<?php
/**
 * Kunena Component
 * @package    Kunena.Framework
 *
 * @copyright  (C) 2008 - 2018 Kunena Team. All rights reserved.
 * @license    https://www.gnu.org/copyleft/gpl.html GNU/GPL
 * @link       https://www.kunena.org
 **/
defined('_JEXEC') or die();

/**
 * Class KunenaError
 */
abstract class KunenaError
{
	static $enabled = 0;

	static $handler = false;

	static $debug = false;

	static $admin = false;

	static $format;

	/**
	 * @throws Exception
	 */
	public static function initialize()
	{
		if (!self::$enabled)
		{
			self::$format = JFactory::getApplication()->input->getWord('format', 'html');
			self::$debug = JDEBUG || KunenaFactory::getConfig()->debug;
			self::$admin = JFactory::getApplication()->isAdmin();

			// Make sure we are able to log fatal errors.
			class_exists('KunenaLog');

			register_shutdown_function(array('KunenaError', 'shutdownHandler'), self::$debug || self::$admin || KUNENA_PROFILER);

			if (!self::$debug)
			{
				return;
			}

			@ini_set('display_errors', 1);
			self::$handler = true;
			@error_reporting(E_ALL | E_STRICT);
			JFactory::getDbo()->setDebug(true);
			set_error_handler(array('KunenaError', 'errorHandler'));

			self::$enabled++;
		}
	}

	/**
	 *
	 */
	public static function cleanup()
	{
		if (self::$enabled && (--self::$enabled) == 0)
		{
			if (self::$handler)
			{
				restore_error_handler();
				self::$handler = false;
			}
		}
	}

	/**
	 * @param        $msg
	 * @param   string $where
	 *
	 * @throws Exception
	 */
	public static function error($msg, $where='default')
	{
		if (self::$debug)
		{
			$app = JFactory::getApplication();
			$app->enqueueMessage(JText::sprintf('COM_KUNENA_ERROR_' . strtoupper($where), $msg), 'error');
		}
	}

	/**
	 * @param        $msg
	 * @param   string $where
	 *
	 * @throws Exception
	 */
	public static function warning($msg, $where='default')
	{
		if (self::$debug)
		{
			$app = JFactory::getApplication();
			$app->enqueueMessage(JText::sprintf('COM_KUNENA_WARNING_' . strtoupper($where), $msg), 'notice');
		}
	}

	/**
	 * Return different error if it's an admin or a simple user
	 *
	 * @param $exception
	 *
	 * @return string
	 * @since 5.0
	 */
	public static function displayDatabaseError($exception)
	{
		$app = JFactory::getApplication();
		$db = JFactory::getDBO();

		if (JFactory::getApplication()->isAdmin())
		{
			$app->enqueueMessage($exception->getMessage(), 'error');
		}
		elseif (self::$debug || self::$admin)
		{
			$app->enqueueMessage('Kunena ' . JText::sprintf('COM_KUNENA_INTERNAL_ERROR_ADMIN', '<a href="http:://www.kunena.org/">www.kunena.org</a>'), 'error');
		}
		else
		{
			$app->enqueueMessage('Kunena ' . JText::_('COM_KUNENA_INTERNAL_ERROR'), 'error');
		}
	}

	/**
	 * Return the error in the database query (deprecated use exception in queries instead)
	 *
	 * @deprecated
	 *
	 * @return boolean
	 * @throws Exception
	 */
	public static function checkDatabaseError()
	{
		$db = JFactory::getDBO();

		if ($db->getErrorNum())
		{
			$app = JFactory::getApplication();

			if (JFactory::getApplication()->isAdmin())
			{
				$app->enqueueMessage($db->getErrorMsg(), 'error');
			}
			elseif (self::$debug || self::$admin)
			{
				$app->enqueueMessage('Kunena ' . JText::sprintf('COM_KUNENA_INTERNAL_ERROR_ADMIN', '<a href="http:://www.kunena.org/">www.kunena.org</a>'), 'error');
			}
			else
			{
				$app->enqueueMessage('Kunena ' . JText::_('COM_KUNENA_INTERNAL_ERROR'), 'error');
			}

			return true;
		}

		return false;
	}

	/**
	 * Get the last error message from database
	 *
	 * @deprecated
	 *
	 * @return string
	 */
	public static function getDatabaseError()
	{
		$db = JFactory::getDBO();

		if ($db->getErrorNum())
		{
			if (self::$debug || self::$admin)
			{
				return $db->getErrorMsg();
			}
			else
			{
				return 'Kunena ' . JText::_('COM_KUNENA_INTERNAL_ERROR');
			}
		}
	}

	/**
	 * @param $errno
	 * @param $errstr
	 * @param $errfile
	 * @param $errline
	 *
	 * @return boolean
	 */
	public static function errorHandler($errno, $errstr, $errfile, $errline)
	{
		if (error_reporting() == 0 || !strstr($errfile, 'kunena'))
		{
			return false;
		}

		switch ($errno)
		{
			case E_NOTICE :
			case E_USER_NOTICE :
				$error = "Notice";
				break;
			case E_WARNING :
			case E_USER_WARNING :
			case E_CORE_WARNING :
			case E_COMPILE_WARNING :
				$error = "Warning";
				break;
			case E_ERROR :
			case E_USER_ERROR :
			case E_PARSE :
			case E_CORE_ERROR :
			case E_COMPILE_ERROR :
			case E_RECOVERABLE_ERROR :
				$error = "Fatal Error";
				break;
			case E_STRICT :
				return false;
			default :
				$error = "Unknown Error $errno";
				break;
		}

		// Clean up file path (take also care of some symbolic links)
		$errfile_short = strtr($errfile, '\\', '/');
		$errfile_short = preg_replace('%' . strtr(JPATH_ROOT, '\\', '/') . '/%', '\\1', $errfile_short);
		$errfile_short = preg_replace('%^.*?/((administrator/)?(components|modules|plugins|templates)/)%', '\\1', $errfile_short);

		if (self::$debug || self::$admin)
		{
			printf("<br />\n<b>%s</b>: %s in <b>%s</b> on line <b>%d</b><br /><br />\n", $error, $errstr, $errfile_short, $errline);
		}

		if (ini_get('log_errors'))
		{
			error_log(sprintf("PHP %s:  %s in %s on line %d", $error, $errstr, $errfile, $errline));
		}

		return true;
	}

	/**
	 * @param $debug
	 */
	public static function shutdownHandler($debug)
	{
		static $types = array (E_ERROR, E_USER_ERROR, E_PARSE, E_CORE_ERROR, E_COMPILE_ERROR, E_RECOVERABLE_ERROR);

		$error = error_get_last();

		if ($error && in_array($error['type'], $types))
		{
			KunenaLog::log(KunenaLog::TYPE_ERROR, KunenaLog::LOG_ERROR_FATAL, $error);

			if ($debug)
			{
				// Clean up file path (take also care of some symbolic links).
				$file = strtr($error ['file'], '\\', '/');
				$file = preg_replace('%' . strtr(JPATH_ROOT, '\\', '/') . '/%', '\\1', $file);
				$file = preg_replace('%^.*?/((administrator/)?(components|modules|plugins|templates)/)%', '\\1', $file);
				$errorMsg = sprintf(
					"<p><b>Fatal Error</b>: %s in <b>%s</b> on line <b>%d</b></p>",
					$error['message'], $file, $error['line']
				);
				$parts = explode('/', $file);
				$dir = (string) array_shift($parts);

				if ($dir == 'administrator')
				{
					$dir = (string) array_shift($parts);
				}

				$extension = strtr((string) array_shift($parts), '_', ' ');

				switch ($dir)
				{
					case 'components';
						$extension = ucwords(substr($extension, 4)) . ' Component';
						break;
					case 'modules';
						$extension = ucwords(substr($extension, 4)) . ' Module';
						break;
					case 'plugins';
						$plugin = preg_replace('/\.php/', '', strtr((string) array_shift($parts), '_', ' '));
						$extension = ucwords($extension) . ' - ' . ucwords($plugin) . ' Plugin';
						break;
					case 'templates';
						$extension = ucwords($extension) . ' Template';
						break;
					default:
						$extension = ucwords($dir);
				}
			}
			else
			{
				$errorMsg = 'Internal Server Error';
				$extension = $file = '';
			}

			while(@ob_end_clean()) {}

			ob_start();
			header('HTTP/1.1 500 Internal Server Error');

			if (self::$format == 'json')
			{
				header('Content-type: application/json');

				// Emulate JResponseJson.
				$response = new StdClass;
				$response->success = false;
				$response->message = '500 ' . $errorMsg;
				$response->messages = null;

				// Build data from exceptions.
				$exception = array(
					'code' => 500,
					'message' => $errorMsg
				);

				if (JDEBUG)
				{
					$exception += array(
						'type' => 'Fatal Error',
						'file' => $error['file'],
						'line' => $error['line']
					);
				}

				$response->data = array('exceptions' => array($exception));

				// Create response.
				echo json_encode($response);

				return;
			}

			echo '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<html xmlns="https://www.w3.org/1999/xhtml" xml:lang="en-gb" lang="en-gb">
	<head>
		<meta http-equiv="content-type" content="text/html; charset=utf-8" />
		<title>500 Internal Server Error</title>
	</head>
	<body>
	';
			echo '<div style="max-width:760px;margin:0 auto;text-align:center;background:#d9e2ea top left repeat-x;-webkit-box-shadow: 3px 3px 5px #777;-moz-box-shadow: 3px 3px 5px #777;box-shadow: 3px 3px 5px #777;-webkit-border-radius:20px; -moz-border-radius:20px;border-radius:20px;">';
			echo '<h1 style="background-color:#5388b4;color:white;text-shadow: 1px 1px 1px #000000;filter: dropshadow(color=#000000, offx=1, offy=1);padding-left:20px;-webkit-box-shadow: 1px 1px 2px #444;-moz-box-shadow: 1px 1px 2px #444;box-shadow: 1px 1px 2px #444;-webkit-border-radius: 20px; -moz-border-radius:20px;border-radius:20px;">500 Internal Server Error</h1>';
			echo '<h2>Fatal Error was detected!</h2>';

			if ($debug)
			{
				echo "<p>The error was detected in the <b>{$extension}</b>.</p>";
				echo $errorMsg;

				if (strpos($file, 'kunena') !== false)
				{
					echo '<p>For support click here: <a href="https://www.kunena.org/forum">Kunena Support</a></p>';
				}
			}
			else
			{
				echo '<p>Please contact the site owner.</p>';
			}

			echo '<hr /><p><a href="javascript:window.history.back()">Go back</a></p><br />';
			echo '</div>';
			echo '
	</body>
	</html>';
		}

		// Flush Kunena Logger if it was used.
		KunenaLog::flush();
	}
}