<?php // vim:ts=4:sw=4:noet

/** @mainpage Php4KjwLib
 *
 * @section intro_sec Introduction
 *
 * This is the introduction.
 *
 * @section install_sec Installation
 *
 * @subsection step1 Step 1: Opening the box
 *  
 * etc...
 */

require_once(dirname(__FILE__) . '/KjwCompat.php');
require_once(dirname(__FILE__) . '/KjwObject.php');

/** @defgroup globals Library globals
 *
 * KjwLib global functions.
 */

/** @ingroup globals
 *
 * Stores a suppressed error. When you use the at-sign (@) to suppress
 * an error, the error message is stored in this global.
 * Normally, you do not need to suppress many errors.
 * Think twice before using it.
 */
$kjw_suppressed_error = null;

/** @ingroup globals
 *
 * The KjwLib error handler. This handles all PHP errors which are trapped
 * by the `error_reporting` ini variable. All non-suppressed errors get sent
 * to kjw_croak(). If you suppress the error, the error message is stored
 * in the $kjw_suppressed_error global.
 *
 * @param $errno An error number.
 * @param $errstr An error message.
 * @param $errfile The full path of the file in which the error occurred.
 * @param $errline The line in the file where the error occurred.
 * @param $errcontext The variables local to where the error occurred.
 * @note You do not call this. PHP calls this.
 */
function kjw_error_handler($errno, $errstr, $errfile, $errline, $errcontext) {
	// If error_reporting returns 0, the user suppressed the error (e.g. with '@').
	if (error_reporting() != 0) {
		//// Check exceptions.. this is here for PHP4/5 compatibility (4 doesn't have the static keyword). */
		//if (preg_match('/^Non-static method .* should not be called statically$/', $errstr))
		//	return;
		//if (preg_match('/^is_a\(\): Deprecated\./', $errstr)) // DAMMIT!
		//	return;
	
		// Die die die, with a nice message.
		kjw_croak('(global)', 'Internal Server Error', "$errstr.", 1);
	} else {
		global $kjw_suppressed_error;
		$kjw_suppressed_error = $errstr;
	}
}

/** @ingroup globals
 *
 * Print a message to the resource pointed to by KJW_STDLOG.
 * If you want to debug SQL queries for example, fopen() a file in write mode
 * and assign it to the KJW_STDLOG define. Some KjwLib functions and methods
 * call this. It might be useful for profiling.
 *
 * @param $msg The message to print.
 * @param $level The importance (DEBUG, INFO, NOTICE, WARNING, ERROR).
 * @param $namespace The tracing object name or context.
 */
function kjw_trace($msg, $level = 'DEBUG', $namespace = '(global)') {
	if (defined('KJW_STDLOG'))
		fwrite(KJW_STDLOG, strftime('%y-%m-%d %H:%M:%S %z: ') . "$level: $namespace: $msg\n");
}

/** @ingroup globals
 *
 * Report an error and die. This function checks php_sapi_name() to see
 * if we're running CLI or non-CLI (CGI) mode. In non-CLI mode we add HTML
 * to the error message for extra readability.
 *
 * The KJW_EMAIL_ERRORS_TO decides whether we should print the detailed message as well
 * or print only the short one and send the detailed message by email.
 * A call to trace()/kjw_trace() is also made.
 *
 * @param $namespace The class/namespace where the croaking was initiated.
 * @param $shortMsg An accompanying message which contains no information an
 *          attacker might use.
 * @param $detailedMsg An accompanying message with all the details.
 * @param $backtraceShift How many functions we should pop from the stack so we don't show
 *			the error handling itself.
 * @return This function does *not* return.
 */
function kjw_croak($namespace, $shortMsg, $detailedMsg, $backtraceShift = 0) {
	// User might expect the error and ignore (@-prefix).
	// This is not recommended though.
	if (error_reporting() == 0) {
		global $kjw_suppressed_error;
		$kjw_suppressed_error = $detailedMsg;
		return;
	}
		
	// What will it be?
	$print_html = php_sapi_name() != 'cli';

	// Set message content
	$shortTextMsg = "** $shortMsg **\n\n"
			. "An error has occurred. We apologise for the inconvenience and ask you to try again later.\n"
			. "Most likely, the webmaster is working on fixing this error at this very moment.\n";
	$shortHtmlMsg = "<div style=\"display:block;color:black;font-family:sans-serif;font-size:18px;margin:0;padding:0 0 5px 0;"
			. "font-weight:bold;background:none;\">"
			. htmlentities($shortMsg) . "</div>\n"
			. "An error has occurred. We apologise for the inconvenience and ask you to try again later.<br/>\n"
			. "Most likely, the webmaster is working on fixing this error at this very moment.<br/><br/>\n"
			. "<a href=\"/\">Go back to home to if refreshing this page does not help.</a>\n";

	// Run htmlentities over all, regardless
	$details = array();
	$details[] = "Date: " . strftime('%Y-%m-%d %H:%M:%S.') . sprintf('%06d', (int)substr(microtime(), 2, 6));
	$details[] = "Detailed message:\n   " . htmlentities($detailedMsg);
	$details[] = "Croak namespace/object: [" . htmlentities($namespace) . "]";
    if (isset($_SERVER['REMOTE_ADDR']))
		$details[] = "Caller IP: [" . htmlentities($_SERVER['REMOTE_ADDR']) . "]";
	if (isset($_SERVER['HTTP_HOST']) && isset($_SERVER['REQUEST_URI']))
		$details[] = "Viewed URL: " . htmlentities("http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]") . " ($_SERVER[REQUEST_METHOD])";
 	if (isset($_SERVER['HTTP_REFERER']))
		$details[] = "Referrer URL: " . htmlentities($_SERVER['HTTP_REFERER']);
	if (isset($_SERVER['HTTP_USER_AGENT']))
		$details[] = "User-Agent: " . htmlentities($_SERVER['HTTP_USER_AGENT']);

	// The backtrace
	$backtrace = '';
	$back = debug_backtrace();
	while ($backtraceShift--)
		array_shift($back);
	foreach($back as $k => $v) {
		$backtrace .= sprintf("   %-20s  %s()\n", htmlentities(basename(@$v['file'])) . ':'
					. htmlentities(@$v['line']), htmlentities(@$v['function']));
	}

	// Client data (not secret)
	$cookie = serialize($_COOKIE);
	$post = serialize($_POST);
	// Session data (secret!)
	$session = serialize(@$_SESSION);
	$server = serialize($_SERVER);

	// Send the message by mail if appropriate
	if (KJW_EMAIL_ERRORS_TO != '') {
		require_once(dirname(__FILE__) . '/KjwMail.php');
		kjwmail_sendplain(
			KJW_EMAIL_ERRORS_TO,
			'KjwLib::kjw_croak: ' . substr($shortMsg, 0, 40),
			$shortTextMsg . "\n[DETAILS]\n * " . implode("\n * ", $details) . "\n\n[BACKTRACE]\n$backtrace\n"
					. "[POST]\n   $post\n\n[COOKIE]\n   $cookie\n\n[SESSION]\n   $session\n\n[SERVER]\n   $server\n\n"
		);
	}

	// Add the message to a trace log
	kjw_trace($shortMsg, 'ERROR', $namespace);
	kjw_trace("DETAILS\n * " . implode("\n * ", $details), 'DEBUG', $namespace);
	kjw_trace("BACKTRACE\n$backtrace", 'DEBUG', $namespace);
	kjw_trace("POST = $post", 'DEBUG', $namespace);
	kjw_trace("COOKIE = $cookie", 'DEBUG', $namespace);
	kjw_trace("SESSION = $session", 'DEBUG', $namespace);
	kjw_trace("SERVER = $server", 'DEBUG', $namespace);

	// Display the message
	if (!$print_html) {
		echo $shortTextMsg;
		if (KJW_EMAIL_ERRORS_TO == '')
			echo "\n[DETAILS]\n * ", implode("\n * ", $details), "\n\n[BACKTRACE]\n", $backtrace;
	} else {
		// Break out of all sorts of html crapzola.
		echo "<!-- '\"/> --></a></iframe></select></script></textarea><br style=\"clear:both;\"/>\n";
		// Assemble total message
		$totalMsg = "<div style=\"display:block;font-weight:normal;font-family:sans-serif;font-size:12px;color:black;"
				. "background-color:white;padding:12px;margin:0;\">$shortHtmlMsg<br/>\n";
		if (KJW_EMAIL_ERRORS_TO == '')
			$totalMsg .= "<pre style=\"color: #903000;\">[DETAILS]\n * " . implode("\n * ", $details)
					. "\n\n[BACKTRACE]\n$backtrace</pre>\n";
		$totalMsg .= "</div>";

		// Echo the message
		echo $totalMsg;
		// Echo it again, in a script so it replaces the entire body.
		echo "<style>html, body {display:block;position:static;text-align:left;margin:0;padding:0;background:none;}</style>";
		echo "<script type=\"text/javascript\">document.body.innerHTML = '"
			. str_replace("</", "<\\/", addcslashes($totalMsg, "\x01..\x1f'\\")) . "';</script>";
	}

	// And finally.. 
	die(-1);
}


/**
 * Initialize constants/defines.
 */
if (!defined('KJW_DEBUG'))
	define('KJW_DEBUG', false);
if (!defined('KJW_STDLOG')) // Where to write log output.
	if (defined('STDERR')) // If we have stderr, write there, else don't write.
		define('KJW_STDLOG', STDERR);
if (!defined('KJW_DIE_ON_TRANSIENT_ERROR')) // KjwSql uses this when connection fails.
	define('KJW_DIE_ON_TRANSIENT_ERROR', false);
if (!defined('KJW_EMAIL_ERRORS_TO')) // Mail the errors instead of displaying them..
	define('KJW_EMAIL_ERRORS_TO', '');

/**
 * Initialize error handler.
 */
set_error_handler('kjw_error_handler');


?>