##
## 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 defined($ftp) && 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;

return 0 unless defined($ftp);
$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;