#!/usr/bin/perl

##########################################################################
## OpenAPRS.Net                                                         ##
##########################################################################
## OpenAPRS, Perl Direct Client Connection - Client                     ##
## Copyright (C) 2008 Gregory A. Carter                                 ##
##                                                                      ##
## This program is free software; you can redistribute it and/or modify ##
## it under the terms of the GNU General Public License as published by ##
## the Free Software Foundation; either version 1, or (at your option)  ##
## any later version.                                                   ##
##                                                                      ##
## This program is distributed in the hope that it will be useful,      ##
## but WITHOUT ANY WARRANTY; without even the implied warranty of       ##
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        ##
## GNU General Public License for more details.                         ##
##                                                                      ##
## You should have received a copy of the GNU General Public License    ##
## along with this program; if not, write to the Free Software          ##
## Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.            ##
##########################################################################

use Socket;
use Switch;

###
# Edit the following two variables if you have an actual
# account with OpenAPRS.
#
# To signup for an account point your web browser at
# http://www.openaprs.net/ and click the "Options" icon
# at the top, then "Signup" in the popup window.
#
# Signing up and verifying an account with OpenAPRS will
# allow you to send positions, objects and APRS messages
# from both the OpenAPRS web page and DCC interface.
#

$email = "guest";
$pass = "guest";
$client = "OpenAPRS-Perl-1.0";

###
# To filter the live output down to a specific area, change
# the following lines (and set $filter to 1).
#

$filter = 0;
$lat = 38.00;
$lon = -122.00;
$range = 50; # in kilometers

###
# Display live data in NMEA waypoints.
#
# This example client can easly be turned into a full
# client that is able to parse and send data to the server
# with a few modificaitons.  To parse a DCC live data stream
# in realtime, set the following to 0 and see `case "318"'
# below in the code.
#

$nmea = 0;

###
# Shouldn't need to edit anything past this line unless you want
# to parse things differently.
#

#############################################################################

$remote_host = "dcc.openaprs.net";
$remote_port = 2620;

print "*** Connecting to " . $remote_host . ":" . $remote_port . "\n";

# create a socket
socket(Server, PF_INET, SOCK_STREAM, getprotobyname('tcp'));

# build the address of the remote machine
$internet_addr = inet_aton($remote_host)
    or die "Couldn't convert $remote_host into an Internet address: $!\n";
$paddr = sockaddr_in($remote_port, $internet_addr);

# connect
if (!connect(Server, $paddr)) {
  die "Couldn't connect to $remote_host:$remote_port: $!\n";
} # if

select((select(Server), $| = 1)[0]);  # enable command buffering

# read the remote answer
while(<Server>) {
  ($r, $m) = split(/ /, $_, 2);
  print $_;

  switch($r) {
    ###
    # Received welcome, send our login information.
    #
    case "002" {
      Send(".LN $email $pass $client\n");
    } # case 002
    ###
    # Server pinged us, we must respond with .PN within 180 seconds
    # or connection will be timed out.
    #
    case "106" {
      Send(".PN\n");
    } # case 106
    ###
    # We've logged in successfully, now let's tell the server
    # to send us live data.
    #
    case "100" {
      if ($filter == 0) {
        if ($nmea) {
          Send(".LV NMA:YES\n");
        } # if
        else {
          Send(".LV\n");
        } # else
      } # if
      else {
        if ($nmea) {
          Send(".LV NMA:YES|CN:$lat,$lon,$range\n");
        } # if
        else {
          Send(".LV CN:$lat,$lon,$range\n");
        } # else
      } # else
    } # case 100
    ###
    # Reply 318 is DCC format live data from the server.
    #
    # NOTE:  This is not NMEA waypoint data.  To receive the DCC format
    # live data and use this section change $nmea = 1 to $nmea = 0 above.
    #
    case "318" {
      ###
      # This is an example of how to parse data from the live data stream
      # (not in NMEA mode).
      #
      # To test, set $nmea at the top of this file to 1 and uncomment
      # the lines below.
      #
      # Then, uncomment the lines below:
      #%v = Vars($m);
      #print "Source(" . $v{"SR"} . ")\n";      
      #print "Latitude(" . $v{"LA"} . ")\n";      
      #print "Longitude(" . $v{"LN"} . ")\n";      
    } # case 318
  } # switch
  if ($r eq "002") {
  } # if
} # while

print "*** Disconnected from " . $remote_host . "\n";

# terminate the connection when done
close(Server);

sub Send {
  my($message) = @_;

  print Server "$message";
  print "> $message";
} # sub Send

sub Escape {
  my($parseMe) = @_;
  my $ret;

  $ret = "";
  for($pos=0; $pos < length($parseMe); $pos++) {
    if ($parseMe[$pos] eq '|' || $parseMe[$pos] eq '\\') {
      $ret .= "\\" . $parseMe[$pos];
    } # if
    else {
      $ret .= $parseMe[$pos];
    } # else
  } # for

  return $ret;
} # sub Escaped

sub Vars {
  my($parseMe) = @_;
  my $field;
  my $name;

  $parseMe =~ s/\r//g;
  $parseMe =~ s/\n//g;

  %varMap = ();

  while(length($parseMe)) {
    $name = "";

    for($pos=0; $pos < length($parseMe) && substr($parseMe, $pos, 1) ne ':'; $pos++) {
      $name .= substr($parseMe, $pos, 1);
    } # for

    $parseMe = substr($parseMe, $pos+1);

    #print "name($name)\n";
    #print "parseMe($parseMe)\n";

    $field = "";
    $isEscaped = 0;
    for($pos=0; $pos < length($parseMe); $pos++) {
      $p = substr($parseMe, $pos, 1);

      if (!$isEscaped && ord($p) == 124) {
        last;
      } # if

      if (!$isEscaped && ord($p) == 92) {
        $isEscaped = 1;
      } # if
      else {
        $isEscaped = 0;
        $field .= $p;
      } # else
    } # for

    if (length($parseMe) >= $pos+1) {
      $parseMe = substr($parseMe, $pos+1);
    } # if
    else {
      $parseMe = "";
    } # else

    #print "field($field)\n";

    if (length($name) > 0 && length($field) > 0) {
      $varMap{$name} = $field;
    } # if

  } # while

  return %varMap;
} # sub Vars