#! /usr/bin/perl -w

use strict;
use lib "/nss/nfx/shmem/lib/lib";
use lib "/nss/nfx/shmem/lib/lib64";
use lib "/nss/nfx/shmem/lib/lib/perl5/site_perl/";

use File::Basename;
use Getopt::Long;
use File::Copy;
use Data::Dumper;
use strict;
######################
######## Shared Memory Decl. #########
use IPC::Shareable;
################

my $child;
my $serv_id;
my $maxRcvrCount;
my $stripeInstance;
my $maxStripeInstance;

my $user;
my @ftpDirectoryListing=();
my @deDuppedArray=();
my @filesDownloaded=();
my $glue = 'data';
my %options = (
     create    => 1,
     exclusive => 0,
     mode      => 0644,
     destroy   => 0,
 );

my $deDuppedArrayHandle = tie @deDuppedArray, 'IPC::Shareable', undef, \%options;
my $filesDownloadedHandle = tie @filesDownloaded, 'IPC::Shareable', undef, \%options;

sub pollDaemonParent
{
    my $error = "";
    my $user = $_[0];
    my $tmpIntervalHolder = .5;
    my @previousListing=(); my @currentListing=();

    ConnectAndLogin();

    while (1)
    {
        @previousListing = @currentListing;
        @currentListing = getListing($user);

        $deDuppedArrayHandle->shlock();
        @deDuppedArray = deDupArray1(\@previousListing, \@currentListing);
        if ($#deDuppedArray >=  0)
        {
            print "\nParent: currentListing: @currentListing    deDuppedArray: @deDuppedArray\n";
        }
        $deDuppedArrayHandle->shunlock();

        deleteRemoteFiles1();

        select (undef, undef, undef,$tmpIntervalHolder);
    }
}
sub deleteRemoteFiles1
{
    # TODO: Get list and delete from server. once deleted
    $filesDownloadedHandle->shlock();
    if ($#filesDownloaded >=  0)
    {
        print "\nParent: deleteListing: @filesDownloaded\n";
    }
    foreach (@filesDownloaded)
    {
        print "Deleting File: $_\n";
    }
    @filesDownloaded=();
    $filesDownloadedHandle->shunlock();
}
sub pollDaemonChild
{
    my $error = "";
    my $user = $_[0];
    my $tmpIntervalHolder = 1;

    print "ChildStarted: $stripeInstance\n";
    while (1)
    {

        @ftpDirectoryListing = ();

        $deDuppedArrayHandle->shlock();
        @ftpDirectoryListing = @deDuppedArray;
        $deDuppedArrayHandle->shunlock();

        if ($#ftpDirectoryListing >=  0)
        {
            print "Child: @ftpDirectoryListing\n";
        }
        select (undef, undef, undef,$tmpIntervalHolder);
        processList($user);

    }
}
sub ConnectAndLogin
{
        return;
}
sub getListing
{
    my @ftpListing1 = ();
    push (@ftpListing1, "abc.xml");
    push (@ftpListing1, "xyz.xml");

    return @ftpListing1;
}
sub deDupArray1
{
    my ($previousArray, $currentArray) = @_;

    my @union;my @intersection;my@difference;
    @union = @intersection = @difference = ();
    my %count = ();
    my $element="";

    #####################################################################################################
    # get Difference of two arrays.
    #####################################################################################################
    # go into foreach loop for any element that exist in both previousArray and currentArray and increment
    # count of element value.
    foreach $element (@$previousArray, @$currentArray)
    {
        $count{$element}++
    }
    foreach $element (keys %count)
    {
        #print "$element:$count{$element}\n";
        push @union, $element;
        push @{ $count{$element} > 1 ? \@intersection : \@difference }, $element;
    }

    #####################################################################################################
    # Remove any element that existed in previous list from not in current list.
    #####################################################################################################
    my @elements_needs_to_be_removed = (@intersection, @$previousArray);
    %count = ();
    foreach $element (@elements_needs_to_be_removed, @difference)
    {
        $count{$element}++
    }
    @difference=();
    foreach $element (keys %count)
    {
    #   print "$element:$count{$element} ";
        push @union, $element;
        push @{ $count{$element} > 1 ? \@intersection : \@difference }, $element;
    }
    return @difference;
}
sub addToDeleteList
{
    $|++;
    #print "\nAdding file to Delete List: $_[0]\n";

    $filesDownloadedHandle->shlock();
    push (@filesDownloaded, "$_[0]");
    $filesDownloadedHandle->shunlock();
}
# main
{
    $user = "IAmUser";
    $serv_id = "1";
    $maxRcvrCount = "5";
    $stripeInstance = "1" ;
    $maxStripeInstance = "2";

    $SIG{'ALRM'} = 'sig_alrm';

my $startingInstanceNum=1;
my @kids;
for (1 .. $maxStripeInstance)
{

    $stripeInstance = $startingInstanceNum;
    print "stripeInstance: $startingInstanceNum\n";

    unless ($child = fork)
    {        # i'm the child
        die "cannot fork: $!" unless defined $child;
        pollDaemonChild($user);
        exit;
    }

    push @kids, $child;  # in case we care about their pids
    $startingInstanceNum++;
}
print "@kids\n";
pollDaemonParent($user);

}