#!/usr/bin/env php
<?php

	$location_cmd = "/usr/sbin/scselect";
	$scan_cmd = "/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport";

	$locations = array();
	$current_location = NULL;
	$new_location = NULL;

	exec($location_cmd, $rows, $error_code);

	if($error_code)
    {
        trigger_error("Location command failed: '{$location_cmd}'");
        die($error_code);
    }

    foreach($rows as $row)
    {
        if(preg_match("#(?<selected>\*\s+)?(?<id>[-0-9A-F]+)\s+\((?<name>.*)\)#", $row, $m))
        {
            if($m['selected'])
            {
                $current_location = $m['id'];
            }
            $locations[$m['id']] = $m['name'];
        }
    }

    if(!$locations)
    {
        trigger_error("No locations found");
        die(1);
    }

    $ssid = parse_ini_file(__DIR__ . '/ssid.ini');

	if(!$ssid)
    {
        trigger_error("No ssid-settings found");
        die(1);
    }

    exec("{$scan_cmd} -s", $rows, $error_code);

    if($error_code)
    {
        trigger_error("Scan command failed: '{$scan_cmd} -s'");
        die($error_code);
    }

    foreach($rows as $row)
    {
        if(preg_match("#^\s*\b(?<name>.*)\b (?<address>[0-9a-f][0-9a-f](:[0-9a-f][0-9a-f]){5}) #", $row, $m))
        {
            if(!empty($ssid[$m['address']]))
            {
                $new_location = $ssid[$m['address']];
                break;
            }
            if(!empty($ssid[$m['name']]))
            {
                $new_location = $ssid[$m['name']];
                break;
            }
        }
    }

    if(!$new_location)
    {
        if(!empty($ssid['*']))
        {
            $new_location = $ssid['*'];
        }
    }

    if(!$new_location)
    {
        die(0);
    }

    if(empty($locations[$new_location]))
    {
        $location_by_name = array_flip($locations);
        if(empty($location_by_name[$new_location]))
        {
            trigger_error("Unknown Location: '{$new_location}'" . PHP_EOL . print_r($ssid, TRUE));
            die(1);
        }
        $new_location = $location_by_name[$new_location];
    }

    if($new_location == $current_location)
    {
        die(0);
    }

    if($current_location AND !empty($locations[$current_location]))
    {
        echo "Switching from '{$locations[$current_location]}' ({$current_location}) to '{$locations[$new_location]}' ({$new_location})" . PHP_EOL;
    }
    else
    {
        echo "Switching to '{$locations[$new_location]}' ({$new_location})" . PHP_EOL;
    }

    passthru($location_cmd . ' ' . escapeshellarg($new_location), $error_code);
    die($error_code);