#!/usr/local/bin/perl -w
# Fetch the latest production data
use Getopt::Long;
use Pod::Usage;
use Net::FTP;
use strict;

# Parse command line arguments and assign corresponding variables
GetOptions
(
    'd|date=s'      => \( my $date = undef ),
    'v|verbose'     => \( my $VERBOSE = 0 ),
    'r|root=s'      => \( my $root = '.' ),
);

unless ( defined $date )
{
    pod2usage( -exitval => 1, -output => \*STDERR );
}

# Create the local directories
-d "$root/data" or mkdir("$root/data");

# Establish an FTP connection
my $ftp = Net::FTP->new("prod", Debug => 0)
    or die "Cannot connect to the production box: $@";

$ftp->login("user","passwd") or die "Cannot login ", $ftp->message;

&FetchRemoteFiles($ftp, "/opt/data", $date, "$root/data");
$ftp->quit;

exit(0);

# Fetch files under given directory
sub FetchRemoteFiles
{
  my ($ftp, $dir, $date, $localdir) = @_;

  $ftp->cwd($dir)
    or die "Cannot change working directory ", $ftp->message;

  my @remote_files = $ftp->ls("*.txt");
  my $latest_date;
  if (uc $date eq "LATEST"){
    $latest_date = @{[reverse sort map {/(\d{8})/;$1} @remote_files]}[0];
  } else {
    $latest_date = $date;
  }

  print "Fetching data for $latest_date...\n" if $VERBOSE;

  foreach my $file (@remote_files){
    if ($file =~ /$latest_date/){
      print ">> $file\n" if $VERBOSE;
      $ftp->get($file, "$localdir/$file")
              or die "Can not fetch file ", $ftp->message;
    }
  }

  print "Ok!\n" if $VERBOSE;
}


sub Today()
{
  my ($day, $month, $year) = (localtime)[3,4,5];
  return sprintf "%04d%02d%02d", $year + 1900, $month+1, $day;
}


__END__

=pod

=head1 NAME

fetchdata.pl

=head1 SYNOPSIS

fetchdata.pl [options]

=head1 ARGUMENTS

All arguments except date to this script are optional.

=over 4

=item B<-d|--date [YYYYMMDD|latest]>

Specify the date of data to fetch from production.

=item B<-r|--root [directory]>

Specify the root directory to store the data files. Under the directory
there are two sub directories, aus and asia.

=item B<-v|--verbose>

Let the script print out more debug information.

=back

=cut