package Smgp::BoundAtomic;
use strict;
use warnings FATAL => 'all';
sub new {
    my ($class, %args) = @_;
    my $self = {
        min     => $args{min},
        max     => $args{max},
        value   => $args{min},
    };
    bless $self, $class;
    return $self;
}
sub increment {
    my ($self) = @_;
    if ($self->{value} >= $self->{max}) {
        $self->{value} = $self->{min};
    } else {
        $self->{value}++;
    }
    return $self->{value};
}
sub get {
    my ($self) = @_;
    return $self->{value};
}
1;

package Smgp::Protocol;
use strict;
use warnings FATAL => 'all';
use Smgp::Constant;
sub new_login {
    my ($class, %args) = @_;
    my $self = {
        clientId            => $args{clientId},
        authenticatorClient => $args{authenticatorClient},
        loginMode           => $args{loginMode},
        timeStamp           => $args{timeStamp},
        version             => $args{version},
    };
    return bless $self, $class;
}
sub encode_login {
    my ($self) = @_;
    return pack("A8A16CNC", @{$self}{qw(clientId authenticatorClient loginMode timeStamp version)});
}
sub decode_login_resp {
    my ($class, $buffer) = @_;
    my ($status, $authenticatorServer, $version) = unpack("N4A16C", $buffer);
    return bless {
        status              => $status,
        authenticatorServer => $authenticatorServer,
        version             => $version,
    }, $class;
}
sub new_header {
    my ($class, %args) = @_;
    my $self = {
        total_length   => $args{total_length},
        request_id     => $args{request_id},
        command_status => $args{command_status},
        sequence_id    => $args{sequence_id},
    };
    return bless $self, $class;
}
sub encode_header {
    my ($self, $total_length) = @_;
    return pack("N3", $total_length, @{$self}{qw(request_id sequence_id)});
}
sub new_pdu {
    my ($class, %args) = @_;
    my $self = {
        header => $args{header},
        body   => $args{body},
    };
    return bless $self, $class;
}
sub encode_login_pdu {
    my ($self) = @_;
    my $encoded_body = $self->{body}->encode_login();
    return $self->{header}->encode_header(length($encoded_body) + 12) . $encoded_body;
}
sub decode_pdu {
    my ($class, $buffer) = @_;
    my ($request_id, $sequence_id) = unpack("N2", substr($buffer, 0, 8));
    my $body_buffer = substr($buffer, 8);
    my $header = $class->new_header(
        total_length   => 0,
        request_id     => $request_id,
        sequence_id    => $sequence_id,
    );
    my $body;
    if ($request_id == Smgp::Constant::LOGIN_RESP_ID) {
        $body = $class->decode_login_resp($body_buffer);
    } else {
        die "Unsupported request_id: $request_id";
    }
    return $class->new_pdu(
        header => $header,
        body   => $body,
    );
}
1;

package Smgp::Constant;
use strict;
use warnings FATAL => 'all';
use constant {
    LOGIN_ID               => 0x00000001,
    LOGIN_RESP_ID          => 0x80000001,
    SUBMIT_ID              => 0x00000002,
    SUBMIT_RESP_ID         => 0x80000002,
    DELIVER_ID             => 0x00000003,
    DELIVER_RESP_ID        => 0x80000003,
    ACTIVE_TEST_ID         => 0x00000004,
    ACTIVE_TEST_RESP_ID    => 0x80000004,
    FORWARD_ID             => 0x00000005,
    FORWARD_RESP_ID        => 0x80000005,
    EXIT_ID                => 0x00000006,
    EXIT_RESP_ID           => 0x80000006,
    QUERY_ID               => 0x00000007,
    QUERY_RESP_ID          => 0x80000007,
    MT_ROUTE_UPDATE_ID     => 0x00000008,
    MT_ROUTE_UPDATE_RESP_ID => 0x80000008,
};
1;

package Smgp::Client;
use strict;
use warnings FATAL => 'all';
use IO::Socket::INET;
use Smgp::Protocol;
use Smgp::Constant;
sub new {
    my ($class, %args) = @_;
    my $self = {
        host => $args{host} // 'localhost',
        port => $args{port} // 9000,
        socket => undef,
        sequence_id => 1,
    };
    bless $self, $class;
    return $self;
}
sub connect {
    my ($self) = @_;
    $self->{socket} = IO::Socket::INET->new(
        PeerHost => $self->{host},
        PeerPort => $self->{port},
        Proto => 'tcp',
    ) or die "Cannot connect to $self->{host}:$self->{port} $!";
}
sub login {
    my ($self, $body) = @_;
    my $header = Smgp::Protocol->new_header(
        request_id     => Smgp::Constant::LOGIN_ID,
        sequence_id    => 1,
    );
    my $pdu = Smgp::Protocol->new_pdu(
        header => $header,
        body   => $body,
    );
    $self->{socket}->send($pdu->encode_login_pdu());
    $self->{socket}->recv(my $response_length_bytes, 4);
    my $total_length = unpack("N", $response_length_bytes);
    my $remain_length = $total_length - 4;
    $self->{socket}->recv(my $response_data, $remain_length);
    return Smgp::Protocol->decode_pdu($response_data)->{body};
}
sub disconnect {
    my ($self) = @_;
    close($self->{socket}) if $self->{socket};
}
1;

package smgp_client_login_example;
use strict;
use warnings FATAL => 'all';
use Smgp::Client;
use Smgp::Protocol;
use Smgp::Constant;
sub main {
    my $client = Smgp::Client->new(
        host => 'localhost',
        port => 9000,
    );
    $client->connect();
    my $login = Smgp::Protocol->new_login(
        clientId            => '12345678',
        authenticatorClient => '1234567890123456',
        loginMode           => 1,
        timeStamp           => time(),
        version             => 0,
    );
    my $response = $client->login($login);
    if ($response->{status} == 0) {
        print "Login successful!\n";
    }
    else {
        print "Login failed! Status: ", (defined $response->{status} ? $response->{status} : 'undefined'), "\n";
    }
    $client->disconnect();
}
main() unless caller;
1;