge',
        -height=>  2,
        -width=>   10,
        -command=> \&linkIt_Ext,
        )->pack();

$listButton=$sideBar->Button(      #Hitting this button casuses many instances of the listBrowse widget
        -text=>   'list',
        -height=>  2,
        -width=>   10,
        -relief=>  'ridge',
        -command=> \&listBrowse,
        )->pack();
        
$resetAll=$sideBar->Button(
        -text=>      'Reset All',
        -height=>     3,
        -width=>     10,
        -relief=>    'groove',
        -background=>'white',
        -command=>sub{
                for($textArea, $prevArea){
                 $_->delete('1.0','end');
                        }
                }
        )->pack(-fill=>'x', -expand=>'1', -side=>'bottom');



                        ## Since lists are either ordered or unordered I made a BrowseEntry ###
                       ##  to show lists types upon hitting the List Button.               ###

require Tk::BrowseEntry;
require Tk::DialogBox;
require Tk::Dialog;

my $choice="number"; #the default list item.
sub listBrowse{
        $listTag=$sideBar->BrowseEntry(
                -variable=>\$choice,
                -browsecmd=>\&Verify
                )->pack();
        $listTag->insert("end","Number");
        $listTag->insert("end","Bullet");
        }



my ($number,$listItems, $dialog, $errorDialog, $entry);
$dialog=$main->DialogBox(
        -title=>'Enter List Length',
        -buttons=>['ok', 'cancel']
        );

$errorDialog=$main->Dialog(                #this is an error message when the user enters
        -title=>'error',                   #an invalid choice in the DialogBox.
        -text=>'invalid number',
        -bitmap=>'error',
        -buttons=>['Ok']
        );

$entry = $dialog->add(                   #adding an entry widget to the dialog box body.
        'Entry',
        -width=>40,
        )->pack();

$prevTag=$sideBar->Button(
        -text=>'PREVIEW',
        -relief=>'ridge',
        -height=> 2,
        -width=>10,
        -command=> \&SeeIt,
        )->pack();
MainLoop;


{                                #setting scope for $srting#

sub CodeIt{
        my ($string, $pos);
        $string = "<code>\nPlace Code Here\n</code>";
        $textArea->insert('end',"$string");
        }

sub ParaIt{
        my ($string, $pos);
        $string = "<p>\nenter some lines of text\n</p>";
        $textArea->insert('end',"$string");
        }

sub SeeIt{
        #this subroutine would create a temporary file to write the text area content to and then
        #would use the temporary file as the source to write to the preview area from.
        #N.B: I COULD NOT unlink OR delete THE TEMPORARY FILE THUS CREATED AND COULDN'T HANDLE THE while
        #LOOP TO WORK OFF THE TEXT AREA DIRECTLY WITHOUT CREATING AN INTERMEDIARY CHANNEL.
        
        my (@data, $line, $filename);
        $html_var=$textArea->get('1.0','end'); #get the text from the widget into a string variable.
        $filename="FileInputSample.tmp";
        open FH, ">$filename" or die "$!";
        print FH $html_var;
        open FH, "$filename", or die "$!";
        while(@data=<FH>){
                foreach $line (@data){   #This has been thorny because one list type overrules the other.
                                        #Could not get to allow mixing of list types.
                                $line =~ s/(<.?code>)//;
                                $line =~ s/(<p>|<ol>)/\n/;
                                $line =~ s/<\/p>//;
                                if($line =~ s/<.?ol>//){
                                        my $i=1;
                                        map {s/<li>/"\t".$i++."-"/e} @data;
                                        map {s/<\/li>//} @data;
                                        }elsif($line =~ s/<.?ul>//){
                                                map {s/<li>/"\t*  "/e} @data;
                                                map {s/<\/li>//} @data;
                                                } #elsif
                                } #foreach
                $prevArea->delete('1.0', 'end');
                $prevArea->insert('1.0',"@data");
                }#while
        close ('FH');
        unlink("$filename") or die "Failed to delete the temporary file $!\n";  #deleting the file
        }

#sub LineIt{                               #related to the deactivate <br>
#        $string="<br>Enter a new Line";
#        $pos=$textArea->index('insert');  #get current cursor position
#        $textArea->insert("$pos","$string");
#        }

sub LinkIt{       #When I tested this one, I don't think I can make it work as it should by
                  #retracting the linked page to a mere hypertext.
        my ($string, $pos);
        $string=qq("<readmore title="Link Title Here"> Text Goes here </readmore>");
        $pos=$textArea->index('insert');
        $textArea->insert("$pos","$string");
        }

sub linkIt_Intern{
        my ($string, $pos);
        $string = "[Node Name or Node ID, pad: or doc: or username]";
        $pos = $textArea->index('insert');
        $textArea->insert("$pos","$string");
        }

sub linkIt_Ext{
        my ($string, $pos);
        $string = qq([href://http://www.Site.com|Label]);
        $pos=$textArea->index('insert');
        $textArea->insert("$pos", "$string");
        }
        
my $result;  #the result from the DialogBox which can be ok or cancel.
my $flag;    #a flag returned to control subroutines flow.
sub Verify{
        #whether the choice is equal to bulltes or numbers and act accordingly
        if($choice eq "Bullet"){
                $entry->delete('0.0','end');    #reset the entry widget in the dialog box.
                my $result=$dialog->Show;       #show the dialog box and capture response.
                if($result eq "ok"){
                        $number=$entry->get();
                        #if the return value of VerifyListNumber is 1 or 0 and acts accordingly:
                        Bullets() if(VerifyListNumber());             #dont go to bullets() unless flag is 1
                        $errorDialog->Show() if(!VerifyListNumber()); #when the flag is 0.
                        }elsif($result eq "cancel"){
                                $entry->delete('0.0','end');
                                return;
                                }
                }elsif($choice eq "Number"){
                        $entry->delete('0.0','end');
                        my $result=$dialog->Show;
                        if($result eq "ok"){
                                $number=$entry->get();
                                Numbers() if (VerifyListNumber());
                                $errorDialog->Show() if(!VerifyListNumber());
                                }elsif($result eq "cancel"){
                                        $entry->delete('0.0','end');
                                        return;
                                        }
                        }
        }

sub VerifyListNumber{
        chomp $number;
         if($number=~/\D+/){
                $flag=0;
                return $flag;
                        }else{$flag=1; return $flag;}
                }

sub Bullets{
        my ($string, $pos);
        $listItems="<li>Enter Item</li>\n";
        $string = "<ul>\n".($listItems x $number)."\n</ul>";
        $pos = $textArea->index('insert');
        $textArea->insert("$pos","$string");
        }

sub Numbers{
        my ($string, $pos);
        $listItems="<li>Enter Item</li>\n";
        $string = "<ol>\n".($listItems x $number)."\n</ol>";
        $pos = $textArea->index('insert');
        $textArea->insert("$pos","$string");
        }
}#ending the subroutines scope.

       # Any ideas, feedback and criticism are accepted with an open heart.
      # Thanks for your time, your efforts and your assitance.
      
      
#This has been when I could come up with to the best of my abilities, I could not simulate underlined text to
#represent links to websites, I couldn't get the program distinguish multiple instances of lists and operate
#accordingly, there might be other bugs lurking around but I could not unearth them for a critical eye scanning
#is sharper and finer than a learner's eye.