use strict;
use warnings;
use diagnostics;

use File::Copy::Recursive qw(fcopy rcopy);
use File::Path qw(make_path remove_tree);
use Digest::MD5;

use Time::HiRes qw( time );

my $start = time();

my $dir1 = $ARGV[0];
my $dir2 = $ARGV[1];

if ( not defined $dir1 ) {
    print "\nUsage: rexscan.pl [folder]\n";
    exit(0);
}
elsif ( not defined $dir2 ) {
    $dir2 = '';
}

remove_tree( "CEX", "DEX" );

my @first_arg     = ();
my @second_arg    = ();
my @dex_md5_array = ();
my @cex_md5_array = ();



my $countera = 0;
my $counterb = 0;

first_arg($dir1);
second_arg($dir2);
get_files();


sub first_arg {

    my ($dir) = @_;
    my ($dh);
    if ( !opendir( $dh, $dir ) ) {
        return;
    }
    while ( my $file = readdir($dh) ) {
        next if ( -d $file );
        my $path = "$dir/$file";

        if ( -d $path ) {
            first_arg("$path");
        }
        else {
            push( @first_arg, "$dir/$file" );
        }
    }
}

sub second_arg {

    my ($dir) = @_;
    my ($dh);

    if ( !opendir( $dh, $dir ) ) {
        return;
    }
    while ( my $file = readdir($dh) ) {
        next if ( -d $file );
        my $path = "$dir/$file";
        if ( -d $path ) {
            second_arg("$path");
        }
        else {
            push( @second_arg, "$dir/$file" );
        }
    }
}

sub get_files {

    for my $element1 (@first_arg) {
	
        next if ( -d $element1 );
		$element1 =~ m#^(.*?)([^/]*)$#;
		
        my ( $dex_directory, $dex_temp_file) = ( $1, $2 );
        my $dex = "$dex_directory$dex_temp_file";
        
		open (my $dex_file, '<', $dex)|| die "line 90 $!"; 
        my $dex_md5 = Digest::MD5->new->addfile($dex_file)->hexdigest;    
        push @dex_md5_array, "$dex_md5 $dex_directory $dex_temp_file\n";
    }
    for my $element2 (@second_arg) {
        
		next if -d $element2;
        $element2 =~ m#^(.*?)([^/]*)$#;
		
			my ( $cex_directory, $cex_temp_file ) = ( $1, $2 );
			my $cex = "$cex_directory$cex_temp_file";
        
		open (my $cex_file, '<', $cex) || die "line 101";
		my $cex_md5 = Digest::MD5->new->addfile($cex_file)->hexdigest;
        push @cex_md5_array, "$cex_md5 $cex_directory $cex_temp_file";
    }
	
	for my $cex_md5_array (@cex_md5_array) {
        my ( $md5c, $cpath, $cfile ) = split /\s+/, ($cex_md5_array);    #cex md5 filepath and file stored here
		chomp ( $md5c, $cpath, $cfile );
	
	
        for my $dex_md5_array (@dex_md5_array) {
            my ( $md5d, $dpath, $dfile ) = split (/\s+/,$dex_md5_array);    #dex md5 filepath and file stored here
			chomp ( $md5d, $dpath, $dfile );
		
			
			
			if ($md5c ne $md5d && $cfile eq $dfile){  
			
			
			make_path("DEX");
			fcopy("$dpath$dfile", "DEX/$cpath"); 
			
			#or use this to copy directly to the other directory.
			#fcopy("$dpath$dfile", "$cpath"); 
                
            }
            else {
			print '';
            }
        }
    }
}


my $end_run = time();
my $end     = time();
my $runtime = sprintf( "%.5f", $end - $start );
print "This script took $runtime seconds to execute\n";