#!/usr/bin/perl

use strict;
use warnings;

use Net::EasyTCP;

use constant LOG_DIR    => '/tmp';
use constant LOG_FILE   => 'daemon.log';
use constant PIDDIR     => LOG_DIR;

use Proc::PID_File;
use Proc::Daemon;
use Log::Dispatch;
use Log::Dispatch::File;
use Date::Format;
use File::Spec;

sub dienice ($);

our $ME = $0; $ME =~ s|.*/||;
our $PIDFILE = PIDDIR."/$ME.pid";
startDaemon();

our $HOSTNAME = `hostname`;
chomp $HOSTNAME;
my $log = new Log::Dispatch( callbacks => sub { 
  my %h=@_; return Date::Format::time2str('%B %e %T', time)." ".$HOSTNAME." $0\[$$]: ".$h{message}."\n"; } );
  $log->add( Log::Dispatch::File->new( 
    name      => 'file1',
    min_level => 'warning',
    mode      => 'append',
    filename  => File::Spec->catfile(LOG_DIR, LOG_FILE),
    )
  );
  $log->warning("Starting Processing:  ".time()
);


my $daemon_path = $0;
my $perl_path; 
open(SOURCE, $daemon_path);
<SOURCE> =~ /^#!(\S+)/; $perl_path = $1;
close(SOURCE);
if (!-x $perl_path) { $perl_path = $^X; }

my @daemon_argv = @ARGV;
my $server;

$server = Net::EasyTCP->new(
  mode     => "server",
  port     => 12345,
  ) || die "ERROR CREATING SERVER: $@\n";

$server->setcallback(
  data       => \&gotdata,
  connect    => \&connected,
  disconnect => \&disconnected
  ) || die "ERROR SETTING CALLBACKS: $@\n";
$log->warning('Server starting...');
$server->start() || die "ERROR STARTING SERVER: $@\n";
$log->warning('Server has stopped - we need to restart!');
&restart_daemon;



#------------------------------------------------------------------------------
# sub gotdata
#------------------------------------------------------------------------------
sub gotdata
{
  my $client = shift;
  my $serial = $client->serial();
  my $data   = $client->data();

  $log->warning( "Client sent data: $data" );

  if( $data eq "HUP" ){
    $server->stop();
    $log->warning( 'Server sent HUP by client!' );
  }
}


#------------------------------------------------------------------------------
# sub connected
#------------------------------------------------------------------------------
sub connected
{
  my $client = shift;
  my $serial = $client->serial();
  $log->warning( "Client $serial just connected." );
}


#------------------------------------------------------------------------------
# sub disconnected
#------------------------------------------------------------------------------
sub disconnected
{
  my $client = shift;
  my $serial = $client->serial();
  $log->warning( "Client $serial just disconnected." );
}


#------------------------------------------------------------------------------
# sub restart_daemon
#------------------------------------------------------------------------------
sub restart_daemon
{
  $log->warning( "RESTART: $perl_path, $daemon_path, @daemon_argv" );
  release_the_pid_file();
  exec($perl_path, $daemon_path, @daemon_argv) || $log->warning("EXEC failed:  $! $? $@");
  die "Failed to restart daemon";
}


#------------------------------------------------------------------------------
# sub restart_daemon
#------------------------------------------------------------------------------
sub startDaemon 
{
  eval { Proc::Daemon::Init; };
  dienice("Unable to start daemon:  $@") if $@;
  dienice("Already running!")            if hold_pid_file($PIDFILE);
}

#------------------------------------------------------------------------------
# sub dienice
#------------------------------------------------------------------------------
sub dienice ($) 
{
  my ($package, $filename, $line) = caller;
  $log->critical("$_[0] at line $line in $filename");
  die $_[0];
}
__END__