<?php

namespace Vn\Web;

require_once (__DIR__.'/service.php');
require_once (__DIR__.'/rest-request.php');

use Vn\Lib;

/**
 * Base class for REST application.
 **/
class RestService extends Service
{
	function run ()
	{
		ini_set ('display_errors', _DEBUG_MODE);
		set_error_handler ([$this, 'errorHandler'], E_ALL);
		set_exception_handler ([$this, 'exceptionHandler']);

		$this->startSession ();

		$method = $this->app->loadMethod (
			$_REQUEST['method'], __NAMESPACE__.'\RestRequest', './rest');
		$method->run ();
	}

	/**
	 * Tries to retrieve user credentials from many sources such as POST,
	 * SESSION or COOKIES. If $_POST['remember'] is defined the user credentials 
	 * are saved on the client brownser for future logins, cookies names are
	 * 'vn_user' for the user name and 'vn_pass' for user password, the
	 * password is encoded using base64_encode() function and should be decoded
	 * using base64_decode().
	 **/
	function login ()
	{
		if ($this->conn)
			return $this->conn;
	
		$user = NULL;
		$password = NULL;
		$rememberUser = TRUE;
		$rememberPass = FALSE;
		$credentialsChanged = TRUE;
		$wasLoged = isset ($_SESSION['user']);
		
		if (isset ($_POST['guest']))
		{
			$sysConn = $this->app->getSysConn ();
			$row = $sysConn->getRow (
				'SELECT guest_user, guest_pass FROM config');

			if ($row)
			{
				$user = $row['guest_user'];
				$password = base64_decode ($row['guest_pass']);
				$rememberUser = FALSE;
			}
		}
		elseif (isset ($_POST['user']) && isset ($_POST['password']))
		{
			$user = $_POST['user'];
			$password = $_POST['password'];

			if (isset ($_POST['remember']) && $_POST['remember'])
				$rememberPass = TRUE;
		}
		elseif (isset ($_SESSION['user']))
		{
			$user = $_SESSION['user'];
			$password = $_SESSION['password'];
			$credentialsChanged = FALSE;
		}
		elseif (isset ($_COOKIE['vn_user']) && isset ($_COOKIE['vn_pass']))
		{
			$user = $_COOKIE['vn_user'];
			$password = base64_decode ($_COOKIE['vn_pass']);
			$rememberPass = TRUE;
		}

		if (!isset ($user))
			throw new SessionExpiredException ();

		try {
			$db = $this->app->createConnection ($user, $password);
			$db->query ('CALL user_session_start (#)', [session_id ()]);
			$this->conn = $db;

			if ($rememberUser)
			{
				$cookieLife = time () + 7 * 86400; // 7 Days
				setcookie ('vn_user', $user, $cookieLife);

				if ($rememberPass)
					setcookie ('vn_pass',
						base64_encode ($password), $cookieLife);
			}

			$_SESSION['user'] = $user;
			$_SESSION['password'] = $password;
		}
		catch (\Exception $e)
		{
			$this->conn = NULL;
			throw new BadLoginException ();
		}

		// Registering the user access

		if (!$wasLoged)
			unset ($_SESSION['visitUser']);

		if (isset ($_SESSION['access'])
		&& !isset ($_SESSION['visitUser']))
		{
			$sysConn = $this->getSysConn ();
			$_SESSION['visitUser'] = $sysConn->getValue (
				'CALL visit_user_new (#, #, #)',
				[
					 $_SESSION['access']
					,nullIf ($_SESSION, 'visitUser')
					,session_id ()
				]
			);
	
			if (!isset ($_SESSION['visitUnknown']))
				$_SESSION['visitUnknown'] = $_SESSION['visitUser'];
		}
		
		return $db;
	}
	
	/**
	 * Cleans the last saved used credentials.
	 **/
	function logout ()
	{
		$_SESSION['visitUser'] = nullIf ($_SESSION, 'visitUnknown');
		
		setcookie ('vn_pass', '', -1);
		unset ($_COOKIE['vn_pass']);
		unset ($_SESSION['user']);
		unset ($_SESSION['password']);
		
		if ($this->conn)
		{
			$this->conn->query (
				'DELETE FROM user_session_view '
				 .'WHERE connection_id = CONNECTION_ID()'
			);
			$this->conn->close ();
			$this->conn = NULL;
		}
	}

	/**
	 * Deinitializes the Application. When init method is called, this 
	 * function is called automatically at the end of the script .
	 **/
	function deinit ()
	{
		if ($this->conn)
			$this->conn->query ('CALL user_session_end ()');
			
		parent::deinit ();
	}
	
	function statusFromException ($e)
	{
		try {
			throw $e;
		}
		catch (SessionExpiredException $e)
			{ $status = 401; }
		catch (BadLoginException $e)
			{ $status = 401; }
		catch (Lib\UserException $e)
			{ $status = 400; }
		catch (\Exception $e)
			{ $status = 500; }
			
		http_response_code ($status);
	}
	
	function errorHandler ($errno, $message, $file, $line, $context)
	{
		$eFlag =
			  E_USER_NOTICE
			| E_USER_WARNING
			| E_USER_DEPRECATED
			| E_NOTICE
			| E_WARNING
			| E_DEPRECATED;

		if (!($errno & $eFlag))
			http_response_code (500);
		
		return FALSE;
	}

	function exceptionHandler ($e)
	{
		$this->statusFromException ($e);
		throw $e;
	}
}

?>