#!/usr/bin/perl -w

use strict;
use YAML;
sub POE::Kernel::ASSERT_DEFAULT () { 1 }
use POE;
use POE::Component::Server::TCP;
use POE::Filter::Reference;

# This hash will keep track of every connected client.  It is used by
# the updater session and each connection, so it's scoped where
# everything can see it.
my %connected_clients;

{
  POE::Component::Server::TCP->new(
    Alias        => 'TOF',
    Port         => 2222,
    ClientFilter => ['POE::Filter::Reference'],
    ClientInput  => \&client_input,

    # Register handlers for client connection and disconnection.  They
    # will manage the contents of %connected_clients.
    ClientConnected => \&add_new_client,
    ClientDisconnected => \&remove_old_client,

    # InlineStates are for each client, not for the server as a whole.
    InlineStates => {
      update_client => \&update_client,
    },
  );

  sub client_input {
    my $input = $_[ARG0];
    print 'my input = ' . YAML::Dump($input);
  }

  # Each client session has its own "update" method, scoped to the
  # single client.
  sub update_client {
    my $update = $_[ARG0];
    my $client = $_[HEAP]->{client};
    if ($client) {
      print 'my update is ' . YAML::Dump($update);
      $client->put($update);
    }
  }

  sub add_new_client {
    $connected_clients{$_[SESSION]->ID} = {
      # Store information about the client here.
      # Remote user ID?  Address?  Port?  Whatever.
      # The code to send updates to clients can examine this data to
      # decide whether a client needs an update.  For now, it's empty,
      # and all clients receive all updates.
    };
  }

  sub remove_old_client {
    delete $connected_clients{$_[SESSION]->ID};
  }
}

{
  POE::Session->create(
    inline_states => {
      _start       => \&_start,
      Send_updates => \&send_update,
      _stop        => \&_stop,
    },
  );

  sub _start {
    my $kernel = $_[KERNEL];
    print "session started\n";
    $kernel->yield('Send_update');
  }

  sub send_update {
    my $kernel = $_[KERNEL];
    my $update = {
      Header => 'update',
      Msg    => 'Hello Server',
    };

    # At update time, send an update to every currently connected
    # client.  As previously mentioned, this code can examine the
    # contents of $connected_clients{$client_id} and skip clients that
    # don't need or deserve updates.
    foreach my $client_id (keys %connected_clients) {
      $kernel->post($client_id, 'update_client', $update);
    }

    $kernel->delay('Send_update', 10);
  }

  sub _stop {
    print "session end\n";
  }
}

POE::Kernel->run();
exit;
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