<?php declare(strict_types=1);

/**
 * This file is part of the Tracy (https://tracy.nette.org)
 * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 */

namespace Tracy;

use ErrorException;
use function in_array, is_bool, is_int, is_string;
use const PHP_VERSION;


/**
 * Debugger: displays and logs errors.
 */
class Debugger
{
	public const Version = '2.11.3';

	/** server modes for Debugger::enable() */
	public const
		Development = false,
		Production = true,
		Detect = null;

	public const CookieSecret = 'tracy-debug';

	/** @deprecated use Debugger::Version */
	public const VERSION = self::Version;

	/** @deprecated use Debugger::Development */
	public const DEVELOPMENT = self::Development;

	/** @deprecated use Debugger::Production */
	public const PRODUCTION = self::Production;

	/** @deprecated use Debugger::Detect */
	public const DETECT = self::Detect;

	/** @deprecated use Debugger::CookieSecret */
	public const COOKIE_SECRET = self::CookieSecret;

	/** in production mode is suppressed any debugging output */
	public static ?bool $productionMode = self::Detect;

	/** whether to display debug bar in development mode */
	public static bool $showBar = true;

	/** size of reserved memory */
	public static int $reservedMemorySize = 500_000;

	private static bool $enabled = false;

	/** reserved memory; also prevents double rendering */
	private static ?string $reserved = null;

	/** initial output buffer level */
	private static int $obLevel;

	/** @var ?array<int, array<string, mixed>>  output buffer status @internal */
	public static ?array $obStatus = null;

	/********************* errors and exceptions reporting ****************d*g**/

	/** determines whether any error will cause immediate death in development mode; if integer that it's matched against error severity */
	public static bool|int $strictMode = false;

	/** disables the @ (shut-up) operator so that notices and warnings are no longer hidden; if integer than it's matched against error severity */
	public static bool|int $scream = false;

	/** @var array<callable(\Throwable): void>  functions that are automatically called after fatal error */
	public static array $onFatalError = [];

	/********************* Debugger::dump() ****************d*g**/

	/** how many nested levels of array/object properties display by dump() */
	public static int $maxDepth = 15;

	/** how long strings display by dump() */
	public static int $maxLength = 150;

	/** how many items in array/object display by dump() */
	public static int $maxItems = 100;

	/** display location by dump()? */
	public static ?bool $showLocation = null;

	/** @var string[] sensitive keys not displayed by dump() */
	public static array $keysToHide = [];

	/** theme for dump() */
	public static string $dumpTheme = 'light';

	/** @deprecated */
	public static $maxLen;

	/********************* logging ****************d*g**/

	/** name of the directory where errors should be logged */
	public static ?string $logDirectory = null;

	/** log bluescreen in production mode for this error severity */
	public static int $logSeverity = 0;

	/** @var string|string[]|null  email(s) to which send error notifications */
	public static string|array|null $email = null;

	/** for Debugger::log() */
	public const
		DEBUG = ILogger::DEBUG,
		INFO = ILogger::INFO,
		WARNING = ILogger::WARNING,
		ERROR = ILogger::ERROR,
		EXCEPTION = ILogger::EXCEPTION,
		CRITICAL = ILogger::CRITICAL;

	/********************* misc ****************d*g**/

	/** timestamp with microseconds of the start of the request */
	public static float $time;

	/** URI pattern mask to open editor */
	public static ?string $editor = 'editor://%action/?file=%file&line=%line&search=%search&replace=%replace';

	/** @var array<string, string>  replacements in path */
	public static array $editorMapping = [];

	/** command to open browser (use 'start ""' in Windows) */
	public static ?string $browser = null;

	/** custom static error template */
	public static ?string $errorTemplate = null;

	/** @var string[] */
	public static array $customCssFiles = [];

	/** @var string[] */
	public static array $customJsFiles = [];

	/** @var array<\Closure(string, int): ?array{file: string, label: string, line?: int, column?: int, active?: bool}> */
	private static array $sourceMappers = [];

	/********************* services ****************d*g**/

	private static BlueScreen $blueScreen;
	private static Bar $bar;
	private static ILogger $logger;

	/** @var array<int, DevelopmentStrategy|ProductionStrategy> */
	private static array $strategy;
	private static SessionStorage $sessionStorage;


	/**
	 * Static class - cannot be instantiated.
	 */
	final public function __construct()
	{
		throw new \LogicException;
	}


	/**
	 * Enables displaying or logging errors and exceptions.
	 * @param  bool|string|string[]  $mode  use constant Debugger::Production, Development, Detect (autodetection) or IP address(es) whitelist.
	 * @param  string  $logDirectory  error log directory
	 * @param  string|string[]|null  $email  administrator email; enables email sending in production mode
	 */
	public static function enable(
		bool|string|array|null $mode = null,
		?string $logDirectory = null,
		string|array|null $email = null,
	): void
	{
		if ($mode !== null || self::$productionMode === null) {
			self::$productionMode = is_bool($mode)
				? $mode
				: !self::detectDebugMode($mode);
		}

		self::$reserved ??= str_repeat('t', self::$reservedMemorySize);
		self::$time ??= $_SERVER['REQUEST_TIME_FLOAT'] ?? microtime(as_float: true);
		self::$obLevel ??= ob_get_level();
		// logging configuration
		self::$email = $email ?? self::$email;
		self::$logDirectory = $logDirectory ?? self::$logDirectory;

		if (self::$logDirectory) {
			if (!preg_match('#([a-z]+:)?[/\\\]#Ai', self::$logDirectory)) {
				self::exceptionHandler(new \RuntimeException('Logging directory must be absolute path.'));
				exit(255);
			} elseif (!is_dir(self::$logDirectory)) {
				self::exceptionHandler(new \RuntimeException("Logging directory '" . self::$logDirectory . "' is not found."));
				exit(255);
			}
		}

		// php configuration
		if (function_exists('ini_set')) {
			ini_set('display_errors', '0'); // or 'stderr'
			ini_set('html_errors', '0'); // additionally turns off stack trace displaing by xdebug
			ini_set('log_errors', '0');
			ini_set('zend.exception_ignore_args', '0');
		}

		error_reporting(E_ALL);

		$strategy = self::getStrategy();
		$strategy->initialize();
		self::dispatch();

		if (self::$enabled) {
			return;
		}

		register_shutdown_function(self::shutdownHandler(...));
		set_exception_handler(function (\Throwable $e) {
			self::exceptionHandler($e);
			exit(255);
		});
		set_error_handler(self::errorHandler(...));

		foreach ([
			'Bar/Bar',
			'Bar/DefaultBarPanel',
			'BlueScreen/BlueScreen',
			'BlueScreen/CodeHighlighter',
			'Dumper/Describer',
			'Dumper/Dumper',
			'Dumper/Exposer',
			'Dumper/Renderer',
			'Dumper/Value',
			'Logger/Logger',
			'Session/SessionStorage',
			'Session/FileSession',
			'Session/NativeSession',
			'Helpers',
		] as $path) {
			require_once dirname(__DIR__) . "/$path.php";
		}

		self::$enabled = true;
	}


	public static function dispatch(): void
	{
		self::getStrategy()->dispatch();
	}


	/**
	 * Renders loading <script>
	 */
	public static function renderLoader(): void
	{
		self::getStrategy()->renderLoader();
	}


	public static function isEnabled(): bool
	{
		return self::$enabled;
	}


	/**
	 * Shutdown handler to catch fatal errors and execute of the planned activities.
	 * @internal
	 */
	public static function shutdownHandler(): void
	{
		$error = error_get_last();
		if (in_array($error['type'] ?? null, [E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_PARSE, E_RECOVERABLE_ERROR, E_USER_ERROR], strict: true)) {
			$e = new ErrorException($error['message'], 0, $error['type'], $error['file'], $error['line']);
			if (!empty($error['trace'])) {
				(new \ReflectionClass(\Exception::class))->getProperty('trace')->setValue($e, $error['trace']);
			}
			self::exceptionHandler($e);

		} elseif (($error['type'] ?? null) === E_COMPILE_WARNING) {
			error_clear_last();
			self::errorHandler($error['type'], $error['message'], $error['file'], $error['line']);
		}

		self::$reserved = null;

		if (self::$showBar) {
			try {
				self::getStrategy()->renderBar();
			} catch (\Throwable $e) {
				self::exceptionHandler($e);
			}
		}
	}


	/**
	 * Handler to catch uncaught exception.
	 * @internal
	 */
	public static function exceptionHandler(\Throwable $exception): void
	{
		$firstTime = (bool) self::$reserved;
		self::$reserved = null;
		self::$obStatus = ob_get_status(full_status: true);

		@http_response_code(500);
		Helpers::improveException($exception);
		self::removeOutputBuffers(errorOccurred: true);

		self::getStrategy()->handleException($exception, $firstTime);

		try {
			foreach ($firstTime ? self::$onFatalError : [] as $handler) {
				$handler($exception);
			}
		} catch (\Throwable $e) {
			self::tryLog($e, self::EXCEPTION);
		}
	}


	/**
	 * Handler to catch warnings and notices.
	 * @throws ErrorException
	 * @internal
	 */
	public static function errorHandler(
		int $severity,
		string $message,
		string $file,
		int $line,
	): bool
	{
		$error = error_get_last();
		if (($error['type'] ?? null) === E_COMPILE_WARNING) {
			// compile-warning does not trigger the handler, so we are testing it now
			error_clear_last();
			self::errorHandler($error['type'], $error['message'], $error['file'], $error['line']);
		}

		if ($severity === E_RECOVERABLE_ERROR || $severity === E_USER_ERROR) {
			throw new ErrorException($message, 0, $severity, $file, $line);

		} elseif (
			($severity & error_reporting())
			|| (is_int(self::$scream) ? $severity & self::$scream : self::$scream)
		) {
			self::getStrategy()->handleError($severity, $message, $file, $line);
		}

		return false; // calls normal error handler to fill-in error_get_last()
	}


	/** @internal */
	public static function removeOutputBuffers(bool $errorOccurred): void
	{
		while (ob_get_level() > self::$obLevel) {
			$status = ob_get_status();
			if (in_array($status['name'], ['ob_gzhandler', 'zlib output compression'], strict: true)) {
				break;
			}

			$fnc = $status['chunk_size'] || !$errorOccurred
				? 'ob_end_flush'
				: 'ob_end_clean';
			if (!@$fnc()) { // @ may be not removable
				break;
			}
		}
	}


	/********************* services ****************d*g**/


	public static function getBlueScreen(): BlueScreen
	{
		if (empty(self::$blueScreen)) {
			self::$blueScreen = new BlueScreen;
			self::$blueScreen->info = [
				'PHP ' . PHP_VERSION,
				$_SERVER['SERVER_SOFTWARE'] ?? null,
				'Tracy ' . self::Version,
			];
		}

		return self::$blueScreen;
	}


	public static function getBar(): Bar
	{
		if (empty(self::$bar)) {
			self::$bar = new Bar;
			self::$bar->addPanel(new DefaultBarPanel('info'), 'Tracy:info');
			self::$bar->addPanel(new DefaultBarPanel('warnings'), 'Tracy:warnings'); // filled by errorHandler()
		}

		return self::$bar;
	}


	public static function setLogger(ILogger $logger): void
	{
		self::$logger = $logger;
	}


	public static function getLogger(): ILogger
	{
		if (empty(self::$logger)) {
			self::$logger = new Logger(self::$logDirectory, self::$email, self::getBlueScreen());
			self::$logger->directory = &self::$logDirectory; // back compatiblity
			self::$logger->email = &self::$email;
		}

		return self::$logger;
	}


	/** @internal */
	public static function getStrategy(): ProductionStrategy|DevelopmentStrategy
	{
		$key = (int) (bool) self::$productionMode;
		if (empty(self::$strategy[$key])) {
			self::$strategy[$key] = $key
				? new ProductionStrategy
				: new DevelopmentStrategy(self::getBar(), self::getBlueScreen(), new DeferredContent(self::getSessionStorage()));
		}

		return self::$strategy[$key];
	}


	public static function setSessionStorage(SessionStorage $storage): void
	{
		if (isset(self::$sessionStorage)) {
			throw new \Exception('Storage is already set.');
		}

		self::$sessionStorage = $storage;
	}


	/** @internal */
	public static function getSessionStorage(): SessionStorage
	{
		if (empty(self::$sessionStorage)) {
			self::$sessionStorage = @is_dir($dir = (string) session_save_path())
				|| @is_dir($dir = (string) ini_get('upload_tmp_dir'))
				|| @is_dir($dir = sys_get_temp_dir())
				|| ($dir = (string) self::$logDirectory)
				? new FileSession($dir)
				: new NativeSession;
		}

		return self::$sessionStorage;
	}


	/********************* useful tools ****************d*g**/


	/**
	 * Dumps information about a variable in readable format.
	 * @tracySkipLocation
	 * @template T
	 * @param  T     $var     variable to dump
	 * @param  bool  $return  return output instead of printing it? (bypasses $productionMode)
	 * @return ($return is true ? string : T)
	 */
	public static function dump(mixed $var, bool $return = false): mixed
	{
		if ($return) {
			$options = [
				Dumper::DEPTH => self::$maxDepth,
				Dumper::TRUNCATE => self::$maxLength,
				Dumper::ITEMS => self::$maxItems,
			];
			return Helpers::isCli()
				? Dumper::toText($var)
				: Helpers::capture(fn() => Dumper::dump($var, $options));

		} elseif (!self::$productionMode) {
			$html = Helpers::isHtmlMode();
			echo $html ? '<tracy-div>' : '';
			Dumper::dump($var, [
				Dumper::DEPTH => self::$maxDepth,
				Dumper::TRUNCATE => self::$maxLength,
				Dumper::ITEMS => self::$maxItems,
				Dumper::LOCATION => self::$showLocation,
				Dumper::THEME => self::$dumpTheme,
				Dumper::KEYS_TO_HIDE => self::$keysToHide,
			]);
			echo $html ? '</tracy-div>' : '';
		}

		return $var;
	}


	/**
	 * Starts/stops stopwatch.
	 * @return float   elapsed seconds
	 */
	public static function timer(?string $name = null): float
	{
		static $time = [];
		$now = hrtime(as_number: true);
		$name ??= '';
		$delta = isset($time[$name]) ? $now - $time[$name] : 0;
		$time[$name] = $now;
		return $delta / 1e9;
	}


	/**
	 * Dumps information about a variable in Tracy Debug Bar.
	 * @tracySkipLocation
	 * @template T
	 * @param  T  $var
	 * @param  array<string, mixed>  $options
	 * @return T
	 */
	public static function barDump(mixed $var, ?string $title = null, array $options = []): mixed
	{
		if (!self::$productionMode) {
			static $panel;
			if (!$panel) {
				self::getBar()->addPanel($panel = new DefaultBarPanel('dumps'), 'Tracy:dumps');
			}

			$panel->data[] = ['title' => $title, 'dump' => Dumper::toHtml($var, $options + [
				Dumper::DEPTH => self::$maxDepth,
				Dumper::ITEMS => self::$maxItems,
				Dumper::TRUNCATE => self::$maxLength,
				Dumper::LOCATION => self::$showLocation ?: Dumper::LOCATION_CLASS | Dumper::LOCATION_SOURCE,
				Dumper::LAZY => true,
				Dumper::KEYS_TO_HIDE => self::$keysToHide,
			])];
		}

		return $var;
	}


	/**
	 * Logs message or exception.
	 */
	public static function log(mixed $message, string $level = ILogger::INFO): mixed
	{
		return self::getLogger()->log($message, $level);
	}


	/** @internal */
	public static function tryLog(mixed $message, string $level = ILogger::INFO): ?\Throwable
	{
		try {
			self::log($message, $level);
		} catch (\Throwable $e) {
		}
		return $e ?? null;
	}


	/**
	 * @param  callable(string, int): ?array{file: string, label: string, line?: int, column?: int, active?: bool}  $mapper
	 * @internal
	 */
	public static function addSourceMapper(callable $mapper): void
	{
		self::$sourceMappers[] = $mapper(...);
	}


	/** @return ?array{file: string, label: string, line: int, column: int, active: bool} */
	public static function mapSource(string $file, int $line): ?array
	{
		foreach (self::$sourceMappers as $mapper) {
			if ($res = $mapper($file, $line)) {
				return $res + ['line' => 0, 'column' => 0, 'active' => true];
			}
		}

		return null;
	}


	/**
	 * Detects debug mode by IP address.
	 * @param  string|string[]|null  $list  IP addresses or computer names whitelist detection
	 */
	public static function detectDebugMode(string|array|null $list = null): bool
	{
		$addr = $_SERVER['REMOTE_ADDR'] ?? php_uname('n');
		$secret = isset($_COOKIE[self::CookieSecret]) && is_string($_COOKIE[self::CookieSecret])
			? $_COOKIE[self::CookieSecret]
			: null;
		$list = is_string($list)
			? preg_split('#[,\s]+#', $list)
			: (array) $list;
		if (!isset($_SERVER['HTTP_X_FORWARDED_FOR']) && !isset($_SERVER['HTTP_FORWARDED'])) {
			$list[] = '127.0.0.1';
			$list[] = '::1';
			$list[] = '[::1]'; // workaround for PHP < 7.3.4
		}

		return in_array($addr, $list, strict: true) || in_array("$secret@$addr", $list, strict: true);
	}
}
