##
## Generic data connection package
##

package Net::FTP::dataconn;

use Carp;
use vars qw(@ISA $timeout $VERSION);
use Net::Cmd;
use Errno;

$VERSION = '0.11';
@ISA = qw(IO::Socket::INET);

sub reading
{
 my $data = shift;
 ${*$data}{'net_ftp_bytesread'} = 0;
}

sub abort
{
 my $data = shift;
 my $ftp  = ${*$data}{'net_ftp_cmd'};

 # no need to abort if we have finished the xfer
 return $data->close
    if ${*$data}{'net_ftp_eof'};

 # for some reason if we continously open RETR connections and not
 # read a single byte, then abort them after a while the server will
 # close our connection, this prevents the unexpected EOF on the
 # command channel -- GMB
 if(exists ${*$data}{'net_ftp_bytesread'}
	&& (${*$data}{'net_ftp_bytesread'} == 0)) {
   my $buf="";
   my $timeout = $data->timeout;
   $data->can_read($timeout) && sysread($data,$buf,1);
 }

 ${*$data}{'net_ftp_eof'} = 1; # fake

 $ftp->abort; # this will close me
}

sub _close
{
 my $data = shift;
 my $ftp  = ${*$data}{'net_ftp_cmd'};

 $data->SUPER::close();

 delete ${*$ftp}{'net_ftp_dataconn'}
    if exists ${*$ftp}{'net_ftp_dataconn'} &&
        $data == ${*$ftp}{'net_ftp_dataconn'};
}

sub close
{
 my $data = shift;
 my $ftp  = ${*$data}{'net_ftp_cmd'};

 if(exists ${*$data}{'net_ftp_bytesread'} && !${*$data}{'net_ftp_eof'}) {
   my $junk;
   $data->read($junk,1,0);
   return $data->abort unless ${*$data}{'net_ftp_eof'};
 }

 $data->_close;

 $ftp->response() == CMD_OK &&
    $ftp->message =~ /unique file name:\s*(\S*)\s*\)/ &&
    (${*$ftp}{'net_ftp_unique'} = $1);

 $ftp->status == CMD_OK;
}

sub _select {
 my ($data, $timeout, $do_read) = @_;
 my ($rin,$rout,$win,$wout,$tout,$nfound);

 vec($rin='',fileno($data),1) = 1;

 ($win, $rin) = ($rin, $win) unless $do_read;

 while (1) {
   $nfound = select($rout=$rin, $wout=$win, undef, $tout=$timeout);

   last if $nfound >= 0;
   
   croak "select: $!"
     unless $!{EINTR};
 }

 $nfound;
}

sub can_read
{
 _select(@_[0,1],1);
}

sub can_write
{
 _select(@_[0,1],0);
}

sub cmd
{
 my $ftp = shift;

 ${*$ftp}{'net_ftp_cmd'};
}

sub bytes_read {
 my $ftp = shift;

 ${*$ftp}{'net_ftp_bytesread'} || 0;
}

1;