#!/usr/bin/php
<?php
/**
 * Checks the status of bluetooth devices and logs the data
 *
 * @package bluetooth_device_status
 *
 * @todo function to fork to background
 * @todo add logging
 * @todo connect to multiple mysql databases for logging device status 
 * (one on laptop, one on main server, one at office, etc)
 */

/** CONSTANTS **/
define('EXIT_STATUS_NORMAL', 0);
define('EXIT_STATUS_USAGE', 1);
define('EXIT_STATUS_CONFIG_ERROR', 2);
define('DAEMON_FOREGROUND', 0);
define('DAEMON_BACKGROUND', 1);
define('DEVICE_WAIT_TIME', 7);


/** LIBRARIES **/
require_once 'Console/Getopt.php';


/** VARIABLES **/
// BlueTooth Device Status
$GLOBALS['btds']['progname']    = 'btdevstatus';
$GLOBALS['btds']['version']     = '0.1';
$GLOBALS['btds']['config_file'] = 'btdevstatus.xml';
$GLOBALS['btds']['config']      = null;
$GLOBALS['btds']['hostname']    = null;
$GLOBALS['btds']['devices']     = array();
$GLOBALS['btds']['db_conn']     = null;
$GLOBALS['btds']['action']      = null;


/** MAIN **/

// parse arguments and perform actions
$short_options = 'h?c:fdla:r:';
$long_options = array(
	'help',
	'config',
	'foreground',
	'daemon',
	'list',
	'add=',
	'remove=',
);
$options = Console_Getopt::getopt($_SERVER['argv'], $short_options, $long_options);
if (PEAR::isError($options))
{
	Usage("Error in command line: " . $options->getMessage());
}
if (0 < count($options[0]))
{
	foreach ($options[0] as $option)
	{
		$option_switch = $option[0];
		$option_value  = $option[1];
		switch ($option_switch)
		{
			// config file
			case 'c':
			case '--config':
				$GLOBALS['btds']['config_file'] = $option_value;
			
			// help
			default:
			case 'h':
			case '?':
			case '--help':
				// no action - default
				break;
			
			// list devices
			case 'l':
			case '--list':
				$GLOBALS['btds']['action'] = 'list';
				break;
			
			// add device
			case 'a':
			case '--add':
				$GLOBALS['btds']['action'] = 'add';
				$add_name    = $option_value;
				$add_address = $options[1][0];
				break;
			
			// remove device
			case 'r':
			case '--remove':
				$GLOBALS['btds']['action'] = 'remove';
				$remove_device = $option_value;
				break;
			
			// foreground
			case 'f':
			case '--foreground':
				$GLOBALS['btds']['action'] = 'foreground';
				break;
			
			// daemon
			case 'd':
			case '--daemon':
				$GLOBALS['btds']['action'] = 'daemon';
				break;
		} // end switch option
	} // end foreach option
} // end if options


// parse config file
$GLOBALS['btds']['config'] = parse_config_file($GLOBALS['btds']['config_file']);

// determine hostname
$GLOBALS['btds']['hostname'] = get_hostname();

// connect to db
db_connect();


// perform proper action
switch ($GLOBALS['btds']['action'])
{
	// help
	default:
		Usage();
		break;
	
	// list devices
	case 'list':
		list_devices();
		break;
	
	// add device
	case 'add':
		add_device($add_name, $add_address);
		break;
	
	// remove device
	case 'remove':
		remove_device($remove_device);
		break;
	
	// foreground
	case 'foreground':
		$GLOBALS['btds']['devices'] = get_devices();
		monitor_devices(
			$GLOBALS['btds']['hostname'],
			$GLOBALS['btds']['devices']);
		break;
	
	// daemon
	case 'daemon':
		daemonize();
		db_connect();
		$GLOBALS['btds']['devices'] = get_devices();
		monitor_devices(
			$GLOBALS['btds']['hostname'],
			$GLOBALS['btds']['devices']);
		break;
} // end switch option



/** FUNCTIONS **/

function Usage($message = '', $exit_code = EXIT_STATUS_USAGE)
{
	$error_message = null;
	if (!empty($message))
	{
		$error_message = rtrim($message)."\n\n";
	} // end if message
	
	$usage_message =<<< END
== {$GLOBALS['btds']['progname']} v{$GLOBALS['btds']['version']} ==
{$_SERVER['argv'][0]} [-h|-?|--help] [-c|--config <config_file.xml>]
    [-l|--list] [-a|--add <name> <address>] [-r|--remove <name>|<address>]
    [-f|--foreground] [-d|--daemon]


END;
	
	fwrite(STDOUT, $error_message);
	fwrite(STDOUT, $usage_message);
	
	exit($exit_code);
} // end function Usage()

function parse_config_file($config_file)
{
	if (!file_exists($config_file))
	{
		Usage("Config File '$config_file' doesn't exist", EXIT_STATUS_CONFIG_ERROR);
	} // end if no file
	
	return simplexml_load_file($config_file);
} // end function parse_config_file()

function db_connect()
{
	$GLOBALS['btds']['db_conn'] = mysql_connect(
		$GLOBALS['btds']['config']->db->hostname,
		$GLOBALS['btds']['config']->db->username,
		$GLOBALS['btds']['config']->db->password,
		true)
		or die ("DBERROR: Couldn't connect to server - ".mysql_error());
	mysql_select_db(
		$GLOBALS['btds']['config']->db->database,
		$GLOBALS['btds']['db_conn'])
		or die ("DBERROR: Couldn't select database - ".mysql_error());
	
	return $GLOBALS['btds']['db_conn'];
} // end function db_connect()

/**
 * Quotes and escapes the specified value
 * 
 * @param string $value
 * @return string
 */
function db_quote($value)
{
	$needs_quoted = !is_int($value);
	$value = mysql_real_escape_string($value, $GLOBALS['btds']['db_conn']);
	if ($needs_quoted)
	{
		$value = '\'' . $value . '\'';
	} // end if needs quoted
	
	return $value;
} // end function db_quote()

function get_hostname()
{
	return preg_replace('/^(\w+)\..*$/', '$1', $_ENV['HOSTNAME']);
} // end function get_hostname()

function address2int($address)
{
	$return_val = null;
	
	// remove colons from address
	// 00:0F:DE:8B:58:8A => 000FDE8B588A
	$address = str_replace(':', '', $address);
	
	// validate address
	if (12 != strlen($address))
	{
		return $return_val;
	} // end if not 12 characters
	
	$return_val = hexdec($address);
	
	return $return_val;
} // end function address2int()

function int2address($address)
{
	$return_val = null;
	$address = (double) $address;
	
	if (!is_numeric($address) && 0 > $address)
	{
		return $return_val;
	} // end if not number or negative
	
	// convert the integer address to hex string
	$return_val = dechex($address);
	
	// make the string 12 characters
	$return_val = str_pad($return_val, 12, '0', STR_PAD_LEFT);
	
	// uppercase the hex
	$return_val = strtoupper($return_val);
	
	// insert the colons
	$return_val = preg_replace('/^(..)(..)(..)(..)(..)(..)$/', '$1:$2:$3:$4:$5:$6', $return_val);
	
	return $return_val;
} // end function int2address()

function get_devices()
{
	$return_array = array();
	
	$device_query = "SELECT `name`, `address` FROM `btdev_list`";
	$result = mysql_query($device_query, $GLOBALS['btds']['db_conn'])
		or die ("DBERROR: Couldn't perform query - ".mysql_error());
	
	while ($row = mysql_fetch_array($result))
	{
		$return_array[$row['name']] = int2address($row['address']);
	} // end while rows
	
	return $return_array;
} // end function get_devices()

function list_devices()
{
	$device_array = get_devices();
	
	if (0 == count($device_array))
	{
		fwrite(STDOUT, "No Devices\n");
	} // end if no devices
	
	foreach ($device_array as $device_name => $device_address)
	{
		fwrite(STDOUT, $device_name . ' ' . $device_address . "\n");
	} // end foreach device
} // end function list_devices()

function add_device($add_name, $add_address)
{
	// validate name
	if (0 > strlen($add_name))
	{
		Usage("Name must be set ($add_name)");
	} // end if no name
	
	$add_address_int = address2int($add_address);
	if (!is_numeric($add_address_int) || 0 > $add_address_int)
	{
		Usage("Address must be set ($add_address)");
	} // end if not numeric address
	
	$add_query = 'REPLACE INTO `btdev_list` ' .
		'SET `name` = \'' . mysql_real_escape_string($add_name) . '\', ' .
		'`address` = \'' . $add_address_int . '\'';
	
	fwrite(STDOUT, "Adding '$add_name' with address '$add_address'\n");
	mysql_query($add_query, $GLOBALS['btds']['db_conn'])
		or die ("DBERROR: Couldn't perform query - ".mysql_error());
} // end function add_device(

function remove_device($device)
{
	$remove_type = 'name';
	
	// check if $device is a name or an address
	$device_as_address = address2int($device);
	if (is_numeric($device_as_address) && 0 < $device_as_address)
	{
		$remove_type = 'address';
		$device = $device_as_address;
	} // end if device address

	// remove the proper device
	$remove_query = 'DELETE FROM `btdev_list` ' .
		'WHERE `' . $remove_type . '` = \'' . mysql_real_escape_string($device) . '\'';
	mysql_query($remove_query, $GLOBALS['btds']['db_conn'])
		or die ("DBERROR: Couldn't perform query - ".mysql_error());
} // end function remove_device()

/**
 * Daemonizes script
 */
function daemonize()
{
	if (pcntl_fork())
	{
		exit(EXIT_STATUS_NORMAL);
	}
	
	posix_setsid();
	chdir('/');
	umask(0);
	
	fclose(STDIN);
	fclose(STDOUT);
	fclose(STDERR);
	// STDIN = fopen('/dev/null');
	// STDOUT = fopen('/dev/null');
	// STDERR = fopen('/dev/null');
} // end function daemonize()
	
/**
 * Monitors the various devices status
 * 
 * @param string $hostname local host name
 * @param array $device_list
 */
function monitor_devices($hostname, $device_list)
{
	// loop forver
	while (true)
	{
		foreach ($device_list as $device_name => $device_address)
		{
#			fwrite(STDOUT, "Checking $device_name ($device_address)\n");
			$device_status = poll_device($device_address);
#			fwrite(STDOUT, "  Device status: " . ($device_status ? 'seen' : 'not seen') . "\n");
			
			// log device status
			log_device_seen($hostname, $device_name);
		} //end foreach device
		
		sleep(DEVICE_WAIT_TIME);
	} // end never end
} // end function monitor_devices()

/**
 * checks if the device can be seen
 * 
 * @param string $device_address
 * @return boolean whether device could be seen
 */
function poll_device($device_address)
{
	$return_val = false;
	
	// check if the device can be seen
	$hcitool = escapeshellcmd($GLOBALS['btds']['config']->hcitool);
	$device_address = escapeshellarg($device_address);
	$device_check_cmd = "$hcitool name $device_address";
	$device_name = `$device_check_cmd 2> /dev/null`;
	if (!empty($device_name))
	{
		$return_val = true;
	} // end if device name
	
	return $return_val;
} // end function poll_device()

/**
 * Logs that the specified device was seen
 * 
 * @param string $hostname
 * @param string $device_name
 */
function log_device_seen($hostname, $device_name)
{
	$query = 'REPLACE INTO `btdev_status` SET ' .
		'`dev_name` = ' .
			db_quote($device_name) . ', ' .
		'`host` = ' .
			db_quote($hostname) . ', ' .
		'`last_seen` = NOW()';
	mysql_query($query, $GLOBALS['btds']['db_conn'])
		or die ("DBERROR: Couldn't perform query - ".mysql_error());
} // end function log_device_status()