#!/usr/bin/perl
## $Id: huawei-ussd,v 1.5 2015/06/08 09:05:03 pdc Exp $

use Getopt::Std;	# devel/p5-Getopt-Long
use Device::Gsm::Pdu;	# comms/p5-Device-Gsm
use Encode;

# defaults
$opt_r = "/dev/ttyUSB2";
$opt_s = "/dev/ttyUSB0";
$opt_r = "/dev/cuaU0.2";
$opt_s = "/dev/cuaU0.2";
$opt_r = "/dev/huawei0.2";
$opt_s = "/dev/huawei0.2";

my $USAGE = <<__EOU;

Usage: $0 [-r input_port] [-s output_port] [-n] [-h] [-v] [-w] ussd_msg

Description:
  Send and receive 7-bit PDU-encoded USSD messages.
  Written and tested for Huawei E1550 GSM/UMTS USB modem.

Options:
  -r port   Port to receive data from. Default: $opt_r
  -s port   Port to send AT commands to. Default: $opt_s
  -n        Do not send any data to port. Useful with -v.
  -h        Print this help.
  -v        Be verbose.
  -w        reply workaround (try it if script can not decode reply)
__EOU

sub HELP_MESSAGE {print "$USAGE\n"; exit 64;}
sub VERSION_MESSAGE {};
getopts ('r:s:hnvw');
$opt_v=1;
HELP_MESSAGE() and exit if (! defined $ARGV[0]) or defined($opt_h);

print "USSD MSG: $ARGV[0]\n" if $opt_v;
my $ussd_req = Device::Gsm::Pdu::encode_text7($ARGV[0]);
$ussd_req =~ s/^..//;
print "PDU ENCODED: $ussd_req\n" if $opt_v;

my $ussd_reply;
if (! $opt_n) {
	
	print STDERR "open send port...\n";
    #open (SENDPORT, '+<', $opt_s) or die "Can't send open '$opt_s': $!\n";
    open (SENDPORT, '+>', $opt_s) or die "Can't send open '$opt_s': $!\n";
	print STDERR "sending...\n";
    print SENDPORT 'AT+CUSD=1,',$ussd_req,",15\r\n";
    close SENDPORT;
    open (RCVPORT, $opt_r) or die "Can't recv open '$opt_r': $!\n";
    print "Waiting for USSD reply...\n" if $opt_v;
    while (<RCVPORT>) {
        chomp;
        die "USSD ERROR\n" if $_ eq "+CUSD: 2";
        if (/^\+CUSD: [01],\"([A-F0-9]+)\"/) {
            $ussd_reply = $1;
            print "PDU USSD REPLY: $ussd_reply\n" if $opt_v;
            last;
	}
	elsif(/^\+CME ERROR/) {
		print "$_\n";
	}
	elsif(/^NO CARRIER/) {
		die "$_\n";
	}
        else { print ">>> $_\n" if $_!~/^\s*$/ && $opt_v };
        print "Got unknown USSD message: $_\n" if /^\+CUSD:/ and $opt_v;
    }
}

if ($ussd_reply) {
    if(!$opt_w && $ussd_reply=~/^04|^..04|^....04/) { 	# utf16
	my $s=pack('H*', $ussd_reply);
	$decoded_ussd_reply=decode('UTF-16BE', $s);
    }
    unless(defined $decoded_ussd_reply) {
    	$decoded_ussd_reply = $opt_w ? pack('H*', $ussd_reply) : Device::Gsm::Pdu::decode_text7('ff'.$ussd_reply);
    }
    if($ENV{charset}=~/KOI/) { $decoded_ussd_reply = encode('koi8-u',$decoded_ussd_reply) }
    print STDOUT "USSD REPLY: $decoded_ussd_reply\n";
}
else
{
    print "No USSD reply!\n";
}