<?php
require_once('config.php');

$config = get_config();

/*******************************
* Load authentication plugin ..
*******************************/
if ( preg_match('/^\w+$/', $config['auth_backend']))
{
	if ( !@include_once ( 'lib/auth_plugins/' . $config['auth_backend'] . ".php" ) )
	{  print json_encode( array( 'response' => 'error', 'cause' => 'auth-load' ) ); exit; }
}
else
{  print json_encode( array( 'response' => 'error', 'cause' => 'config-error' ) ); exit; }
/*******************************/

function apikey_verify( $key )
{
	if ( $key == "6327c08b70f9" ) return 1;
	return false;
}

function new_key( $hex = false )
{
	// Basically this is at the moment a slightly modified
	// version of generate_password() from user_functiions.php
	// The behaviour/output of this function is expected to change
	// so using generate_password() directly does not make sense...
	$length = 16;
	$string = "";
	 while ( strlen( $string ) < $length )
	 {
		if ( $hex )
			$string .= substr(md5(rand().rand()), 0, $length);
		else
		{
			$string .= crypt( substr(sha1(rand()), 0, $length) );
			$string = preg_replace( '/\W/', '', $string);
		}
	 }
	return substr( $string, 0, $length );
}

function simple_authfail()
{
	print json_encode( array( 'response' => 'failed', 'cause' => 'unauthorized', 'description' => 'Not authorized') );
	exit;
}

function token_auth( )
{
	global $_GET;

	// TODO: Part of ping/pong requirement.
	// Run a function to clear all authkeys older than 5 minutes.
	// expire_authkeys();

	if ( array_key_exists('session', $_GET ) 
	     && array_key_exists('auth_key', $_GET ) )
	{ 
		if ( ! check_session($_GET['session'] ) ) simple_authfail();
		if ( ! check_authkey($_GET['auth_key'] ) ) simple_authfail(); 
	}
	else simple_authfail();
}

function get_cookie_path ()
{
	$name = $_SERVER["SCRIPT_NAME"];
	$file = basename($name);
	$path = preg_replace("/".$file."/", "", $name);
	return $path;

}

function check_authkey ( $key )
{
	// TODO: Make real, actual checks...
	if ( $key ) return true;
	return false;
}

function update_authkey ( $session, $authid )
{
	$key = substr(new_key(), 0, 8);
	return $key;
}

function check_session ( $name )
{
	session_name( $name );
	session_start();
	if ( ! $_SESSION['authid'] )
	{
		return clear_credentials($name);
	}
	if ( ! $_COOKIE['client_key'] )
	{
		return clear_credentials($name);
	}

	$authid = $_SESSION['authid'];
	$type   = $_SESSION['type'];
	$client_key = $_COOKIE['client_key'];

	$level = get_authorization( $type, $authid );
	if ( $level == false )
	{
		return clear_credentials($name);
	}

	$session_key = md5( $name . $authid );
	if ( $client_key != $session_key )
	{
		return clear_credentials($name);
	}

	// TODO: Database checks?

	// TODO: Refresh cookie

	// If we got this far, things are looking good.
	return true;
}

function set_credentials( $authid, $type )
{
	$name = new_key(true);
	session_name( $name );
	session_start();
	$_SESSION['authid'] = $authid;
	$_SESSION['type']   = $type;

	$client_key  = md5( $name . $authid );
	setcookie('client_key', $client_key, time()+180*60, get_cookie_path() );

	// TODO: Stuff data to database for further checks?
	// TODO: Do magic with the KEY

	return $name;
}

function clear_credentials($name)
{
	setcookie('client_key', '', 0, get_cookie_path() );
	setcookie($name, '', 0, "/");

	$_SESSION = array();
	session_destroy();
	return false;
}
function get_authorization()
{
	return 1;
}
function can_write ( )
{
	// Stub, to be called on any API nodes that write data in the DB.
	$authid = $_SESSION['authid'];
	$type   = $_SESSION['type'];
	$level = get_authorization( $type, $authid );
	return true;
}

?>