#!/usr/bin/perl

use 5.12.0;
use Params::Validate qw(:all);
use PPI;
use PPI::Dumper;
use PPI::Find;
use Win32::Clipboard;

use strict;
use warnings;

    # Clear the screen
    system 'cls';
    FindAndReplaceHereDocs($ARGV[0],"$ARGV[0].upd")
        if (-f $ARGV[0]);
    exit;

    sub _Comment {
        return "# Just A Test";
         };

    sub FindAndReplaceHereDocs {
        @_=Params::Validate::validate_pos(@_
                ,{ type=>SCALAR, callbacks=>{ "File not found"=> sub { -f shift() } }}
                ,{ type=>SCALAR }
                ,{ type=>SCALAR, optional=>1, default=>_Comment() });
        ### @_
        my ($ExistingCodeFilename_S,$UpdatedCodeFilename_S,$Comment_S)=@_;

        my $Document_o=PPI::Document->new($ExistingCodeFilename_S);
        #PPI::Dumper->new($Document_o,whitespace=>0,locations=>1)->print;
        # Stripping out comments
        #$Document_o->prune('PPI::Token::Comment');

        # Sub to find HereDocs
        local *HereDocs = sub {
            $_[1]->isa('PPI::Token::HereDoc')
             };

        # Buffer for HereDocs required by the updated document
        my @NewHereDoc_a;

        # We'll need a clipboard ...
        my $Clipboard_o=Win32::Clipboard->new();

        # Find the HereDocs in the existing code
        my $ExistingCodeHereDoc_ar=$Document_o->find(\&HereDocs) || [];
        for my $HereDoc_o (@$ExistingCodeHereDoc_ar) {
            #PPI::Dumper->new($HereDoc_o,whitespace=>0,locations=>1)->print;
            $Clipboard_o->Empty();
            $Clipboard_o->Set(join('',$HereDoc_o->heredoc()));
            print join('',$HereDoc_o->heredoc())."\n";
            {
                local $|=1;
                print STDOUT "Update the clipboard then 'Enter':";
                <STDIN>;
                 };
            # See if the clipboard has been changed
            if ((my $NewText_s=$Clipboard_o->GetText()) ne join('',$HereDoc_o->heredoc())) {
                print "Replaced with:\n$NewText_s\n\n";
                chomp($NewText_s);
                push @NewHereDoc_a,PPI::Document->new(\(
                        $HereDoc_o->content()
                        ."\n"
                        ."/* $Comment_S\n"               # Comment
                        .join('',$HereDoc_o->heredoc())  # ... original commented out
                        ."*/\n"                          #
                        .$NewText_s                      # ... replacement
                        ."\n"
                        #.$HereDoc_o->terminator()       # Prevents spurious terminator
                         ));
                my $HereDoc_ar=$NewHereDoc_a[-1]->find(\&HereDocs) || [];
                #PPI::Dumper->new($HereDoc_ar->[0],whitespace=>1,locations=>1)->print;
                #print join('',$HereDoc_ar->[0]->heredoc())."\n";
                if ($HereDoc_o->insert_before($HereDoc_ar->[0])) {
                    $HereDoc_o->delete();
                     } else {
                    warn "insert_before failed!";
                     };
                 };
             };
        #PPI::Dumper->new($Document_o,whitespace=>0,locations=>1)->print;
        $Document_o->save($UpdatedCodeFilename_S)
         };