<?php
/*
	COPYRIGHT 2009 Damien Keitel
		
	This file is part of Facebook 2011.

    Facebook 2011 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 3 of the License, or
    (at your option) any later version.

    Facebook 2011 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 Facebook 2011.  If not, see <http://www.gnu.org/licenses/>.*/
if (!defined('IN_PHPBB'))
{
	exit;
}

define('FB2011_FACEBOOK_LOGIN', 0);
define('FB2011_FACEBOOK_PROFILE', 1);

define('FB2011_HIDE_POST_LOGON', 2);	// Does the user want to be asked if they want to see the 'hide online' and autologin screen after verification?

define('FB2011_USER_OPTION_COUNT', 3);


function fb_language_select($default = '')
{
	global $config, $phpbb_root_path ;
  $get_locale =	simplexml_load_file($phpbb_root_path . '/fb2011/FacebookLocales.xml');
  $arr = $get_locale->locale;

	$fb_lang_options = '';
  foreach($arr as $locale)
	{
		$selected = ($locale->codes->code->standard->representation == $default) ? ' selected="selected"' : '';
		$fb_lang_options .= '<option name="' . $locale->codes->code->standard->representation . '" id="' . $locale->codes->code->standard->representation . '" value="' . $locale->codes->code->standard->representation . '"' . $selected . '>' . $locale->englishName . '</option>';
	}

	return $fb_lang_options;
}

/**
* Extract an fb2011 settings value
* break it down and convert it to an array.

* @param integer $settings An Integer value that is retrieved from the congif table.
*
* @return array $fb_settings An array containing 0 or 1 values to determine the settings.
*/
function parse_signed_request($signed_request, $secret) 
{
  list($encoded_sig, $payload) = explode('.', $signed_request, 2); 

  // decode the data
  $sig = self::base64_url_decode($encoded_sig);
  $data = json_decode(self::base64_url_decode($payload), true);

  if (strtoupper($data['algorithm']) !== 'HMAC-SHA256') 
  {
    error_log('Unknown algorithm. Expected HMAC-SHA256');
    return null;
  }

  // check sig
  $expected_sig = hash_hmac('sha256', $payload, $secret, $raw = true);
  if ($sig !== $expected_sig) {
    error_log('Bad Signed JSON signature!');
    return null;
  }

  return $data;
}

function base64_url_decode($input) 
{
    return base64_decode(strtr($input, '-_', '+/'));
}

function get_fb2011_cookie($app_id, $app_secret) 
{
  $args = array();
  @parse_str(trim($_COOKIE['fbs_' . $app_id], '\\"'), $args);
  ksort($args);
  $payload = '';
  foreach ($args as $key => $value) 
  {
    if ($key != 'sig') 
    {
      $payload .= $key . '=' . $value;
    }
  }
  if (md5($payload . $app_secret) != @$args['sig']) 
  {
    return null;
  }
  return $args;
}

function get_fb2011_settings($settings)
{
	if($settings == 0)
	{
		$fb2011_settings = array_fill(0, FB2011_USER_OPTION_COUNT, 0);
	}
	else
	{
		$fb2011_settings = decbin($settings);
	
		$fb2011_settings = strrev($fb2011_settings);
	
		$fb2011_settings = str_split($fb2011_settings);
	}
	return $fb2011_settings;
}

/**
* Converts fb2011 settings array to an Interger value that 
* is stored in the $config array.
*
* @param array $fb2011_settings An array containing boolean values to determine the settings.
*/

function set_fb2011_settings($settings)
{
	$fb2011_settings = implode($settings);
	
	$fb2011_settings = strrev($fb2011_settings);
	
	$fb2011_settings = bindec($fb2011_settings);
	
	return $fb2011_settings;
}

/**
* Retrieve the Alternate Login settings value stored in the
* alternatelogin_settings table.
*
* @param integer $user_id The user id from the $user array.
*
* @return An integer value for conversion if neccesary.
*/
function get_fb2011_user_settings($user_id)
{
	global $db;
	$sql = 'SELECT fb2011_user_settings' .
			' FROM ' . FB2011_USER_DATA .
			" WHERE user_id = '$user_id'";
			
	$result = $db->sql_query($sql);
	
	if(!$result)
	{
		return false;
	}
	
	$ret_value = $db->sql_fetchfield('fb2011_user_settings');
	
	return $ret_value;
}

/**
* Set the Alternate Login settings value stored in the
* alternatelogin_settings table.
*
* @param integer $user_id The user id can be found in the $user array.
*
* @param integer $settings The integer value of the user settings.  Can be converted from the get_al_settings() function.
*
* @return A boolean value indicating whether or not the operation succeded.
*/
function set_fb2011_user_settings($user_id)
{
	global $db;
	$sql = 'UPDATE ' . FB2011_USER_DATA .
			" SET fb2011_user_settings = '$settings'
			 WHERE user_id = '$user_id'";
			
	$result = $db->sql_query($sql);
	
	if(!$result)
	{
		return false;
	}
	else
	{
		return true;
	}
}
?>