#! perl

#:META:RESOURCE:%.store:string:the command used to store the selection
#:META:RESOURCE:%.fetch:string:the command used to fetch the selection

=head1 NAME

remote-clipboard - manage a shared and possibly remote clipboard

=head1 DESCRIPTION

Somewhat of a misnomer, this extension adds two menu entries to the
selection popup that allows one to run external commands to store the
selection somewhere and fetch it again.

We use it to implement a "distributed selection mechanism", which just
means that one command uploads the file to a remote server, and another
reads it.

The commands can be set using the C<URxvt.remote-selection.store> and
C<URxvt.remote-selection.fetch> resources. The first should read the
selection to store from STDIN (always in UTF-8), the second should provide
the selection data on STDOUT (also in UTF-8).

The defaults (which are likely useless to you) use rsh and cat:

   URxvt.remote-selection.store: rsh ruth 'cat >/tmp/distributed-selection'
   URxvt.remote-selection.fetch: rsh ruth 'cat /tmp/distributed-selection'

=cut

use Fcntl ();

sub msg {
   my ($self, $msg) = @_;

   my $ov = $self->overlay (-1, 0, $self->strwidth ($msg), 1, urxvt::OVERLAY_RSTYLE, 0);
   $ov->set (0, 0, $msg);

   $self->{msg} =
      urxvt::timer
              ->new
              ->after (5)
              ->cb (sub { delete $self->{msg}; undef $ov; });
}

sub wait_pipe {
   my ($self, $fh, $pid, $msg) = @_;

   $self->msg ("waiting for selection process to finish...");

   my $wait_pipe; $wait_pipe = urxvt::pw->new->start ($pid)->cb (sub {
      my ($undef, $status) = @_;
      undef $wait_pipe;
      close $fh;
      $status >>= 8;
      $self->msg ("$msg (status $status)");
   });
}

sub store {
   my ($self) = @_;

   my $txt = $self->selection;

   local %ENV = %{ $self->env };
   if (my $pid = open my $fh, "|-:utf8", $self->{store_cmd}) {
      fcntl $fh, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK;
      $self->{iow} = urxvt::iow
                     ->new
                     ->fd (fileno $fh)
                     ->events (urxvt::EV_WRITE)
                     ->start
                     ->cb (sub {
         if (my $len = syswrite $fh, $txt) {
            substr $txt, 0, $len, "";
            $self->msg ((length $txt) . " chars to go...");
         } else {
            delete $self->{iow};
            $self->wait_pipe ($fh, $pid, "selection stored");
         }
      });
   }
}

sub fetch {
   my ($self) = @_;

   my $txt;

   local %ENV = %{ $self->env };
   if (my $pid = open my $fh, "-|:utf8", $self->{fetch_cmd}) {
      fcntl $fh, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK;
      $self->{iow} = urxvt::iow
                     ->new
                     ->fd (fileno $fh)
                     ->events (urxvt::EV_READ)
                     ->start
                     ->cb (sub {
         if (my $len = sysread $fh, $txt, 8192, length $txt) {
            $self->msg ((length $txt) . " chars read...");
         } else {
            delete $self->{iow};
            $self->selection_clear;
            $self->selection ($txt);
            $self->selection_grab (urxvt::CurrentTime);
            $self->msg ("selection fetched");
         }
      });
   }
}

sub on_start {
   my ($self) = @_;

   $self->{store_cmd} = $self->x_resource ("%.store")
                        || "rsh ruth 'cat >/tmp/distributed-selection'";

   $self->{fetch_cmd} = $self->x_resource ("%.fetch")
                        || "rsh ruth 'cat /tmp/distributed-selection'";

   push @{ $self->{term}{selection_popup_hook} }, sub {
      ("selection => remote" => sub { $self->store })
   };
   push @{ $self->{term}{selection_popup_hook} }, sub {
      ("remote => selection" => sub { $self->fetch })
   };

   ()
}