use strict;
use warnings;

use IO::Socket::INET;
use Time::Piece;
use Time::HiRes qw(sleep);
use DBI;
use POSIX qw(:signal_h);
use threads;

################################################################################
# global variable
################################################################################
my $shost = '192.168.0.201';
my $sport = 60004;

my $mhost    = '192.168.0.201';
my $dbname   = 'enterprise';
my $dbuser   = 'root';
my $dbpasswd = '123456';

# send message
sub send_message {

    # get message
    my $message = shift;

    #    print $message, "\n";

    # connect the remote server
    my $sock = IO::Socket::INET->new(
        PeerAddr => $shost,
        PeerPort => $sport,
        Proto    => 'tcp'
    ) or die "Connect failed!";

    print $sock $message;

}

sub get_message {

    # connect the mysql
    my $dbh = DBI->connect( "DBI:mysql:database=$dbname;host=$mhost",
        $dbuser, $dbpasswd, { PrintError => 0, RaiseError => 1 } );

    # execute SELECT query
    my $sth = $dbh->prepare("SELECT IMEI FROM SessionIMEI");
    $sth->execute();

    # iterate through resultset
    # print values
    my @elements;

    while ( my $ref = $sth->fetchrow_hashref() ) {
        push( @elements, $ref->{IMEI} );
    }

    my $buf = '$0';

    for my $ref (@elements) {
        $buf .= ",$ref";
    }

    # add the tail
    $buf .= "@\r\n";

    #    print $buf;

    # clean up
    $dbh->disconnect();

    # return the message
    return $buf;

}

###########################################################################
# signal handler
###########################################################################
my $sigset = POSIX::SigSet->new;

my $signal = undef;

# we use SIGUSR1 as the target signal
$sigset->delset(&POSIX::SIGUSR1);
$sigset->delset(&POSIX::SIGINT);
$sigset->delset(&POSIX::SIGALRM);

my $old_sigset = POSIX::SigSet->new;

# load the signal handler
sub user_handler {
    print "Get a user defined signal.\n";
    $signal = shift;
}

sub int_handler {
    print "Get a interrupt signal.\n";
    $signal = shift;

    print $signal, "\n";
}

sub alarm_handler {
    print "Get a alarm signal.\n";
    $signal = shift;
}

$SIG{USR1} = \&user_handler;
$SIG{INT}  = \&int_handler;
$SIG{ALRM} = \&alarm_handler;

# define the signals to block
# where the old sigmask will be kept
unless ( defined sigprocmask( SIG_BLOCK, $sigset, $old_sigset ) ) {
    die "Could not block SIGINT\n";
}

# suspend until a specific signal come to process.
sub sig_process {
    sigsuspend($sigset);

    my $message = undef;
    if ( $signal eq 'INT' ) {
        $message = get_message();
        send_message($message);

    }

}

###########################################################################
# create threads
###########################################################################
sub create_alarm {
    my $thr = threads->create( \&alarm_thread );
    $thr->detach();

}

sub alarm_thread {
    alarm(10);
}

###########################################################################
# main
###########################################################################
create_alarm();
sig_process();