<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Common Functions
 *
 * Loads the base classes and executes the request.
 *
 * @package		CodeIgniter
 * @subpackage	codeigniter
 * @category	Common Functions
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/
 */

// ------------------------------------------------------------------------

/**
 * Determines if the current version of PHP is greater then the supplied value
 *
 * Since there are a few places where we conditionally test for PHP > 5
 * we'll set a static variable.
 *
 * @access	public
 * @param	string
 * @return	bool	TRUE if the current version is $version or higher
 */
if (!function_exists('is_php')) {
	function is_php($version = '5.0.0')
	{
		static $_is_php;
		$version = (string)$version;

		if (!isset($_is_php[$version])) {
			$_is_php[$version] = (version_compare(PHP_VERSION, $version) < 0) ? FALSE : TRUE;
		}

		return $_is_php[$version];
	}
}

// ------------------------------------------------------------------------

/**
 * Tests for file writability
 *
 * is_writable() returns TRUE on Windows servers when you really can't write to
 * the file, based on the read-only attribute.  is_writable() is also unreliable
 * on Unix servers if safe_mode is on.
 *
 * @access	private
 * @return	void
 */
if (!function_exists('is_really_writable')) {
	function is_really_writable($file)
	{
		// If we're on a Unix server with safe_mode off we call is_writable
		if (DIRECTORY_SEPARATOR == '/' and @ini_get("safe_mode") == FALSE) {
			return is_writable($file);
		}

		// For windows servers and safe_mode "on" installations we'll actually
		// write a file then read it.  Bah...
		if (is_dir($file)) {
			$file = rtrim($file, '/') . '/' . md5(mt_rand(1, 100) . mt_rand(1, 100));

			if (($fp = @fopen($file, FOPEN_WRITE_CREATE)) === FALSE) {
				return FALSE;
			}

			fclose($fp);
			@chmod($file, DIR_WRITE_MODE);
			@unlink($file);
			return TRUE;
		} elseif (!is_file($file) or ($fp = @fopen($file, FOPEN_WRITE_CREATE)) === FALSE) {
			return FALSE;
		}

		fclose($fp);
		return TRUE;
	}
}

// ------------------------------------------------------------------------

/**
 * Class registry
 *
 * This function acts as a singleton.  If the requested class does not
 * exist it is instantiated and set to a static variable.  If it has
 * previously been instantiated the variable is returned.
 *
 * @access	public
 * @param	string	the class name being requested
 * @param	string	the directory where the class should be found
 * @param	string	the class name prefix
 * @return	object
 */
if (!function_exists('load_class')) {
	function &load_class($class, $directory = 'libraries', $prefix = 'CI_')
	{
		static $_classes = array();

		// Does the class exist?  If so, we're done...
		if (isset($_classes[$class])) {
			return $_classes[$class];
		}

		$name = FALSE;

		// Look for the class first in the local application/libraries folder
		// then in the native system/libraries folder
		foreach (array(APPPATH, BASEPATH) as $path) {
			if (file_exists($path . $directory . '/' . $class . '.php')) {
				$name = $prefix . $class;

				if (class_exists($name) === FALSE) {
					require($path . $directory . '/' . $class . '.php');
				}

				break;
			}
		}

		// Is the request a class extension?  If so we load it too
		if (file_exists(APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . '.php')) {
			$name = config_item('subclass_prefix') . $class;

			if (class_exists($name) === FALSE) {
				require(APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . '.php');
			}
		}

		// Did we find the class?
		if ($name === FALSE) {
			// Note: We use exit() rather then show_error() in order to avoid a
			// self-referencing loop with the Excptions class
			exit('Unable to locate the specified class: ' . $class . '.php');
		}

		// Keep track of what we just loaded
		is_loaded($class);

		$_classes[$class] = new $name();
		return $_classes[$class];
	}
}

// --------------------------------------------------------------------

/**
 * Keeps track of which libraries have been loaded.  This function is
 * called by the load_class() function above
 *
 * @access	public
 * @return	array
 */
if (!function_exists('is_loaded')) {
	function &is_loaded($class = '')
	{
		static $_is_loaded = array();

		if ($class != '') {
			$_is_loaded[strtolower($class)] = $class;
		}

		return $_is_loaded;
	}
}

// ------------------------------------------------------------------------

/**
 * Loads the main config.php file
 *
 * This function lets us grab the config file even if the Config class
 * hasn't been instantiated yet
 *
 * @access	private
 * @return	array
 */
if (!function_exists('get_config')) {
	function &get_config($replace = array())
	{
		static $_config;

		if (isset($_config)) {
			return $_config[0];
		}

		// Is the config file in the environment folder?
		if (!defined('ENVIRONMENT') or !file_exists($file_path = APPPATH . 'config/' . ENVIRONMENT . '/config.php')) {
			$file_path = APPPATH . 'config/config.php';
		}

		// Fetch the config file
		if (!file_exists($file_path)) {
			exit('The configuration file does not exist.');
		}

		require($file_path);

		// Does the $config array exist in the file?
		if (!isset($config) or !is_array($config)) {
			exit('Your config file does not appear to be formatted correctly.');
		}

		// Are any values being dynamically replaced?
		if (count($replace) > 0) {
			foreach ($replace as $key => $val) {
				if (isset($config[$key])) {
					$config[$key] = $val;
				}
			}
		}

		$_config[0] = &$config;
		return $_config[0];
	}
}

// ------------------------------------------------------------------------

/**
 * Returns the specified config item
 *
 * @access	public
 * @return	mixed
 */
if (!function_exists('config_item')) {
	function config_item($item)
	{
		static $_config_item = array();

		if (!isset($_config_item[$item])) {
			$config = &get_config();

			if (!isset($config[$item])) {
				return FALSE;
			}
			$_config_item[$item] = $config[$item];
		}

		return $_config_item[$item];
	}
}

// ------------------------------------------------------------------------

/**
 * Error Handler
 *
 * This function lets us invoke the exception class and
 * display errors using the standard error template located
 * in application/errors/errors.php
 * This function will send the error page directly to the
 * browser and exit.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('show_error')) {
	function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered')
	{
		$_error = &load_class('Exceptions', 'core');
		echo $_error->show_error($heading, $message, 'error_general', $status_code);
		exit;
	}
}

// ------------------------------------------------------------------------

/**
 * 404 Page Handler
 *
 * This function is similar to the show_error() function above
 * However, instead of the standard error template it displays
 * 404 errors.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('show_404')) {
	function show_404($page = '', $log_error = TRUE)
	{
		$_error = &load_class('Exceptions', 'core');
		$_error->show_404($page, $log_error);
		exit;
	}
}

// ------------------------------------------------------------------------

/**
 * Error Logging Interface
 *
 * We use this as a simple mechanism to access the logging
 * class and send messages to be logged.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('log_message')) {
	function log_message($level = 'error', $message, $php_error = FALSE)
	{
		static $_log;

		if (config_item('log_threshold') == 0) {
			return;
		}

		$_log = &load_class('Log');
		$_log->write_log($level, $message, $php_error);
	}
}

// ------------------------------------------------------------------------

/**
 * Set HTTP Status Header
 *
 * @access	public
 * @param	int		the status code
 * @param	string
 * @return	void
 */
if (!function_exists('set_status_header')) {
	function set_status_header($code = 200, $text = '')
	{
		$stati = array(
			200	=> 'OK',
			201	=> 'Created',
			202	=> 'Accepted',
			203	=> 'Non-Authoritative Information',
			204	=> 'No Content',
			205	=> 'Reset Content',
			206	=> 'Partial Content',

			300	=> 'Multiple Choices',
			301	=> 'Moved Permanently',
			302	=> 'Found',
			304	=> 'Not Modified',
			305	=> 'Use Proxy',
			307	=> 'Temporary Redirect',

			400	=> 'Bad Request',
			401	=> 'Unauthorized',
			403	=> 'Forbidden',
			404	=> 'Not Found',
			405	=> 'Method Not Allowed',
			406	=> 'Not Acceptable',
			407	=> 'Proxy Authentication Required',
			408	=> 'Request Timeout',
			409	=> 'Conflict',
			410	=> 'Gone',
			411	=> 'Length Required',
			412	=> 'Precondition Failed',
			413	=> 'Request Entity Too Large',
			414	=> 'Request-URI Too Long',
			415	=> 'Unsupported Media Type',
			416	=> 'Requested Range Not Satisfiable',
			417	=> 'Expectation Failed',

			500	=> 'Internal Server Error',
			501	=> 'Not Implemented',
			502	=> 'Bad Gateway',
			503	=> 'Service Unavailable',
			504	=> 'Gateway Timeout',
			505	=> 'HTTP Version Not Supported'
		);

		if ($code == '' or !is_numeric($code)) {
			show_error('Status codes must be numeric', 500);
		}

		if (isset($stati[$code]) and $text == '') {
			$text = $stati[$code];
		}

		if ($text == '') {
			show_error('No status text available.  Please check your status code number or supply your own message text.', 500);
		}

		$server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;

		if (substr(php_sapi_name(), 0, 3) == 'cgi') {
			header("Status: {$code} {$text}", TRUE);
		} elseif ($server_protocol == 'HTTP/1.1' or $server_protocol == 'HTTP/1.0') {
			header($server_protocol . " {$code} {$text}", TRUE, $code);
		} else {
			header("HTTP/1.1 {$code} {$text}", TRUE, $code);
		}
	}
}

// --------------------------------------------------------------------

/**
 * Exception Handler
 *
 * This is the custom exception handler that is declaired at the top
 * of Codeigniter.php.  The main reason we use this is to permit
 * PHP errors to be logged in our own log files since the user may
 * not have access to server logs. Since this function
 * effectively intercepts PHP errors, however, we also need
 * to display errors based on the current error_reporting level.
 * We do that with the use of a PHP error template.
 *
 * @access	private
 * @return	void
 */
if (!function_exists('_exception_handler')) {
	function _exception_handler($severity, $message, $filepath, $line)
	{
		// We don't bother with "strict" notices since they tend to fill up
		// the log file with excess information that isn't normally very helpful.
		// For example, if you are running PHP 5 and you use version 4 style
		// class functions (without prefixes like "public", "private", etc.)
		// you'll get notices telling you that these have been deprecated.
		if ($severity == E_STRICT) {
			return;
		}

		$_error = &load_class('Exceptions', 'core');

		// Should we display the error? We'll get the current error_reporting
		// level and add its bits with the severity bits to find out.
		if (($severity & error_reporting()) == $severity) {
			$_error->show_php_error($severity, $message, $filepath, $line);
		}

		// Should we log the error?  No?  We're done...
		if (config_item('log_threshold') == 0) {
			return;
		}

		$_error->log_exception($severity, $message, $filepath, $line);
	}
}

// --------------------------------------------------------------------

/**
 * Remove Invisible Characters
 *
 * This prevents sandwiching null characters
 * between ascii characters, like Java\0script.
 *
 * @access	public
 * @param	string
 * @return	string
 */
if (!function_exists('remove_invisible_characters')) {
	function remove_invisible_characters($str, $url_encoded = TRUE)
	{
		$non_displayables = array();

		// every control character except newline (dec 10)
		// carriage return (dec 13), and horizontal tab (dec 09)

		if ($url_encoded) {
			$non_displayables[] = '/%0[0-8bcef]/';	// url encoded 00-08, 11, 12, 14, 15
			$non_displayables[] = '/%1[0-9a-f]/';	// url encoded 16-31
		}

		$non_displayables[] = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S';	// 00-08, 11, 12, 14-31, 127

		do {
			$str = preg_replace($non_displayables, '', $str, -1, $count);
		} while ($count);

		return $str;
	}
}

// ------------------------------------------------------------------------

/**
 * Returns HTML escaped variable
 *
 * @access	public
 * @param	mixed
 * @return	mixed
 */
if (!function_exists('html_escape')) {
	function html_escape($var)
	{
		if (is_array($var)) {
			return array_map('html_escape', $var);
		} else {
			return htmlspecialchars($var, ENT_QUOTES, config_item('charset'));
		}
	}
}

/* End of file Common.php */
/* Location: ./system/core/Common.php */