error.php: wip

inc/error.php

@@ -1,9 +1,134 @@
 <?php
+namespace Vichan;
 
-function error_handler($errno, $errstr, $errfile, $errline) {
-	if (error_reporting() & $errno) {
-		$config['debug'] = true;
-		error("$errstr in $errfile at line $errline");
+class ErrorHandler {
+	private bool $include_details;
+	/**
+	 * @var callable
+	 */
+	private mixed $logger_fn;
+
+	private static function errnoToLogLevel(int $errno): int {
+		switch ($errno) {
+			default:
+			case \E_ERROR:
+			case \E_PARSE:
+			case \E_CORE_ERROR:
+			case \E_COMPILE_ERROR:
+			case \E_RECOVERABLE_ERROR:
+				return  \LOG_EMERG;
+			case \E_USER_ERROR:
+				return  \LOG_ERR;
+			case \E_WARNING:
+			case \E_CORE_WARNING:
+			case \E_COMPILE_WARNING:
+			case \E_USER_WARNING:
+				return \LOG_WARNING;
+			case \E_NOTICE:
+			case \E_DEPRECATED:
+			case \E_USER_NOTICE:
+			case \E_USER_DEPRECATED:
+				return \LOG_NOTICE;
+		}
+	}
+
+	public static function handle_error(
+		int $level,
+		string $message,
+		callable $logger,
+		bool $display_details,
+		?string $file,
+		?int $line,
+		?string $trace,
+	): void {
+
+	}
+
+	private function default_logger(int $level, string $message) {
+		global $config;
+
+		if (isset($config['syslog']) && $config['syslog']) {
+			_syslog($level, $message);
+		} else {
+			\error_log($message);
+		}
+	}
+
+	public function setIncludeDetails(bool $include_details) {
+		$this->include_details = $include_details;
+		$this->logger_fn = [ __CLASS__, 'default_logger' ];
+	}
+
+	public function setLogger(?callable $logger_fn) {
+		$this->logger_fn = $logger_fn !== null ? $logger_fn : [ __CLASS__, 'default_logger' ];
+	}
+
+	public function installGlobally() {
+		$logger_fn = $this->logger_fn;
+		$include_details = $this->include_details;
+
+		\set_error_handler(function($errno, $errstr, $errfile, $errline) use ($logger_fn, $include_details) {
+			$errno = \error_reporting() & $errno;
+			if ($errno !== 0) {
+				$level = self::errnoToLogLevel($errno);
+
+				// https://stackoverflow.com/a/35930682
+				$trace = (new \Exception)->getTraceAsString();
+				self::handle_error($level, $errstr, $logger_fn, $include_details, $errfile, $errline, $trace);
+			}
+			return false;
+		});
+
+		\set_exception_handler(function($exception) use ($logger_fn, $include_details) {
+			$message = $exception->getMessage();
+			$file = $exception->getFile();
+			$line = $exception->getLine();
+			$trace = $exception->getTraceAsString();
+
+			self::handle_error(\LOG_EMERG, $message, $logger_fn, $include_details, $file, $line, $trace);
+		});
+
+		\register_shutdown_function(function() use ($logger_fn, $include_details) {
+			$error = \error_get_last();
+			if ($error !== null) {
+				$level = self::errnoToLogLevel($error['type']);
+				$message = $error['message'];
+				$file = $error['file'];
+				$line = $error['line'];
+
+				self::handle_error($level, $message, $logger_fn, $include_details, $file, $line, null);
+			}
+		});
+	}
+}
+
+/**
+ * Install a fancy error handler with the given logger.
+ *
+ * @param ?callable $logger Called when there is to log something. Use null to use the minimal default implementation.
+ *                          The callable is invoke with two parameters, the first being the log level (integer), as
+ *                          listed by the syslog constants, the second is the log message (string).
+ *                          Consider that $config may not have been initialized yet.
+ */
+function install_error_handler(bool $basic, ?callable $logger_fn): void {
+	global $config;
+
+	$logger_fn ??= function($level, $message) use ($config) {
+		if (isset($config['syslog']) && $config['syslog']) {
+			_syslog($level, $message);
+		} else {
+			\error_log($message);
+		}
+	};
+
+	if (!$basic) {
+		\set_error_handler(function($errno, $errstr, $errfile, $errline) use ($config) {
+			if (\error_reporting() & $errno) {
+				$config['debug'] = true;
+				\error("$errstr in $errfile at line $errline");
+			}
+			return false;
+		});
 	}
 	return false;
 }