#!/usr/bin/php
<?php
/** 
* script for a server to automatically self-locate, using Google's MAC address lookup
*/
// Run wifi AP scan
exec( "/sbin/iwlist wlan0 scan", $output );

$output = implode( "\n", $output );

$aAPs = array();

$m = preg_split( "/          Cell/", $output );

$aLabels = array( "mac" => "mac_address", "signal" => "signal_strength", "ssid" => "ssid" );

foreach( $m as $info ){
  preg_match( "/( (\d+) - Address: (?P<mac>[:0-9A-Z]+)(.*)Signal level=(?P<signal>[-\d]+) dBm(.*)ESSID:\"(?P<ssid>[^\"]+)\")+/s", $info, $ap );
  $a = array();
  foreach( $aLabels as $k => $l ){
    if( is_array( $ap[$l] ) ) continue;
    $a[$l] = $ap[$k];
  }
  if( $a["mac_address"] == "" ) continue;
  if( sizeof( $a ) > 0 ) $aAPs[] = $a;
}

// list of AP's MAC addresses from scan
$loc = mac2loc( $aAPs );
echo "Google's location estimate:\n";
print_r( $loc );
echo "http://maps.google.co.uk/maps?q=".$loc->location->latitude.",".$loc->location->longitude."\n";

// submit each to google's lookup

/*
POST /loc/json HTTP/1.0
Host: www.google.com
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv; 1.9.2b4) Gecko/20091124 Firefox/3.6b4
Accept: text/html,aookication/xhtml+xml,application/xml;q=0.9,"/";q=0.6
Accept-Language: en-us,en;q=0.5
Accept-Encoding: none
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Content-Length: 127
Content-Type: text/plain; charset=UTF-8
Pragma: no-cache
Cache-Control: no-cache

{"version":"1.1.0","request_address":true,"wifi_towers":[{"mac_address":"$mac","ssid":"g","signal_strength":-72}]}
*/

function mac2loc( $aAPs ){
  
  echo "Attempting to find location via Google location API\n";
  if( sizeof( $aAPs ) > 0 ){
    echo "Using the following nearby access points:\n";
    foreach( $aAPs as $ap ){
      echo $ap["ssid"].",".$ap["mac_address"].",".$ap["signal_strength"]."\n";
    }
  }else{
    echo "Couldn't find any nearby access points, trying location API anyway...\n";
  }

  $ch = curl_init("http://www.google.com/loc/json");
  $aPost = array();
  $aPost["version"] = "1.1.0";
  $aPost["request_address"] = true;
  $aPost["wifi_towers"] = $aAPs;
  $data = json_encode( $aPost );
  // echo "Sending: ".$data."\n";
  curl_setopt($ch, CURLOPT_POST, 1 );
  curl_setopt($ch, CURLOPT_POSTFIELDS, $data );
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true );
  $rlt = curl_exec( $ch );
  return json_decode( $rlt );
}


// create "my maps" scatter of estimated locations

// log results to twitter
?>